Blind channel estimation using fractional sampling

We consider the problem of blind estimation of a communication channel based on the oversampled channel output. We propose a nonparametric approach that, based on the cyclic spectrum of the output, finds the channel phase response without neither the need of phase unwrapping nor channel length information. For band-limited channels, the cyclic spectrum has limited support. For this case, we propose an approximation for the discretized phase of the cyclic spectrum that, under certain conditions, results in a simpler channel estimation method. The proposed approach is applied to simulated data and real recordings and is compared to existing methods.

[1]  Eric Moulines,et al.  Subspace methods for the blind identification of multichannel FIR filters , 1994, Proceedings of ICASSP '94. IEEE International Conference on Acoustics, Speech and Signal Processing.

[2]  Hui Liu,et al.  Recent developments in blind channel equalization: From cyclostationarity to subspaces , 1996, Signal Process..

[3]  Jean Pierre Delmas,et al.  Blind channel approximation: effective channel order determination , 1998, Conference Record of Thirty-Second Asilomar Conference on Signals, Systems and Computers (Cat. No.98CH36284).

[4]  W. Gardner.  Exploitation of spectral redundancy in cyclostationary signals , 1991, IEEE Signal Processing Magazine.

[5]  Chrysostomos L. Nikias,et al.  On blind system identification from its output autocorrelation , 1993, Proceedings of 27th Asilomar Conference on Signals, Systems and Computers.

[6]  Karim Abed-Meraim,et al.  Blind equalization with controlled delay robust to order over estimation , 2001, Proceedings of the Sixth International Symposium on Signal Processing and its Applications (Cat.No.01EX467).

[7]  Lang Tong,et al.  Blind channel identification based on second-order statistics: a frequency-domain approach , 1995, IEEE Trans. Inf. Theory.

[8]  Athina P. Petropulu,et al.  Frequency domain blind MIMO system identification based on second and higher order statistics , 2001, IEEE Trans. Signal Process..

[9]  Michael P. Fitz,et al.  Blind estimation of multipath channel parameters: a modal analysis approach , 1999, IEEE Trans. Commun..

[10]  John G. Proakis,et al.  Digital Communications , 1983 .

[11]  E. Moulines,et al.  A parametric subspace-based blind estimation of a SIMO-FIR with unknown channel order , 1999, 1999 2nd IEEE Workshop on Signal Processing Advances in Wireless Communications (Cat. No.99EX304).

[12]  Z. Ding.  Characteristics of band-limited channels unidentifiable from second-order cyclostationary statistics , 1996, IEEE Signal Process. Lett..

[13]  Chrysostomos L. Nikias,et al.  Blind indentifiability of a band-limited nonminimum phase system from its output autocorrelation , 1993, 1993 IEEE International Conference on Acoustics, Speech, and Signal Processing.

[14]  Lang Tong,et al.  Blind identification and equalization based on second-order statistics: a time domain approach , 1994, IEEE Trans. Inf. Theory.

[15]  Ye Li,et al.  ARMA system identification based on second-order cyclostationarity , 1994, IEEE Trans. Signal Process..