Time domain leakage in DFT-based channel estimation for OFDM systems with guard bands

摘要

In this paper, a mathematical analysis of the time domain leakage problem in the discrete Fourier transform (DFT) based channel estimation technique is presented. The time domain leakage is because of the absence of pilots in the guard band. Several solutions to this problem were previously proposed based on reducing the leakage in the frequency domain. These solutions significantly increase the receiver complexity. In this paper, the root cause of the leakage problem is linked to the time domain and a modification is proposed carrying slight additional complexity over the conventional DFT-based estimator. Performance evaluation is assessed in terms of the bit error rate and the mean square error. The proposed modification significantly decreases the error floor of the conventional DFT-based channel estimation technique. In addition, its performance is comparable to other more complex techniques recently proposed.Copyright (c) 2013 John Wiley & Sons, Ltd.