Abstract: A control unit (51) measures a phase error (&lgr;) between a reference timing of a mobile station and a reception timing from a base station based on reception data (45t) from a reception unit (45) and a count (36t) from a reference timing counter unit (36), determines a frequency deviation correction value calculation period (35r) corresponding to the measured phase error (&lgr;), and outputs it to a frequency deviation correction value calculation unit (35). The frequency deviation correction value calculation unit (35) does not calculate a deviation at every reception time when intermittent reception is repeated, but calculates a deviation at intervals following the frequency deviation correction value calculation period (35r) given from the control unit (51).

Abstract: A mobile communication system which comprises a base station and a mobile station that communicates therewith while performing frequency hopping based on a predetermined hopping sequence. Based on the received power of a signal received from the base station at a first frequency in the hopping sequence, the mobile station switches the first frequency to a second one next thereto in the hopping sequence and keeps on communicating with the base station at the second frequency.