Patent ID: 7773682
Filing Date: 2010-08-10
Classification: H04L

Abstract:
1. An OFDM reception apparatus for receiving an OFDM (Orthogonal Frequency Division Multiplexing) signal constituted by a plurality of carriers, comprising: a fast Fourier transform section for converting a received time-domain OFDM signal into a frequency-domain OFDM signal; an equalization section for performing waveform equalization with respect to the frequency-domain OFDM signal, and outputting a waveform-equalized OFDM signal; and a modulation scheme estimating section for estimating a modulation scheme, among candidate modulation schemes, for the carriers based on signal points of carriers constituting the waveform-equalized OFDM signal, and outputting an obtained estimation result, wherein the received OFDM signal is subjected to a process for obtaining transmitted information, depending on the estimation result, the modulation scheme estimating section calculates an average value of I-axis coordinates and an average value of Q-axis coordinates of signal points in a predetermined region corresponding to one of the candidate modulation schemes on an I-Q plane among the signal points, and determines whether the modulation scheme for the carriers is the one of the candidate modulation schemes based on the calculated I-axis coordinate average value and Q-axis coordinate average value.