Compensation apparatus and compensation method for frequency drift in MSK differential detection and demodulation circuit

The invention pertaining to the field of frequency-drift compensation of communication systems discloses a frequency-drift compensation device of an MSK differential detection and demodulation circuit and a compensation method thereof. The device of the invention comprises an accumulator, a time schedule controller, a constant divider, a constant subtracter, an offset register and a subtracter. The method of the invention comprises steps of detecting an additional phase of receiving signals relative to a carrier wave, delaying the additional phase by a code element period to obtain a delayed additional phase, subtracting the delayed additional phase from the additional phase to obtain a differential phase, accumulating the additional phases and averaging the additional phases to obtain a differential phase offset, and subtracting the differential phase offset from the differential phase to complete the frequency-drift compensation. The frequency-drift compensation device that is simplified in the invention has a simple structure.