In a communication system including a mobile station that transmits a data signal and a plurality of base stations receiving the data signal transmitted by the mobile station, the communication system includes: as the base stations, at least, one first base station having a first signal detector detecting the data signal transmitted by the mobile station; and, at least, one second base station having a second signal detector that detects the data signal received by the station per se, using the detection result which the first base station has detected from the data signal transmitted by the mobile station. As a result, it is possible to provide a communication system and the like capable of providing good transmission characteristics in the uplink cooperative communication without addition of CPs having a longer length than usual.