Design and Evaluation of Antenna Selection Methods for Interference Rejection Combining

Co-channel interference is one of the major factors limiting the capacity in modern cellular networks. Interference rejection combining (IRC) is an effective technique to suppress co-channel interference, requiring receivers with multiple antennas. For terminals using IRC, the larger the number of available antennas, the more interfering signals that can be suppressed. However, production cost, size and energy consumption of the required radio-frequency units impose a limit in the number of practical antenna elements. In this paper, we investigate the combination of IRC with antenna selection (AS), as a cost-effective approach to improve the interference suppression performance of wireless receivers, and present different low-complexity AS algorithms. In addition, we propose algorithmic modifications in case the estimates of interfering channels are unknown at the receiver, and an estimate of the interference-plus-noise covariance matrix (CM) has to be used. It is found that, in the presence of channel estimation errors, AS techniques using the CM approach are able to provide better performance than techniques using estimates of interfering channels. These findings and the effectiveness of the proposed algorithms are validated by both computer simulations and experimental testing using a hardware prototype.