A communication apparatus including a clock generation circuit outputting a plurality of clocks, each clock having a different phase from the other, a synchronization detection block receiving a sync word and a payload having a predetermined length after receiving the payload, sampling the sync word by using each of the plurality of clocks and to output a first signal indicating a clock or clocks capable of sampling the sync word successfully, the synchronization detection block being capable of sampling the payload by using a clock or clocks, a clock phase selection block coupled to the synchronization detection block to receive the first signal, and a clock gate unit to receive each of the plurality of clocks and the second signal to output the selected one of the plurality of clocks, and not to output a rest of the plurality of the clocks based on the second signal.