A data transmitting apparatus generates a plurality of pilot signals to be used for channel estimation by a data receiving apparatus, performs symbol mapping of a plurality of input data signals and a plurality of pilot signal into a plurality of data symbols and a plurality of pilot symbols, converts input symbols in the frequency domain including the plurality of data symbols and the plurality of pilot symbols into a real signal in the time domain, and performs angle modulation of the real signal. The data transmitting apparatus controls the amplitude of the sine component of the angle-modulated real signal by a gain that varies with a control signal and then transmits the real signal.