Hybrid-selection/optimum combining

We propose and study hybrid-selection/optimum combining (H-S/OC). With this technique, L out of M diversity branches are weighted and combined to maximize the output signal-to-interference-plus-noise ratio. We first present computer simulation results for L=1, showing that selecting the antenna with the largest signal-to-interference power ratio (S/I), rather than the largest signal power, can significantly improve performance when a few strong interferers are present. Our results with equal-power interferers show that H-S/OC can greatly suppress more than L interferers when M>L. Finally, we present computer simulation results for an ANSI-136 TDMA cellular system which show a 7-fold increase in capacity for H-S/OC with L=1, M=12 or L=2, M=4. Thus, H-S/OC offers the potential for systems to operate with multiple strong cochannel interferers and obtain diversity gain with only a few receiver chains.