PURPOSE: To remove both inter-code interference and phase fluctuation even under an environment using RLS algorithm by applying a phase circuit to the input of a complex transversal filter and supplying the result of applying phase rotation to a tap coefficient control part.

CONSTITUTION: For the output of a judgement equipment 19 to judge and output transmitting data, a multiplier 21 executes complex multiplication with the output of a complex conjugate part 22, and the phase rotation is applied corresponding to the amount of the phase fluctuation. The output is turned to the input of a rear filter formed by a shift register 151 and a multiplier 152, and the output of the rear filter is supplied to a tap coefficient control part 18. Thus, even when high convergent speed algorithm such as the RLS algorithm is used for the control part 18, a tap coefficient is updated by the same process regardless of whether the phase fluctuation exists or not, and both the inter-code interference and the phase fluctuation can be removed even under the environment of the RLS algorithm.