本文先对MIMO 系统进行了简单介绍，并推导出其容量计算公式，随后对比分析了SISO、MISO、SIMO、MIMO 等各自的特点，并将研究的焦点放到信道相关性对系统容量的作用方面。在理论分析之后，借助Matlab 对整个实验进行 模拟，并得出如下结论：如果无线间距不断增加，而角度的拓展却不断较少，那么平均到达角和阵列之间的垂直性就越强，那么 信道相关度会大大降低，使得容量增加。从相关性角度，相关系数较小（小于0.3）时，对容量影响不大，当其较大（大于0.7）时， 信道容量明显降低。

This paper analyzes and simulates some ergodic capacities of several typical systems such as SISO, SIMO, MISO and MIMO, especially studies on the channel capacity for MIMO system. Then, the research on the effects of correlation on the capacity of MIMO systems is emphasized. The results of the analysis and Matlab simulation show that as the wireless space increases and the spread angle becomes smaller, the angle of arrival of the receiving signal will be vertical with the array, the capacity of the channel will roll-off. Also, the effect on capacity is negligible with a correlation coefficient between two antennas blow 0.3, but when the correlation coefficient is as large as 0.7, the capacity will fall significantly.