Pole-Zero Decision Feedback Equalization with a Rapidly Converging Adaptive IIR Algorithm

A decision feedback equalizer (DFE) containing a feedback filter with both poles and zeros is proposed for high-speed digital communications over the subscriber loop. The feedback filter is composed of a relatively short FIR filter that cancels the initial part of the channel impulse response, which may contain rapid variations due to bridge taps, and a pole-zero, or IIR, filter that cancels the smoothly decaying tail of the impulse response. Modifications of an adaptive IIR algorithm, based on the Steiglitz-McBride (1965) identification scheme, are proposed to adapt the feedback filter. A measured subscriber loop impulse response is used to compare the performance of the adaptive pole-zero DFE, assuming a two-pole feedback filter, with a conventional DFE having the same number of coefficients. Results show that the pole-zero DFE offers a significant improvement in mean squared error relative to the conventional DFE. The speed convergence of the adaptive pole-zero DFE is comparable to that of the conventional DFE using the standard least mean square (LMS) adaptive algorithm. >

[1]  W. Kenneth Jenkins,et al.  An investigation of an adaptive IIR echo canceller: advantages and problems , 1988, IEEE Trans. Acoust. Speech Signal Process..

[2]  Anis Ahmed. Abousaada Echo tail canceller based on AIFIR filtering. , 1990 .

[3]  L. Mcbride,et al.  A technique for the identification of linear systems , 1965 .

[4]  David D. Falconer,et al.  Minimum Mean Square Equalization in Cyclostationary and Stationary Interference-Analysis and Subscriber Line Calculations , 1991, IEEE J. Sel. Areas Commun..

[5]  David G. Messerschmitt,et al.  Convergence models for adaptive gradient and least squares algorithms , 1981, ICASSP.

[6]  W. Y. Chen,et al.  An all pole IIR echo canceller , 1990, IEEE International Symposium on Circuits and Systems.

[7]  B. Widrow,et al.  Adaptive noise cancelling: Principles and applications , 1975 .

[8]  Hong Fan,et al.  Application of Benveniste's convergence results in the study of adaptive IIR filtering algorithms , 1988, IEEE Trans. Inf. Theory.

[9]  Tyseer Aboulnasr,et al.  Efficient implementation of echo cancellers for ISDN applications , 1989, International Conference on Acoustics, Speech, and Signal Processing,.

[10]  C.A. Belfiore,et al.  Decision feedback equalization , 1979, Proceedings of the IEEE.

[11]  Hong Fan,et al.  On error surfaces of sufficient order adaptive IIR filters: proofs and counterexamples to a unimodality conjecture , 1989, IEEE Trans. Acoust. Speech Signal Process..

[12]  David G. Messerschmitt,et al.  Design Issues in the ISDN U-Interface Transceiver , 1986, IEEE J. Sel. Areas Commun..

[13]  T. Söderström,et al.  The Steiglitz-McBride identification algorithm revisited--Convergence analysis and accuracy aspects , 1981 .

[14]  John M. Cioffi The block-processing FTF adaptive algorithm , 1986, IEEE Trans. Acoust. Speech Signal Process..

[15]  C. Richard Johnson,et al.  Adaptive IIR filtering: Current results and open issues , 1984, IEEE Trans. Inf. Theory.

[16]  J. Shynk Adaptive IIR filtering , 1989, IEEE ASSP Magazine.

[17]  David Falconer,et al.  Reduced-complexity trellis coding/decoding for high bit rate digital subscriber loop transmission , 1989, IEEE International Conference on Communications, World Prosperity Through Communications,.

[18]  David W. Lin Wide-band digital subscriber access with multidimensional block modulation and decision-feedback equalization , 1989, IEEE J. Sel. Areas Commun..

[19]  D. Falconer,et al.  Study of a pole - zero adaptive echo canceller , 1987 .

[20]  D. D. Falconer,et al.  Reduced complexity echo cancellation using orthonormal functions , 1991 .

[21]  S. Koike,et al.  Design techniques and performance of an LSI-based 2B1Q transceiver , 1988, IEEE Global Telecommunications Conference and Exhibition. Communications for the Information Age.

[22]  T. R. Hsing,et al.  The DSP implementation of a new timing recovery technique for high-speed digital data transmission , 1990, International Conference on Acoustics, Speech, and Signal Processing.

[23]  B. Friedlander,et al.  Lattice filters for adaptive processing , 1982, Proceedings of the IEEE.

[24]  W. Jenkins,et al.  A new adaptive IIR filter , 1986 .