Pulse or digital communications – Equalizers – Automatic
Reexamination Certificate
2006-04-11
2006-04-11
Ghebretinsae, Temesghen (Department: 2637)
Pulse or digital communications
Equalizers
Automatic
C708S323000, C348S607000
Reexamination Certificate
active
07027500
ABSTRACT:
A single-axis receiver processing, for example, complex vestigial sideband modulated signals with an equalizer with forward and feedback filters. Forward and feedback filters have parameters that are initialized and adapted to steady state operation. Adaptive equalization employs linear predictive filtering and error term generation based on various cost criteria. Adaptive equalization includes recursive update of parameters for forward and feedback filtering as operation changes between linear and decision-feedback equalization of either single or multi-channel signals. An adaptive, linear predictive filter generates real-valued parameters that are employed to set the parameters of the feedback filter. In an initialization mode, filter parameters are set via a linear prediction filter to approximate the inverse of the channel's impulse/frequency response and a constant modulus error term for adaptation of the filter parameters. In an acquisition mode, equalization is as linear equalization with a constant modulus error term, and possibly other error terms in combination, for adaptation of the filter parameters. In a tracking mode, equalization is as decision feedback equalization with decision-directed error terms for adaptation of the filter parameters. For some equalizer configurations, feedback filtering is applied to real-valued decisions corresponding to complex-valued received data, and includes real-part extraction of the error term employed for recursive update of filtering parameters. Where a training sequence is available to the receiver, initial parameters for forward filtering are estimated by correlation of the received signal with the training sequence.
REFERENCES:
patent: 5872815 (1999-02-01), Strolle et al.
patent: 5909466 (1999-06-01), Labat et al.
patent: 5930296 (1999-07-01), Kot
patent: 6240133 (2001-05-01), Sommer et al.
patent: 6313885 (2001-11-01), Patel et al.
patent: 6370191 (2002-04-01), Mahant-Shetti et al.
patent: 6668014 (2003-12-01), Endres et al.
patent: 6724844 (2004-04-01), Ghosh
patent: 6775322 (2004-08-01), Zangi et al.
patent: 6775334 (2004-08-01), Liu et al.
patent: 6816548 (2004-11-01), Shiue et al.
patent: 6842495 (2005-01-01), Jaffe et al.
patent: 2002/0054634 (2002-05-01), Martin et al.
Hardware architectures of adaptive equalizers for the HDTV receiver; Seung Soo Chae, et al; Signal Processing, IEEE Transactions on, vol.: 46 , Issue: 2 , Feb. 1998 pp.: 391-404.
A decision-directed constant modulus algorithm for higher-order source constellations; Endres, T.J., et al; Acoustics, Speech, and Signal Processing, 2000. ICASSP '00. Proceedings. 2000 IEEE Int'l Conference on , vol. 6 , Jun. 5-9, 2000 pp.: 3382-3385.
“Phase recovery based on minimization of Single-Axis Constant Modulus criterion: Performance analysis” by A. Touzni, et al., 2001 Conference on Information Sciences and Systems, The John Hopkins University, Mar. 21-23, 2001.
“A New Approach to Multipath Correction of Constant Modulus Signals” by John R. Treichler and Brian G. Agee, IEEE Transactions on Acoustics, Speech, and Signal Processing, vol. ASSP-31, No. 2, Apr. 1983; pps. 459-471.
“Global Convergence of a Single-Axis Constant Modulus Algorithm” by A. Shah, et al.,Proceedings of the Statistical Signal and Array Processing Workshop,Pocono Manor, PA, Aug. 2000.
“Self-Recovering Equalization is Two-Dimensional Data Communications Systems” by D. N. Goddard,IEEE Transactions on Communications,Oct. 1980, vol. 28, No. 11, pps. 1867-1875.
Biracree Stephen L.
Casas Raúl A.
Endres Thomas J.
Hulyalkar Samir N.
Strolle Christopher H.
ATI Research, Inc.
Ghebretinsae Temesghen
Meek Jacob
Mendelsohn Steve
LandOfFree
Linear prediction based initialization of a single-axis... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Linear prediction based initialization of a single-axis..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Linear prediction based initialization of a single-axis... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3557592