Interference-Aware Relay Selection Scheme for Two-Hop Relay Networks With Multiple Source–Destination Pairs

Abstract—An interference-aware relay selection scheme is proposed for two-hop relay networks with multiple source– destination (S–D) pairs, each of which is assisted by a relay selected from the candidates. We address the interference from relays to their nonintended destinations, and the interference level at any destination is jointly affected by relay selections of all S–D pairs. Upper and lower bounds of the two-hop transmission rate are derived, and the joint impact of the interference from multiple relays is decoupled to each S–D pair. Based on these bounds, an interference-aware relay selection metric for each S–D pair is pro-posed, which reflects both the relay-assisted two-hop rate and the induced interference to other destinations. The decoupled metric enables us to formulate the relay selection as a weighted bipartite matching problem, with the S–D pairs and the candidate relays as the two sides. Both the centralized scheme based on the Hungarian algorithm and the distributed scheme based on matching games are presented. Simulation results show that the distributed scheme performs nearly the same as the centralized scheme, and both schemes substantially outperform the conventional min–max relay selection scheme in terms of network sum rate. Index Terms—Bipartite matching, collaborative relay, interfer-ence limited system, relay selection. I