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.