Joint Subcarrier-pairing and Resource Allocation for Two-way Multi-relay OFDM Networks

In this paper, we investigate the joint subcarrier-pairing and resource allocation scheme for multi-relay aided two-way relay OFDM networks, where power allocation, subcarriers assignment and relay selection are taken into account. It is assumed that amplify-and-forward relaying protocol is deployed on all relay nodes to assists the information exchange between two sources via orthogonal subchannels. In this case, we formulate an optimization problem to maximize the total end-to-end transmission rate of the system under individual power constraints at each node. The goal is to seek the jointly optimized subcarrier pairing, subcarrier-pair-to-relay selection and power allocation. To solve the problem, we derive an asymptotically optimal scheme by adopting the dual decomposition approach of mixed-integer programming problems. Finally, simulation results are presented to demonstrate the performance of the proposed scheme.