A communication device of the present invention includes channel compensations, an adaptive processor, a MAC and a controller. The channel compensations weight each of signals received by a plurality of antennas based on an SN ratio of the received signals so as to control the antennas to operate as combining diversity systems. The adaptive processor weights each of the signals received by the plurality of antennas so as to suppress the interference signal and to control the antennas to operate as adaptive array antennas. The MAC detects frequency hopping information of the received signals. The controller changes between the operation of the combining diversity systems and the operation of the adaptive array antennas, based on the frequency hopping information.