CHANNEL ESTIMATION SYSTEM ON THE BASIS OF BE SIMPLIFIED DFT FOR OFDM SYSTEM AND THE METHOD THEREOF

摘要

A DFT(Discrete Fourier Transform)-based channel estimation system simplified for an OFDM system and an estimating method thereof are provided to save a design cost for a receiver and a system memory by using the simplified channel estimation method in the OFDM or OFDMA(Orthogonal Frequency Division Multiple Access) with different subcarrier allocating method. An LS channel estimating unit(110) demodulates an OFDM receiving symbol and extracts a pilot subcarrier of the Np(0=Np=N-1) from the whole subcarrier of N(0=N) and outputs the LS estimation vector. A wiener filter(120) receives the LS estimation vector and outputs the channel frequency response estimation vector in an ideal pilot subcarrier position. An M-point IDFT unit(130) performs the inverse discrete Fourier transform of the channel frequency response estimation vector and obtains the time domain channel impulse response estimation vector. An N-point DFT unit(140) receives the time domain channel impulse response estimation vector into which the 0 of (N-M) is inserted and transforms the vector into a frequency domain channel estimation vector by performing the discrete Fourier transform.