摘要: |
多输入多输出(MIMO)技术作为新一代移动宽带通信的核心技术,面临着天线数目增大带来的系统增益和高信道相关性导致的检测误码之间的矛盾.对此提出一种新的格基规约(LR)辅助的K-Best算法,由于经LR处理后K-Best算法中每一个父节点的子节点不确定,本文采用基于需求的扩展方案扩展子节点,并基于候选最小堆的排序算法降低排序复杂度,平均时间复杂度从O(KNlog2(KN))降低至O(Klog2K),空间复杂度从O(KN)降低至O(K).并且针对经LR处理后,星座图不再是有限的所带来的检测误码,提出了一种越界控制方案提高检测的准确率.仿真结果表明,越界控制方案使得算法在高信道相关性下其误码率(BER)性能得到了3 dB的增益.并且本算法与最大自然ML算法仅有1 dB的差距,算法复杂度远小于ML算法,仅仅随着天线数呈线性增长,是一种适用于大规模天线系统的高效的MIMO检测算法. |
关键词: MIMO 信道相关性 格基规约 K-Best |
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基金项目:国家科技重大专项“TD-LTE/FDD-LTE/TD-SCDMA/WCDMA/GSM多模基带商用芯片研发”(2013ZX03001007-004) |
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An efficient MIMO detection algorithm with the resistance to channel correlation |
QIU Mengting, ZHAO Pu, YU Hui, LUO Hanwen
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School of Electronic Information and Electrical Engineering,Shanghai Jiao Tong University
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Abstract: |
MIMO,the core technology of next generation wireless broadband communication,is faced with the contradiction between the system gain benefit by increasing antennas and the detection error due to high channel correlation.Therefore,we propose a new Lattice-Reduction(LR)-assisted K-Best algorithm.Since the children nodes of every parent node are uncertain after LR processing,on-demand expansion scheme is adopted to expand children nodes,and the sorting algorithm based on minimum candidate heap is used to decrease the sorting complexity.Then the average time complexity is decreased from O(KNlog2(KN)) to O(Klog2K),and the spatial complexity is decreased from O(KN) to O(K).In order to solve the problem of detection error caused by no longer limited constellation map after LR processing,a boundary control scheme is put forward to improve the detection accuracy.Simulations show that with the aid of boundary control,the BER performance has obtained 3dB gain when channel correlation is high.And the proposed algorithm only lost 1dB gain compared to ML algorithm with much smaller computational complexity,the complexity is only linearly increased with the number of antennas.So this proposed efficient algorithm is suitable for large scale antenna system. |
Key words: MIMO channel correlation lattice reduction K-Best |