Method and device for modifying work period distortion

The utility model discloses a method and device used for correcting the distortion of the working period. For example, the direct current displacement can be removed from the input signal to correct the working period distortion of the communication system's receiver. The direct current displacement in the input signal can be determined by the recovery clock and the data signal of the logic signal and the magnitude of voltage can be produced to correct the input signal. The change signal is the sampled data at the fringe position where the logic signal is changed as per the code element of the clock signal; such change signal is also used as to produce the correction voltage which symbolizes the direct current displacement of the input signal.