协同OFDM放大前传空时编码系统中的功率分配  

The power allocation of cooperative OFDM-based amplify-and-forward STBC system

作　　者：王丽洁[1] 唐艺[1] 黄勤飞 魏急波[1] 

机构地区：[1]国防科技大学电子科学与工程学院,湖南长沙410073 [2]中国电子系统设备工程总公司,北京100141

出　　处：《国防科技大学学报》2012年第3期142-147,共6页Journal of National University of Defense Technology

基　　金：国家自然科学基金资助项目(61002032;60903206);教育部高等学校博士点专项科研基金资助项目(2009430711004)

摘　　要：针对由源节点和单个中继节点形成的协同正交频分复用(OFDM)Alamouti空时块码系统,分析了放大前传(AF)模式下的系统容量,给出了解析表达式。考虑节点功率独立约束的应用场景,提出了分步迭代的功率分配算法(SIPAA)来提高系统容量。该算法的核心思想是在每次迭代中,分步对源和中继节点分别进行注水功率分配,注水功率分配前对目标函数进行线性化处理,功率分配后对功率分配向量进行线性化处理以降低算法复杂度。仿真结果表明,相对于等功率分配算法,所提出的分步迭代功率分配算法可以显著提高系统容量,且仅需很少几次迭代运算就可以完成功率分配。A cooperative orthogonal frequency division multiplexing （OFDM） system with a source and a non-regenerative relay transmitting according to Alamouti＇ s STBC is considered. The capacity of the system is analyzed and the analytical expression is presented. To improve the capacity of the individual power constrained system, a power allocation algorithm named as the Stepwise Iterative Power Allocation Algorithm （SIPAA） is proposed. The basic principle of SIPAA is that the water-filling power allocation is implemented stepwise for both the source and the relay within iterations. To reduce the complexity of SIPAA, the object function is linearly processed before the water-filling power allocation, and the power vector is also linearly processed after the water-filling power allocation. It is confirmed by the simulation results that a significant system capacity improvement can be achieved by the proposed algorithm, compared with conventional equal power allocation algorithm. Moreover, the power allocation can be completed within a few iterations.

关 键 词：正交频分复用 空时块码 协同传输 放大前传 注水功率分配 

分 类 号：TN929.5[电子电信—通信与信息系统]