PURPOSE: To reduce background noise by devising the receiver such that a correction coefficient with respect to an amplitude variable is decreased for the tap correction by an LMS algorithm or correlation processing at polar coordinate conversion processing and the coefficient with respect to a phase variable is increased.

CONSTITUTION: A deciding signal distributed to each tap of a replica filter comprising a delay element 105 and a replica error signal being the output of a subtractor 111 are subjected to polar coordinate conversion by polar coordinate converters 106, 113. On the other hand, a polar coordinate LMS computing element 107 applies tap coefficient correction according to the polar coordinate LMS algorithm based on the deciding signal and the replica error signal subjected to polar coordinate conversion. Then a tap coefficient outputted from the computing element 107 is restored again to the orthogonal coordinate system by an orthogonal coordinate converter 108 and the result is fed to a complex multiplier 109 of the orthogonal coordinate system as a tap coefficient. Thus, the tap coefficient tracking error noise is reduced without use of a carrier recovery phase locked loop circuit and synchronization detection and elimination of multi-path distortion are implemented.