关键词: 最大似然信道估计器, 全相位傅里叶变换, 空间信道模型, 正交频分复用

Abstract: This paper proposes a new Maximum Likelihood Channel Estimator（MLE） based on all-phase FFT（ap-FFT） algorithm for Orthogonal Frequency Division Multiplexing（OFDM） system.In the case that the ap-FFT algorithm has the square amplitude gain，which restrains the inherent noise in MLE at high SNR（Signal Noise Ratio），the ap-FFT MLE can get more exact channel information to equalize the distortion signal.The OFDM system that employs ap-FFT instead of FFT as demodulation algorithm also has the ability to overcome the frequency offset in system to some extent.It focuses on the performance of ap-FFT OFDM system using ap-FFT MLE in Spatial Channel Model（SCM） of the Third Generation Partnership Project（3GPP），utilizing Ment Carlo method，simulation results validate the accuracy of ap-FFT MLE over traditional MLE in terms of mean square error，and proposed system has better BER performance.

Key words: Maximum Likelihood Channel Estimator（MLE）, all-phase FFT（ap-FFT）, Spatial Channel Model（SCM）, Orthogonal Frequency Division Multiplexing（OFDM）