FREQUENCY CHARACTERISTIC DETECTOR FOR OFDM, FREQUENCY CHARACTERISTIC COMPENSATOR FOR OFDM, AND REPEATER FOR OFDM

摘要

PROBLEM TO BE SOLVED: To highly accurately detect original frequency characteristics provided in an OFDM (orthogonal frequency division multiplex) transmission signal by eliminating discontinuity in the input data of inverse Fourier transform. SOLUTION: When detecting the frequency characteristics of a frequency axis signal obtained by converting the OFDM (orthogonal frequency division multiplex) transmitting signal multiplexed by putting symbol data in a plurality of mutually orthogonal subcarriers which are not the number of 2 ((n) is a natural number), B/A-fold interpolation processing is performed by an interpolation processor 261 so that a data size A of a frequency characteristic signal on the frequency axis from a frequency characteristic signal generator 25 can be changed into data size B of 2 and after this frequency characteristic signal made into data size B of 2 is converted to a signal on the time base by performing inverse Fourier transform in an inverse Fourier transformer 262 having the number of 2 input points, decimation processing is performed by a decimation processor 263 so that the signal can become A/B-fold. Thus, the frequency characteristic signal on the time base can be found.