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Research Article A Fast LMMSE Channel Estimation Method for OFDM Systems | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2009 Article ID 752895 13 pages doi 10.1155 2009 752895 Research Article A Fast LMMSE Channel Estimation Method for OFDM Systems Wen Zhou and Wong Hing Lam Department of Electrical and Electronics Engineering The University of Hong Kong Hong Kong Correspondence should be addressed to Wen Zhou wenzhou@eee.hku.hk Received 20 July 2008 Revised 10 January 2009 Accepted 20 March 2009 Recommended by Lingyang Song A fast linear minimum mean square error LMMSE channel estimation method has been proposed for Orthogonal Frequency Division Multiplexing OFDM systems. In comparison with the conventional LMMSE channel estimation the proposed channel estimation method does not require the statistic knowledge of the channel in advance and avoids the inverse operation of a large dimension matrix by using the fast Fourier transform FFT operation. Therefore the computational complexity can be reduced significantly. The normalized mean square errors NMSEs of the proposed method and the conventional LMMSE estimation have been derived. Numerical results show that the NMSE of the proposed method is very close to that of the conventional LMMSE method which is also verified by computer simulation. In addition computer simulation shows that the performance of the proposed method is almost the same with that of the conventional LMMSE method in terms of bit error rate BER . Copyright 2009 W. Zhou and W. H. Lam. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. Introduction Orthogonal frequency division multiplexing OFDM is an efficient high data rate transmission technique for wireless communication 1 . OFDM presents advantages of high spectrum efficiency simple and efficient implementation by using the fast Fourier transform FFT and the