Blind identification of FIR channels in the presence of unknown noise
EURASIP Journal on Applied Signal Processing
Frequency domain estimation of time varying channels in OFDMA systems: an EM approach
DSP'09 Proceedings of the 16th international conference on Digital Signal Processing
Channel estimation in OFDM systems with unknown interference
IEEE Transactions on Wireless Communications
Co-channel interference mitigation for 3G LTE MIMO-OFDM systems
ICC'09 Proceedings of the 2009 IEEE international conference on Communications
An efficient channel estimation algorithm under narrow-band jamming for OFDM systems
MILCOM'06 Proceedings of the 2006 IEEE conference on Military communications
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We develop a frequency-domain channel estimation algorithm for single-user multiantenna orthogonal frequency division multiplexing (OFDM) wireless systems in the presence of synchronous interference. In this case, the synchronous interferer's signal on each OFDM subcarrier is correlated in space with a rank one spatial covariance matrix. In addition, the interferer's spatial covariance matrix is correlated in frequency based on the delay spread of the interferer's channel. To reduce the number of unknown parameters we develop a structured covariance model that accounts for the structure resulting from the synchronous interference. To further reduce the number of unknown parameters, we model the covariance matrix using a priori known set of frequency-dependent functions of joint (global) parameters. We estimate the interference covariance parameters using a residual method of moments (RMM) estimator and the channel parameters by maximum likelihood (ML) estimation. Since our RMM estimates are invariant to the mean, this approach yields simple noniterative estimates of the covariance parameters while having optimal statistical efficiency. Hence, our algorithm outperforms existing channel estimators that do not account for the interference, and at the same time requires smaller number of pilots than the MANOVA method and thus has smaller overhead. Numerical results illustrate the applicability of the proposed algorithm.