SINR Enhancement of Interference Rejection Combining for the MIMO Interference Channel

Interference rejection combining (IRC) is an effective technique to suppress the spatial interference in multiple input multiple-output (MIMO) systems. In general, more receive antennas result in better interference-suppression capability. However, as the number of receive antennas increases, the receiver becomes more complex and loses its scalability. Therefore, an increased attention was turned by industry to find efficient ways to enable the use of more receive antennas, e.g., scaling the number of receive antennas to increase interference rejection capability. In this paper, a baseband preprocessing scheme is proposed by maximizing the signal-to- interference-plus noise ratio (SINR). It involves minimum modification of the existing receiver structure when additional receive antennas become available. Substantial improvements are provided by exploiting the channel estimates or the SINR feedback from the original receiver. The main idea is to generate a new channel matrix for the original receiver such that the interference can be suppressed after the proposed processing. Since the proposed scheme does not rely on the receiver structure, it can be easily generalized to different kind of receivers.