Research Update September 2009
The communications research group focuses on the design, analysis and simulation of cutting-edge wireless communication systems (primarily physical and link layers aspects). The current wireless communication projects are focused on:
- Cognitive radio systems – sensing, detection, deployment methods and analysis.
- Cooperative and distributed communications systems – protocol and code design, and analysis.
- High throughput communication system design.
- Channel estimation and equalization, and advanced receiver structures.
- Computationally feasible single and multiuser detection algorithms for various environments.
Additional upcoming projects link: http://www.elec.canterbury.ac.nz/research/communications/research.shtml
Recent research results:
- Michael Krause, Prof. Desmond Taylor and Dr. Philippa Martin have developed an iterative list based detection approach for overloaded multiuser systems operating on fading channels.
- Rui Lin and Dr Martin have developed a HARQ scheme for a family of high rate non-orthogonal space-time block codes. A list algorithm was developed to reduce decoding complexity for retransmissions.
- One exciting output from Assoc. Prof. Peter Smith’s work with Dr. Matthew McKay is an analysis of the effects of correlation on the time-varying performance of MIMO-SVD systems. The results appear to be the first to explain this behaviour and have the added bonus of being simple and intuitive.
- Mr. Abdulla Firag , Matthew McKay (HKUST) and Assoc. Prof. Peter Smith have performed an analytical characterization of the capacity of MIMO relays including multiple relays and source-to-destination links.
- In the area of MIMO-OFDM a simple algorithm has been developed to achieve optimal power allocation around 90% of the time. This is work by Krishna Kongara, John Chung and Assoc. Prof. Smith and delivers enormous complexity reductions for large systems.
- Mr. Krishna Kongara, Drs. Ping-heng Kuo and Lee Garth and Assoc. Prof Peter Smith were the first to look at the detailed behaviour of the MIMO channel across frequency and apply the results to the fundamentals of OFDM performance. Their results can be used in sub-band allocation and feedback design problems.
- Prof. Taylor and Dr. Nick Baas have developed a generalized per-survivor processing (PSP) receiver for dispersive wireless channels. This is the first explicit use of PSP for dispersive channels.
- For cognitive radio (CR) systems work by Assoc. Prof. Smith and Fainan Hanif has shown that intelligent power control of the CR devices can make huge differences to the number of devices allowed by the primary users.
- Mr. Fainan Hanif and Assoc. Prof. Peter Smith have investigated the use of 2 fundamentally different deployment methods for cognitive radios (CRs): Exclusion zones and radio environment maps. Their results demonstrate that exclusion zones can outperform REMs despite the huge knowledge embedded in the REMs. For the REM approach to provide its promised improvements, the allocation of channels to the CRs is critical and cannot be based on a first-come-first-served philosophy.
- Dr. Rachel Maw and Prof. Des Taylor have developed high rate space-time trellis codes for use with continuous phase frequency shift keying. These codes achieve throughputs as high as 6 bits/sec/Hz.
- Drs. Rachel Maw and Philippa Martin and Prof. Des Taylor have developed and evaluated a cooperative relying communication system based on continuous phase frequency shift keying. It uses relaying of space-time trellis code components to achieve diversity and good error rate performance.
- Dr. Yau Hee Kho and Prof. Des Taylor have developed integrated multiple input multiple output equalizers with integrated channel estimation that are based on the use of polynomial predictors to achieve near optimal channel estimation.
- Drs. Nick Pau and Philippa Martin along with Prof. Des Taylor have developed high performance, high rate space time coded systems based on the use of iterative parallel interference cancellation coupled with iterative decoding of multiple low density parity check codes.
- Assoc Prof. Peter Smith in conjunction with Marco Chiani and Andrea Giorgetti (Uni. of Bologna) has investigated channel metrics. The old question of what constitutes a good radio channel has been looked at from new perspectives. They have derived novel channel metrics which give simple and intuitive results, are physically based and have reasonable properties.
News:
- Dr Philippa Martin and Mr Michael Krause were awarded a Build IT postdoctoral Fellow award. This will allow Michael to be a fellow in the communications group until May 2011.
- Assoc. Prof. Peter Smith is about to sign a contract with Intel for communications research approximately $80,000.
- Dr Philippa Martin was awarded a $5000 College of Engineering Operational Research grant, which will fund a 3 week visit by Prof. Martin Tomlinson and Dr Marcel Ambroze, University of Plymouth, in October – November 2009.
Recent thesis completions/ submissions 2009
- Tim King, "Algorithms for approaching the capacity of the MIMO broadcast channel", University of Canterbury, PhD, submitted 2009.
- Krishna Kongara, "Adaptive MIMO OFDM systems with IOTA", University of Canterbury, PhD, submitted 2009.
- Michael Krause
- Judy Zhou
Arrivals
- Mr Khawaja Tauseef Tasneem started his PhD with Dr Philippa Martin in June.
Upcoming visitors
- Prof. Martin Tomlinson and Dr Marcel Ambroze, University of Plymouth, in October – November 2009.
Last updated: September 2009.
Next updated: March 2010.