Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Performance Analysis of the Blind Minimum Output Variance Estimator for Carrier Frequency Offset in | Hindawi Publishing Corporation EURASIP Journal on Applied Signal Processing Volume 2006 Article ID 49257 Pages 1-8 DOI ASP 2006 49257 Performance Analysis of the Blind Minimum Output Variance Estimator for Carrier Frequency Offset in OFDM Systems Feng Yang Kwok H. Li and Kah C. Teh School of Electrical and Electronic Engineering Nanyang Technological University Singapore 639798 Singapore Received 18 November 2004 Revised 13 July 2005 Accepted 29 December 2005 Recommended for Publication by Alexei Gorokhov Carrier frequency offset CFO is a serious drawback in orthogonal frequency division multiplexing OFDM systems. It must be estimated and compensated before demodulation to guarantee the system performance. In this paper we examine the performance of a blind minimum output variance MOV estimator. Based on the derived probability density function PDF of the output magnitude its mean and variance are obtained and it is observed that the variance reaches the minimum when there is no frequency offset. This observation motivates the development of the proposed MOV estimator. The theoretical mean-square error MSE of the MOV estimator over an AWGN channel is obtained. The analytical results are in good agreement with the simulation results. The performance evaluation of the MOV estimator is extended to a frequency-selective fading channel and the maximal-ratio combining MRC technique is applied to enhance the MOV estimator s performance. Simulation results show that the MRC technique significantly improves the accuracy of the MOV estimator. Copyright 2006 Hindawi Publishing Corporation. All rights reserved. 1. INTRODUCTION Orthogonal frequency division multiplexing OFDM has been considered as a promising modulation scheme for the next generation wireless communication systems. OFDM signals are transmitted in parallel subchannels which are frequency-nonselective and overlapped in spectra. Hence OFDM systems are robust to frequency-selective fading and enjoy high .
