Patent ID: 6970686

Claim:
A diversity system for implementing space diversity for each carrier in an OFDM signal demodulation system having a plurality of antennas, comprising: symbol synchronous signal position detection units which are provided for the respective antenna series, and which detect symbol synchronous signals of OFDM symbols; carrier demodulators which are provided for the respective antenna series, and which demodulate carriers of OFDM, and calculate reliability of each of said carriers; a delay measurement unit which measures the amount of relative delay between the antenna series on the basis of said symbol synchronous signals of said antenna series; a delay amount notification unit which outputs the amount of relative delay obtained by said delay measurement unit; at least one memory unit which temporarily holds carriers of the antenna series in which at least the position detection of a synchronous signal is earlier than that of other series; and a diversity operation implementation unit which takes out the carriers held in said memory unit on the basis of the amount of relative delay received from said delay amount notification unit, which temporally aligns the positions of the carriers obtained from the respective antenna series, and which selects or combines for each carrier.