Filter-and-Forward Distributed Beamforming in Relay Networks With Frequency Selective Fading

• Published in: IEEE transactions on signal processing Vol. 58; no. 3; pp. 1251 - 1262
• Main Authors: Haihua Chen, Gershman, A.B., Shahbazpanahi, S.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.03.2010; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Acoustical engineering; Applied sciences; Array signal processing; Beamforming; Constraint optimization; Convex analysis; Councils; Decoding; Detection, estimation, filtering, equalization, prediction; Distributed beamforming; Exact sciences and technology; Fading; filter-and-forward relaying; Finite impulse response filter; Frequency; Impulse response; Information, signal and communications theory; Mathematical analysis; Miscellaneous; Optimization; Optimization techniques; Quality of service; Relay; Relay networks; Relays; Selective fading; Signal and communications theory; Signal processing; Signal, noise; Strategy; Studies; Telecommunications and information theory; Performance evaluation; Relaying; Relay; filter-and-forward relaying; Transmitter; Distributed beamforming; relay networks; Convex programming; Beam forming; Duplex process; Selective fading; Digital filter; Relay channel; Frequency selection; Simulation; Signal processing; Finite impulse response filter; Service quality
• ISSN: 1053-587X; 1941-0476
• DOI: 10.1109/TSP.2009.2035986

A new approach to distributed cooperative beamforming in relay networks with frequency selective fading is proposed. It is assumed that all the relay nodes are equipped with finite impulse response (FIR) filters and use a filter-and-forward (FF) strategy to compensate for the transmitter-to-relay and relay-to-destination channels. Three relevant half-duplex distributed beamforming problems are considered. The first problem amounts to minimizing the total relay transmitted power subject to the destination quality-of-service (QoS) constraint. In the second and third problems, the destination QoS is maximized subject to the total and individual relay transmitted power constraints, respectively. For the first and second problems, closed-form solutions are obtained, whereas the third problem is solved using convex optimization. The latter convex optimization technique can be also directly extended to the case when the individual and total power constraints should be jointly taken into account. Simulation results demonstrate that in the frequency selective fading case, the proposed FF approach provides substantial performance improvements as compared to the commonly used amplify-and-forward (AF) relay beamforming strategy.