Single and multiple relay selection for cooperative communication under frequency selective channels

In this paper, a relay selection scheme for cooperative communication with amplify-and-forward (AF) under frequency selective channels is proposed. In the scheme, to tackle with the difficulty caused by frequency selective channel, the output SNR of equalization detector is used as the end-to-end SNR to order the relays. According to relay ordering, one or multiple relay can be sequentially selected out from N relays. The numerical results verify the method of relay ordering and show that the multiple relay selection scheme outperforms conventional optimal single relay selection scheme.