BER Analysis of decouple-and-forward relaying for dual-hop Alamouti transmissions over Rayleigh fading channels

In this paper, decouple-and-forward (CF) relaying for dual-hop Alamouti transmissions is proposed as enhanced amplify-and-forward relaying to improve spatial diversity gains achieved by multiple antennas at a source, relay, and destination. To attain spatial diversity gains, the CF relaying requires a process for decoupling and re-encoding at the relay. Assuming uncorrelated Rayleigh fading channels, we derive an expression for the end-to-end bit error rate (BER) with M-ary PSK constellations for the CF system. Numerical investigation shows that the BER equation provided in the paper makes an exact match with the simulation results. The result also shows that the proposed CF system achieves spatial diversity gains provided from multiple antennas at all nodes.