Performance Analysis of MIMO Relay Wireless Networks With Orthogonal STBC

In this paper, we investigate the performance of a wireless relay network with each of its nodes equipped with N antennas and the same orthogonal space-time block coding (OSTBC) scheme adopted at its destination and relays for transmission. By deriving the performance expressions for a single-relay system, we obtain the maximum diversity order achievable by the channel-state information (CSI)-assisted amplify-and-forward (CAF) protocol. Then, by focusing on CAF multirelay systems subject to a total power constraint, we derive a simple approximate symbol error rate (SER) expression for the multiple-relay channels with and without relay selection revealing a higher achievable diversity order by using relay selection than its counterpart with fixed relay configuration.