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Performance Improvement of Channel Estimation based on Time-domain Threshold for OFDM Systems  

Lee, You-Seok (부산대학교 전자전기공학과 통신 및 신호처리 연구실(컴퓨터 및 정보통신 연구소))
Kim, Hyoung-Nam (부산대학교 전자전기공학과 통신 및 신호처리 연구실(컴퓨터 및 정보통신 연구소))
Publication Information
The Journal of Korean Institute of Communications and Information Sciences / v.33, no.9C, 2008 , pp. 720-724 More about this Journal
Abstract
Channel estimation in OFDM systems is usually carried out in frequency domain based on the least-squares (LS) method and the minimum mean-square error (MMSE) method with known pilot symbols. The LS estimator has a merit of low complexity but may suffer from the noise because it does not consider any noise effect in obtaining its solution. To enhance the noise immunity of the LS estimator, we consider estimation noise in time domain. Residual noise existing at the estimated channel coefficients in time domain could be reduced by reasonable selection of a threshold value. To achieve this, we propose a channel-estimation method based on a time-domain threshold which is a standard deviation of noise obtained by wavelet decomposition. Computer simulation shows that the estimation performance of the proposed method approaches to that of the known-channel case in terms of bit-error rates after the Viterbi decoder in overall SNRs.
Keywords
Channel estimation; Time-domain approach; Threshold; OFDM; wavelet;
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Times Cited By KSCI : 2  (Citation Analysis)
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