2015-12-17 Master thesis presentation by Leo Bärring and Niclas Thuning

Published: 2015-12-11

Date: Dec 17, 2015 
Time: 13.15 
Place: E:2349 
Title: “Hardware Architectures for the Inverse Square Root and the Inverse Functions using Harmonized Parabolic Synthesis” 

Abstract
This thesis presents a comparison between implementations of the inverse square root function, using two approximation algorithms; Harmonized Parabolic Synthesis and Newton-Raphson approximation. The input is a 15 bit fixed-point number of which the range is selected so that the implementation is suitable for use as a block implementing the inverse square root for floating point numbers, and the designs are constrained by the error which must be < 2^15. Multiple implementations of both algorithms have been implemented as simulated ASICs using STMicroelectronics 65.0nm CMOS technology libraries for Low Power (LP) and General Purpose (GP), VDD levels of 1.00V and 1.10V, and for various clock speeds. Error distribution, area, speed, power, and energy consumption are analyzed for variants implementations of the two algorithms. Depending on how the properties rank in desirability when choosing an implementation, the recommended choice will vary. The thesis finds that if mean error, and error distribution are important, The implementations of Harmonized Parabolic Synthesis show superiority regarding implementable clock speed, area requirements, and energy consumption, whereas an implementation of Newton Raphson is favored if power consumption and/or area requirements are prioritized above all others, although the difference is small regarding the latter property.

2015-12-15 Licentiate seminar by William Tärneberg

Published: 2015-11-18

Date: Tuesday Dec 15 2015 
Time: 13.15 
Place: E:2517, E-huset, LTH 
Opponent: Dr Andreas Johnsson, Ericsson Research 
Supevisor: Professor Maria Kihl, EIT 
Examinator: Univ.lektor Christian Nyberg, EIT 
Title: Performance modelling and simulation of the Mobile Cloud Network 

Abstract: 

The Mobile Cloud Network is an emerging distributed cloud infrastructure paradigm that attempts to accommodate the evolution of application's execution paradigms and how content is distributed. The Mobile Cloud Network employs a distributed cloud infrastructure with data centres of varying capacity, embedded in the core and access networks. Resources are thinned over the network and arguably decay in capacity towards the capillaries of the network. For an operator of such an infrastructure, cost and infrastructure integrity is their primary concern. Although these aspirations seem trivial, achieving them in a highly dynamic and heterogeneous distributed infrastructure, successfully at scale is non trivial. In this work, I have focused on modelling the dynamics of the Mobile Cloud Network infrastructure and what methods the operator of a Mobile Cloud Network can employ to minimise the cost of operating the infrastructure. The reduced parameter model, reveals the non-linear nature of the Mobile Cloud Network. The system's performance is evaluated using a cost function that encompasses the cost of executing the applications, the cost of the incurred link usage, and the expected performance of the application. Furthermore, simulations reveal that the proposed methods can achieve near optimal placement at reduced time-complexity.

2015-12-06 Massive MIMO workshop @ IEEE GLOBECOM 2015 (San Diego, CA)

Published: 2015-04-17

EIT researchers in Massive MIMO arranging a workshop (December 6-10) at IEEE GLOBECOM 2015 in San Diego, CA.

"Massive MIMO: From theory to practice"

Read more: mamiws.eit.lth.se.

2015-11-30 Licentiate seminar: Yezi Huang

Published: 2015-11-04

Date: 30 Nov 2015 
Time: 10.15 
Place: E:3139, E-Huset, LTH

Welcome to attend the licentiate seminar where Yezi  Huang will present and defend his thesis "Crosstalk in Wideband Wireline Systems – Curse and Blessing"
Opponent is Jochen Maes from Alcatel-Lucent
Supervisor is Professor Thomas Magesacher, EIT
Examinator is Professor Björn Landfeldt, EIT

Abstract

The fourth generation broadband (4GBB) concept aims for ubiquitous and high-speed data communication over the existing twisted copper pairs between the last distribution point and the customer premise equipment. Although it saves deployment cost for the last-mile communication, using the existing copper infrastructure makes the system vulnerable to crosstalk due to electromagnetic coupling from the neighboring pairs. 

Crosstalk is frequency-dependent and its interfering effects vary with implementation scenarios. When exploring higher frequencies and more functionality for the copper-based infrastructure, new practical problems emerge which opens up a space of unknowns to be investigated. This thesis deals with crosstalk, its effects, its mitigation, and approaches to exploit it in emerging systems and applications. Dividing the frequency range into three bands and taking into account the respective architecture’s characteristics, precoding schemes are proposed that properly process the crosstalk to improve end-users’ quality of experience. 

2015-11-30 Licentiate seminar: Eduardo Lins de Medeiros

Published: 2015-11-04

Date: 30 Nov 2015 
Time: 13.15 
Place: E:3139, E-Huset, LTH

Welcome to attend the licentiate seminar where Eduardo Lins de Medeiros will present and defend his thesis "Copper Access Networks for Wireline and Wireless Services"

Opponent is Jochen Maes from Alcatel-Lucent
Supervisor is Professor Per Ödling, EIT
Examinator is Professor Björn Landfeldt, EIT

Abstract

In the last few years, technologies for broadband delivery over copper have dealt with increased capacity demands by using high frequencies and transmitter coordination, also known as vectoring. At the same time, to provide high capacity mobile broadband, operators have resorted to small cells. The work compiled into this dissertation covers both vectoring in traditional and future wireline services as the use of copper access infrastructure to deploy high capacity small cells. 

In the first part of this dissertation, chapters 2 to 5, we investigate issues with vectoring deployment, namely side effects of impedance changes and its consequences for the stability and performance of vectoring bundles. 

In the second part of this dissertation, chapters 6 and 7, we investigate the feasibility of using the copper access network infrastructure to offer mobile broadband services via co-deployment of Digital Subscriber Line (DSL) and Long Term Evolution (LTE) equipment. The proposed architecture is based on analog transmission of the radio signal at frequencies adequate to the copper medium. 

2015-11-27 PhD thesis defense Iman Vakili

Published: 2015-11-13

Date: 2015-11-27 
Time: 10:15 
Place: E:1406 
Opponent: Andrea Neto. Technical University of Delft. 
Title: Time-Domain Antenna and Scattering Analysis for Micro- and Millimeter-Wave Applications 

Abstract

Telecommunications industries are investing tremendously to meet the ever-increasing demands for higher data rates and capacity. In particular to develop standardization for 5G, which is expected around 2020. The existing spectrum for traditional mobile networks is limited to highly occupied bands at microwave frequencies below 6 GHz. It is expected that 5G will use millimeter-waves to enable higher data rates. Even though losses at millimeter-waves are higher, higher data rates for short range applications can be achieved due to the available wide bandwidth. 

The radio channel between a transmitter and a receiver has a great impact on the quality of the received signals. The channel includes everything between the transmitter and receiver that may impact the signals, such as buildings, walls, windows, etc. High data rate transmission at millimeter-wave frequencies requires size- and cost-efficient circuitry. The recent advances in nanotechnology and semiconductor devices enable the signal generation at millimeter-waves. The existence of the available extreme bandwidth at millimeter-wave frequencies enables the application of impulse radio using high frequency ultra-short pulses. Transmission of a short pulse through antennas and a free-space radio channel without significant distortion requires a wideband antenna with high fidelity.

In this thesis a time-domain antenna system with ultra-short pulse transmission and reception at millimeter-waves is presented. The antenna system consists of wideband and non-dispersive leaky lens antennas and a high frequency short pulse (wavelet) generator based on III-V technology. The time-domain system is presented in Paper I. The transmission of 100 ps long pulses at 60 GHz produced by the wavelet generator through different antennas is investigated. It is shown that the leaky lens antennas have negligible pulse distortion and preserve the shape of the generated high frequency short pulses. Further characterizations of the leaky lens antennas for the 60 GHz band, using a time-domain gating method is presented in Paper III. The results show that the antenna has a low dispersion and can thereby transmit short pulses with high fidelity. 

A time-domain characterization method at millimeter-waves using the antenna system is presented in Paper II. The complex permittivity of low loss non-magnetic materials with low dispersion is estimated directly from the received time-domain pulses. The wide bandwidth of the wavelet is also used to determine the frequency dependence of dispersive materials.

Time-domain scattering analysis of periodic structures is presented in Paper IV and Paper V. A sum rule for scattering in parallel-plate waveguides based on energy conservation and the optical theorem is derived in Paper IV. A parallel-plate waveguide with wideband TEM horn antennas and a parallel-plate capacitor are used for dynamic and low frequency (static) measurements, respectively. The results show that the all wavelengths electromagnetic interaction introduced by the object is given by the static polarizability. 

The broad bandwidth and high resolution of the time-domain system are utilized for radar imaging application in Sec. 6 of the Research Overview. The images are obtained through gridding method which is a classical Fourier reconstruction and l1-minimization problem. It is shown that the resolution achieved by the time-domain system is similar to the frequency-domain measurements using a vector network analyzer.

2015-11-12 Seminar on intellectual properties

Published: 2015-10-26

Date: Nov 12, 2015 
Time: 15.00 - 17.00 
Place: E:A, John Ericssons v 4 
Speaker: Ulf Petrusson, Handelshögskolan, Gothenburg.

The seminar deals with handling of intellectual propertiies (IP) at the university.

Sign up at info@lth.se 

2015-11-26 Workshop on addressing impact in grant applications

Published: 2015-10-26

Date: Nov 26, 2015 
Time 9:00-12:00 or 13:00-16:00. 
Place: Palaestra 105, Universitetsplatsen, Lund. 
Organizer: Research Services

Welcome to a half-day workshop on addressing impact in grant applications

In many grant applications the importance of impact of the proposed research project is essential. In order to be successful with your project proposal you need to analyze and describe the impact your work will have. This workshop aims to give an understanding of the concept impact and measures to use in order to maximize impact. Workshop participants are encouraged to bring their own research project ideas for discussion during the workshop.

The workshop will be led by Monica Schofield, Director of International Cooperation & EU Office at TuTech Innovation GmbH, Hamburg, who has been an expert advisor in various capacities to the European Commission and has extensive experience in evaluating grant proposals.

Target group for workshop: Researchers from postdoctoral level at LU

Registration: latest on 16 November. There are a limited number of places and you will receive a confirmation of your attendance later on. The registration link will be closed when the workshops are fully booked.

Click to register

* Free of charge, but if you have registered and are no longer able to participate, we urge you to inform us as soon as possible. A colleague can be given the opportunity to participate instead! Please e-mail to Sophie Hydén Picasso

2015-11-26 Seminar with Prof. Andrea Neto

Published: 2015-11-24

Speaker: Prof. Andrea Neto, Technical University of Delft 
Title: Norton Equivalent Circuit Model for Photoconductive Antennas 
Place: E:2517 
Time: 15.15-16, Nov. 26 

Abstract 

A novel Norton equivalent circuit for characterizing the photoconductive feed of photoconductive antenna is introduced. The model takes into account for the electrical properties of the photoconductive material, for the features of the optical power excitation, as well as for the geometrical dimensions of the electrodes gap, by which the antenna couples to the photoconductive material. The proposed model effectively describes the antenna feeding mechanism by the photoconductor when it is illuminated by a laser operating in a pulsed mode or in a continuous mode. A validation of the proposed model is provided by comparing power measurements of different photoconductive antennas found in the literature with the estimated power using the novel model. The proposed solution is effective for analyzing and designing photoconductive antennas. It is a useful tool for optimizing the antenna design in order to maximize the THz power radiation, and it is therefore useful to be employed in the design of terahertz time-domain systems.

Bio

Andrea Neto (M'00-SM'10) received the Laurea degree (summa cum laude) in electronic engineering from the University of Florence, Florence, Italy, in 1994, and the Ph.D. degree in electromagnetics from the University of Siena, Siena, Italy, in 2000. Part of his Ph.D. degree was developed at the European Space Agency Research and Technology Center, Noordwijk, The Netherlands, where he worked for the antenna section for over two years. In 2000-2001, he was a Post-Doctoral Researcher at the California Institute of Technology, Pasadena, CA, USA, working for the sub-mm wave Advanced Technology Group. From 2002 to January 2010, was Senior Antenna Scientist at TNO Defence, Security, and Safety, The Hague, The Netherlands. In February 2010, he has been appointed Full Professor of Applied Electromagnetism at the EEMCS Department, Technical University of Delft, Delft, The Netherlands, where he formed and leads the THz Sensing Group. His research interests are in the analysis and design of antennas, with emphasis on arrays, dielectric lens antennas, wideband antennas, EBG structures, and THz antennas. Dr. Neto was corecipient of the H. A. Wheeler award for the best applications paper of the year 2008 in the IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION. He was co-recipient of the best innovative paper prize at the 30th ESA Antenna Workshop in 2008. He was co-recipient of the best antenna theory paper prize at the European Conference on Antennas and Propagation (EuCAP) in 2010. He served as an Associate Editor of the IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION (2008-2013) and IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS (2005-2013). He is member of the Technical Board of the European School of Antennas and organizer of the course on Antenna Imaging Techniques. He is a member of the steering committee of the network of excellence NEWFOCUS, dedicated to focusing techniques in mm and sub-mm wave regimes. In 2011, he was awarded the European Research Council Starting Grant to perform research on Advanced Antenna Architectures for THz Sensing Systems. He is the Awards and Grants Chair for EUCAP 2014.

2015-11-24 PhD thesis defense Anders Nejdel

Published: 2015-10-28

Date: 2015-11-24 
Time: 10:15 
Place: E:1406 
Opponent: Eric Klumperink. University of Twente
Title: Flexible Receivers in CMOS for Wireless Communication 

Abstract:

Consumers are pushing for higher data rates to support more services that are introduced in mobile applications. As an example, a few years ago video-on-demand was only accessed through landlines, but today wireless devices are frequently used to stream video. To support this, more flexible network solutions have merged in 4G, introducing new technical problems to the mobile terminal. New techniques are thus needed, and this dissertation explores five different ideas for receiver front-ends, that are cost-efficient and flexible both in performance and operating frequency. All ideas have been implemented in chips fabricated in 65 nm CMOS technology and verified by measurements. Paper I explores a voltage-mode receiver front-end where sub-threshold positive feedback transistors are introduced to increase the linearity in combination with a bootstrapped passive mixer. Paper II builds on the idea of 8-phase harmonic rejection, but simplifies it to a 6-phase solution that can reject noise and interferers at the 3rd order harmonic of the local oscillator frequency. This provides a good trade-off between the traditional quadrature mixer and the 8-phase harmonic rejection mixer. Furthermore, a very compact inductor-less low noise amplifier is introduced. Paper III investigates the use of global negative feedback in a receiver front-end, and also introduces an auxiliary path that can cancel noise from the main path. In paper IV, another global feedback based receiver front-end is designed, but with positive feedback instead of negative. By introducing global positive feedback, the resistance of the transistors in a passive mixer-first receiver front-end can be reduced to achieve a lower noise figure, while still maintaining input matching. Finally, paper V introduces a full receiver chain with a single-ended to differential LNA, current-mode downconversion mixers, and a baseband circuity that merges the functionalities of the transimpedance amplifier, channel-select filter, and analog-to-digital converter into one single power-efficient block.

2015-11-24 Seminar with Dr. Eric Klumperink from University of Twente.

Published: 2015-11-22

Date: Tuesday Nov 24 
Time: 14.00 - 15.00 (sharp) 
Place: E:2311 
Subject: Cognitive Radio Transceiver Chips. 

Abstract:

A Cognitive Radio transceiver senses its radio environment and adaptively utilizes free parts of the radio spectrum. CMOS IC-technology

is the mainstream technology to implement smart signal processing and for reasons of cost and size it is attractive to also integrate the

radio frequency (RF) hardware in CMOS. This lecture discusses design challenges and ideas for radio transceiver ICs designed for cognitive

radio applications, with focus on analog RF. Cognitive radio asks for new functionality, e.g. spectrum sensing and more agility in the radio

transmitter and flexibility in the receiver. Moreover, the technical requirements on the building blocks are more challenging than for

traditional single standard applications, e.g. in bandwidth, programmability, sensing sensitivity, blocker tolerance, linearity and spurious

emissions. Circuit ideas that address these challenges will be discussed, and examples of chips and their achieved performance will be given.

Biography (copied from http://icd.ewi.utwente.nl/persons/klumperink/ ):

Eric A. M. Klumperink (IEEE Member '98, Senior Member '06) was born on April 4th, 1960, in Lichtenvoorde, The Netherlands. He received

the B.Sc. degree from HTS, Enschede, The Netherlands, in 1982. After a short period in industry, he joined the University of Twente in 1984,

participating in analog CMOS circuit research resulting in several publications and his Ph.D. thesis "Transconductance Based CMOS Circuits"

(1997). In 1998, Eric started as Assistant Professor at the IC-Design Laboratory in Twente and his research focus changed to RF CMOS circuits.

In april-august 2001, he extended his RF expertise during a sabbatical at the Ruhr Universitaet in Bochum, Germany. Since 2006, he is an

Associate Professor, teaching Analog & RF IC Electronics. Eric participates in the CTIT Research Institute, guiding PhD and MSc projects related

to RF CMOS circuit design with focus on Software Defined Radio, Cognitive Radio and Beamforming. He served as an Associate Editor for the

IEEE TCAS-II (2006-2007), IEEE TCAS-I (2008-2009) and the IEEE JSSC (2010-2014) and is a member of the technical program committees of the

ISSCC and IEEE RFIC Symposium. Eric served as IEEE SSC Distinguished Lecturer in 2014/2015, holds 10+ patents, authored and co-authored

150+ internationally refereed journal and conference papers, and was recognized as 20+ ISSCC paper contributor over 1954-2013. He is a

co-recipient of the ISSCC 2002 and the ISSCC 2009 "Van Vessem Outstanding Paper Award".

2015-11-19 Tårtseminarium med Åsa Hansson

Published: 2015-11-16

Datum: Torsdag 19 Nov 

Tid: 14:06 
Plats: E:1406 
Titel: ”Min vandring genom skatteforskningen och skattepolitiken i Sverige – en ganska trång och enslig stig” 

Föredragshållare: Åsa Hansson.

2015-11-12 Seminar with Miloslav Capek

Published: 2015-11-09

Date: Thursday November 12, 2015 
Time: 15.15 
Place: E:2349 
Title:  Implementation of Characteristic Mode Decomposition 

Speaker: Miloslav Capek, Czech Technical University in Prague

2015-11-12 Seminarium om IP

Published: 2015-11-08

Datum: 12 Nov 
Tid: 15-17 
Plats: E-huset E:A 
Titel: Vad varje forskare bör veta om IP 

Seminarium med Ulf Petrusson, professor på Juridiska institutionen vid Handelshögskolan i Göteborg och föreståndare för Institutet för innovation och samhällsförändring, om universitetets hantering av intellektuella tillgångar under namnet Forskning och Nytta.

Anmälan till info@lth.se  senast den 9 november.

2015-11-11 Seminar on Intel SGX Architecture

Published: 2015-11-03

Date: Wednesday Nov 11 
Time: 13.15-15.00 
Place: E:1426 

You are most welcome at Nicolae Paladi's  seminar as part of his PhD work at SICS/LTH on the Intel SGX security architecture.

Summary:

Software developers that create applications operating on sensitive data face the challenge of maintaining the confidentiality of data in the presence of potentially vulnerable, privileged code running on the same platform.

To overcome this, Intel has developed SGX, a novel set of x86-64 ISA extensions allowing to create multiple protected execution environments (enclaves) on the platform. The processor protects enclave memory, thus reducing the trusted computing base to the processor hardware, processor firmware and the software loaded into the enclave.

In this presentation I will present the rationale of SGX enclaves, describe the attestation and data sealing procedures, dive into the internals of setting up and operating the enclaves and discuss several recently published results that rely on SGX. Finally I will outline a set of challenges and limitations of this technology in the light of previous security vulnerabilities of the x86 architecture.

2015-11-11 Seminar with Lukas Jelinek

Published: 2015-11-09

Date: Wednesday November 11, 2015 
Time: 15.15 
Place: E:3139 
Title:  Properties of Stored Electromagnetic Energy in Time Domain 

Speaker: Lukas Jelinek, Czech Technical University in Prague

Colors of Math ? filmvisning med regissören på plats

Published: 2015-10-29

Fotomodellen, matematikern och regissören Ekaterina Eremenko besöker LTH i november. Det gör hon i samband med att Lunds Matematiska Sällskap visar hennes dokumentärfilm ?Colors of Math? i Kårhusets hörsal på LTH. Filmen försöker beskriva matematik, matematikforskning och matematiker. Efter visningen blir det diskussion och frågestund med Ekaterina Eremenko, följt av en eftersits.

Fotomodellen, matematikern och regissören Ekaterina Eremenko besöker LTH i november. Det gör hon i samband med att Lunds Matematiska Sällskap visar hennes dokumentärfilm ?Colors of Math? i Kårhusets hörsal på LTH. Filmen försöker beskriva matematik, matematikforskning och matematiker. Efter visningen blir det diskussion och frågestund med Ekaterina Eremenko, följt av en eftersits. 

Tid: tisdagen den 10 november klockan 18:30

Plats: Kårhusets hörsal, Lunds Tekniska Högskola

Pris: Gratis! Men anmäl dig på http://bit.ly/colorsofmath

Läs mer på: http://www.lth.se/nyheter-och-press/nyheter/visa-nyhet/article/filmvisning-med-matematiksaellskap/

2015-11-06 Seminar on 'Radar Warning, EW Antennas, and Interferometry

Published: 2015-10-26

Date: Friday November 6, 2015 
Time: 10.15 
Place: E:2517 
Speaker: Christian Sohl, Saab, Järfälla 
Title:  Radar Warning, EW Antennas, and Interferometry 

Abstract

The goal of this talk is to give an overview of my work at Saab Electronic Defense Systems, in particular radar warning and the type of wideband antenna problems I work with today. I will also touch upon important subjects such as interoperability, numerical methods and computational hardware. In the end of the talk interferometry is discussed and some numerical results are shown.

Biography

Christian Sohl received the Ph.D. degree in Engineering in 2008, the Licentiate degree in Engineering in 2007, and the M.Sc. degree in Engineering Physics in 2004, all from Lund University, Lund, Sweden. Since 2008 he has been with Saab Electronic Defense Systems (formerly Saab Microwave Systems) in Järfälla, Sweden, working with antenna and microwave engineering for radar, electronic warfare, and electronic surveillance. During the years 2010-2012 he was on leave as a Postdoctoral Research Fellow in Electromagnetic Theory at Lund University, Lund, Sweden. In 2015 he was appointed Specialist in Antennas at Saab AB. His main research interests are in field and wave electromagnetics, especially scattering of electromagnetic waves and antenna modelling.

2015-10-21 Master Thesis Presentation by Jeena Rachel John

Published: 2015-10-19

Date: Wednesday Oct 21 
Time: 14:15 
Location E:2517 
Title: "Analysis of IPv6 Neighbor Discovery for Mobile and Wireless Networks" 

Jeena Rachel John will present her master thesis work. The project is a collaboration between Ericsson Research in Kista, Ericsson AB in San Diego and LTH. 

Abstract

The majority of the current 3GPP and M2M networks use or will use IPv6 for accessing the internet. These IPv6 networks use Neighbor Discovery as defined in RFC 4861 to identify their neighbors on the link and see if they are active. The increase in the complexity of wireless networks and introduction of battery operated devices sets forth notable challenges to certain assumptions in the RFC 4861. The RFC 4861 is more suited for wired networks and its implementation in wireless networks makes it more inefficient. This thesis work focuses on the energy efficient implementation of RFC 4861 using the protocols mentioned in draft-chakrabarti-nordmark-6man-efficient-nd-06. The draft suggests a method of registering all the nodes in the network to their default router, so that the router takes care of all the basic neighbor discovery functionalities without disturbing the battery operated devices which are in sleepy mode. Alongside the legacy Neighbor Discovery, the optimizations proposed by the draft are implemented, on a RADVD based router and an Ubuntu host, to reduce redundant multicast signaling in mobile networks. These optimizations are theoretically analyzed to check if the draft is beneficial for scalability and transient nature of the wireless networks.

2015-10-08 ELLIIT Distinguished Lecture by Matt Ettus

Published: 2015-10-02

Date: Oct 8, 2015 
Time: 15.15-16.00 
Location: E:A 
Title: Technologies for Rapid Prototyping and Low Cost Deployment of Novel Radio Systems 

Abstract:

Software defined radio (SDR) promises rapid prototyping and development cycles for new radio communication systems.  Some of that promise has been realized, but there is still room for improvement in the process, largely due to the deep gulfs between the design tools used in various aspects of the design.  In particular, the various processing architectures used (FPGAs, CPUs, GPUs, etc.) all require the designer to operate in separate walled gardens.  We will discuss some exciting new technologies which allow the bridging of these gaps, allowing the use of a consistent design methodology across all computational devices in the system as well as all phases of the system life cycle.  These technologies ease the design, evaluation, and deployment while at the same time reducing costs and time to market for radio systems.  Extensive code reuse and open source lead to low cost and reproducible experimentation and deployment.

Lecturer: Matt Ettus, President and founder of Ettus Research

Biography:

Matt Ettus is a core contributor to the GNU Radio project, a free framework for Software Radio, and is the creator of the Universal Software Radio Peripheral (USRP).  In 2004, Matt founded Ettus Research to develop, support and commercialize the USRP family of products.  Ettus Research was acquired by National Instruments in 2010, and Matt continues as its president.  USRPs are in use in over 110 countries for everything from cellular and satellite communications to radio astronomy, medical imaging, and wildlife tracking.  In 2010, the USRP family won the Technology of the Year award from the Wireless Innovation Forum. In the past Matt has designed Bluetooth chips, GPS systems, and high performance microprocessors.  Before that, he received BSEE and BSCS degrees from Washington University and an MSECE degree from Carnegie-Mellon University.  In 2011, Matt was named an eminent member of Eta Kappa Nu, and was awarded the Wireless Innovation Forum International Achievement Award in 2015.  He is based in Silicon Valley.

2015-10-07 Seminar with John B Anderson on Faster than Nyquist

Published: 2015-10-01

Date: October 7, 2015 (Wednesday) 
Time: 13:15 
Room: E:2349 
Title:  Faster than Nyquist Transmission with 4-level Modulation 

Abstract:    FTN transmission works with narrowband, non-orthogonal pulses, and leads to high bits/Hz-s coding schemes that perform rather close to the Shannon limit. We extend the method to 4PAM modulation. Good coded systems exist at 6 bits/Hz-s, six times the bandwidth efficiency of binary modulation + rate ½ convolutional coding. 4-level and binary FTN are based on the same principles, but 4-level implementations have some surprises.

FTN is a digital transmission technique that enables an increase in system throughput without any increase in bandwidth, transmitted power or number of antennas, and is a candidate technique for the next generation of Digital Video Broadcast – Satellite (DVB – S) systems. Many important results and advances in this topic originated from the research done in the Communications Group in previous years.

2015-10-07 Microwave medical imaging seminar with Susan Hagness.

Published: 2015-10-05

Date: Wednesday Oct 7, 2015 
Time: 14.15 
Place: E:2311 
Title:  Low-Cost, Non-Ionizing Medical Imaging and Minimally Invasive Cancer Treatment with Microwaves 
Speaker: Susan Hagness, University of Wisconsin-Madison 

Susan has also recevied the Sven Berggren 2015 award from the Royal Physiographic Society of Lund to be presented in the evening 7/10, see http://www.fysiografen.se/sv/aktuellt/sallskapets-moten-2014/

Abstract: 

Microwave imaging (MWI) techniques that reconstruct the endogenous (and possibly exogenously influenced) dielectric properties of tissue show promise for medical imaging applications in need of a low-cost, non-ionizing, 3-D quantitative imaging modality. This presentation will highlight recent theoretical and experimental advances in MWI techniques for several applications in breast health and disease management, namely evaluating breast density as part of a patient’s individualized risk assessment, screening women who are at higher risk for cancer, and monitoring changes in breast tissue in response to prevention and treatment protocols. This presentation will also highlight recent advances in microwave ablation (MWA) -- a promising low-cost, less invasive alternative to surgical resection for the treatment of primary tumors. MWA employs an interstitial antenna to deliver microwave energy directly into the tumor and heat it to cytotoxic temperatures. Antenna miniaturization strategies that minimize the invasiveness of MWA will be discussed.

Bio: 

Susan C. Hagness received the B.S. degree with highest honors and the Ph.D. degree in electrical engineering from Northwestern University in 1993 and 1998, respectively.  Since 1998, she has been with the Department of Electrical and Computer Engineering at the University of Wisconsin-Madison, where she currently holds the title of Philip D. Reed Professor and serves as the Associate Dean for Research and Graduate Affairs in the College of Engineering. She is also a Faculty Affiliate of the Department of Biomedical Engineering and a member of the UW Carbone Comprehensive Cancer Center.  Dr. Hagness was the recipient of the Presidential Early Career Award for Scientists and Engineers (PECASE) presented by the White House in 2000. In 2002, she was named one of the 100 top young innovators in science and engineering in the world by the MIT Technology Review magazine. She is also the recipient of the UW-Madison Emil Steiger Distinguished Teaching Award (2003), the IEEE Engineering in Medicine and Biology Society Early Career Achievement Award (2004), the URSI Isaac Koga Gold Medal (2005), the IEEE Transactions on Biomedical Engineering Outstanding Paper Award (2007), the IEEE Education Society Mac E. Van Valkenburg Early Career Teaching Award (2007), the UW System Alliant Energy Underkofler Excellence in Teaching Award (2009), the Physics in Medicine and Biology Citations Prize (2011), the UW-Madison Kellett Mid- Career Award (2011), and the UW-Madison College of Engineering Benjamin Smith Reynolds Award for Excellence in Teaching Engineers (2014). She was elected Fellow of the IEEE in 2009.  She has held numerous leadership positions within the IEEE Antennas and Propagation Society (AP-S) and the United States National Committee (USNC) of the International Union of Radio Science (URSI).  She was the Technical Program Chair of the 2012 IEEE International Symposium on Antennas and Propagation and USNC/URSI National Radio Science Meeting in Chicago, IL, and most recently completed a term as Chair of the IEEE AP-S Fellows Evaluation Committee.

2015-10-05 International "Steep Transistors Workshop" in Indiana US.

Published: 2015-08-26

Place: University of Notre Dame 
Date: October 5-6, 2015 
Organizers: University of Notre Dame and Lund University 

Abstract

Watch the video!!

Steep transistors are being developed worldwide to achieve less than 60 mV/decade subthreshold swing. Realization of this transistor will enable electronic systems with sub-half-volt supply voltages achieving lower power dissipation and greater energy efficiency than can be achieved with modern transistors.

The "Steep Transistors Workshop" is a specialists meeting. Leading engineers and scientists from more than 30 industry and academic research teams worldwide have been invited to participate in the workshop. Because it is a specialists meeting, speakers will skip introductory material and address key new findings or issues of interest to the community. It is the purpose of this meeting to provide a forum to compare and contrast approaches, air technical challenges, and form collaborations to accelerate development.

The workshop will be held at the University of Notre Dame, Notre Dame, IN, October 5-6, 2015. It is being co-organized by the SRC/DARPA STARnet Center for Low Energy System Technology (LEAST) and the European Energy Efficient Tunnel FET Switches and Circuits program (E2 SWITCH).

See more on http://least.nd.edu/steeptransistorsworkshop

The meeting is open to interested researchers, postdocs, and students. Organisation responsible from LU is Professor Lars-Erik Wernersson.

2015-10-05 Master Thesis Presentation by Niklas Aldén

Published: 2015-09-29

Date: Oct 5th 
Time: 13:15 
Place: E:2349 
Title: Hardware Implementation of AGC for Active Hearing Protectors 

Niklas Aldén will present his master thesis and the presentation will include a demonstration.

Abstract

This thesis focus on implementing an automatic gain controller (AGC) in hardware
for usage in active hearing protectors. The AGC works by estimating the
decibel level of an audio sample and applying an appropriate gain. In case the
noise level is so high that the users hearing might be damaged, the sample is
attenuated to a harmless level. Otherwise, the sample is outputted without any
dampening. The proposed solution is verified on an FPGA and prepared for fabrication
of an ASIC in 65nm CMOS technology.The aim has been to optimized the algorithm to result in an integrated circuit with a small area and low power consumption. By implementing a time multiplexed resource sharing algorithm, the circuit area is reduced by a third. Together with
the use of voltage scaling, the simulated power dissipation is reduced with 99%.

2015-10-02 Master Thesis Presentation by André Ericsson and Christoffer Cederberg.

Published: 2015-10-01

Date: Oct 2, 2015 
Time: 13.15 
Place: E:3139 
Title:  Investigation of inertial navigation system implemeted by microelectromechanical system accelerometers and gyroscopes or "Quadcopter Project".

Abstract:

An inertial navigation system is based upon measurements of an objects movement, such as acceleration. The acceleration data in this particular project will be collected by microelectromechanical system (MEMs) sensors. The goal is to produce a navigation system with high accuracy by reasonable actions and a fordable expenses. The test platform for the navigation system has been selected to be a quad-rotor helicopter. Both basic functions, such as fully manageable flight characteristics, and the design of the helicopter are included in the project. The ability to fly in accordance with a predetermined flight route will also be incorporated to fully evaluate the performance of the navigation system. Finally a safe mode will be integrated which will guide the quad-copter helicopter to safety while a system or communication error occurs.

2015-10-01 Master thesis presentation by Nina Khayyami and Jens Nilsson.

Published: 2015-09-29

Date: Thursday, October 1 
Time: October 1, 10:15 
Location: E:3139 
Title: Adaptive Gain Control and Psycho-acoustic Modeling for Near End Listening Enhancement 

Abstract:

We are living in a noisy world. Communication is an important part of our everyday life and is easily disturbed by noisy environments, making communication difficult at times. When listening to a speech signal through a loudspeaker in a noisy environment, it can be troublesome to comprehend the speech. A solution to this is an Adaptive Gain Control, AGC, and a Psychoacoustic Filter for the loudspeaker.

This thesis presents a digital AGC for a loudspeaker where the gain will depend on the near end noise. The noise is recorded by a single microphone and the AGC adjusts the output gain of the loud speaker so it increases the signal to noise ratio for the near end user. This can for example be used by door-station devices at train stations, near busy streets, street alleys or indoor environments. The proposed system consists of a Voice Activity Detector, VAD, based on kurtosis, a power estimator to estimate the noise power without possible speech and a gain block which calculates the output gain factor. The system will not only consider the loudness of the noise but also its frequency characteristics. By using psycho acoustics, an adaptive filter is applied to the far end speech signal in order to enhance the speech intelligibility, based on the frequency information obtained from the near end noise signal. The system is implemented in MATLAB in real time.

2015-09-29 PhD defense Martin Bergh

Published: 2015-08-29

Date: Sept 29, 2015 
Time: 10.15
Place: E:1406 
Title: Vertical InAs Nanowire Devices and RF Circuits
Opponent: Dr. Walter M. Weber, NaMLab, Dreseden, Germany 

Abstract:

Recent decades have seen an exponential increase in the functionality of electronic circuits, allowing for continuous innovation, which benefits society. This increase in functionality has been facilitated by scaling down the dimensions of the most important electronic component in modern electronics: the Si-based MOSFET. By reducing the size of the device, more transistors per chip area is possible. Smaller MOSFETs are also faster and more energy-efficient. In state of the art MOSFETs, the key dimensions are only few nanometers, rapidly approaching a point where the current scaling scheme may not be maintained. Research is ongoing to improve the device performance, mainly focusing on material and structural improvements to the existing MOSFET architecture.      

In this thesis, MOSFETs based on nanowires, are investigated. Taking advantage of the nanowire geometry, the gate can be wrapped all-around the nanowires for excellent control of the channel. The nanowires are made in a high-mobility III-V semiconductor, InAs, allowing for faster electrons and higher currents than Si. This device type is a potential candidate to either replace or complement Si-based MOSFETs in digital and analogue applications. Single balanced down-conversion mixer circuits were fabricated, consisting of three vertically aligned InAs nanowire MOSFETs and two nanowire resistors. These circuits are shown to operate with voltage gain in the GHz-regime. Individual transistors demonstrated operation with gain at several tens of GHz.              

A method to characterise the resistivity and metal-semiconductor contact quality has been developed, using the transmission line method adapted for vertical nanowires. This method has successfully been applied to InAs nanowires and shown that low-resistance contacts to these nanowires are possible. To optimise the performance of the device and reach as close to intrinsic operation as possible, parasitic capacitances and resistances in the device structure need to be minimised. A novel self-aligned gate-last fabrication method for vertical InAs nanowire transistors has been developed, that allows for an optimum design of the channel and the contact regions. Transistors fabricated using this method exhibit the best DC performance, in terms of a compromise between the normalised transconductance and sub-threshold swing, of any previously reported vertical nanowire MOSFET.

Lund Circuit Design Workshop

Published: 2015-09-04

At this annual event we present research results within the broader area of circuit design to our industrial and academic partners.

The workshop will provide:

 -Overview of the research activities in IC design at Lund University.

-Presentations by senior researchers at Lund University.

-Project presentations by research students.

-Thematic presentation by world leading experts from academia .

-Industry presentations.

-Networking with people from academia and industry.

See. detailed program here.

2015-09-23 Lund Circuit Design Workshop, 2015

Published: 2015-09-01

Date: Sept 23-24, 2015 
Place: Grand Hotel, Lund and Faculty of Engineering, Lund University, Lund, Sweden

At this annual event we present research results within the broader area of circuit design to our industrial and academic partners. The workshop will provide:

-Overview of the research activities in IC design at Lund University.
-Presentations by senior researchers at Lund University.
-Project presentations by research students.
-Thematic presentation by world leading experts from academia .
-Industry presentations.
-Networking with people from academia and industry.

See detailed program here.

2015-09-22 Seminar by A.D. Yaghjian: An Overview of Maxwell's Treatise

Published: 2015-09-15

Date: Tuesday September 22, 2015 
Time: 14.15 
Place: E:2517 
Title: An Overview of Maxwell's Treatise 
Speaker: Arthur D. Yaghjian 

Abstract:

Over a period of about twenty years, Maxwell's determination and unification of the equations of electricity and magnetism evolved from his first paper on the subject in 1855-56, “On Faraday's Lines of Force,” to the publication of the first edition of his Treatise on Electricity and Magnetism in 1873. Notwithstanding the many historical accounts and textbooks devoted to Maxwell's work, I have not been able to find a reasonably concise, yet definitive summary of the fundamentals of exactly what Maxwell did in his Treatise and how he did it. This talk is based on the paper “Reflections on Maxwell’s Treatise” (PIER, 2014), which represents my own attempt to provide such a summary.

Bio:

Arthur D. Yaghjian received the B.S., M.S., and Ph.D. degrees in electrical engineering from Brown University, Providence, RI in 1964, 1966, and 1969. After teaching for a year, he joined the research staff of the National Institute of Standards and Technology (NIST), Boulder, CO. He transferred in 1983 to the Air Force Research Laboratory (AFRL), Hanscom AFB, MA, where he was employed as a research scientist until 1996.

He was a Guest Professor in the EEC Department of the Indian Institute of Technology (Kharagpur) in 1987, in the Electromagnetics Institute of the Technical University of Denmark in 1989, and in the Laboratory of Applied Electromagnetics of the University of Siena in 2007. He presently works as an independent consultant in electromagnetics. His work has led to the fundamental determination of electric and magnetic fields in material media, as well as to the development of exact, numerical, and high-frequency methods for predicting and measuring the near and far fields of antennas and scatterers in both the time and frequency domains. In addition, he has contributed significantly to the development and understanding of electrically small antennas, including supergain endfire arrays, and metamaterials, and to the determination of the classical equations of motion of accelerated charged particles. He is a Fellow of the IEEE and has received best paper awards from the IEEE, NIST, and AFRL.

2015-09-17 Tårtseminarium med Maria Kihl

Published: 2015-09-08

Tårtseminarium med Maria Kihl 
Titel: Me and the Internet --- Past, present, and the future 
Datum: 17 Sept, 2015 
Tid: 14.06 
Plats: E:1406

2015-09-11 PhD defense Kristofer Jansson

Published: 2015-08-27

Date: Sept 11, 2015 
Time: 10.15
Place: E:1406 
Title: InAs Nanowire Devices and Circuits
Opponent: Dr. Sanjeev Manhas. Department of Electronics and Communication Engineering, Indian Institute of Technology Roorkee, India

Abstract:

Since the introduction of the transistor and the integrated circuit, the semiconductor industry has developed at a remarkable pace. By continuously fabricating smaller and faster transistors, it has been possible to maintain an exponential increase in performance, a phenomenon famously described by Moore?s Law. Today, billions of transistors are integrated on a single chip and the size of a transistor is on the scale of tens of nanometres. Until recently, the improvements in performance and integration density have been mostly driven by scaling down the transistor size. However, as the length scale is rapidly approaching that of only a few atoms, this scaling paradigm may not continue forever. Instead, the research community, as well as the industry, is investigating alternative structures and materials in order to further increase the performance.

One emerging technology for use in future electronic circuits is transistors based on nanowires. The nanowire transistor structure investigated in this work combines a number of key technologies to achieve a higher performance than traditional Si-based transistors. Epitaxially grown nanowires are naturally oriented in the vertical direction, which means that the devices may be fabricated from the bottom and up. This three-dimensional structure allows a higher integration density and enables the gate to completely surround the channel in a gate-all-around configuration. Combined with a high-k dielectric, this results in an excellent electrostatic gate control. Furthermore, nanowires have the unique ability to combine semiconductor materials with significantly different lattice constants. By introducing InAs as a channel material, a much higher electron mobility than for Si is achieved.

In this work, simulations of nanowire-based devices are performed and the ultimate performance is predicted. A nanowire transistor architecture with a realistic footprint is proposed and a roadmap is established for the scaling of the device structure, based on a set of technology nodes. Benchmarking is performed against competing technologies, both from a device and circuit perspective. The physical properties of nanowire transistors, and the corresponding capacitor structure, are investigated by band-structure simulations. Based on these simulations, a ballistic transport model is used to derive the intrinsic transistor characteristics. This is combined with an extensive evaluation and optimization of the parasitic elements in the transistor structure for each technology node. 

It is demonstrated that an optimized nanowire transistor has the potential to operate at terahertz frequencies, while maintaining a low power consumption. A high quality factor and extremely high integration density is predicted for the nanowire capacitor structure. It is concluded that InAs nanowire devices show great potential for use in future electronic circuits, both in digital and analogue applications.

2015-09-10 Master Thesis Presentation, Carl Igelström

Published: 2015-09-06

Title:  HDMI Signal Tapping and Digital Encoding for IP Monitor Surveillance  
Date:  Sep 10, 2015 
Time: 13.15 
Place: E:2349 
Examinator: Peter Nilsson

Abstract:

In high security surveillance scenarios there is a demand of recording the activity of the surveillance operators computer screens. The will has risen out of the need to establish that the personnel is following protocol in certain situations or making sure that the software is working as intended. Creating a way of analyzing the behavior of both employees, software and how the hardware works together gives way to establish better protocols, find improvements in software and ultimately develop better products. Having the potential of creating a safer environment where it really matters, for instance at airports or nuclear power plants. 

However, given that the areas where this feature is interesting are characterized by high risk and responsibility, the electronic devices used must have a very high emphasis on safety. If inserting a monitoring device between the surveillance operators’ computer and screen it must under no circumstances leave the operator without a video stream. That means there must exist a passive throughput that is free from electronic components and software implementation. The device must not substantially degrade the signal integrity and in the event that it loses power it must send the signal through. A demand that prohibits the use of traditional IC based High Definition Multimedia Interface (HDMI) splitters since they in the event of a power loss situation does not output any signal. 

Hence the birth of this project: To create a safe way of sniffing an HDMI signal without corrupting it. The solution is based on analogue operational amplifiers, something that has been proven quite difficult, given that the TMDS signaling used are very high frequency and the sheer lack of documentation on this subject. 

After successfully creating a circuit that can extract the signal, a function prototype will be created. It will be done using one of Axis Communications existing cameras and reconfiguring it to act as an encoder. To complete the prototype there is a need to rewrite drivers and convert the video stream to the right format. 

2015-08-28 Master Thesis Presentation Johan Malmgren and Christoffer Lauri

Published: 2015-08-21

Title:    Synchronization of streamed audio between multiple playback devices using RTP/RTCP 

Date:   2015-08-28 
Time:  10:15 
Place: E:2517 

Supervisors: Olle Blomgren  (Axis Communications), Anders Persson (Axis Communications), Stefan Höst (EIT) and Jens A Andersson (EIT)

Examinator: Maria Kihl (EIT)

Abstract:

Synchronizing an audio stream to multiple destinations which are not necessarily located at for example the same network is a well-known problem and a lot of research has been carried out in order to find an good way to handle this. However, it is still not clear what technique that may be best suitable given that a few constraints are present, further elaborated below.

The thesis aims to examine and discuss techniques to synchronize audio streams between multiple playback devices with regard to

- the streaming protocol being RTP/RTCP
- receivers running embedded Linux with GStreamer1 for audio playback
- sender running the .NET-platform

Further, a prototype is to be implemented with the selected technique, which will be evaluated with regard to how well the audio is synchronized, audio quality, and quality of service.

2015-08-28 PhD guest talk on digital communication

Published: 2015-08-25

Title: "Digital Communications with Low Latency and Applications for Constant Envelope Signaling" 
Speaker: Fabian Schuh 
Date: August 28, 2015 (Friday) 
Time: 13.15 
Room: E:3139

Mr. Fabian Schuh, who is a PhD student – researcher at Friedrich-Alexander University Erlangen-Nürnberg in Germany will visit our department and give a presentation of his research work. Mr. Schuh previously spent some time as a guest researcher with the Communications Group at our department, working with professor Michael Lentmaier.

Abstract:

This talk considers the problem of digital point-to-point communication with low latency, where the data is protected by an error-correction code.  A solution was found by G. Ungerböck in 1982 where he invented trellis-coded modulation (TCM). His approach deploys a convolutional code for signal points in a larger signal constellation that are most difficult to distinguish on a noisy channel and by this achieves a high bandwidth- and power-efficiency.

However, if communication takes place over a channel introducing inter-symbol interference (ISI) and, additionally, a flexible rate-adjustment is desired to adjust the transmission schemes to different transmission environments, the classical TCM approach reaches its limits.

In such a communication scenario, the receiver faces two problems: that of mitigating the effects of ISI (equalization or detection) and that of decoding. In practice, both can be approached separately at a loss in performance.

In this talk, the classical TCM approach will be extended for joint equalization and decoding, and in particular, for decoding of punctured convolutional codes. It will be shown that by means of efficiently merging the ISI-channel with the convolutional encoder, a reduced-complexity but still optimum joint equalization and decoding can be performed at the receiver.

Furthermore, even though a flexible rate is achieved by puncturing (i.e.  discarding code symbols), an optimal decoder will be derived that can also be extended for ISI-channel and higher transmission rates. Finally, the proposed algorithms are adapted to Continuous-Phase Modulation (CPM) with a non-coherent receiver which enables the use of high-power amplifiers at the transmitter, allows for applications in battery-powered devices and enables a makes cheap receivers possible.

2015-08-26 Licentiate seminar: Magnus Gustafsson

Published: 2015-06-17

Welcome to attend the licentiate seminare where Magnus Gustafsson will present his "Methods of calculating and measuring the scattered field by rough surfaces and random scatterers" in E:2311, August 26th @ 10.15.

Opponent: Samel Arslanagic, Associate professor
Department of Electrical Engineering
Technical University of Denmark

Supervisors: Mats Gustafsson (EIT), Gerhard Kristensson (EIT) and Niklas Wellander (FOI).

Examiner: Anders Karlsson

Abstract

The nature can often be described with stochastic processes. This thesis deals with the electromagnetic scattering by objects, like surfaces or volumes, where the scatterers are considered randomly positioned. A fundamental parameter for describing the electromagnetic scattering from a stochastic ground surface is the bistatic ground scattering coefficient. This parameter is fundamental in radar system design and determines, in average, what signal-to-clutter ratio that might be expected from a target in a certain environment. It also has to be included when computing the average electromagnetic coupling between a terrain type, described by stochastic parameters, and for instance a vehicle.

To mimic an experimental setup, this thesis presents an extension of an existing model, the Advanced Integral Equation Method, (AIEM), for calculation of the bistatic scattering coefficient of a rough surface in the Fraunhofer near-field. Also, a new measurement methodology has been developed and experimental results are compared with the theoretical results.

2015-08-24 Master Thesis Presentation by Christofer Ericsson

Published: 2015-08-21

Title:   Tow-factor authentication in smart phones – implementations and attacks
Date:  2015-08-24
Time:  13:15
Place:  E:3139

Examinator: Martin Hell

Abstract:

Two-factor authentication is the method of combining two so called authentication
factors in order to enhance the security of user authentication. An authentication factor is defined as ”Something the user knows, has or is”. Something the user knows
is often the traditional username and password, something the user has is something
that the user is in physical possession of and something the user is is a physical trait
of the user, such as biometrics. Two-factor authentication greatly enhances security
attributes compared to traditional password-only methods. With the advent of the
smartphone, new convenient authentication methods have been developed in order
to take advantage of the versatility such devices provide. However, older two-factor
authentication methods such as sending codes via SMS are still widely popular and
in the case of the smartphone opens up new attack vectors for criminals to exploit
by creating malware that is able to gain control over SMS functionality.
This thesis explores, discusses and compares three distinct two-factor authentication
methods used in smartphones today in the sense of security and usability.
These are mTAN (mobile Transaction Authentication Number), TOTP (Timebased
One Time Password Algorithm) and PKI (Public Key Infrastructre). Both
practial and theoretical attacks against these methods are reviewed with a focus on
malicious software and advantages and disadvantages of each method are presented.
An in-depth analysis of an Android smartphone SMS-stealing trojan is done in
order to gain a deeper understanding of how smartphone malware operates.

2015-08-24 Summer Internship Presentations by Meris Bahtijaragic and Niklas Lindskog.

Published: 2015-08-21

Course: Ingenjörsinriktad yrkesträning 
Date:   2015-08-24 
Time:  10:15 
Place: E:2311 

Supervisor: Martin Hell

Hariharasudhan Vigneswaran will present thesis.

Published: 2015-06-03

Date: Friday 12th of June 
Time: 13:15 
Place: E:3139 
Title: "Analysis of IPv6 Neighbour Discovery for Mobile and Wireless Networks". 

Hariharasudhan Vigneswaran will present thesis.

This project is a collaboration between Ericsson Research in Kista and our department.

Abstract:

The majority of the current 3GPP and M2M networks use or will use IPv6 for accessing the internet. These IPv6 networks use Neighbor Discovery as defined in RFC 4861 to identify their neighbors on the link and see if they are active. The increase in the complexity of wireless networks and introduction of battery operated devices sets forth notable challenges to certain assumptions in the RFC 4861. The RFC 4861 is more suited for wired networks

but its implementation in wireless networks makes it more inefficient. This thesis work focuses on the energy efficient implementation of RFC 4861 using the draftchakrabarti-nordmark-6man-efficient-nd-06 implementation. The draft suggests a method of registering all the nodes in the network to their default router, so that the router takes care of all the basic neighbor discovery functionalities without disturbing the battery operated devices which are in sleepy mode. Alongside the legacy Neighbor Discovery, the optimizations proposed by the draft are implemented, on a RADVD based router and an Ubuntu host, to reduce redundant multicast signaling in mobile networks. These optimizations are

theoretically analyzed to check if the draft is beneficial for scalability and transient nature of  the wireless networks.

Master Thesis Presentation by Robert Olsson and Victor Gylling

Published: 2015-05-28

Date: June 11 
Time: 13.15 
Place: E:2349 
Title: "Implementation of a 100-200 MSps 12-bit SAR ADC" 

Robert Olsson and Victor Gylling will present their Master's thesis "Implementation of a 100-200 MSps 12-bit SAR ADC", performed at Ericsson Research.

Abstract

Analog-to-digital converters (ADCs) with high conversion frequencies, often based on pipelined architectures, are used for measuring instruments, wireless communication and video applications. Successive approximation register (SAR) converters offer a compact and power efficient alternative but the conversion speed is typically designed for lower frequencies. In this thesis a low-power 12-bit 200 MSps SAR ADC based on charge redistribution was designed for a 28 nm CMOS technology.

The proposed design uses an efficient SAR algorithm (merged capacitor switching procedure) to reduce power consumption due to capacitor charging by 88 % compared to a conventional design, as well as reducing the total capacitor area by half. Sampling switches were bootstrapped for increased linearity compared to that of simple transmission gates and a method for compensating signal-dependent charge-injection effects was used. Another feature of the low power design is a fully-dynamic comparator which does not require a pre-amplifier.

Pre-layout simulations of the SAR ADC shows an SNDR of 64.8 dB, corresponding to an ENOB of 10.5, and an SFDR of 75.3 dB. The total power consumption is 1.87 mW with an estimated value of 500 µW for the unimplemented digital logic. The Schreier figure-of-merit is calculated to 171 dB.

Ola Runeson will present his thesis.

Published: 2015-06-03

Date: Thursday June 11
Time: 13.15
Place: E:2517
Title:  “Investigation of scanning conversion algorithms using DEM (Digital Elevation Modelling) for AESA radar”

Ola Runeson will present his thesis.

The work has been done at Saab in Linköping, with company supervisors Ulf Rajgård and Alexander Rajula, and department supervisor Torleif Martin. I am the examiner.

Abstract:

In this thesis the problem of estimating terrain elevation using two-dimensional radar data from the Gripen multirole fighter aircraft is considered. Radar data contains information about range from the airplane to the reflecting terrain, as well as horizontal angle. In general, radar data has high resolution in range and low resolution in angle, giving rise to interesting problems. A new radar with higher resolution is in development for the next-generation Gripen. This thesis aims at answering whether estimation of terrain height can be done using available radar data, in order to evaluate the plausibility of doing this with data from the new radar. The approach is to find matching terrain features in subsequent images of the ground, and use this information to calculate terrain elevation. Two approaches are implemented and studied, both on simulated radar data and on real datasets. One approach uses Harris corner detection and the other uses Speeded-Up Robust Features (SURF). Conclusions drawn are that the algorithms do not work for the available radar data, but that they possibly could work when higher resolution data from the new radar is available.

Project presentation by Christoffer Lundgren, EITN35

Published: 2015-06-01

Date: Friday June 5, 2015 
Time: 14:15 
Place: E:2517 
Title: A New Physical Access Control System Solution at Lund University 

Abstract:

Lund University has approximately 100 000 RFID-cards and 26 different physical access control systems in use to control 20 000 doors, in addition to a vast number of classical metal keys. Since 2009 a common card for all buildings and access control systems ​is in use, which reduces the number of cards needed. The card is distributed to all employees and students at the university, and costs approximately 40 SEK excl. VAT each. On average a card lasts for 4 years, which results in that every student attending a 5-year program uses two cards during his/her education. To reduce the card-related costs and improve the user experience an Internet-of-Things and BYOD inspired solution using the employees’ and students’ smartphones to unlock doors was investigated and developed. The solution is similar to what the company Zaplox uses in their product and service, but optimized for Lund University by using the existing network infrastructure. The new hardware, which is required in addition to the existing infrastructure, is cheap, easy to install and energy efficient.

The presentation will include a short demo.

Millimeter-wave seminar by Prof. Antti V. Räisänen

Published: 2015-06-01

Date: Thursday June 4, 2015 
Time: 15.30 
Place: E 2311 
Title: Millimeter-wave and THz research topics at Aalto University 

Welcome to a millimeter-wave seminar by Prof. Antti V. Räisänen at Aalto University in preparation for the PhD defense of Lars Ohlsson on Friday. 

ABSTRACT:

First, Aalto University, School of Electrical Engineering, and Department of Radio Science and Engineering are briefly introduced. Second, the talk gives an overview of recent millimeter-wave and THz research activities at Aalto University. The main recent emphasis has been on antennas with electronic beam steering and antenna measurements techniques. For electronic beam steering, lens antennas, reflectarrays, leaky-wave antennas, tunable high-impedance surface, and various phase shifters to be used with a dielectric rod waveguide antenna have been studied. As an example of the latter topic, carbon nanotube (CNT) membrane MEMS has been demonstrated and a high-impedance surface based on CNT membrane MEMS is under development. In antenna measurements, methods for both very high gain antennas as well as for small integrated antennas on-wafer have been studied.

CV:

Antti V. Räisänen received the Doctor of Science (Tech.) degree in electrical engineering from the Helsinki University of Technology (TKK) (now Aalto University), Espoo, Finland, in 1981. In 1989, he was appointed Professor Chair of Radio Engineering with TKK, after holding the same position pro tem in 1985 and 1987–1989. He has been a Visiting Scientist and Professor with the Five College Radio Astronomy Observatory (FCRAO) and the Univ. of Massachusetts at Amherst, MA, USA (1978–1979, 1980, 1981); the Chalmers Univ. of Technology, Göteborg, Sweden (1983); the Univ. of California at Berkeley, CA, USA (1984–1985); the Jet Propulsion Laboratory (JPL) and California Institute of Technology, Pasadena, CA, USA (1992–1993); Observatoire de Paris and Universite de Paris 6, France (2001–2002), and Universidad Carlos III de Madrid, Spain (2013-2014).

He supervises research in mm-wave and THz components, antennas, receivers, microwave measurements, etc., with the School of Electrical Engineering, Aalto University, Department of Radio Science and Engineering and Millimetre Wave Laboratory of Finland - ESA External Laboratory (MilliLab). He has authored or coauthored some 500 scientific or technical papers and several books; he is one of the editors of Semiconductor Terahertz Technology – Devices and Systems at Room Temperature Operation (Wiley 2015).

Dr. Räisänen is Fellow of IEEE since 1994 and Fellow of the Antenna Measurement Techniques Association (AMTA) since 2008. He was the recipient of the AMTA Distinguished Achievement Award in 2009. The Chair of Excellence by the University Carlos III of Madrid was awarded to him in 2013. He has been Conference Chairman of several international microwave and millimeter-wave conferences including the 1992 European Microwave Conference. He was an Associate Editor of the IEEE Transactions on Microwave Theory and Techniques (2002–2005). He was a member of the Board of Directors of the European Microwave Association (EuMA) (2006–2011). He is currently Chair of the Board of Directors, MilliLab.

Master Thesis presentation by Victor Fors

Published: 2015-06-01

Date: Wednesday, June 3, 2015 
Time: 14.15 
Place: E:2517 
Title: Three-way Lateral Shearing Interferometry with partially coherent light 

The work was performed at Luleå University with Mikael Sjödahl as  supervisors. Mats Gustafsson has been the supervisor at LTH and Daniel Sjöberg is the examiner.

Abstract
This thesis takes a look at a method for lateral shearing interferometry. The focus
is on the properties due to the degree of spatial coherence in the light source. The
thesis creates a simulation of the system, looks at some analytical solutions for the
interaction between some parameters, and finally conducts an experimental setup with
a simplified implementation of the system. One problem with classic holography is that it is very sensitive to vibrations, another is that you get speckles from using a coherent light source. The method in this thesis uses lateral shearing, where the reference is not split before the object. This has been shown to be more robust against vibrations. It also makes use of partially coherent light to limit speckles appearing from dust particles. The method works by splitting the wavefront into three parts, shear two of the new wavefronts in lateral directions, shift them in spatial frequency, and let them interfere. By the shifting of spatial frequency the mutual intensity can be separated into lobes in the spatial frequency domain. Because of the lateral shear two pairs of mutual intensity will contain information about the phase gradients in perpendicular directions. The operations of shifting and shearing takes place in the Fourier plane of an imaging system. As such it is shown that one can defocus close to the image in order to perform the shearing. Therefore one can implement the system without any dedicated part to perform the shear, but control it by adjusting the defocus. This is indeed how the experimental setup demonstrated is implemented. To get multiple speckle patterns in the experiment a rotating diffuser is used. This is shown to be very effective at averaging out the speckles. The simulation is built upon the theory of some simpler imaging theory and diffrac- tion. Some significant time has been spent optimizing its implementation in Matlab. The input plane waves consist of randomized spatial frequencies limited in some way to create correlation. Because of the random elements the statistical properties of the system emerges without any further work. This thesis does however limit itself to simpler cases that can also be solved analytically. The work method of creating a simulation and then solving for some parameters complimented each other very well. When either does not agree with that of the other one immediately knows there is an error. The simulation also provides what parameters actually are important, so you don’t have to do a lot of work that leads to boring conclusions.

Liesbet Van der Perre talks on bits, spectrum and energy.

Published: 2015-05-13

Date: Thursday May 28 
Time: 13.15-14.00 
Place: Lecture Hall E:B 
Title: Precious bits, sharing the spectrum, on elegant energy 
Speaker: This year's honorary doctor, Prof. Liesbet Van der Perre 
Extra feature: Coffee and cake will be served after the talk!

Abstract: Smart mobile devices offer ever nicer and more applications and services. Consequently, wireless communication witnesses a continued spectacular growth. The innovative power of nano-electronics has brought about this digital revolution. This huge success is bound: you can not fool physics! The limits of radio propagation and technology scaling are a fact, and the confrontation with the scarcity of resources (energy and spectrum), is evident. Researchers join forces to embark on a fascinating journey, conquering appealing new wireless capacity territories. 

Biography: Liesbet Van der Perre is active in a very competitive area, wireless communications. A combination of deep scientific knowledge, fearless analytical skills, and strong leadership qualities makes her thrive in an environment where basic research is mixed with highly specialized commercial projects. Integrated circuits developed by her have been nominated among the best in the last fifty years. Traces of her designs may hide in your pocket right now, making your smart phone better performing and batteries last longer. She has participated in many European research projects, often in leading roles, where her experience and expertise has been a very valuable asset. She has contributed to the research at Lund University in different ways, both through joint projects and as scientific advisor in several center constellations.

Liesbet Van der Perre is currently a director at Imec, Belgium, a world-leading research institute in nanoelectronics, and professor at the KU Leuven, Belgium, where she is teaching advanced wireless systems. She is author and co-author of over 250 scientific publications.

Ivaylo Vasilev PhD defense

Published: 2015-03-27

Date: 28 Apr, 2015 
Time: 10.15 
Place: E:1406 
Title: User Effect Mitigation in MIMO Terminal Antennas 

Abstract:

The rapid growth of cellular technology over the past decade transformed our lives, enabling billions of people to enjoy interactive multimedia content and ubiquitous connectivity through a device that can fit into the palm of a hand. In part the explosive growth of the smartphone market is enabled by innovative antenna system technologies, such as multiple-input multiple-output (MIMO) systems, facilitating high data rates and reliable connections. Even though future deployment of Long Term Evolution Advanced (LTE-A) is expected to provide seamless internet connectivity at even higher speeds over a wide range of devices with different form factors, fundamental terminal antenna limitations can severely impact the actual performance of the terminal. One of the key challenges in terminal antenna design are user-induced losses. It has been shown that electromagnetic absorption in body tissues as well as antenna impedance mismatch due to user proximity significantly degrade terminal antenna performance. Moreover, user interactions are non-static, which further complicates terminal design by leading to the requirement of evaluating a wide range of hand grips and usage scenarios. This doctoral thesis explores these challenges and offers useful insight on effective user interaction mitigation. In particular, state-of-the-art multiple antenna designs have been investigated in an attempt to formulate guidelines on efficient terminal antenna design in the presence of a user (Paper I). Moreover, the major part of the thesis considers the method of adaptive impedance matching (AIM) for performance enhancements of MIMO terminals. Both ideal and very practical and realistic AIM systems have been studied in order to extend the knowledge in the area by determining achievable performance gains and providing insights on AIM gain mechanisms for different terminal antenna designs, propagation environments and user scenarios.

In Paper I, five different MIMO terminal antenna designs were evaluated in 11 representative user scenarios. Two of the prototypes were optimized with the Theory of Characteristic Modes (TCM), whereas the remaining three were based on more conventional antenna types. Multiplexing efficiency (ME) was used as the MIMO system performance metric, assuming an ideal uniform 3D propagation environment. The paper focuses on performance at frequency bands below 1 GHz due to the more stringent size limitations.

Paper II presents a simulation model of the complete physical channel link based on ideal lossless AIM and evaluates the potential of AIM to mitigate user effects for three terminal antennas in four user scenarios. The prototypes studied have different performances in terms of bandwidth and isolation. MIMO capacity was used as the main performance metric. In order to gain insight on the impact of terminal bandwidth, as well as system bandwidth on AIM performance, capacity calculations were performed both for the center frequency and over the full LTE Band 13.

In Paper III, a practical AIM system was set up and measured in both indoor and outdoor propagation scenarios for a one-hand and a two-hand grip, including a torso phantom. The AIM system consisted of two Maury mechanical tuners controlled with LabView. MIMO capacity was used to determine performance in the different user and channel cases. The impact of different propagation environments and user cases was discussed in detail. Moreover, tuner loss estimation was done to enable the calculation of AIM net gains.

In Paper IV, the simulation model from Paper II was extended to include real antenna parameters as well as simulated environments with non-uniform angular power spectra. Two fundamentally different antenna designs were measured in three user scenarios involving phantom hands, whereas non-uniform environments of different angular spreads were simulated in post-processing. The study presents results and analysis on the impact of user scenarios and environment on the AIM gains for the terminals with different antenna designs.

Finally, Paper V describes a realistic AIM system with custom-designed CMOS-SOI impedance tuners on a MIMO terminal antenna. Measurement setup control, as well as MIMO system evaluation, was achieved through a custom-developed LabView software. Detailed propagation measurements in three different environments with both phantom users and real test subjects were performed. The analysis and discussions provided insights on the practical implementation of AIM as well as on its performance in realistic conditions.

mmWave-Massive MIMO seminar

Published: 2015-04-15

Date: Tue, April 28, 2015
Speaker: Assist. Prof. Katsuyuki Haneda, Aalto University, Finland
Time: 15.15-16.00 (30 min + questions)
Location: E:2517, E-building, LTH
Title: On the Mutual Orthogonality of Millimeter-wave Massive MIMO Channels

Abstract: Mutual orthogonal user channels in multiuser (MU)- multiple-input multiple-output (MIMO) systems are desirable and can be approximately obtained under independent and identically distributed (i.i.d.) Rayleigh fading assumption with a very large number of base station antennas. However, it has been shown that at millimeter-wave (mmW) frequencies, this assumption is not valid due to the limited number of multipath components and spatial channel correlation. In this paper, we examine the mutual orthogonality of a realistic 60-GHz outdoor propagation channel with practical large antenna arrays, and determine the factors deciding it based on the channel data generated by means of deterministic field prediction with experimental calibration. The results obtained reveal relationships between mutual orthogonality, inter-user distance, number of active users, transmit array dimensions, and downlink system capacity at 60-GHz band, which are useful for designing future mmW massive MU-MIMO systems.

Speaker’s Bio: Katsuyuki Haneda received the Doctor of Engineering from the Tokyo Institute of Technology, Tokyo, Japan, in 2007. Dr. Haneda is presently an assistant professor in the Aalto University School of Electrical Engineering. Dr. Haneda was the recipient of the best paper award of the antennas and propagation track in the IEEE 77th Vehicular Technology Conference (VTC2013-Spring), Dresden, Germany, and of the best propagation paper award in the 7th European Conference on Antennas and Propagation (EuCAP2013), Gothenburg, Sweden. Dr. Haneda has been serving as an associate editor for the IEEE Transactions on Antennas and Propagation since 2012 and as an editor for the Antennas, Channel Models, and Location Area of the IEEE Transactions on Wireless Communications since 2013. He also served as a co-chair of the topical working group on indoor environment and has been an active member of the European COST Action IC1004 “Cooperative radio communications for green smart environments”. His current research activity focuses on high-frequency radios such as millimeter-wave and beyond, wireless for medical and post-disaster scenarios, radio wave propagation prediction, and in-band full-duplex radio technologies.

Software award ceremony.

Published: 2015-04-14

Date: April 27, 2015 
Time: 12.30 
Place: E-husets foajé 

Invitation to the first Lufoss open source software scholarship award ceremony.

You are sincerely welcome to attend the first award ceremony of the Lufoss scholarship. Lufoss is the Lund University Fund for Open Source Software that gives scholarships to students and newly graduated contributing to open source software projects with significant utility and impact.

After the ceremony, Emil Eifrem will give a talk on open source in business with the title:

"From zero till million downloads and zero to $30m - Lessons Learned from Neo4j".

Emil is the founder of Neo4j, the most widely deployed graph database on the planet, CEO of its commercial sponsor Neo Technology and a co-author of the O'Reilly book Graph Databases. He plans to save the world with graphs and own Larry's yacht by the end of the decade. He tweets at @emileifrem.

More information here: http://www.lth.se/lufoss/finalists/

Register today at: https://www.eventbrite.com/e/lufoss-scholarship-2015-spring-award-tickets-16446872037

Welcome!

//Bjorn Regnell

Professor in Software Engineering

Presentation on BAN

Published: 2015-04-27

Date: April 27 
Time: 16.15 
Place: E:3139  
Title: Designing an Antenna for Body Area Networks  

Authors: Team Gerhards Grabbar: Georg Wolgast, Casimir Ehrenborg, Alexander Israelsson, Edvard Johansson, and Hampus Månefjord

Abstract: For the past six months we have worked on our submission for IEEE AP-S Student Design Contest 2015. Earlier this month we found out that we will be going to the finals. During this presentation we will present our journey from idea to reality. Our goal was to create a BAN that could measure ECG data continuously and wirelessly, where the readings would be sent to a smartphone for data processing. The purpose of this device is to be able to detect a heart attack and automatically raise an alarm.

This work has partly been conducted within the context of the course EITN35 Project in Electrical and Information Technology, and the presentation is also an examination part of this course. I am acting examiner.

Welcome!
Daniel

Seminar in Electromagnetic Theory.

Published: 2015-04-15

Date: Friday April  24, 
Time: 11.15 - 12.00, 
Place: E:2349, 
Speaker: Peter Olsson, Professor Chalmers 

Title:

A dubious idea for a radial directional decomposition in spherical geometries (and some questions about the relation between wave splitting and transformational cloaking).

Welcome!

Seminarium KTH, 21 April. Tar datorn över arbetet?

Published: 2015-03-24

Seminarium i vetenskaplig kommunikation

Published: 2015-02-04

Tid: den 9 april kl. 13.15-15.00
Plats: Lundmarksalen, Astronomihuset

Så tränas kommunikation i naturvetenskapliga utbildningar

”Naturvetarstudenterna vid Lunds universitet ska vara skickliga – inte bara på naturvetenskap, utan också på att kommunicera sina kunskaper.”

Detta har varit målet med det nyss avslutade KomNU-projektet (Kommunikation i Naturvetenskaplig Utbildning). Det EQ11-finansierade projektet sträckte sig över tre terminer och involverade mer än sjuttio lärare från den naturvetenskapliga fakulteten.

De medverkande lärarna har under projektets gång utvecklat muntlig och skriftlig kommunikationsträning för den egna undervisningen. Resultatet är att studenterna nu tränar kommunikation integrerat med ämnesstudierna, med successivt högre ställda krav under sin utbildning.

Vid ett öppet seminarium redovisas KomNU-projektet i sin helhet. Vi ger exempel på kommunikationsträning inom olika ämnen och visar vilka resultat det kan ge, både vad gäller kommunikationskompetens och ämnesförståelse.

Ingen föranmälan - sprid gärna inbjudan vidare på era institutioner eller motsvarande.

Välkomna!

Susanne Pelger, Naturvetenskapliga fakulteten

Sara Santesson, Institutionen för kommunikation och medier

Ericsson Wireless Network Seminar

Published: 2015-03-25

Date: March 26 
Time: 13.00 (sharp!) 
Place: E:2517 

Tomorrow we will have visitors from Ericsson in Lund, Torbjörn Sölve and Bo Lincoln, giving a seminar about wireless network development general, and Ericsson Wireless Network Performance in particular.

This seminar will go through Ericsson’s way of assessing and improving wireless (mobile) network performance, starting on a broad level and narrowing down to a concrete example where we apply MU-MIMO techniques to a specific location.

5G-seminar by Ms Yaning Zou, Tampere University

Published: 2015-03-16

Title: “System-level radio design of 5G networks”
Speaker: Yaning Zou, Tampere University of Technology
Date: Wednesday, March 25th, 2015
Time: 13:15
Room: E:2311

This Wednesday Ms. Yaning Zou, who is a postdoctoral researcher at Tampere University of Technology and will be staying with the Communication Group for a short research visit, will give a seminar talk entitled “System-level radio design of 5G networks”.

Ms. Zou’s research focus is on the impact of RF impairments in Massive MIMO systems, and the target of this seminar talk is to describe how RF circuit design and baseband processing can be integrated in the design of such systems to deliver efficient solutions. Massive MIMO is one of the candidate technologies for future 5G systems and this talk can give interesting information on this emerging technology to system and hardware component designers (and researchers) alike.

Abstract:

The vision of future 5G networks lies in the development of ubiquitous and ultra high-speed communication infrastructure to create a truly networked digital society. The enabling physical layer technologies range from adding new spectrum, extra antennas, new network topologies and new waveforms to improving efficiency of current spectrum and network usage. Within all those candidate areas, efficient radio implementation is the key to achieve success and form viable solutions for 5G network development. Compared to traditional performance driven methodology, the importance of design efficiency, cost efficiency and energy efficiency is emphasized. In this context, it calls for rethinking  radio design paradigm and methodology. For example, for efficient RF and transceiver implementation, it is critical to integrate the design of RF circuits, baseband processing and transceiver architectures together. In this regard, system-level radio design is a must element for the development of future 5G networks. Here we provide some design examples and show how the system-level view can help gain insights on potential problems and find efficient ways to improve radio performance. By combining analog/digital signal processing approaches with system-level modeling of radio network and transceiver component/architecture, we can bring all the possible design elements to the radio design and help devise the most sensible solutions for the development of high performance yet cost and energy efficient communication networks.

Welcome!

The Communications Group

Master Thesis presentation by Mao Hatto

Published: 2015-03-16

Date: March 24  
Time: 09.15  
Place: E:3139  
Title: Acceleration of Pedestrian Detection System using Hardware-Software Co-design

The project will be presented via Skype

Abstract:

Object detection technologies, represented by face detection system which has been studied for a long time, have developed recently because of the development of technologies of high performance computing and pattern recognition technique. Especially, pedestrian detection system has gathered attention recently, and it will be applied to an automobile safety system and monitoring camera system. While many research of acceleration and improvement of detecting accuracy have been published, system design as distributed system is also required. While a centralized computing system which sends raw image data to central processing node presses networks, distributed system which operates some calculation before sending data to the network decreases the total amount of data volume. When we take account of using environment of pedestrian detection system, user flexibility is also important criteria. Pedestrian detection system should be set some parameters such as detecting window size, slide width of window and operating speed depending on each using environment. When you implement the whole system on an FPGA, you will lose flexibility of the system. Hardware-Software Co-design enables to enhance flexibility. Thinking of demands mentioned in above, this thesis aims acceleration of pedestrian detection system using Hardware-Software Co-design. In the implementation, our system adopts HOG (Histogram of Oriented Gradients) feature value and Real Adaboost as a classification algorithm. Also, our system aim data reduction without decrease of detecting accuracy, design as distributed system by implement on a single FPGA, and enhancement of flexibility using Hardware-Software Co-design. HOG feature data is reduced by segmenting to 6bit after converting HOG feature value from floating-point number to fixed-point number. In addition, output of classifier by Real Adaboost algorithm is calculated by high-precision in advance, and these values are stored to ROM on the FPGA. This enables to reduce data volume without much loss of detecting accuracy. As a result, whole pedestrian detection system is implemented on a single FPGA board, and it accelerated in 3.22 faster than software only operation. In addition, feature data is reduced by 93.5% without much loss of detecting accuracy. Enhancement of flexibility using Hardware-Software Co-design also accomplished with ZedBoard FPGA and ARM Coretex-A9 processor on the board.

Master Thesis presentation by Ayla Chabouk and Carlos Gómez

Published: 2015-03-16

Date: March 20  
Time: 09.15  
Place: E:3139  
Title: High Level Synthesis for design of video processing blocks

The project was conducted at ARM Sweden with Thomas Lenart as a supervisor.

Abstract:

Nowadays the technology is progressing continuously. The designers are developing products with new features and always giving to the user an innovative technological solution for the society problems. The standard methods to design new devices are becoming slower for the demand of the products. Due to this growing complexity, some possible substitutes of the traditional Register Transfer Level (RTL) design flow has been appeared. This situation is becoming a bigger problem which needs to be solved and that is why many opened researches exist about it. In the early 90s started the idea of High Level Synthesis (HLS) and in the actual market is getting more relevance like a substitution of the standard designing methods. In a brief description, High Level Synthesis is an automatic compilation technique that translates a software program to a hardware circuit. The critical step to jump to this new field is if High Level Synthesis will give to the designers, at least, the same design possibilities and the same quality of results as handwritten hardware design. During the last ten years many companies and academic organizations has emerged which have been developing new tools for High Level Synthesis.The scope of this Master’s Thesis is to evaluate one of these commercial tools (Catapult from Calypto), to understand the possibilities and the limitations of it. The purpose of the thesis is to study, analyze and test the tool with reference models (video blocks) provided by ARM Sweden. The handwritten RTL description of the models, were provided by ARM to be used to verify and compare the correctness and the QoR (Quality of Results) of the RTL generated by the HLS tool, Catapult. After developing the Master’s Thesis, Catapult obtained the same functionality, the same performance and the same operating frequency with all the blocks worked with. However, the principal limitation of Catapult that was experienced during the work, is the total area of the generated RTL in more complex designs. The two larger designs developed in Catapult resulted in a larger area score result after synthesis compared with the handwritten RTL. Apart from this issue, HLS gives a huge advantage in comparison with handwritten RTL: the short time it takes to develop a complete hardware design and the possibility to explore different area/performance trade-off.

Master Thesis Presentation by Anh Chu

Published: 2015-03-02

Date: Mar 6, 2015
Time: 10.15
Place: E:2517
Title: Inductorless LNA and Harmonic-rejection Mixer for Wideband Direct-conversion Receiver

This work was done at Ericsson in Lund. 
Supervisors: Anders Nejdel, Henrik Fredriksson (Ericsson) and Magnus Nilsson (Ericsson)
Examiner: Markus Törmänen

All welcome!

Abstract:

In this master thesis, combinations of noise-canceling LNA and harmonic-rejection mixers are investigated and compared to find an optimal inductorless receiver front-end for low-band (600-960MHz) FDD LTE-A network. The work was carried out in a modem development project at Ericsson Modems, Lund. Three receiver versions with different harmonic rejection techniques are compared in terms of noise figure (NF) and power consumption and the receiver with 6 LO phases is selected for optimization. The LNA combines noise cancellation for matching stageand nonlinearity cancellation for output stages so both low noise figure and high linearity are achieved. The final circuit show great potential for FDD LTE-A system with support up to 3 aggregated carriers for higher bandwidth. Low NF at 1.62 dB after the LNA and 1.75 dB after the mixer are observed from 0.4-1GHz. The LNA IIP2 is above 12 dBm and robust with process and temperature. Gain switching with possible reduction of 6 and 12 dB is integrated and the LNA linearity is not significantly suffered by low gain. Input return loss (S11) is better than -12dB regardless of gain, number of carriers and temperature (-30 – 110°C). Inductorless operation saves a lot of chip area and avoid dead package area, which then save cost and make the solution competitive.

E1s projekt i elektronik

Published: 2015-03-03

Redovisning och demo av E1s projekt i elektronik.

Datum: Onsdag 4/3
Tid:13-15 och 15-17
Plats: E2517 och Labsalarna 2424/25

Alla välkomna att deltaga.
Bertil Larsson 

Master thesis "NFC Proximity Payment".

Published: 2015-03-02

Presentation of master thesis "NFC Proximity Payment"

Date: Mar 3, 2015
Time: 15.15
Place: E:3139

All welcome to attend!

Maria Kihl

Abstract

NFC, Near Field Communication is a rapidly growing technology, primarily aimed at
the mobile phone industry. As implied in the name, the technology works within a short
range. It opens up a wide range of new applications. With mobile phones implementing
NFC services, one can quickly access methods for information, payment, network connections
or media sharing. Our phones go everywhere with us ?from work to the beach.
One missing piece is wallet related services, like payment, membership cards and bus
passes.

This thesis is a commissioned work for Sony Mobile Communications in Lund.
There are three parts that has been conducted to discuss the security aspects for NFC
from a payment perspective and how payment is performed today, and how NFC can complement it.

Part 1: On-site studies were done in order to investigate how customers deal with their
wallets today. Towards this aim, various shops in Malmö were studied for how payments
are performed today.

Part 2: An online survey was conducted in which 200 Swedish residents aged between
17 and 69 years, responded to a total of eight questions regarding payments, familiarity with NFC and about what kind of mobile devices they were using.

Part 3: Interviews with experts and representatives involved in NFC payment was conducted.
Interview included persons from the following organizations: Nordea, SEB,
WyWallet, ICA, Tapit, Skånetrafiken and SL.

Seminar: Free falling magnets, the skin-effect and power cables

Published: 2015-02-19

Date: Thursday February 26

Time: 15.15 - 16.00

Place: E:2517

Speaker:

Sven Nordebo, Linnaeus University

Title:

Free falling magnets, the skin-effect and power cables

Abstract:

An electromagnetic analysis which is based on several recent publications is presented for experiments with strong permanent disc magnets. The analysis is based on the well known experiment that demonstrates the effect of circulating eddy currents by dropping a strong magnet through a vertically placed metal cylinder and observing how the magnet is slowly falling through the cylinder with a constant velocity.

This experiment is quite spectacular with a super strong neodymium magnet and a thick metal cylinder made of copper or aluminum. A rigorous theory for this experiment is provided based on the quasi-static approximation of the Maxwell equations, an infinitely long cylinder (no edge effects) and a homogeneous magnetization of the disc magnet.

It is also very interesting to note the somewhat unexpected behavior in the limit of perfectly conducting (or super conducting) cylinders where the skin-effect will play a significant role. The results can be useful for teachers and students in electromagnetics who wish to obtain a deeper insight into the analysis and experiments regarding this phenomenon.

Several experiments and numerical computations are included to illustrate the theory.

An understanding of this phenomenon is also very important for a proper treatment of similar loss mechanisms (induced eddy currents and the skin-effect) in AC power cables.

Disputation Carl Löndahl

Published: 2015-01-29

Date:   2015-02-06

Time:  10:15
Place: E:1406

Welcome to attend the disputation of Carl Löndahl where he defends his doctoral dissertation "Some Notes on Code-Based Cryptography". Faculty Opponent is Dr. Nicolas Sendrier, INRIA, France.

Abstract

This thesis presents new cryptanalytic results in several areas of coding-based cryptography. In addition, we also investigate the possibility of using convolutional codes in code-based public-key cryptography.

The first algorithm that we present is an information-set decoding algorithm, aiming towards the problem of decoding random linear codes. We apply the generalized birthday technique to information-set decoding, improving the computational complexity over previous approaches.

Next, we present a new version of the McEliece public-key cryptosystem based on convolutional codes. The original construction uses Goppa codes, which is an algebraic code family admitting a well-defined code structure. In the two constructions proposed, large parts of randomly generated parity checks are used. By increasing the entropy of the generator matrix, this presumably makes structured attacks more difficult.

Following this, we analyze a McEliece variant based on quasi-cylic MDPC codes. We show that when the underlying code construction has an even dimension, the system is susceptible to, what we call, a squaring attack. Our results show that the new squaring attack allows for great complexity improvements over previous attacks on this particular McEliece construction.

Then, we introduce two new techniques for finding low-weight polynomial multiples. Firstly, we propose a general technique based on a reduction to the minimum-distance problem in coding, which increases the multiplicity of the low-weight codeword by extending the code. We use this algorithm to break some of the instances used by the TCHo cryptosystem. Secondly, we propose an algorithm for finding weight-4 polynomials. By using the generalized birthday technique in conjunction with increasing the multiplicity of the low-weight polynomial multiple, we obtain a much better complexity than previously known algorithms.

Lastly, two new algorithms for the learning parities with noise (LPN) problem are proposed. The first one is a general algorithm, applicable to any instance of LPN. The algorithm performs favorably compared to previously known algorithms, breaking the 80-bit security of the widely used (512,1/8) instance. The second one focuses on LPN instances over a polynomial ring, when the generator polynomial is reducible. Using the algorithm, we break an 80-bit security instance of the Lapin cryptosystem.

Tårtseminarium med Per Eriksson

Published: 2015-01-29

Datum:   2015-02-05
Tid:  14:06
Plats: E:1406

Det är dags för vårens första tårtseminarium och föredragshållare är LUs före detta rektor  Per Eriksson. Titeln på föredraget är:

”Lite erfarenheter från 25 år som statlig myndighetschef, framgångar och misslyckanden."

Som vanligt startar vi klockan 14.06 och vi skall vara i E1406.

Välkommen!
/Mats Cederwall

Disputation Yuan Li

Published: 2015-01-08

Date:   2015-01-22

Time:  10:15
Place: E:1406

Welcome to attend the disputation of Yuan Li where he defends his doctoral dissertation "Mathematical Models and Algorithms for Wireless Network Design and Optimization". Faculty Opponent is Assistant Prof. Matteo Cesana, Politecnico di Milano, Italy. 

Abstract 

Optimization techniques always play an important role in designing high-performance wireless systems. This presented thesis studies a selected set of optimization problems for different kinds of wireless networks, making use of mathematical programming techniques to find optimal solutions and of efficient heuristics to find near-optimal solutions. The basic contribution of the thesis consists in a thorough study of the notion of the compatible set, and utilizing it for formulating and solving various wireless network optimization problems. The treatment is as follows. Firstly, an overview of problem formulations for compatible set optimization is made, and an enhanced formulation based on the matching polytope is proposed (Paper I). Then, an end-to-end delay minimization problem in wireless networks based on compatible sets is formulated (Paper II). Next, a max-min fair flow problem in wireless mesh networks is studied, and three related resource allocation problems are formulated, again using the notion of the compatible set. These three optimization problems include joint optimizing static rate control with transmission scheduling (Paper III), joint optimizing transmission scheduling, dynamic rate control, routing and directional antenna placement (Paper IV), and optimizing link metrics to design routing (Paper V). Finally, an emerging technology, free space optics, is considered in order for upgrading a cellular backhaul network for which a resilient topology design problem is studied (Paper VI).

The six research papers included in this thesis not only make a contribution to improve the wireless network performance and efficiently use network resources but also bridge the gap between mathematical theory, specifically mathematical programming, and engineering problems.

Paper I presents two formulations for finding an optimal compatible set, differing in the way of linearizing the signal-to-noise-plus-interference ratio (SINR) constraint. By incorporating a matching polytope, an enhanced formulation is developed that can be solved by the branch-and-cut method. The numerical study shows that the enhanced formulation works more efficiently than general formulations.

Paper II studies the end-to-end delay minimization problem in wireless networks. The delay refers to the required number of time slots to deliver a given set of packets. Depending on different application scenarios, two scheduling schemes are proposed. One scheme extends from the minimal frame-length scheduling, then permutates the compatible sets in the resulting frame and repeats the frame to minimize the delay.The other scheme aims at minimizing the delay by optimizing the transmission scheduling directly.

Paper III studies the problem of maximizing the minimal flow in wireless mesh networks with static rate control. In wireless mesh networks, several modulation and coding schemes (MCS) are applied and each of them corresponds to a data rate and a SINR threshold. Static rate control means that each link will use one selected MCS whenever it is active. A mixed integer programming model is formulated and an efficient simulated-annealing based heuristic is proposed. This heuristic makes use of a special character of this problem which greatly helps to reduce the searching space of the solution.

With the same objective as in paper III, paper IV provides optimal solutions for placing directional antennas. Directional antennas can focus the energy between a pair of communicating nodes, resulting in better spatial reuse and increased transmission range. However, they may also bring more interference to non-intended receivers within the beam, as compared with omni-directional antennas. The paper considers the use of a combination of directional and omni-directional antennas, presents a mixed integer programming model and provides several heuristics. The results show that the minimal flow is greatly increased when directional antennas are placed at proper places, and also illustrate that it is not always optimal to deploy directional antennas at all nodes.

Paper V proposes a metric-driven routing design for wireless mesh networks to resolve the trade-off between the implementation simplicity and the network traffic performance. The metric-driven routing design uses link metrics as variables and computes the routes according to shortest-path algorithms. A mixed integer programming model is formulated for this issue---the results show that the metric-driven routing can achieve good network performance in terms of the maximum minimal flow.

Finally, paper VI focuses on resilient topology design for cellar backhaul networks with free space optics, a technology for high-speed wireless connections. Due to unreliability of free space optical links, a network optimization method is proposed to assure k-connectivity. The optical fibers already existing in the backhaul network are reused to decrease the deployment cost and increase the system reliability. On top of that, mirrors are considered to connect nodes not in the line of sight. A comprehensive mixed integer programming model and a heuristic based on problem decomposition is developed.

Seminar: Planning a Post-doc

Published: 2015-01-14

Welcome to the seminar: Planning a Post-doc

-         Where should I go?

-         How do I fund it?

-         Do I need to choose between family and work?

-         How much can I earn – financially? Strategically? In published papers?

Date and venue: Tuesday 20 January 2015, Elite Hotel Ideon, Lund

Welcome to a seminar with focus on how and where to apply for funding to go on a post-doc!

And most likely we will also be able to discuss ideas of how to get a successful post-doc planned – to kick-off the rest of the career after you have finished your PhD.

Please sign up here before Friday 16 January 2015, kl 10.00 (for the fika-order to work!)

Who is welcome?

We specifically welcome Phd-students who are in the end of their time, but also encourage those Phd-students in their early stages to come, and start the process of the next step. Young researchers and supervisors are also very welcome of course!

This invitation will be circulated to the ClimBEco-school, to the faculties at LU, and to the networks within the strategic research areas BECC and MERGE. We encourage you to pass it on if you have a colleague who has not received it. We welcome people from all faculties, and our invited speakers are instructed to talk about all the general conditions that apply. In the sign-up you will be asked to state your faculty-belonging, in order to assist the speakers with information on who is in the audience. We also welcome people from other universities than Lund University!

Prel program:

9.00                     Registration

9.30                     Welcome by professor Erik Swietlicki

9.40                     Applying for Post-doc money from FORMAS – Mobility grants and Young researcher (15 min talk + 15 min discussion) Speaker: Elisabet Göranssson, FORMAS

10.10                  Applying for Post-doc money from VR (15 min talk + 15 min discussion) Speaker: tbc

10.40                  PAUS with Fika (tea/coffea + little thing)

11.00                  What do I need to think about when working in another country? (SACO/SULF) tbc

11.30                  Support from Forskningsservice at Lund University, Speaker: Sophie Hydén Picasso and Teresia Rindefjäll

11.45                  Support from CEC Speaker: Carin Nilsson

11.55                  Conclusions

12.00                  End of the day

Place:                 Elite hotell Ideon, Lund, room: Tera
Cost:                   No costs are involved, Coffea/tea and something are provided for all participants

If you have any questions - please contact carin.nilsson@cec.lu.se

Kind regards,

Carin Nilsson, Erik Swietlicki and Sophie Hydén Picasso

This seminar is organized by Centre for Environmental and Climate Research, in collaboration with LU Forskningsservice.

Carin Nilsson

Fil.Dr. Forskningskoordinator, Centrum för miljö- och klimatforskning, Lunds universitet
PhD Research Coordinator, Centre for Environmental and Climate Research, Lund University

Carin.Nilsson@cec.lu.se
phone: +46 46 222 9814

Disputation Dimitar Nikolov

Published: 2015-01-07

Date:   2015-01-19
Time:  10:15
Place: E 1406

Welcome to attend Dimitar Nikolovs disputation where he defends his doctoral dissertation "Fault Tolerance for Real-Time Systems: Analysis and Optimization of Roll-back Recovery with Checkpointing". Faculty Opponent is Professor Kishor S Trivedi, Duke University, USA. 

Abstract 

Increasing soft error rates in recent semiconductor technologies enforce the usage of fault tolerance. While fault tolerance enables correct operation in the presence of soft errors, it usually introduces a time overhead. The time overhead is particularly important for a group of computer systems referred to as real-time systems (RTSs) where correct operation is defined as producing the correct result of a computation while satisfying given time constraints (deadlines). Depending on the consequences when the deadlines are violated, RTSs are classified into soft and hard RTSs. While violating deadlines in soft RTSs usually results in some performance degradation, violating deadlines in hard RTSs results in catastrophic consequences. To determine if deadlines are met, RTSs are analyzed with respect to average execution time (AET) and worst case execution time (WCET), where AET is used for soft RTSs, and WCET is used for hard RTSs. When fault tolerance is employed in both soft and hard RTSs, the time overhead caused due to usage of fault tolerance may be the reason that deadlines in RTSs are violated. Therefore, there is a need to optimize the usage of fault tolerance in RTSs.

To enable correct operation of RTSs in the presence of soft errors, in this thesis we consider a fault tolerance technique, Roll-back Recovery with Checkpointing (RRC), that efficiently copes with soft errors. The major drawback of RRC is that it introduces a time overhead which depends on the number of checkpoints that are used in RRC. Depending on how the checkpoints are distributed throughout the execution of the job, we consider the two checkpointing schemes: equidistant checkpointing, where the checkpoints are evenly distributed, and non-equidistant checkpointing, where the checkpoints are not evenly distributed. The goal of this thesis is to provide an optimization framework for RRC when used in RTSs while considering different optimization objectives which are important for RTSs. 

The purpose of such an optimization framework is to assist the designer of an RTS during the early design stage, when the designer needs to explore different fault tolerance techniques, and choose a particular fault tolerance technique that meets the specification requirements for the RTS that is to be implemented. By using the  optimization framework presented in this thesis, the designer of an RTS can acquire knowledge if RRC is a suitable fault tolerance technique for the RTS which needs to be implemented. The proposed optimization framework includes the following optimization objectives.

For soft RTSs, we consider optimization of RRC with respect to AET. For the case of equidistant checkpointing, the optimization framework provides the optimal number of checkpoints resulting in the minimal AET. For non-equidistant checkpointing, the optimization framework provides two adaptive techniques that estimate the probability of errors and adjust the checkpointing scheme (the number of checkpoints over time) with the goal to minimize the AET.

While for soft RTSs analyses based on AET are sufficient, for hard RTSs it is more important to maximize the probability that deadlines are met. To evaluate to what extent a deadline is met, in this thesis we have used the statistical concept Level of Confidence (LoC). The LoC with respect to a given deadline defines the probability that a job (or a set of jobs) completes before the given deadline. As a metric, LoC is equally applicable for soft and hard RTSs. However, as an optimization objective LoC is used in hard RTSs. Therefore, for hard RTSs, we consider optimization of RRC with respect to LoC. For equidistant checkpointing, the optimization framework provides (1) for a single job, the optimal number of checkpoints resulting in the maximal LoC with respect to a given deadline, and (2) for a set of jobs running in a sequence and a global deadline, the optimization framework provides the number of checkpoints that should be assigned to each job such that the LoC with respect to the global deadline is maximized. For non-equidistant checkpointing, the optimization framework provides how a given number of checkpoints should be distributed such that the LoC with respect to a given deadline is maximized.

Since the specification of an RTS may have a reliability requirement such that all deadlines need to be met with some probability, in this thesis we have introduced the concept Guaranteed Completion Time which refers to a completion time such that the probability that a job completes within this time is at least equal to a given reliability requirement. The optimization framework includes Guaranteed Completion Time as an optimization objective, and with respect to the Guaranteed Completion Time, the framework provides the optimal number of checkpoints, while assuming equidistant checkpointing,  that results in the minimal Guaranteed Completion Time.

Workshop on electromagnetic structures

Published: 2015-01-12

Workshop ’ complex analysis and convex optimization for optimal and automated design of electromagnetic structures’

Date: January 14, 2015
Time: 9.15 -17.00
Location: E 3139

09.30: Ragnar Sigurdsson, Complex analysis in several variables
10.00: Annemarie Luger , Herglotz functions and several variables
11.00: Lars Jonsson, Passive systems and Herglotz functions
11.30: Applications of Herglotz functions  
13.30: Daniel Sjöberg,  Sum rules and convex optimization
14.00: Approximations of Herglotz functions 
14.30: Sven Nordebo,  EM modeling and power cables      
15.30: Mats Gustafsson,  EM energy and antennas
16.00: Anja Skrivervik,  Optimal W-BAN antennas

To project

PhD thesis defence Iman Vakili

Published: 2015-11-04

Date: 2015-10-27, at 10:15
Place: Lecture hall E:1406, Building E, John Erikssons väg 4, Lund University, Faculty of Engineeering LTH, Lund
Opponent: Prof. Andrea Neto. Technical University of Delft, Netherlands
I. Vakili:
Time-Domain Antenna and Scattering Analysis for Micro- and Millimeter-Wave Applications
Vol. 76, ISSN 1654-790X, 2015.
Abstract: Telecommunications industries are investing tremendously to meet the ever-increasing demands for higher data rates and capacity. In particular to develop standardization for 5G, which is expected around 2020. The existing spectrum for traditional mobile networks is limited to highly occupied bands at microwave frequencies below 6 GHz. It is expected that 5G will use millimeter-waves to enable higher data rates. Even though losses at millimeter-waves are higher, higher data rates for short range applications can be achieved due to the available wide bandwidth.

The radio channel between a transmitter and a receiver has a great impact on the quality of the received signals. The channel includes everything between the transmitter and receiver that may impact the signals, such as buildings, walls, windows, etc.
High data rate transmission at millimeter-wave frequencies requires size- and cost-efficient circuitry. The recent advances in nanotechnology and semiconductor devices enable the signal generation at millimeter-waves. The existence of the available extreme bandwidth at millimeter-wave frequencies enables the application of impulse radio using high frequency ultra-short pulses. Transmission of a short pulse through antennas and a free-space radio channel without significant distortion requires a wideband antenna with high fidelity.

In this thesis a time-domain antenna system with ultra-short pulse transmission and reception at millimeter-waves is presented. The antenna system consists of wideband and non-dispersive leaky lens antennas and a high frequency short pulse (wavelet) generator based on III-V technology. The time-domain system is presented in Paper I. The transmission of 100 ps long pulses at 60 GHz produced by the wavelet generator through different antennas is investigated. It is shown that the leaky lens antennas have negligible pulse distortion and preserve the shape of the generated high frequency short pulses. Further characterizations of the leaky lens antennas for the 60 GHz band, using a time-domain gating method is presented in Paper III. The results show that the antenna has a low dispersion and can thereby transmit short pulses with high fidelity.

A time-domain characterization method at millimeter-waves using the antenna system is presented in Paper II. The complex permittivity of low loss non-magnetic materials with low dispersion are estimated directly from the received time-domain pulses. The wide bandwidth of the wavelet is also used to determine the frequency dependence of dispersive materials.

Time-domain scattering analysis of periodic structures is presented in Paper IV and Paper V. A sum rule for scattering in parallel-plate waveguides based on energy conservation and the optical theorem is derived in Paper IV. A parallel-plate waveguide
with wideband TEM horn antennas and a parallel-plate capacitor are used for dynamic and low frequency (static) measurements, respectively. The results show that the all waveleghts electromagnetic interaction introduced by the object is given by the static polarizability.

The broad bandwidth and high resolution of the time-domain system is utilized for radar imaging application in Sec. 6 of the Research Overview. The images are obtained through gridding method which is a classical Fourier reconstruction and l1-minimization problem. It is shown that the resolution achieved by the time-domain system is similar to the frequency-domain measurements using a vector network analyzer.