Performance Analysis of Selection Combining For Differential Amplify and Forward Relaying Over Rayleigh Fading Channels

This paper investigates and puts forward the selection combining (SC) at the destination for differential amplify and forward (D-AF) relaying over slow Rayleigh fading channels. The selection combiner opts the link with the maximum magnitude of the decision variable, here no channel state information (CSI) is required at the destination for detection of the transmitted symbols. But for the Semi-Maximum Ration Combining (Semi-MRC), channel state information is required at the destination. Different from Semi-MRC, the selection combiner does not need the second-order statistic of any of the channels, which simplifies the destinations detection task. The exact average bit-error-rate (BER) of the proposed SC is verified with the simulation results. It is also shown that the performance of the SC method is very close to that of the MRC method, even though with lower complexity