Patent ID: 7043680

Claim:
A receiving apparatus which receives a frequency division multiplex transmission signal using a plurality of carriers, comprising: a demodulation circuit which estimates a transfer function of a reception signal in which a time domain has been converted into a frequency domain and demodulates the reception signal according to a demodulation method corresponding to the estimated transfer function; a reliability determining circuit which is connected to said demodulation circuit and determines the reliability of the demodulation signal demodulated by said demodulation circuit based on the transfer function estimated by said demodulation circuit; a variation detecting circuit which is connected to said demodulation circuit and detects a variation amount of the demodulation signal; a distance measuring circuit which is connected to said demodulation circuit, reliability determining circuit and variation detecting circuit and measures a distance between a reception symbol of the demodulation signal and a representative symbol of a transmission signal and whose measuring method is changed according to the result of determination in said reliability determining circuit and the result of detection in said variation detecting circuit; and an error correction circuit which is connected to said distance measuring circuit and makes error correction based on the distance measured by said distance measuring circuit.