Set-membership adaptive equalization and an updator-shared implementation for multiple channel communications systems

This paper considers the problems of channel estimation and adaptive equalization in the novel framework of set-membership parameter estimation. Channel estimation using a class of set-membership identification algorithms known as optimal bounding ellipsoid (OBE) algorithms and their extension to tracking time-varying channels are described. Simulation results show that the OBE channel estimators outperform the least-mean-square (LMS) algorithm and perform comparably with the RLS and the Kalman filter. The concept of set-membership equalization is introduced along with the notion of a feasible equalizer. Necessary and sufficient conditions are derived for the existence of feasible equalizers in the case of linear equalization for a linear FIR additive noise channel. An adaptive OBE algorithm is shown to provide a set of estimated feasible equalizers. The selective update feature of the OBE algorithms is exploited to devise an updator-shared scheme in a multiple channel environment, referred to as updator-shared parallel adaptive equalization (USHAPE). U-SHAPE is shown to reduce the hardware complexity significantly. Procedures to compute the minimum number of updating processors required for a specified quality of service are presented.

[1]  H. Kaufman,et al.  The Kalman Filter for the Equalization of a Digital Communications Channel , 1971 .

[2]  Er-Wei Bai,et al.  Bounded-error parameter estimation: Noise models and recursive algorithms , 1996, Autom..

[3]  E. Walter,et al.  Estimation of parameter bounds from bounded-error data: a survey , 1990 .

[4]  F. Schweppe.  Recursive state estimation: Unknown but bounded errors and system inputs , 1967 .

[5]  J. Deller.  Set membership identification in digital signal processing , 1989, IEEE ASSP Magazine.

[6]  John R. Deller,et al.  Adaptive set-membership identification in O(m) time for linear-in-parameters models , 1992, IEEE Trans. Signal Process..

[7]  S. Haykin,et al.  Adaptive Filter Theory , 1986 .

[8]  Asrar U. H. Sheikh,et al.  Adaptive equalization for co-channel interference in a multipath fading environment , 1995, IEEE Trans. Commun..

[9]  Yih-Fang Huang,et al.  Set-membership identification for adaptive equalization , 1995, 38th Midwest Symposium on Circuits and Systems. Proceedings.

[10]  J.E. Mazo,et al.  Digital communications , 1985, Proceedings of the IEEE.

[11]  Y. F. Huang,et al.  On the value of information in system identification - Bounded noise case , 1982, Autom..

[12]  Yih-Fang Huang,et al.  Updator-shared adaptive parallel equalization (U-SHAPE) using set-membership identification , 1996, 1996 IEEE International Symposium on Circuits and Systems. Circuits and Systems Connecting the World. ISCAS 96.

[13]  Yih-Fang Huang,et al.  Tracking characteristics of an OBE parameter-estimation algorithm , 1993, IEEE Trans. Signal Process..

[14]  Steve McLaughlin,et al.  Adaptive equalisation via Kalman filtering techniques , 1991 .

[15]  Graham C. Goodwin,et al.  Adaptive filtering prediction and control , 1984 .

[16]  S. Kapoor,et al.  Set-Membership State Estimation with Optimal Bounding Ellipsoids , 1996 .

[17]  S. Kapoor,et al.  Tracking of Time-Varying Parameters using Optimal Bounding Ellipsoid Algorithms , 1996 .

[18]  Asrar U. H. Sheikh,et al.  Advances in Equalization and Diversity for Portable Wireless Systems , 1993 .

[19]  J. R. Deller,et al.  Least-square identification with error bounds for real-time signal processing and control , 1993, Proc. IEEE.

[20]  Simon Haykin,et al.  Adaptive filter theory (2nd ed.) , 1991 .

[21]  J. Norton,et al.  State bounding with ellipsoidal set description of the uncertainty , 1996 .

[22]  J. G. Proakis.  Adaptive equalization for TDMA digital mobile radio , 1991 .

[23]  L. Schrage,et al.  Queueing systems, Vol. I: Theory , 1977, Proceedings of the IEEE.

[24]  Yih-Fang Huang,et al.  Asymptotically convergent modified recursive least-squares with data-dependent updating and forgetting factor , 1985, 1985 24th IEEE Conference on Decision and Control.