一种新的低复杂度空间调制信号检测算法

空间调制技术(SM)作为一种新颖的多天线传输方案，近年来受到业界的广泛注意。它将输入信息比特分为两部分，一部分用于激活天线，另一部分用于信号调制，来共同承载发送信息。由于SM系统的最大似然(ML)最优检测算法需要穷举搜索激活天线序号和发送的数字调制符号的所有可能情况，它的检测复杂度很高。为此，人们相继提出了一些简化算法。与这些算法思路不同，本文从传统ML最优表达式出发，引入极坐标得到关于星座点幅度和相角的ML等价表达式，同时根据星座点相角的分布特性对相角进行近似，得到了一种新的次最优检测算法。新算法的检测性能比其他次优算法更接近ML，而且计算复杂度低。最后本文通过计算机仿真，验证了新算法的有效性。 

A New Low-complexity Detection Algorithm for Spatial Modulation

Spatial Modulation(SM) has been paid much attention recently as a novel multi-antenna transmission scheme which makes the input information bits into two parts to convey information: one part is used to activate the transmit antenna, the other is used for signal modulation. The Maximum Likelihood (ML) optimal detection algorithm for SM systems have to exhaustively search all the possible active transmit antenna index and transmitted signal, so the ML search complexity is very high. To solve this problem, some low-complexity algorithms are proposed. Being different from the ideas of these algorithms, in this paper, we start from the conventional ML optimal formula and introduce the polar coordinates to obtain an equivalent ML formula which is related with the constellation point’s amplitude and phase. According to the distribution property of the constellation point’s phase, we obtain a new sub-optimal detection algorithm by the approximate calculation of the phase. The new algorithm is closer to the optimal performance with low computational complexity than other sub-optimal algorithm. Finally, in this paper, the simulation results are presented to verify the validity of the algorithm.