Joint power allocation and subcarrier assignment for two-way OFDM multi-relay system

In this paper, we investigate a joint resource allocation problem for two-way OFDM multi-relay network, where two transceivers exchange OFDM signal with the help of multiple relays. Considering a constraint on the total transmit power consumed in the whole network, the assignment of subcarriers to multiple relays and power allocation at both transceivers as well as relays are jointly optimized to maximize the sum-rate. The maximization problem turns out a mixed integer programming problem, which can be asymptotically solved through Lagrange dual decomposition approach. Further, we propose a suboptimal algorithm to trade off performance for complexity. Finally, simulation results are provided to demonstrate the performance gain of the proposed algorithms.