Study On Receive Antenna Selection Algorithm Based On Capacity In MIMO Systems

Recently proposed Mutiple-Input Mutiple-Output (MIMO) antenna systems can not only multiple the channel capacity, but also multiple the spectrum efficiency without increasing the bandwidth and transmit power by using multipath effect. So the quality of communication can be improved significantly. But at the same time, the cost of RF (radio frequency) chains will be increased greatly. Previous researches show that the performance price ratio of MIMO system can be improved by antenna selection, but the improvement degree will be influenced by the performance of antenna selection algorithms.Most of the previous algorithms concentrate on the research of fixed number of antennas. But in different practical wireless communication systems, the spatial correlations between channels are of great difference. So it is of great importance to study on variable number antenna selection algorithm of link adaptability.Antenna selection algorithms based on maximize capacity have been analysed and summarized in this paper. Based on these algorithms, the improved antenna selection algorithm has been proposed, and comparisons are made between the proposed algorithm and the previous algorithms.The simulating results show that the proposed antenna selection algorithm can not only provide channel capacity which is close to the best selection algorithm, but also change the number of antenna adaptively according to the channel state. More antennas will be selected to improve channel capacity when the correlation coefficient is low, and fewer antennas will be selected to reduce the number of RF chains and decrease the difficulty of demodulation and decoding, under the condition of satisfying the capacity of MIMO system. Therefore the proposed antenna selection algorithm can be applied to wireless environment with different correlation coefficients and it's more flexible in practical applications. In addition, the proposed algorithm has low computational complexity, which can meet the requirement of transmitting signals on real time.