Inter-relay interference management schemes for wireless multi-user decode-and-forward relay networks

In this paper, two cooperative communications schemes with inter-relay interference (IRI) management are proposed for wireless multi-user decode-and-forward (DF) relay networks. The schemes are based on a DF half-duplex (HD) relaying protocol and a relay selection method which maximizes the signal-to-noise ratio (SNR) of the second hop. To minimize the IRI, the first scheme [constellation real part (CRP)] uses a new transmission scheme based on the constellation real parts of the modulated signals, and the second scheme [previous message buffering (PMB)] uses a buffering technique at the relays. To assess the performance, we derive the expressions of the average bit error rate (BER) for the proposed schemes. Numerical results are given to confirm the analytical expressions and the advantage of the proposed schemes in enhancing interference management for wireless cooperative networks.