The present invention relates to a device and a method for detecting a transmission signal in a wireless communication system, and a reception device in a wireless communication system comprises: a transceiver for receiving a signal from a transmitting end; a first correlator for performing a first correlation and outputting a real part among the results of the first correlation; a second correlator for performing a second correlation and outputting an imaginary part among the results of the second correlation; and a control unit for controlling the first correlator and the second correlator on the basis of a channel change rate so as to detect a transmission signal.