OFDM系统中一种改进的低复杂度自适应比特功率分配算法

发布时间：2018-04-02 07:19

本文选题：正交频分复用系统　切入点：比特功率分配　出处：《重庆邮电大学学报(自然科学版)》2017年02期

【摘要】：针对正交频分复用(orthogonal frequency division multiplexing,OFDM)系统在进行自适应比特功率分配时存在过高复杂度的问题,提出了一种基于边缘自适应(margin adaptive,MA)准则的改进低复杂度自适应比特功率分配算法。与贪婪(Greedy)算法相比,提出的改进算法通过预分配和迭代分配2部分来降低算法的计算量。改进算法先在预分配中根据信道条件预先分配部分比特,在迭代分配中通过增大内存开销的方法减少Greedy算法中计算和比较每个子信道功率增量的次数,从而降低算法的复杂度。仿真结果表明,在相同的仿真环境下算法的自适应分配效果和Greedy算法的自适应分配效果基本一致,同时该算法和Greedy算法具有几乎相同的误比特性能。且随着子信道数量的增加,与Greedy算法相比,该算法的运行时间更短,进而说明所提出的算法具有较低的复杂度。
[Abstract]:In order to solve the problem of high complexity of adaptive bit power allocation in orthogonal frequency division multiplexing OFDM (orthogonal Frequency Division Multiplexing) system, an improved low complexity adaptive bit power allocation algorithm based on edge adaptive margin adaptive algorithm is proposed.Compared with the greedy greedyalgorithm, the proposed improved algorithm reduces the computational complexity by two parts: preallocation and iterative allocation.The improved algorithm preallocates some bits according to the channel conditions in the preallocation, and reduces the number of times of calculating and comparing the power increments of each subchannel in the Greedy algorithm by increasing the memory overhead in the iterative allocation, thus reducing the complexity of the algorithm.The simulation results show that the adaptive allocation effect of the algorithm is basically the same as that of the Greedy algorithm in the same simulation environment, and the algorithm and the Greedy algorithm have almost the same bit error performance.With the increase of the number of subchannels, the running time of the proposed algorithm is shorter than that of the Greedy algorithm, which shows that the proposed algorithm has a lower complexity.
【作者单位】：重庆邮电大学光电信息感测与传输技术重庆市重点实验室;
【基金】：国家自然科学基金(61472464) 重庆市基础与前沿研究计划项目(cstc2015jcyj A0554,cstc2013jcyj A40017) 重庆邮电大学(重庆市)研究生科研创新项目(CYS14144)~~
【分类号】：TN929.53

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