Power Allocation for Multi-Relay Amplify-and-Forward Cooperative OFDM

In this paper, we propose an adaptive power allocation algorithm for multi-relay amplify-and-forward cooperative orthogonal frequency division multiplexing (OFDM) systems. However, Conventional power resource allocation schemes based on equal distribution of bandwidth and/or power may not be efficient given the constrained power and bandwidth at the relay node. In this paper, consider a total relay power constraint; we propose an optimal power allocation scheme to maximum the receiver signal-to-noise ratio. Lagrange is used to solve the formulated problem. Numerical results demonstrate the effectiveness of the proposed scheme, and shed interesting throughput-fairness trade-off in the resource allocation problem. Moreover, it is also verified that the proposed transmission scheme outperforms other transmission schemes without considering non-linear distortion.