Cooperative Performance and Diversity Gain of Wireless Relay Networks

Abstract—In this paper, the error rate performance and diversity

gain of amplify-and-forward (AF) wireless relay networks

are studied. The distributed space-time block code (DSTBC)

in a synchronous relay network with multiple relay nodes is

considered. The distributed linear dispersion code is used at the

relays. The symbol (or codeword) error rate is studied in terms

of upper and lower bounds through rigorous derivations, and

the diversity gain of the DSTBC is derived, for any number of

relay nodes. As a corollary, a necessary and sufficient condition

is obtained for achieving full cooperative diversity. Arbitrary

coding matrices at the relays, path loss and general linear power

allocation are considered. Finally, the orthogonal frequencydivision

multiplexing (OFDM)-based space-time transmission

scheme in asynchronous cooperative networks is also discussed