Optimal Relay Power Allocation for Amplify-and-Forward OFDM Relay Networks With Deliberate Clipping

Deliberate clipping is a simple solution to high peak-to-average power ratio problem of OFDM signal. In amplify-and-forward OFDM relay networks, due to the limited resource, deliberate clipping is also suggested. However, clipping is a nonlinear process and may cause significant performance degradation. Based on Bussgang Linearization Theory, the authors provide a linear system model for amplify-and-forward OFDM relay networks. To achieve spatial diversity, they design a practical nonlinear distortion aware receiver at the destination. Considering a total relay power constraint, they propose an optimal power allocation scheme to maximize the signal-to-noise distortion ratio.