A correlation unit (32) sequentially obtains correlation values between a baseband signal and a reference signal and outputs the obtained reference signal to a section division unit (33). The output of the correlation unit (32) is divided into symbol time periods by the section division unit (33). A section position detection unit (34) detects a largest correlation value in each of sections resulting from the division by the correlation unit (32) and outputs, to a synchronization judgment unit (35), first position information that indicates a relative position of each detected largest correlation value. The synchronization judgment unit (35) detects an arrival of a packet signal and estimates a symbol timing based on the first position information of the sections.