A W-CDMA base station is disclosed in which a base band processing device and a plurality of remote radio devices are provided and downward data is transmitted from the plurality of remote radio devices at the same time. The base band processing device inserts a synchronous signal into downward data, and transmits the downward data to the remote radio devices. The remote radio device extracts the synchronous signal from the downward data transmitted from the base band processing device, inserts the synchronous signal into the upward data at an insertion timing based on an extraction timing when the signal is extracted, and transmits the upward data to the base band processing device. Further, the base band processing device extracts the synchronous signal from upward data transmitted from the remote radio devices, and controls the timing for starting the dispersion process for the downward data based on a time from when the synchronous signal has been inserted into the downward data until the synchronous signal has been extracted from the upward data.