Optimum power allocation for OFDM in physical-layer network coding over a flat frequency-selective fading channel

The physical layer network coding (PNC) takes advantages of signal interference at relay node and improves the channel capacity, therefore, PNC becomes an important research topic. However, the frequency-selective fading channel would destroy the performances of PNC. This paper considers orthogonal frequency division multiplex (OFDM) in PNC, when signals transmitted over a frequency-selective fading channel, and an optimum power allocation scheme is proposed. Simulation results show that the presented system not only eliminates the multi-path interference, but also maximizes the channel capacity by the optimum power allocation.