Characterization of SINR uncertainty due to spatial interference variation

We consider the SINR variation generated by the change of spatial interference pattern in a cellular communication system, which is especially severe when using adaptive array for transmission. In this paper, we derive the distribution of SINR variation at the output of Interference Rejection Combining (IRC) and Maximum Ratio Combining (MRC) receivers, assuming equal-power interferers. The analysis can be applied to evaluate a system level SINR variation. According to the results, we found that IRC shows better SINR and SINR variation properties under a narrow antenna beamwidth practical in cellular networks.