最佳中继协作通信系统的功率分配算法

Power Allocation in Opportunistic Cooperative Relaying Systems

为提高基于最佳中继选择的协作通信系统的性能,提出了以最小化系统中断概率为目标的功率分配算法.首先建立了系统的优化模型并证明了待解的优化问题实质是凸优化问题,由此提出了最优功率分配算法并给出了算法步骤.其次,在此基础上提出了一种有效的次最优功率分配算法,该算法计算简单且仅需已知各个中继节点的平均信道状态信息,无需在传输中实时更新,因而不增加系统的额外开销.仿真结果表明,本文提出的最优算法和次最优算法所得到的功率分配方案与穷举搜索方法的结果非常接近;与等功率分配方案相比,这两种算法均能显著提高系统的中断概率性能.

To enhance the performance of opportunistic cooperative relaying systems, this paper proposes the power allocation algorithms aiming at minimizing the outage probability. The optimization model of the system is constructed and proved to be a convex optimization problem. Then the optimal power allocation algorithm and its operation steps are presented. Furthermore a simple and effective near-optimal power allocation strategy is developed, which only depends on the average channel gains of the relays and thus incurs little overhead. Simulation and numerical results show that significant performance gains can be achieved by the two pro- posed power allocation algorithms.