MIMO-OFDM接力通信系统的最优功率分配  

Optimal Power Allocation for MIMO-OFDM Relaying Systems

作　　者：周明宇[1,2] 李立华[1,2] 王海峰 张平[1,2] 

机构地区：[1]泛网无线通信教育部重点实验室(北京邮电大学),北京100876 [2]北京邮电大学无线新技术研究所,北京100876 [3]诺基亚技术平台,上海200002

出　　处：《电子学报》2009年第1期26-30,共5页Acta Electronica Sinica

基　　金：国家自然科学基金(No.60702051);国家863高技术研究发展计划(No.2007AA01Z261;2006AA01Z260);高等学校博士学科点专项科研基金(No.20070013028);北京邮电大学"研究生创新研究基金";诺基亚公司合作项目

摘　　要：针对两跳多入多出-正交频分复用(MIMO-OFDM)接力通信系统进行研究,每一跳传输采用奇异值分解将多载波上的MIMO信道转化为多个独立子通道,并提出最大化系统容量的最优功率分配问题,其中源节点和中继节点能够在多个子通道上进行联合功率分配;继而采用拉格朗日算法提出最优功率分配算法.由于最优算法涉及一元四次方程组,目前的数学方法不能提供其通解的闭合表达式,因此提出采用迭代过程实现最优功率分配的方法,为MI-MO-OFDM接力系统提供了系统容量的上限.数值仿真结果显示,最优功率分配算法能大大提升系统容量,增强系统的传输能力.Two-hop multiple input multiple output- orthogonal frequency division multiplexing（MIMO-OFDM）relaying communication system is researched. Singular value decomposition is employed to transform MIMO channel on multiple sub-carriers into multiple independent sub-channels in each hop transmission, and the optimal power allocation problem is introduced to maximize system capacity. The power can be allocated jointly on multiple sub-channels at both the source node and relay node,and further,the optimal allocation algorithm is proposed with aid of Lagrange algorithm. Since the optimal algorithm is related to quartic equations and mathematical methods nowadays cannot provide its closed form for the general solution, a method is proposed to utilize iteration courses to realize optimal power allocation, and it provides the upper limit for MIMO-OFDM relaying system capacity. Numeral simulation results show that the optimal power allocation algorithm can improve the system capacity and enhance the transmission ability greatly.

关 键 词：多入多出 正交频分复用 接力通信 功率分配 

分 类 号：TN911.2[电子电信—通信与信息系统]