PURPOSE: To allow a frequency offset compensation circuit compensating automatically a frequency error between transmission and reception of a digital signal to attain frequency offset compensation for an MLSE equalizer with high accuracy at a high speed.

CONSTITUTION: The circuit is made up of a correlation detector 2 that stores a known transmission signal over a time N, provides a phase rotation to an output signal by a frequency offset, multiplies the result with a reception signal corresponding to the output signal and integrates the output signal over a time N, a frequency offset estimate device 3 that detects a change in a square sum of output signals of the correlation detector 2 with respect to phase fluctuation within a time caused by the frequency offset, that updates the estimated phase fluctuation so that the square sum is maximized and estimates the phase fluctuation within a time, and a phase compensation section 4 that eliminates the frequency offset of the reception signal based on the phase fluctuation within a time being an output of the frequency offset estimate device 3.