A victim system detector for detecting whether a second wireless communication system uses frequency bands that are used by a first wireless communication system (detecting whether the second wireless communication system is a victim system) includes a correlator and a decision unit. The correlator calculates a correlation value between a frequency domain baseband signal associated with the first wireless communication system and a correlation sequence of the second wireless communication system. The decision unit determines, based on the correlation value, whether the second wireless communication system is a victim system. Therefore, the victim system is detected accurately and efficiently.