针对MISO通信系统的空时分组码盲识别问题,提出了一种基于高阶累积量的空时分组码盲识别算法。首先,给出了MISO接收信号模型,利用高阶累积量的性质分析得到接收信号的四阶累积量的表达式;然后,利用编码矩阵的特性,证明接收信号在不同时延向量下的四阶累积量呈现非零值,其非零值取决于STBC的类型;最后,采用四阶累积量的实验值与理论值的最小欧式距离盲识别空时分组码的类型。仿真结果表明,即使在低信噪比条件下,所提方法能够较好地识别空时分组码。
Aiming at the problems for blind recognition of space-time block code(STBC) in MIMO communication systems, a method was exploited based on higher-order cumulants of received signals. Firstly, the model of received signals was given and the fourth-order cumulants of the received signals in multiple input single output(MISO) systems was obtained. Secondly, using the characteristics of coding matrix, it was proved that the fourth-order cumulants in different delay vectors presented non-null value that depended on the STBC sat the transmitter side. Finally, a classifier for the STBC was presented based on the Euclid distance between the experimental values of fourth-order cumulants and the theoretical ones. Simulations show that the method performs well even for low signal to noise ratio.