面向OFDM无线中继系统的功率分配算法

针对正交频分复用无线中继系统的绿色通信问题，提出一种低复杂度功率分配算法。首先，采用“放大-转发”中继策略，源节点在中继传输的两阶段都发送相同信息。然后，通过联合优化源节点和中继节点在各子载波上的传输功率，使系统以最小功耗代价满足用户通信服务质量要求。由于该问题是一个复杂的多变量耦合非凸问题，直接求解难度高。对此，综合运用拉格朗日松弛法和块坐标连续上界最小化方法，通过交替优化各个功率变量，获得原问题的高质量次优解。仿真结果表明，该算法能有效降低中继系统总体功耗，为无线中继系统的绿色通信提供有效解决方案。

Power allocation algorithm for OFDM wireless relay system

Aiming at the green communication problem of orthogonal frequency division multiplexing(OFDM)wireless relay system,a low complexity power allocation algorithm is proposed.Firstly,the relay strategy of amplify and forward is adopted,in which the source node sends the same information in the two stages of relay transmission.Then,by jointly optimizing the transmission power of the source node and the relay node on each subcarrier,the system can meet the quality of service requirements for the user communication with minimum power consumption.Because the problem is a complex multivariable coupled nonconvex problem,it is difficult to solve it directly.To solve this problem,the Lagrange relaxation method and the block coordinate continuous upper bound minimization method are used to optimize each power variable alternately for obtaining the high-quality suboptimal solution of the original problem.The simulation results show that the algorithm can effectively reduce the overall power consumption of the relay system and provide an effective solution for the green communication of the wireless relay system.