Nyhetsarkiv, 2021
lu.se: Nanotrådtransistor med integrerat minne möjliggör framtidens superdatorer
Publicerad: 2021-12-27
En mångårig flaskhals inom teknikutveckling har varit hur man ska få processorer och minnen att arbeta snabbare tillsammans. Nu har forskare vid LTH presenterat en ny lösning där en minnescell är integrerad med processorn, så att beräkningar kan...
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Länk till artikeln lu.se: Nanotrådtransistor med integrerat minne möjliggör framtidens superdatorer
Mojtaba Mahdavi treats need for speed and reliability with hardware friendly algorithms
Publicerad: 2021-09-22
New applications set new demands on the data-rate, reliability, and latency of wireless communication systems in 5G and beyond, pushing forward technology developments. The thesis work of Mojtaba Mahdavi has been oriented towards the domain of...
New applications set new demands on the data-rate, reliability, and latency of wireless communication systems in 5G and beyond, pushing forward technology developments. The thesis work of Mojtaba Mahdavi has been oriented towards the domain of hardware-efficient realisation of components in the baseband. The focus has been on the design and implementation of the OFDM* demodulator, massive MIMO detector, and channel decoder.
September 24 at 9.15 he defends his PhD thesis ?Baseband Processing for 5G and Beyond: Algorithms, VLSI Architectures, and Co-design? at LTH, Lund University.
Read more about the dissertation.
Download the thesis (PDF)
Applications such as remote surgery and self-driving cars have great demands on the reliability and latency since any failure in such cases would result in a disaster. In these applications, the data transmission should be performed in less than 5 ms with a success rate of 99.999%. Other applications like video streaming and augmented reality rely upon fast and high-volume data transmission. Massive connectivity is another demand, which is required in smart cities and smart homes such that more than 100,000 devices per km2 should be able to communicate.
A simplified block diagram of baseband processing in massive MIMO systems. The highlighted blocks, OFDM demodulator, massive MIMO detector, and channel decoder, are targeted in the thesis. Click to enlarge.
Why research wireless systems??I did my master thesis in the field of baseband processing for 4G wireless systems in the Sharif University of Technology in Teheran. I found the interdisciplinary research of wireless communication and digital hardware design very interesting, and I wanted to learn more about this field. Thus, I decided to pursue PhD studies at the Department for Electrical and Information Technology at Lund University, which has been one of the main pioneers and contributors in the development of 5G systems.? What is the most fascinating or interesting with your thesis subject?
?One of the most fascinating aspects of my thesis work is the realisation of very complex algorithms and mathematical equations in the real hardware using simple circuits. It is interesting to investigate how the system-level features can be utilised to make these algorithms more hardware friendly and develop efficient hardware architectures to perform complicated processing.? What will happen with the findings?
?An important outcome of my research is to demonstrate how system, algorithm, and architecture levels can be co-optimised to improve the efficiency of the final design. This approach can be employed to design and implement the baseband processor for the current and upcoming wireless communication systems in a more efficient way. In this thesis, we have used this design approach for the key functional blocks in the baseband processing of 5G systems and presented that the hardware cost, latency, reliability, and data rate are significantly improved.? ------------- * OFDM: Orthogonal frequency-division multiplexing. Get an overview at Wikipedia.org.
Länk till artikeln Mojtaba Mahdavi treats need for speed and reliability with hardware friendly algorithms
Ny materialmix i nanotrådarna ger bättre transistorer
Publicerad: 2021-09-14
Halvledarindustrin drivs framåt av förbättringar av digitala processorer där transistorn har varit den fundamentala komponenten. Under den senaste tiden har området breddats mot komponenter som är speciellt designade för att vara effektiva inom...
Varför doktorera ? och i Lund?
Tävlar mot jättar
Vad händer med dina forskningsresultat?
Länk till artikeln Ny materialmix i nanotrådarna ger bättre transistorer
H.M. Konungens medalj till Sven Mattisson
Publicerad: 2021-06-10
Professor Sven Mattisson har förlänats H.M. Konungens medalj i 8:e storleken i Serafimerordens band för betydelsefulla tekniska innovationer.
H.M. Konungens medalj, tidigare kallad Hovmedaljen, från 1800-talets förra hälft förlänas för särskilda förtjänster. Kungen har beslutat om medaljförläningar för H.M. Konungens medalj i 8:e storleken till professor Sven Mattisson.
Som nyexaminerad civilingenjör kom Sven Mattisson 1979 till institutionen för tillämpad elektronik på LTH. I början på 80-talet hände en rad saker på institutionen för tillämpad elektronik som fick betydelse för mobiltelefoniforskningen. Bland annat startades ett mobilradiokonsortium där Ericsson och flera högskolor ingick. Under ett par år var Mattisson utbytesstudent vid Caltech i Kalifornien, USA. Det var där hans doktorsavhandling som handlade om att utveckla en kretssimulator som simulerade analoga beteenden hos en integrerad krets tog form.
Mattisson disputerade 1986 och 1994 lämnade han LTH och blev anställd hos Ericsson Mobile Communications. Där placerades han i ett framtidsprojekt som skulle arbeta med en radiolänk på kort håll och med låg effekt. Den kallades till en början MC-Link vilket stod för Multi-Communicator Link. MC-Link skulle senare bli Bluetooth och utvecklingen gick snabbt. 1998 skapades en intressegrupp bestående av flera stora teknik- och telekommunikationsbolag som utvecklade standarden Bluetooth. Namnet Bluetooth var från början ett internt arbetsnamn (efter Harald Blåtand) men blev senare det officiella namnet.
Länk till artikeln H.M. Konungens medalj till Sven Mattisson
Vehicle communication is rushing into the 5G world
Publicerad: 2021-06-01
For ten years, researchers in communications engineering in Lund have worked in close collaboration with Volvo Cars and other vehicle manufacturers to study communication between vehicles. The result is robust communication solutions that function...
There?s been an accident and rapid help is needed. If the car involved is a Volvo, it has already contacted the emergency services. If the vehicle in front slams on its brakes, the car will automatically brake to keep at a suitable distance. Everything is based on robust communication.
?Robust is a key concept here. If we have come to depend on communication technology, it must always work ? with no exceptions?, says Fredrik Tufvesson, professor of radio systems in the Department of Electrical and Information Technology at Lund University.
The systems must function in all weather conditions and in all surroundings: in a snowstorm at -40 °C just as well in baking desert temperatures and a sandstorm, when the vehicle is stationary just as well as when it travels at 200 km/h.
?Communication solutions have become important when people choose a car. The system should be able to communicate with the surroundings if something happens, and it should also be able to receive and stream music and video inside the car?, says Fredrik Tufvesson.
Understand in depth
Within ELLIIT, he has been working with his group at Lund University on vehicle communication for the past 10 years, in collaboration with Volvo Cars and other vehicle manufacturers. ELLIIT has functioned as an umbrella for collaboration within four projects that are part of the Strategic Vehicle Research and Innovation Programme (FFI) financed by Vinnova. Other actors in addition to Volvo Cars have participated in the various projects, such as Volvo Trucks, Terranet, and researchers at the School of Information Technology at Halmstad University. ?We needed in-depth understanding of how the communication between two mobile units, in this case cars, can work. The challenges that must be solved differ from those when one unit is a stationary mast. We have developed models and investigated the physical processes to find out what must be given priority in order to construct a robust system for communication between mobile units?, says Fredrik Tufvesson.Broad experience
The scientists have subsequently analysed possibilities and limitations, and developed models that make it possible to test algorithms and simulate the systems in the computer, instead of building expensive prototypes and carrying out test driving. Many of the researchers and students who have worked in the Vinnova projects are now working at Volvo Cars, and have been able to influence the development of communication solutions. Experiences from the different collaboration projects have also contributed to the design of Volvo?s 5G strategy.The research is now progressing to new objectives: the next step concerns how cars are to help each other, for example to discover an obstacle.
?If a cyclist suddenly appears in front of your car, the cars behind will be informed of this so that they can all brake at the same time?, Fredrik Tufvesson explains.
Well-functioning communication Another important field of use is in vehicle convoys, where trucks drive with small separations.
?We can achieve fuel savings of 20% by driving close behind the truck in front. Even the front truck of a vehicle convoy achieves lower fuel consumption, as a consequence of the changed patterns of air eddies behind it. But it all depends on having a functioning system of signalling between the vehicles, along the complete length of the convoy.?
Another example in which vehicle communication is necessary is motorway driving with two cars travelling parallel to each other at high speed. Both try to move into the same lane at the same time, which is a situation that often leads to accidents.
ELLIIT research within vehicle communication contributes in this way to higher safety, a reduced risk of accidents, lower fuel consumption, and ? not least ? competitive advantages for the vehicle manufacturers who participate. Text: Monica Svenselius Translation from Swedish: George Farrants
Länk till artikeln Vehicle communication is rushing into the 5G world
P4 Malmöhus: Därför kan du få vänta ovanligt länge på en ny dator
Publicerad: 2021-05-31
Lars-Erik Wernersson, professor i nanoelektronik, om bristen på halvledare.
Lyssna och läs på sverigesradio.se.
Länk till artikeln P4 Malmöhus: Därför kan du få vänta ovanligt länge på en ny dator
Vehicle communication is rushing into the 5G world
Publicerad: 2021-05-31
For ten years, researchers in communications engineering in Lund have worked in close collaboration with Volvo Cars and other vehicle manufacturers to study communication between vehicles. The result is robust communication solutions that function...
There?s been an accident and rapid help is needed. If the car involved is a Volvo, it has already contacted the emergency services. If the vehicle in front slams on its brakes, the car will automatically brake to keep at a suitable distance. Everything is based on robust communication.
?Robust is a key concept here. If we have come to depend on communication technology, it must always work ? with no exceptions?, says Fredrik Tufvesson, professor of radio systems in the Department of Electrical and Information Technology at Lund University.
The systems must function in all weather conditions and in all surroundings: in a snowstorm at -40 °C just as well in baking desert temperatures and a sandstorm, when the vehicle is stationary just as well as when it travels at 200 km/h.
?Communication solutions have become important when people choose a car. The system should be able to communicate with the surroundings if something happens, and it should also be able to receive and stream music and video inside the car?, says Fredrik Tufvesson.
Understand in depth
Within ELLIIT, he has been working with his group at Lund University on vehicle communication for the past 10 years, in collaboration with Volvo Cars and other vehicle manufacturers. ELLIIT has functioned as an umbrella for collaboration within four projects that are part of the Strategic Vehicle Research and Innovation Programme (FFI) financed by Vinnova. Other actors in addition to Volvo Cars have participated in the various projects, such as Volvo Trucks, Terranet, and researchers at the School of Information Technology at Halmstad University. ?We needed in-depth understanding of how the communication between two mobile units, in this case cars, can work. The challenges that must be solved differ from those when one unit is a stationary mast. We have developed models and investigated the physical processes to find out what must be given priority in order to construct a robust system for communication between mobile units?, says Fredrik Tufvesson.Broad experience
The scientists have subsequently analysed possibilities and limitations, and developed models that make it possible to test algorithms and simulate the systems in the computer, instead of building expensive prototypes and carrying out test driving. Many of the researchers and students who have worked in the Vinnova projects are now working at Volvo Cars, and have been able to influence the development of communication solutions. Experiences from the different collaboration projects have also contributed to the design of Volvo?s 5G strategy.The research is now progressing to new objectives: the next step concerns how cars are to help each other, for example to discover an obstacle.
?If a cyclist suddenly appears in front of your car, the cars behind will be informed of this so that they can all brake at the same time?, Fredrik Tufvesson explains.
Well-functioning communication Another important field of use is in vehicle convoys, where trucks drive with small separations.
?We can achieve fuel savings of 20% by driving close behind the truck in front. Even the front truck of a vehicle convoy achieves lower fuel consumption, as a consequence of the changed patterns of air eddies behind it. But it all depends on having a functioning system of signalling between the vehicles, along the complete length of the convoy.?
Another example in which vehicle communication is necessary is motorway driving with two cars travelling parallel to each other at high speed. Both try to move into the same lane at the same time, which is a situation that often leads to accidents.
ELLIIT research within vehicle communication contributes in this way to higher safety, a reduced risk of accidents, lower fuel consumption, and ? not least ? competitive advantages for the vehicle manufacturers who participate. Text: Monica Svenselius Translation from Swedish: George Farrants
Länk till artikeln Vehicle communication is rushing into the 5G world
A technology library for vertical nanowire transistors towards 100 GHz wireless communication and beyond
Publicerad: 2021-05-24
Wireless hardware can currently communicate with wavelengths of up to 6 GHz. To go beyond this, towards the interval 10 to 100 GHz, the performance of the parts of the computer chips that process the signals from and to antennas need to be improved....
What made you want to pursue a PhD in nano electronics?
?Initially, it was driven by the job market, as I was not able to find a good position. Additionally, I thought that I could try to merge the electronics bachelor and nanoscience master studies into a single field where they overlap. As luck would have it, that exact position appeared in the Nanoelectronics group at EIT in Lund. The fact that I was able to efficiently combine the two interests of mine: the science of nanostructures, and the electronics engineering, resulted in this thesis. I always considered it to be the greatest asset to the work carried out in the thesis ? both the lab processing and the circuit design and modelling.?How do you believe the results will come to use?
?It is only briefly mentioned in thesis, since it is not the focus of the work, but it permeates every corner of it, and without it, it would not be possible to obtain any circuit response ? the nanowire MOSFET high-frequency compact model as such. The strength of the model allows not only for describing the novel device structures, but also to apply the device in circuit design ? which has a great practical aspect for both industry and academia!What are your plans?
?There is this saying: ?The world is your oyster!? After completing thesis work, I feel that I can in fact tackle any electronics task ahead of me. Such empowerment feels good, truly??, he concludes. Jonas Wisbrant- The thesis for download as PDF
- Abstract and registration for the PhD defence
Länk till artikeln A technology library for vertical nanowire transistors towards 100 GHz wireless communication and beyond
lu.se: ERC Advanced Grant for research on ferroelectric transistors to Lars-Erik Wernersson
Publicerad: 2021-04-22
Lars-Erik Wernersson, professor of nanoelectronics at Lund University, has received an ERC Advanced Grant for the integration of new materials into the high-performance, energy-efficient transistors and circuit solutions of the future. The new...
Länk till artikeln lu.se: ERC Advanced Grant for research on ferroelectric transistors to Lars-Erik Wernersson
lu.se: ERC Advanced Grant för forskning om ferroelektriska transistorer Lars-Erik Wernersson
Publicerad: 2021-04-22
Lars-Erik Wernersson, professor i nanoelektronik, får EU:s ERC Advanced Grant för integration av nya material i framtidens högpresterande och energisnåla transistorer och kretslösningar.
Länk till artikeln lu.se: ERC Advanced Grant för forskning om ferroelektriska transistorer Lars-Erik Wernersson
Breaking Post Quantum Cryptos for Future Internet Security
Publicerad: 2021-01-14
The communication on the internet has to be encrypted if you want to be sure that only the sender and receiver can share the information. Today's encryption is based on mathematical problems that are easy to construct but really difficult to solve....
Doctoral dissertation for download
Register for online participation at the PhD Defence 22 January at 9.15
When you shop online, contact your internet bank or use chat apps, you want to encrypt your data to avoid leaking sensitive information. Encryption as it is used today relies on the assumption that it is hard for computers to factor* large integers and some other similar problems. Despite decades of research no one has been able to efficiently solve these problems on a classical computer.
?On a quantum computer, with enough so called qubits, these problems are quite easy to solve. To prepare for a potential future where today?s encryption is broken, other mathematical problems to base encryption on are studied. This area of study is called post-quantum cryptography?, Erik Mårtensson says.
?I develop algorithms to solve the mathematical problems in post-quantum cryptography as efficiently as possible. In other words, I do cryptanalysis. We can only trust post-quantum encryption methods if considerable efforts at breaking these methods have been made.?
What made you want to pursue a PhD?
?I like math and I like thinking about hard problems. Pursuing a PhD in my area means that I can get payed to do so!?
What?s beautiful about cryptanalysis?
?In many other research areas, a mathematical problem is an approximation of reality. In my research, the mathematical problems I try to solve are constructed precisely, they are not an approximation.?
?Another beautiful aspect of the problems I study is that they are very simple to state and understand, but still very hard to solve. No matter how smart you are and no matter how much computational resources you have access to.?
How will the results come to use?
?When implementing post-quantum encryption schemes in the future, one needs to take into consideration all possible methods for trying to break the schemes, including the methods developed in my research?, Erik Mårtensson concludes.
What are your plans?
?I?m currently applying for a post-doc position.?
Länk till artikeln Breaking Post Quantum Cryptos for Future Internet Security
