A digital broadcast system including a broadcast receiving system and data processing method are disclosed. In the broadcast receiving system receiving broadcast signals, the broadcast receiving system includes a transmission parameter decoding unit, a known sequence detector, and a burst controller. The transmission parameter decoding unit detects information on a burst of a received signal from broadcast data having main service data and mobile service data multiplexed therein within a field of the received signal and outputs the detected information on the burst. The known sequence detector receives burst information from the transmission parameter decoding unit and uses the received burst information and known data position information included in the received data, so as to output burst control information. The burst controller uses the burst control information to control power supply of the broadcast receiving system.