MIMO-OFDM系统中一种高效的分子带自适应比特功率分配算法  

An efficient subband adaptive bit and power allocation algorithm for MIMO-OFDM systems

作　　者：张世超[1] 季仲梅[1] 崔维嘉[1] 

机构地区：[1]解放军信息工程大学信息工程学院,河南郑州450002

出　　处：《电路与系统学报》2012年第4期103-110,共8页Journal of Circuits and Systems

基　　金："十一五"国家863计划重点项目资助(2009AA011504)

摘　　要：自适应比特、功率分配(ABPA)可根据各子载波在频率选择性衰落信道中不同的瞬时增益,动态地分配数据比特和发射功率,从而达到优化系统性能,提高频率效率的目的。针对MIMO-OFDM系统中ABPA算法计算复杂度高的问题,本文提出了一种高效分子带ABPA算法,该算法采用新颖的分簇随机选取的方式进行子带划分及等效,将以子载波为分配单元的Fischer算法扩展为以子带为分配单元的ABPA算法,并对此算法进行改进,使其可在一次迭代过程中剔除多个比特数小于等于0的不可用簇。仿真结果表明,该算法能够在保持系统性能不变的前提下,提高筛选效率,同时可通过选择不同的簇宽度,进一步灵活地调整算法的复杂度,使其在性能与计算量之间取得良好的折衷。According to each subcarrier＇s different instantaneous gain in the frequency selective channel, adaptive bit and power allocation （ABPA） can allocate data bits and transmit power dynamically, which can optimize the system performance and improve the frequency spectrum efficiency. Conventional ABPA algorithms in MIMO-OFDM systems have many problems, including high computational complexity, time consuming etc. The paper proposes an efficient sub-band ABPA algorithm, which extends the Fischer algorithm to set the sub-bands as the allocation unit instead of sub-carriers with a novel cluster randomly selecting method, at the same time enhances it by eliminating multiple un-applicable clusters during one iterative process. The simulation results show that the algorithm can increase the screening efficiency while ensure the system performance, at the same time can neatly adjust the computational complexity with choose different bandwidth of cluster, which can realize a good trade off between performance and complexity.

关 键 词：正交频分复用 多输入多输出 空时分组编码 自适应调制 分子带 

分 类 号：TN929.53[电子电信—通信与信息系统]