Interference Suppression Through Adaptive Subset Antenna Transmission in Interference Limited MIMO Wireless Environments

We consider spatially multiplexed MIMO transmission in the presence of co-channel interference with subset transmit antenna selection. Several algorithms for antenna selection have been proposed in the literature for point-to- point MIMO systems. However, performance of such antenna selection techniques in interference-limited environments is less well understood. In this paper, we propose to use transmission techniques with antenna selection to minimize the effect of co-channel interference. We propose several simplified transmit antenna selection algorithms. V-BLAST detection is used and channel state information (CSI) is assumed to be known only at the receiver. A simple algorithm to adaptively obtain information about the number of transmitted streams and the best antenna subset that minimizes the symbol error rate is also proposed. Several examples to demonstrate the effectiveness of proposed selection algorithms in interference limited environments are presented. Simulation results show that for low to moderate interference power, significant improvement in the system performance is achievable with the use of transmit antenna selection algorithms. It is found that employing transmit antenna selection algorithms, and adaptation of the number of transmitted streams and the signal constellation sizes can significantly enhance the performance of MIMO systems with co-channel interference. The performance improvement is more significant in spatially correlated fading channels.