Network beamforming based on second order statistics of the channel state information

• Published in: 2008 IEEE International Conference on Acoustics, Speech and Signal Processing pp. 2605 - 2608
• Main Authors: Havary-Nassab, V., Shahbazpanahi, S., Grami, A., Zhi-Quan Luo
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.03.2008
• Subjects: Array signal processing; Channel state information; convex feasibility problem; Distributed beamforming; distributed signal processing; Quality of service; relay networks; Relays; semidefinite programming; Signal to noise ratio; Statistical distributions; Statistics; Transmitters; Uncertainty; Wireless sensor networks
• ISBN: 9781424414833; 1424414830
• ISSN: 1520-6149
• DOI: 10.1109/ICASSP.2008.4518182

The problem of distributed beamforming is considered for a network which consists of a transmitter, a receiver, and r relay nodes. Assuming that the second order statistics of the channel coefficients are available, we design a distributed beamforming technique via maximization of the receiver signal-to-noise ratio (SNR) subject to individual relay power constraints. We show that using semi-definite relaxation, this SNR maximization can be turned into a convex feasibility semi-definite programming problem, and therefore, it can be efficiently solved using interior point methods. We also obtain a performance bound for the semi-definite relaxation and show that the semi-definite relaxation approach provides a c-approximation to the (nonconvex) SNR maximization problem, where c = O((log r) -1 ) and r is the number of relays.