Abstract: Power control is efficiently utilized to improve WiMAX system capacity. For the signal interference and noise ratio (SINR) balance criterion based power control technique, the co-channel interference and the diversity combination of base station antenna have important effect on the SINR. In this paper, co-channel interference (CCI) model for WiMAX networks is presented, the outage probability of SINR with respect to power control is derived based on the CCI model and finally, hard/soft limiting combining algorithms are proposed to reduce interference. Simulation results show that the proposed combining algorithms can suppress the co-channel interference and reduce the outage probability of SINR, so that the power control performance of WiMAX uplink can be improved.