Impact of Imperfect Channel on the Performance of Relay Selection

Opportunistic relay selection(ORS) is a promising approach for cooperative communications owing to its low complexity, since it selects only the best relay. Most of studies about relay selection are assumed in imperfect channel state information. However, in real system, imperfect channel caused by channel estimation errors and feedback delay cannot be ignored. The channel state of the selected relay at the relay selection instant may be differ from the actual channel during data transmission. Feedback delay and channel estimation errors can lead to wrong relay selection. In this paper, we focus on studying the impact of imperfect channel on performance of cooperative communication. Simulation results show that the channel capacity and average bit error rate(BER) of system is sensitive to the feedback delay and the estimation error that decrease performance of system obviously.