OFDM FFT The fine FFT window position recovery apparatus for OFDM system

摘要

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for reconstructing a fine fast free-transform window position of an OFDM system receiver, and more particularly, to an apparatus for recovering a phase error of an FFT window by using zero crossing times of phase distortion values calculated between transmit and receive complex values. Analog-digital conversion means for converting the OFDM analog signal received for the purpose of the present invention to a digital signal, symbol start detection means for detecting the beginning of a symbol among the digital signal samples, the analog-digital according to a symbol start signal FFT means for converting the modulation data generated from the conversion means to high-speed pre-free, phase calculation means for calculating phase distortion between the complex value of the data and the promised transmission value, zero crossing counter means for detecting the change in phase and counting the number of zero points And an FFT window control means for activating the FFT of the FFT means at the beginning of a symbol and detecting a sample error of the FFT of the FFT means by detecting a sample unit error from the number of zero crossings. According to the present invention, the reliability of the system can be guaranteed by compensating for an error by using a phase distortion of the FFT output values of carriers used for transmitting a predetermined complex signal value between transmission and reception, or the number of zero crossings of an imaginary part.