Blind Channel Estimation by EM Algorithm for OFDM Systems

Hirokazu ABE  Masahiro FUJII  Takanori IWAMATSU  Hiroyuki HATANO  Atsushi ITO  Yu WATANABE  

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E100-A    No.1    pp.210-218
Publication Date: 2017/01/01
Online ISSN: 1745-1337
DOI: 10.1587/transfun.E100.A.210
Type of Manuscript: Special Section PAPER (Special Section on Wideband Systems)
blind channel estimation,  OFDM,  EM algorithm,  channel frequency response correlation,  fixed wireless communication systems,  

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It is necessary to estimate channel state information coherently to equalize the received signal in wireless communication systems. The pilot symbol, known at the receiver, aided channel estimator degrades the transmission efficiency because it requires the signal spaces and the energy for the transmission. In this paper, we assume a fixed wireless communication system in line of sight slowly varying channel and propose a new blind channel estimation method without help from the pilot symbol for Orthogonal Frequency Division Multiplexing systems. The proposed estimator makes use of the Expectation-Maximization algorithm and the correlation property among the channel frequency responses by considering the assumed channel environment. By computer simulations, we show that the proposed estimator can asymptotically achieve bit error rate performance by using the ideal channel estimation.