An apparatus performs a method for generating information indicating channel quality when a dynamic range of a receive signal strength and an interference signal strength is considerable in a wireless communication system using beamforming. A base station (BS) for processing feedback information for scheduling receives from a mobile station (MS) first feedback information comprising a receive signal strength measurement result in paths selected from a plurality of downlink paths between the BSs and the MS, designates a transmit (TX) resource for interference measurement of the MS based on the first feedback information, receives from the MS second feedback information comprising an interference measurement result in the designated TX resource region, and calculates a Signal to Interference plus Noise Ratio (SINR) of the MS based on the first feedback information and the second feedback information. The designated TX resource includes a resource other than a signal TX resource for the MS.