1. A capture frequency decision method of deciding a capture frequency by executing a frequency search in which a correlation operation on a received Code Division Multiple Access signal is performed at a plurality of search frequencies, the method comprising: executing a first frequency search; setting a frequency for a side lobe check on the basis of a correlation integration time used in the first frequency search; selecting a plurality of search frequencies including the frequency for a side lobe check on the basis of a result of the first frequency search; executing a second frequency search of performing the correlation operation at the plurality of selected search frequencies; and deciding a capture frequency by executing a third frequency search using a result of the second frequency search.