Abstract:

Considering that the channel capacity sharply declines when the array element spacing is relatively small and the average direction of arrival (DOA) is large in multiple-input multiple-output (MIMO) antenna array, a new MIMO receiving antenna model is put forward based on Y-shaped array structure. Utilizing equivalent network model of antenna array's mutual coupling effects, the general closed form expressions is deduced for correlations of Y-shaped array mode and mutual coupling so as to clarify the relations between the correlation with its array mutual coupling effects and the correlation without mutual coupling effects. The influences of incident signal's central DOA and angular spread on the channel capacity of Y-shaped array MIMO is analyzes respectively. Comparing with analysis and performance of MIMO circular array receiving antenna, it is found that Y- shaped MIMO antenna array is of a relatively stable channel capacity and better than that of the circular antenna array. It can effectively improve the array mutual coupling effects so as to enhance the system performance.

Key words: Y-shaped antenna array, mutual coupling effect, spatial correlation, channel capacity of multiple input multiple output