Patent ID: 8559538

Claim:
A correlator comprising: a delay signal generation section that sequentially generates, from an orthogonal frequency division multiplexing (OFDM) signal where one symbol period comprises an effective symbol period and a guard interval in which part of the signal of the effective symbol period has been copied, 2n−1 number of delay OFDM signals whose delay times increase; n number of complex conjugate circuits to which the n th to 2n−1 th delay OFDM signals are inputted, and that generates and outputs corresponding complex conjugates; n number of complex calculation circuits to which the OFDM signal and the first to n−1 th delay OFDM signals are inputted as one input and to which the output signals from the n number of complex conjugate circuits are inputted as another input, and that perform complex multiplication in regard to the two input signals; n number of moving average processing circuits, disposed in correspondence to each of the n number of complex calculation circuits, that take the moving average of the guard interval length with respect to the output signals from the corresponding complex calculation circuits; and an adder circuit that adds the output signals from the n number of moving average processing circuits, and that outputs the addition result; where n is an integer that is greater than or equal to 2.