Multi-user multi-input multi-output multi-hop relay system based on likelicooperative hood detection and sphere decoding

doi:10.11772/j.issn.1001-9081.2015.10.2848

Abstract

Abstract: Concerning the Bit Error Rate (BER) and channel capacity optimization in the data transfer process of Multi-Input Multi-Output (MIMO) system, a multi-user MIMO multi-hop relay system based on cooperative likelihood detection and sphere decoding was proposed. Firstly, it constructed a second-order cooperative MIMO relay system model to analyze the relay transmission process of channel data, as well as path loss and shadow fading. Secondly, the sphere decoding was used to derive the equivalent maximum likelihood rule for log-normal shadow fading detection. Finally, the maximum channel power harmonic mean selection policy was put forward, and an access link with smaller BER was chosen for user based on correlation link metric and maximum channel power threshold value, so as to improve the performance of multi-user MIMO system. Simulation results show that, compared with the multi-user MIMO multi-hop relay system based on mutual information maximization and the relay system based on decoding-forwarding and MIMO orthogonal Space Time Block Code (STBC), the average BER of the proposed system reduced by 27.4% and 32.6% respectively, and the average channel capacity increased by 9.5% and 12.7% respectively. The results demonstrate that the proposed system has a good effect in reducing BER and improving channel capacity.

Key words: Multi-user Multi-Input Multi-Output (MIMO), multi-hop relay, cooperative likelihood detection, sphere decoding, maximum harmonic mean channel power selection policy, Bit Error Rate (BER)

摘要： 针对多输入输出(MIMO)系统在传输数据过程中的误码率(BER)和信道容量优化问题,提出一种基于合作似然检测和球形译码的多用户MIMO多跳中继系统。首先,该系统构建二阶协作的MIMO中继系统模型对信道数据的中继传输过程以及路径损耗、阴影衰落情况进行分析;接着,通过球形译码来推导出等效的最大似然规则进行对数正态阴影衰落检测;最后提出最大调和平均信道功率选择策略,基于相关性链路度量和最大信道功率阈值为用户选择误码率更小的接入链路,从而改善多用户MIMO系统的性能。实验仿真结果显示,与基于互信息最大化的多用户MIMO多跳中继系统以及基于解码转发和多入多出技术正交空时分组编码(STBC)的中继系统相比,该系统在数据传输过程中的平均比特误码率分别降低了27.4%和32.6%,平均信道容量分别提高了9.5%和12.7%,因此在减少误码率和提高信道容量上具有较好的效果。

关键词: 多用户多输入输出, 多跳中继, 合作似然检测, 球形译码, 最大调和平均信道功率选择策略, 误码率

CLC Number:

TP393.0

XU Yuanfei. Multi-user multi-input multi-output multi-hop relay system based on likelicooperative hood detection and sphere decoding[J]. Journal of Computer Applications, 2015, 35(10): 2848-2851.

许元飞. 基于合作似然检测和球形译码的多用户多输入输出多跳中继系统[J]. 计算机应用, 2015, 35(10): 2848-2851.

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