OFDM DEMODULATION DEVICE AND METHOD

摘要

The present invention provides an OFDM demodulation device for demodulating an orthogonal frequency division multiplexed (OFDM) signal whose transmission unit is a transmission symbol produced by quadrature modulation in such a way that information is divided for a plurality of subcarriers in a predetermined band. The OFDM demodulation device includes a carrier frequency offset detecting circuit (20). The carrier frequency offset detecting circuit divides the subcarriers at the positions at which a TMCC signal, an AC signal, or a CP signal is inserted, defined in conformity with the standard when a specific offset amount is assumed, into a plurality of groups; maps the squares of phase rotation amounts with respect to an immediately-previous OFDM symbol on a complex plane; converts the squares to rotation vectors; cumulatively adds the rotation vectors to each other for each of the groups to thereby calculate the absolute values of the cumulative-addition-result values; and adds the absolute values of the cumulative-addition-result values calculated on a group-by-group basis to each other for all the groups to thereby calculate the addition-result absolute value, thereby defining the offset amount assumed when the maximum addition-result absolute value is obtained as the carrier frequency offset amount.