Title :
Collaborative-Relay Beamforming With Perfect CSI: Optimum and Distributed Implementation
Author :
Zheng, Gan ; Wong, Kai-Kit ; Paulraj, Arogyaswami ; Ottersten, Björn
Author_Institution :
Univ. Coll. London, London
fDate :
4/1/2009 12:00:00 AM
Abstract :
This letter studies the collaborative use of amplify-and-forward (AF) relays to form a virtual multiple-input single-output (MISO) beamforming system with the aid of perfect channel state information (CSI) in a flat-fading channel. In particular, we optimize the relay weights jointly to maximize the received signal-to-noise ratio (SNR) at the destination terminal with both individual and total power constraints at the relays. We show that the optimal collaborative-relay beamforming (CRB) solution achieves the full diversity of a MISO antenna system. Another main contribution of this letter is a distributed algorithm that allows each individual relay to learn its own weight, based on the Karush-Kuhn-Tucker (KKT) analysis.
Keywords :
MIMO communication; antenna arrays; array signal processing; distributed algorithms; fading channels; Karush-Kuhn-Tucker analysis; MISO antenna system; channel state information; distributed algorithm; flat-fading channel; optimal collaborative amplify-and-forward-relay; signal-to-noise ratio; virtual multiple-input single-output beamforming system; Array signal processing; Channel state information; Collaboration; Constraint optimization; Distributed algorithms; MIMO; Power system relaying; Relays; Signal to noise ratio; Space technology; Collaborative beamforming; distributed implementation; relay;
Journal_Title :
Signal Processing Letters, IEEE
DOI :
10.1109/LSP.2008.2010810
