Cooperative Transmission for Relay Networks Based on Second-Order Statistics of Channel State Information

• Published in: IEEE transactions on signal processing Vol. 59; no. 3; pp. 1280 - 1291
• Main Authors: Jiangyuan Li, Petropulu, Athina P, Poor, H Vincent
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.03.2011; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Applied sciences; Array signal processing; Channel state information; Channel uncertainty; Channels; cooperative communications; Detection, estimation, filtering, equalization, prediction; Equivalence; Exact sciences and technology; Information, signal and communications theory; Materials; Mathematical models; Miscellaneous; Newton method; Programming; Relay; Relay networks; Relays; semidefinite programming; Signal and communications theory; Signal processing; Signal to noise ratio; Signal, noise; Statistics; Studies; Telecommunications and information theory; Second order; Relaying; Parameter estimation; Relay; Relay network; Transmission protocol; Cooperative systems; Programming; Order statistic; relay networks; Beam forming; Statistical method; semidefinite programming; Relaxation; Channel estimation; Data transmission network; Signal processing; Numerical simulation; Routing protocols; cooperative communications; Newton method; Channel uncertainty; Signal to noise ratio
• ISSN: 1053-587X; 1941-0476
• DOI: 10.1109/TSP.2010.2094614

Cooperative transmission in relay networks is considered, in which a source transmits to its destination with the help of a set of cooperating nodes. The source first transmits locally. The cooperating nodes that receive the source signal retransmit a weighted version of it in an amplify-and-forward (AF) fashion. Assuming knowledge of the second-order statistics of the channel state information, beamforming weights are determined so that the signal-to-noise ratio (SNR) at the destination is maximized subject to two different power constraints, i.e., a total (source and relay) power constraint, and individual relay power constraints. For the former constraint, the original problem is transformed into a problem of one variable, which can be solved via Newton's method. For the latter constraint, this problem is solved completely. It is shown that the semidefinite programming (SDP) relaxation of the original problem always has a rank one solution, and hence the original problem is equivalent to finding the rank one solution of the SDP problem. An explicit construction of such a rank one solution is also provided. Numerical results are presented to illustrate the proposed theoretical findings.