Antenna/Relay Selection for Coded Wireless Cooperative Networks

In this paper, we consider distributed coding for wireless cooperative networks with antenna/relay selection. The aim of this of work is to find ways to improve the reliability of the source-relay link in an effort to maintain the diversity order available in the system. To this end, we propose to use antenna selection at the relay node whereby the antenna with the best instantaneous received signal to noise ratio is selected. This assumes that the relay node is equipped with multiple antennas, but only one radio frequency (RF) chain is employed. The concept of antenna selection can be extended to relay selection. That is, among the available relay nodes, the one with the best source-relay link reliability is selected. Assuming decode-and-forward (DF) relaying, we analyze the antenna/relay selection in conjunction with a previously proposed distributed coded cooperation scheme based on convolutional codes. Specifically, we derive an upper bounded expression for the symbol error rate assuming M-ary phase shift keying (M-PSK) transmission. Our analytical results show that the maximum diversity order of the system is maintained for the entire range of bit error rate of interest, unlike the case without antenna selection. Several numerical and simulation results are presented to demonstrate the efficiency of the proposed scheme.