Low-Complexity ML Detectors for Generalized Spatial Modulation Systems
Low-Complexity ML Detectors for Generalized Spatial Modulation Systems
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DOI：
10.1109/tcomm.2015.2469781
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发表时间：
2015-08
影响因子：
8.3
通讯作者：
Chun-Tao Lin;Wen-Rong Wu;Chia-Yu Liu
中科院分区：
文献类型：
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作者：
Chun-Tao Lin;Wen-Rong Wu;Chia-Yu Liu
空间调制(SM)与空间复用相结合是多输入多输出(MIMO)系统中的一种新的传输方案。所得到的系统被称为广义SM(GSM)，可以使用最大似然(ML)检测器来联合检测天线子集(AS)索引和符号矢量。众所周知，ML检测器可以达到最佳性能；然而，当GSM系统的维度很大时，其计算复杂度可能高得令人望而却步。在本文中，我们提出了解决这一问题的新方法。其主要思想是将检测分成两个阶段，一个用于AS索引，另一个用于符号向量。对于AS指数的检测，我们提出了两种方法，称为高斯逼近法和QR投影法。一旦检测到AS索引，就可以将传统的低复杂度ML检测器应用于符号向量的检测。对所提出的方法的分集阶数进行了进一步的分析，并提出了一种改进的方法以获得接近最优的性能。最后，将所提出的方法扩展到GSM系统的软检测。仿真结果表明，在检测复杂度保持不变的情况下，我们的方法明显优于已有的方法。
Spatial modulation (SM) combined with spatial multiplexing is a newly developed transmission scheme in multiple-input multiple-output (MIMO) systems. The resultant system, referred to as generalized SM (GSM), can use the maximum-likelihood (ML) detector jointly detecting the antenna-subset (AS) index and symbol vector. As known, the ML detector can achieve optimum performance; however, its computational complexity can be prohibitively high when the dimension of the GSM system is large. In this paper, we propose new methods to solve the problem. The main idea is to split the detection into two stages, one for the AS index and the other for the symbol vector. For the detection of the AS index, we develop two methods, referred to as Gaussian approximation and QR projection. Once the AS index is detected, conventional low-complexity ML detectors can be applied for the detection of the symbol vector. The diversity order for the proposed methods are further analyzed and an enhanced method is also proposed to achieve near-optimum performance. Finally, the proposed methods are extended to conduct soft detection of GSM systems. Simulations show that our methods significantly outperform existing ones while the detection complexity remains similar.