Iterative (Turbo) equalization for doubly-selective channels using exponential basis expansion models

We present an adaptive soft-input soft-output (SISO) turbo equalization receiver for doubly-selective channels. The proposed receiver exploits the complex exponential basis expansion model (CE-BEM) for the overall channel variations, and an autoregressive (AR) model for the BEM coefficients. We extend an existing turbo equalization approach based on symbol-wise AR modeling of channels to channels based on BEMs. Simulation examples and an EXIT chart analysis demonstrate that our CE-BEM-based approach outperforms the existing symbol-wise AR model-based turbo equalizer.

[1]  Stephan ten Brink,et al.  Convergence behavior of iteratively decoded parallel concatenated codes , 2001, IEEE Trans. Commun..

[2]  Michael Tüchler,et al.  Iterative channel estimation for turbo equalization of time-varying frequency-selective channels , 2004, IEEE Transactions on Wireless Communications.

[3]  Georgios B. Giannakis,et al.  Optimal training for block transmissions over doubly selective wireless fading channels , 2003, IEEE Trans. Signal Process..

[4]  Georgios B. Giannakis,et al.  Basis expansion models and diversity techniques for blind identification and equalization of time-varying channels , 1998, Proc. IEEE.

[5]  Fabian Vogelbruch,et al.  Low complexity turbo equalization based on soft feedback interference cancellation , 2005, IEEE Communications Letters.

[6]  Andrew C. Singer,et al.  Soft input channel estimation for turbo equalization , 2004, IEEE Transactions on Signal Processing.

[7]  H. Vincent Poor,et al.  Wireless Communication Systems: Advanced Techniques for Signal Reception , 2003 .

[8]  Xin Li,et al.  Turbo equalization with nonlinear Kalman filtering for time-varying frequency-selective fading channels , 2007, IEEE Transactions on Wireless Communications.

[9]  Theodore S. Rappaport,et al.  Wireless communications - principles and practice , 1996 .

[10]  Geert Leus,et al.  On the estimation of rapidly time-varying channels , 2004, 2004 12th European Signal Processing Conference.

[11]  Jitendra K. Tugnait,et al.  Doubly Selective Channel Estimation Using Exponential Basis Models and Subblock Tracking , 2007, IEEE Transactions on Signal Processing.

[12]  T. Zemen,et al.  Time-variant channel estimation using discrete prolate spheroidal sequences , 2005, IEEE Transactions on Signal Processing.

[13]  Lajos Hanzo,et al.  EXIT-chart aided near-capacity Irregular Bit-Interleaved Coded Modulation design , 2009, IEEE Transactions on Wireless Communications.

[14]  Xiaodong Li,et al.  Bit-interleaved coded modulation with iterative decoding , 1997, IEEE Communications Letters.

[15]  R. R. Lopes,et al.  The soft-feedback equalizer for turbo equalization of highly dispersive channels , 2006, IEEE Transactions on Communications.

[16]  Michael Tuchler,et al.  EXIT charts of irregular codes , 2002 .

[17]  Georgios B. Giannakis,et al.  Optimal training for block transmissions over doubly-selective fading channels , 2002, 2002 IEEE International Conference on Acoustics, Speech, and Signal Processing.