DISTRANT. Distributed antenna systems for efficient wireless systems.

2010-02-08 -> 2016-06-30

Research Projects

The project delivered its halftime report in April 2014

The following milestones were stated to have been passed:

-System design proposal
-Optical link signal transmission
-Algorithm-hw co-design
-FPGA-based hw-architecture for centralized processing
-Algorithm-hw evaluation
-Test of correlation and shadowing effects
-Model extension proposal
-Test of dynamic behaviour. 

The project consists of four WPs (Work Packages)

The WPs are running through two time phases, year 1-2 and year 3-5 respectively:

-WP1: System design and analysis.
-WP2: Integrated low-cost units.
-WP3: Centralized processing.
-WP4: Propagation and antennas.

An initial system design is developed and also are hardware and algorithms requirements written down. A test range for propagation channel studies is also created. Circuits and algorithms will be brought forward in the second phase and evaluation of the system will be performed accordingly.

Project outcomes (1-4):

1. Network deployment guidelines for indoor and outdoor cellular and wireless systems when using distributed antenna systems.

Extensive simulations and tests have been performed based on systems with distributed (left) and co-located (right) antennas, see below picture.

2. Suitable hardware architectures and designs for low cost distributed antenna systems.

The work has been performed on RF hw-architecture according to the block diagram below and the designed and measured ICs in this context are:

-CMOS photo diode
-Radio fiber interface
-1W power amplifier
-Transimpedance optical front-end amplifier

3. Low complex base band solutions for centralized processing.

The focus in phase 1 has been to evaluate some of the critical baseband processing blocks and the work is divided into three disciplines:

-Calculation of linear pre-coders.
-Limitation of peak-to-average power across antennas.
-Antenna element selection.

4. Propagation models for distributed antenna systems or large arrays.

Measurements and studies are performed in order to understand behavior of large antenna array systems and distributed antenna systems. The results are to be used in order to improve future system performance, aiming for 5G-standards. The results are classified into three groups:

-Propagation measurements and modeling for distributed antenna systems.
-Propagation measurements and modeling for large arrays.
-Studying the directional properties of uplink and downlink channels in FDD large array systems.

 Future plans:

-A Massive MIMO testbed, LuMaMi, i sbeing assembled, pretested and set to operation.
-The transciever modules from phase 1 will be fully integrated.
-Channel measurements on the distributed antenna system will be performed.
-The phase1 findings on low complex baseband processing will be adapted to a system with higher degree of antenna distribution.
-Waveform design study for the downlink in distributed and Massive MIMO systems.

IPR and innovations created:

-IPR: design of the integrated antenna modules,
-Patent on wireless positioning approach, sold to Sony Mobile,
-Distributed processing architecture for large distributed or co-located antenna systems,
-Ongoing work on an uplink-downlink reciprocity calibration scheme based on a new approach.