Robust Collaborative-Relay Beamforming
2009 (English)In: IEEE Transactions on Signal Processing, ISSN 1053-587X, E-ISSN 1941-0476, Vol. 57, no 8, 3130-3143 p.Article in journal (Refereed) Published
Relay communications is a promising technique to extend the range of wireless communications by forwarding the message from the sender to the intended destination. While fixed or variable-power relays have been previously investigated, this paper addresses the collaborative use of variable-phase variable-power amplify-and-forward (AF) relays for robust beamforming, with the aid of imperfect channel state information (CSI) at the sender. In particular, the maximization of the worst-case signal-to-noise ratio (SNR) at the destination terminal is studied under a bounded spherical region for the norm of the CSI error vector from the relays to the destination. Our main contribution is that we prove, under a condition on the quality of the estimated CSI, the robust-optimal collaborative-relay beamforming (CRBF) can be obtained by S-Procedure and rank relaxation techniques. In addition, a distributed algorithm is developed by examining the structure of the optimal CRBF solution. Results demonstrate a significant gain of CRBF over non-robust approaches.
Place, publisher, year, edition, pages
IEEE , 2009. Vol. 57, no 8, 3130-3143 p.
Collaborative beamforming, MIMO, relay, user cooperation diversity, optimal power allocation, wireless, networks, optimization, mimo, constraints, information, capacity, channel, protocols
Telecommunications Communication Systems
IdentifiersURN: urn:nbn:se:kth:diva-18616DOI: 10.1109/tsp.2009.2021456ISI: 000268106700022ScopusID: 2-s2.0-68249162098OAI: oai:DiVA.org:kth-18616DiVA: diva2:336663
QC 201005252010-08-052010-08-052011-11-29Bibliographically approved