Bit error probability of decode‐and‐forward relaying with efficient partial relay selection in non‐identical Rayleigh fading channels

Efficient partial relay selection (EPRS) is an advanced technique to improve the performance of partial relay selection (PRS) at the cost of a small additional feedback overhead. However, EPRS has the worst performance but lower feedback overhead when compared with best relay selection. In this study, the authors present a bit error probability (BEP) analysis of EPRS in decode‐and‐forward relaying systems over independent and non‐identical Rayleigh fading channels, where the direct link between the source and the destination is available. In particular, they provide an exact and closed‐form expression of the BEP of M ‐ary square quadrature amplitude modulation for EPRS. The BEP analysis is verified through simulations. The numerical results show that EPRS significantly outperforms PRS for a large gap between the average channel powers for the first and the second hops except when all the average channel powers for the first hop are smaller than those for the second hop.