Optimal transmit strategy of a two-hop decode-and-forward MIMO relay system with mean and covariance feedback

Author

Chen, Zhiyong ; Liu, Hui ; Wang, Wenbo

Author_Institution

Key Lab. of Universal Wireless Commun. for Minist. of Educ., Beijing Univ. of Posts & Telecommun., Beijing, China

Volume

14

Issue

6

fYear

2010

fDate

6/1/2010 12:00:00 AM

Firstpage

530

Lastpage

532

Abstract

This letter proposes an optimal transmit strategy to maximize the cut-set bound on the ergodic capacity for the two-hop decode-and-forward (DF) MIMO relay system with the mean and covariance feedback. Upon the analysis of the ergodic capacity, we show that the optimal transmit beamforming directions in the first hop are along the eigenvectors of the difference between the source-relay channel and the source-destination channel. In the second hop, the relay should transmit along the eigenvectors of the relay-destination channel. Using the optimization theory, we then investigate the optimal power allocation for the source and the relay with the constraint of the total transmit power. Simulation results are then presented for illustration.

Keywords

MIMO communication; array signal processing; covariance analysis; eigenvalues and eigenfunctions; feedback; optimisation; telecommunication channels; covariance feedback; eigenvectors; ergodic capacity; mean feedback; optimal power allocation; optimal transmit beamforming; optimal transmit strategy; optimization theory; relay-destination channel; source-destination channel; source-relay channel; two-hop decode-and-forward MIMO relay system; Array signal processing; Constraint optimization; Constraint theory; Covariance matrix; Decoding; Feedback; MIMO; Power system relaying; Relays; Transmitters; MIMO, DF relay systems, mean and covariance feedback; optimality of transmit covariance;

fLanguage

English

Journal_Title

Communications Letters, IEEE

Publisher

ieee

ISSN

1089-7798

Type

jour

DOI

10.1109/LCOMM.2010.06.100143

Filename

5474933