An apparatus and method for processing a signal in a base station transceiver system are disclosed. According to the present invention, a mobile communication service is provided to more mobile stations in a service area of the base station transceiver system by effectively connecting a plurality of RF (Radio Frequency) units (RRUs) to the base station transceiver system of the mobile communication system through a network, the base station transceiver system individually controls the performance of each RF unit, and a uniform quality of service is provided to a plurality of mobile stations, each being provided with the mobile communication service through different RRUs, by applying and processing gain of different weights from each other to a signal exchanged between the plurality of RF units according to the connection structure.