DFE research

Papers dealing with decision feedback equalization.

Keywords: Specific area keywords

D. Williamson, R. A. Kennedy, and G. W. Pulford, "Block Decision Feedback Equalization", IEEE Trans. Commun., vol. 40, no. 2, pp. 255-264, February 1992.
Abstract BibTeX
Official: Link DOI: 10.1109/26.129188 PDF: 00129188.pdf Google-Scholar: [57]
Abstract: A natural generalization of the conventional decision feedback equalizer (DFE) based on block processing and maximum a posteriori decisions is presented. This block DFE is indexed by two parameters depending on the block length p and the number of decisions q⩽p made at each iteration. The block DFE emulates: the conventional DFE when p=q=1; the maximum likelihood sequence estimator when p=q?$\,^\circ$; and the maximum symbol-by-symbol a posteriori optimal detector when q=1, p?$\,^\circ$. For more general (p,q) parameter settings, one achieves combinations and simplifications of these classical nonlinear detectors. The authors also recover more recently developed nonlinear equalizer structures based on forward tree search algorithms in the high SNR limit (for q =1). They simulate the equalizer using a standard literature example. The theoretical framework presented accommodates autoregressive moving average (ARMA) channels models. Investigations into the error performance of the block DFE are briefly discussed.
@article{KennedyJ1992a,
    title = {Block Decision Feedback Equalization},
    author = {Williamson, D. and Kennedy, R. A. and Pulford, G. W.},
    journal = {IEEE Trans. Commun.},
    volume = {40},
    pages = {255-264},
    month = {February},
    year = {1992}}
R. A. Kennedy and B. D. O. Anderson, "Recovery Times of Decision Feedback Equalizers on Noiseless Channels", IEEE Trans. Commun., vol. 35, no. 10, pp. 1012-1021, October 1987.
Abstract BibTeX
Official: Link PDF: 01096682.pdf Google-Scholar: [34]
Abstract: The performance of decision feedback equalizers (DFE's) working on a noiseless channel with correct tap weights is studied. We show that the space of channel parameters can accordingly be partitioned into a finite number of sets. The error recovery performance of a DFE is the same for all DFE's within one such set, and is determinable. We also discuss some tight bounds for recovery time statistics, which are particularly important when the number of equalizer taps is not small. We argue that minimum phase or near minimum phase character for the channel does not necessarily guarantee short recovery time.
@article{KennedyJ1987c,
    title = {Recovery Times of Decision Feedback Equalizers on Noiseless Channels},
    author = {Kennedy, R. A. and Anderson, B. D. O.},
    journal = {IEEE Trans. Commun.},
    volume = {35},
    pages = {1012-1021},
    month = {October},
    year = {1987}}
R. A. Kennedy, B. D. O. Anderson, and R. R. Bitmead, "Tight Bounds on the Error Probabilities of Decision Feedback Equalizers", IEEE Trans. Commun., vol. 35, no. 10, pp. 1022-1029, October 1987.
Abstract BibTeX
Official: Link PDF: 01096679.pdf Google-Scholar: [25]
Abstract: A decision feedback equalizer (DFE) with correct tap weights operating on a noisy channel is considered. We show how the results concerning a noiseless channel can be extended to yield tight bounds on the stationary error probability performance for the noisy case. The effect of noise on DFE performance is classified according to the noise distribution and the channel parameters.
@article{KennedyJ1987d,
    title = {Tight Bounds on the Error Probabilities of Decision Feedback Equalizers},
    author = {Kennedy, R. A. and Anderson, B. D. O. and Bitmead, R. R.},
    journal = {IEEE Trans. Commun.},
    volume = {35},
    pages = {1022-1029},
    month = {October},
    year = {1987}}
R. A. Kennedy, B. D. O. Anderson, and R. R. Bitmead, "Blind adaptation of decision feedback equalizers: Gross convergence properties", Int. J. of Adapt. Contr. and Signal Processing, vol. 7, no. 6, pp. 497-524, November 1993.
Abstract BibTeX
PDF: KennedyJ1993c.pdf Google-Scholar: [24]
Abstract: An analysis of the stochastic dynamics of the blind adaptation of decision feedback equalizers is presented. The analysis accounts for the presence of decision errors which, under feedback, are propagated. A number of blind algorithms are presented and a theory is developed to explain gross convergence properties observed through simulations. The possibility of and mechanism behind undesirable local minima are highlighted and a detailed case study is given. The potential capture by local minima shows the importance of good initialization. These results superficially resemble those obtained for blind adaptation applied to linear equalizers.for blind adaptation applied to linear equalizer.
@article{KennedyJ1993c,
    title = {Blind adaptation of decision feedback equalizers: {G}ross convergence properties},
    author = {Kennedy, R. A. and Anderson, B. D. O. and Bitmead, R. R.},
    journal = {Int. J. of Adapt. Contr. and Signal Processing},
    volume = {7},
    pages = {497-524},
    month = {November},
    year = {1993}}
R. A. Kennedy, B. D. O. Anderson, and R. R. Bitmead, "Channels leading to rapid error recovery for decision feedback equalizers", IEEE Trans. Commun., vol. 37, no. 11, pp. 1146-1155, November 1989.
Abstract BibTeX
Official: Link DOI: 10.1109/26.46506 PDF: 00046506.pdf Google-Scholar: [16]
Abstract: When a decision feedback equalizer is used on a channel satisfying a simple passivity constraint (equivalently expressible in terms of gain-phase constraints) the error recovery time is finite, and thus recovery is rapid, regardless of the initial error state and the particular data sequence. This class of nontrivial channels includes cases of practical interest and identifies some channels for which a decision feedback equalizer is a practical option.
@article{KennedyJ1989c,
    title = {Channels leading to rapid error recovery for decision feedback equalizers},
    author = {Kennedy, R. A. and Anderson, B. D. O. and Bitmead, R. R.},
    journal = {IEEE Trans. Commun.},
    volume = {37},
    pages = {1146-1155},
    month = {November},
    year = {1989}}
R. A. Kennedy, G. W. Pulford, B. D. O. Anderson, and R. R. Bitmead, "When has a Decision Directed Equalizer Converged?", IEEE Trans. Commun., vol. 37, no. 8, pp. 879-884, August 1989.
Abstract BibTeX
Official: Link DOI: 10.1109/26.31188 PDF: 00031188.pdf Google-Scholar: [9]
Abstract: Adaptive decision-directed equalizers can become locked for long periods onto incorrect equilibria. A test involving data available at the equalizer output is proposed for determining whether an equilibrium is correct or not, up to a fixed overall delay. If an independent sequence of random variables taking values $\pm$1 is the input to a finite impulse response filter, and the output of the filter is passed through a slicer, then the slicer output is uncorrelated if and only if it is a delayed version of the filter input. An analogous result for M-ary rather than binary data is outlined.
@article{KennedyJ1989b,
    title = {When has a Decision Directed Equalizer Converged?},
    author = {Kennedy, R. A. and Pulford, G. W. and Anderson, B. D. O. and Bitmead, R. R.},
    journal = {IEEE Trans. Commun.},
    volume = {37},
    pages = {879-884},
    month = {August},
    year = {1989}}