Optimal power allocation and network beamforming for OFDM-based relay networks

We herein consider the problem of optimal power allocation in an OFDM two-way relay network with multiple relays. Assuming two-way relaying is performed using analog network coding, we obtain the optimal power allocation across subcarriers and among a relay and two communicating nodes by minimizing the total power consumption in the network subject to two separate rate constraints for each transceiver. We then present an algorithm to solve the proposed optimization problem. Our simulation result shows that the proposed algorithm significantly outperform an equal power allocation scheme, where all subcarriers at all nodes receive the same levels of power and the total power is equal to that consumed in our proposed solution.