Node Cooperation for Fixed Wireless Access
Lead Research Organisation:
University of Cambridge
Department Name: Computer Science and Technology
Abstract
Broadband Internet access is of growing economic and political importance in both developing and developed countries. Broadband fixed wireless access (FWA) is a technology which permits broadband services to be rolled-out both quickly and cost effectively in competition with incumbent operators or in areas where there is little existing infrastructure. The demands being placed upon broadband networks by multimedia-enabled applications require bit rates far in excess of that available from current wireless systems. Therefore, the fundamental requirement is to be able to deliver multi-megabit data rates in both line of sight (LOS) and non-LOS scenarios.The partners in this current proposal are presently conducting an EPSRC funded project (GR/S46437/01) that is investigating space-time coding and spatial multiplexing techniques to improve the throughput and capacity of broadband FWA systems. However, although useful gains in performance have been achieved, further improvements are likely to be more modest owing to fundamental aspects of the FWA channel. Specifically, FWA systems are in general characterized by LOS or near LOS propagation, yielding slow time variation, mild frequency selectivity and correlated propagation paths. Therefore it is difficult to exploit time, frequency and space diversity in an effective manner in order to improve system performance. Consequently, a new architecture for FWA systems is presented in this current proposal that will overcome the issues previously highlighted. Particularly, the use of node cooperation diversity is proposed as a means of improving performance in the FWA scenario where it is more difficult to exploit other diversity techniques. In node cooperation diversity, nodes assist one another in their transmission to the destination node. For example, a destination node will receive a message directly from the source and in addition a copy of the message from a relay node. Consequently, diversity in cooperative systems is associated with the existence of multiple paths to the destination node that fade independently. Therefore, node cooperation diversity is one of the key concepts to enable further improvements in the performance of FWA systems.
People |
ORCID iD |
Ian Wassell (Principal Investigator) |
Publications
Chatzigeorgiou I
(2010)
Error Probability Analysis of Unselfish Cooperation over Quasi-Static Fading Channels
Chatzigeorgiou I
(2011)
Exact and Asymptotic Outage Probability Analysis for Decode-and-Forward Networks
in IEEE Transactions on Communications
Chatzigeorgiou I
(2009)
Threshold-based frame error rate analysis of MIMO systems over quasistatic fading channels
in Electronics Letters
Chen L
(2011)
Distributed Amplify-and-Forward Cooperation Through Message Partitioning
in IEEE Transactions on Vehicular Technology
Chen L
(2010)
Distributed Amplify-and-Forward with Ring-TCM Codes
Guo W
(2012)
Capacity-Outage-Tradeoff (COT) for Cooperative Networks
in IEEE Journal on Selected Areas in Communications
I Chatzigeorgiou (Author)
(2009)
Packet error probability for decode-and-forward cooperative networks of selfish users
Description | Significant performance benefits are available via the use of node cooperation. Fundamental limits were obtained and various practical schemes were investigated both analytically and via simulation studies. The availability of channel state information (CSI) at the transmitters enables adaptive power allocation to be performed and this can give rise to substantial performance implovements. |
Exploitation Route | This project will make significant contributions to broadband Fixed Wireless Access (FWA) technology, both in terms of fundamental results and technology application. Consequently the results of this work will be of value to both the academic community and industry. For example, it is to be hoped that the project will lead to collaboration with other Institutions, for example those working in the computer-networking arena. In addition, the results of the work will be directly relevant to standardisation bodies such as the IEEE 802.16 committees that are in the process of developing specifications for next generation wireless access systems. The technologies and techniques discovered in this project will be of considerable interest to industry. Indeed, they may find direct application in the products being designed and manufactured by Cambridge Broadband Ltd. (see attached letter of support). The work will also benefit other equipment manufacturers and suppliers wishing to design or improve FWA products. In addition the results will also benefit communications network operators wishing to deploy FWA networks. The original focus of the work was for broadband fixed wireless access (FWA) networks, but we now consider that node cooperation will also be a significant benefit to wireless sensor networks (WSNs) used for monitoring civil infrastructure, e.g., bridges and tunnels. We are now looking to implement some of our algorithms on real wireless nodes by utilising software defined radio (SDR) techniques. This has been enabled by an award of SDR equipment from Microsoft Research. |
Sectors | Digital/Communication/Information Technologies (including Software) |
URL | http://www.cl.cam.ac.uk/research/dtg/www/ |
Description | Cambridge Broadband Ltd |
Organisation | Cambridge Broadband Networks |
Country | United Kingdom |
Sector | Private |
PI Contribution | Investigation concerning the feasibility and performance gain available from a virtual multiple input multiple output (MIMO) enhanced broadband fixed wireless access (FWA) system. |
Collaborator Contribution | Access to radio channel measurements and models. |
Impact | System simulations and analysis for optimum power control for a distributed antenna collaborative fixed wireless access (FWA) system. |
Start Year | 2007 |