Power Allocation Algorithm of Opportunities Cooperative Relay System Over Nakagami-m Fading Channels

摘要

In order to improve the performance of the cooperative relay communication system, this study proposed power allocation algorithm aiming at minimizing the system BER (Bit Error Ratio). Firstly, the relay model of system is constructed, which is proved to be convex optimization problem. Then, BER performance expression and optimal power allocation algorithm are presented. And ξ is defined as power allocation factor. Furthermore, sub-optimal power allocation algorithm of a simple and effective optimal power allocation algorithm is developed, which only depends on the average channel gains of the relays. Therefore, each relay nodes don't need to update channel status information in real-time and the closed form of ξ can be obtained. Simulation and numerical results are shown that power allocation factor is very close to the theoretical value. Compared with equal power allocation algorithm, the BER performance gains can be achieved by optimal and sub-optimal power allocation algorithms.