On efficient use of pilot symbols for multi-path channel equalization of QAM signals

We study a classic problem in wireless data communications in which receivers generally rely on training pilots for equalization of multi-path dispersive channel distortions. Traditional equalizers often require a substantial number of pilot symbols for effective channel compensation. To conserve limited channel bandwidth, we investigate novel equalization algorithms that can make more efficient use of fewer pilot symbols. We present a linear programming algorithm that takes better advantage of the QAM constellation. We further exploit the information inherent in the LDPC forward error correction codes within the linear programming framework to improve the equalization performance and convergence properties.

[1]  Zhi Ding,et al.  A fast linear programming algorithm for blind equalization , 2000, IEEE Trans. Commun..

[2]  Zhi Ding,et al.  Blind Equalization and Identification , 2001 .

[3]  A. Benveniste,et al.  Robust identification of a nonminimum phase system: Blind adjustment of a linear equalizer in data communications , 1980 .

[4]  S. Qureshi,et al.  Adaptive equalization , 1982, Proceedings of the IEEE.

[5]  Alain Glavieux,et al.  Iterative correction of intersymbol interference: Turbo-equalization , 1995, Eur. Trans. Telecommun..

[6]  Martin J. Wainwright,et al.  Using linear programming to Decode Binary linear codes , 2005, IEEE Transactions on Information Theory.

[7]  K.-D. Kammeyer,et al.  Blind identification and equalization of LDPC-encoded MIMO systems , 2005, 2005 IEEE 61st Vehicular Technology Conference.

[8]  Zhi Ding,et al.  Linear programming based joint detection of LDPC coded MIMO systems , 2012, 2012 IEEE Global Communications Conference (GLOBECOM).

[9]  Philip Schniter,et al.  Blind equalization using the constant modulus criterion: a review , 1998, Proc. IEEE.

[10]  Monson H. Hayes,et al.  Statistical Digital Signal Processing and Modeling , 1996 .

[11]  Zhi Ding,et al.  Linear programming based joint detection of LDPC coded MIMO systems , 2012, GLOBECOM.

[12]  Henry D. Pfister,et al.  An Iterative Joint Linear-Programming Decoding of LDPC Codes and Finite-State Channels , 2010, 2011 IEEE International Conference on Communications (ICC).