A fixed-lag particle smoother for blind SISO equalization of time-varying channels

• Published in: IEEE transactions on wireless communications Vol. 9; no. 2; pp. 512 - 516
• Main Authors: Guimaraes, A., Ait-El-Fquih, B., Desbouvries, F.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.02.2010; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Approximation; Approximation algorithms; Bit error rate; Blind equalizers; Blinds; Channels; Coding, codes; Computational efficiency; Computational modeling; Computer simulation; Detection, estimation, filtering, equalization, prediction; Engineering Sciences; Exact sciences and technology; Fixed-lag smoothing; Information, signal and communications theory; Mathematical models; mixture Kalman filter; Monte Carlo methods; Optimization; particle filter; Performance evaluation; Signal and communications theory; Signal and Image processing; Signal, noise; SISO equalization; Smoothing methods; Telecommunications; Telecommunications and information theory; Time-varying channels; Performance evaluation; Cost minimization; Monte Carlo method; Time variable channel; Bit error rate; Kalman filter; Iterative method; mixture Kalman filter; Turbo code; State space method; SISO equalization; Algorithm; Computational complexity; Blind equalization; Fixed-lag smoothing; Optimal solution; Numerical simulation; Cost lowering; Signal detection; Particle filter; Importance sampling; Mixture Kalman filters
• ISSN: 1536-1276; 1558-2248
• DOI: 10.1109/TWC.2010.02.081694

We introduce a new sequential importance sampling (SIS) algorithm which propagates in time a Monte Carlo approximation of the posterior fixed-lag smoothing distribution of the symbols under doubly-selective channels. We perform an exact evaluation of the optimal importance distribution, at a reduced computational cost when compared to other optimal solutions proposed for the same state-space model. The method is applied as a soft input-soft output (SISO) blind equalizer in a turbo receiver framework and simulation results are obtained to show its outstanding BER performance.