Abstract: A vestigial sideband (VSB) modulation minimum output energy (MOE) pre-equalizer operating on a received ATSC 8-VSB DTV signal includes one or more of an adaptive feed-forward filter and an adaptive feedback filter each utilizing only real adaptive coefficients, with the direct term for the overall filter constrained to unity to remove one degree of filter parameterization freedom. Adaptation of the filter(s) is based on minimizing a blind energy cost function, and is independent of adaptation of a conventional adaptive channel equalizer. The pre-equalized signal is passed to the conventional adaptive equalizer for channel equalization utilizing DFE, IIR-CMA, etc., resulting in performance improvements including faster convergence and greater robustness with relatively small implementation costs.
Type:
Application
Filed:
May 6, 2002
Publication date:
December 12, 2002
Applicant:
FOX DIGITAL
Inventors:
Rodney A. Kennedy, Thushara D. Abhayapala
Abstract: The present invention provides a method for generating a timing offset signal applied to a sampling device for recovering a symbol stream from a broadcast signal by characterizing the dispersion of received signal. Preferably, the method includes steps for generating a derivative signal approximating the derivative of the symbol stream, producing a constant representative of an expected symbol stream, and multiplying the derivative signal, the constant, and a signal one of corresponding to and approximating the symbol stream to thereby generate the timing offset signal. A dispersion characterizing receiver and a digital signal processor employed therein are also described.
Type:
Application
Filed:
September 7, 2001
Publication date:
May 23, 2002
Applicant:
FOX DIGITAL
Inventors:
Jaiganesh Balakrishnan, William A. Sethares, Wonzoo Chung, Richard Martin, C. Richard Johnson