PURPOSE: To prevent deterioration in a transmission error rate due to multi-path fading by suppressing increase in an equalization error due to a frequency offset in the waveform equalizer used for digital mobile body communication.

CONSTITUTION: An estimate signal being a sum of output signals of two transversal filters 32, 33 is converted into a phase angle by a coordinate transformation device 41. A phase deviation of one preceding symbol is calculated by a symbol delay device 44 and a subtractor 43 based on the signal and the result is inputted to a data discriminator 37. The phase angle of one preceding symbol obtained based on the estimate signal and an output signal of the data discriminator 37 are added by an adder 46, and the sum is transformed into an orthogonal coordinate signal by a coordinate transformation device 42 and the result is used for an input signal to the transversal filter 33.