In a baseband processing circuit unit, a sample memory stores a received data sequence obtained by sampling a signal received by an RF receiving circuit unit at a given sampling time interval. A data sequence estimating unit estimates an estimated data sequence, which is obtained when the received signal is sampled at a sampling time shifted by a given shift time from the sampling time of the received data sequence, on the basis of the received data sequence stored in the sample memory. A correlation operation unit performs a correlation operation on the estimated data sequence estimated by the data sequence estimating unit 22 and a replica code. An integration unit integrates the correlation operation result from the correlation operation unit at a given integration time interval.