System and method for deriving symbol timing

Details System and method for deriving symbol timing System and method for deriving symbol timing

2005-02-08

2005-02-08

Chin, Stephen (Department: 2634)

Pulse or digital communications

Synchronizers

Phase displacement, slip or jitter correction

C375S372000, C375S373000, C375S374000, C375S375000, C375S376000, C375S222000, C375S229000, C375S230000, C375S231000, C375S232000, C375S233000, C375S234000

Reexamination Certificate

active

06853695

ABSTRACT:
A symbol timing derivation system derives receiver timing from received symbols which avoids the need for a pilot tone, thereby reducing power consumption and expanding usable bandwidth. The system is implemented by using a calculation that finds the timing phase error. The timing phase error is then averaged and controls a phase locked loop (PLL). This PLL in turn controls a voltage-controlled oscillator, which handles the modem receiver timing. A centroid calculation can be included to bias the voltage-controlled oscillator to push the equalizer coefficients back to the ideal position. The system can be implemented in either a point-to-point modem environment or a multi-point environment, for example, but not limited to, MVL or DMT. The voltage-controlled oscillator may also be implemented to control transmitter timing, so that the central office modem and the remote modem will operate more-or-less synchronously, reducing the need for large equalizer corrections at either end.

REFERENCES:
patent: 4815103 (1989-03-01), Cupo et al.
patent: 5353312 (1994-10-01), Cupo et al.
patent: 5426671 (1995-06-01), Bergmans
patent: 5471508 (1995-11-01), Koslov
patent: 5654765 (1997-08-01), Kim
Gitlin, Richard D., et al., “Center-Tap Tracking Algorithms for Timing Recovery”; AT&T Tchnical Journal, pp. 63-78.
Mazo, J.E., “Jitter Comparison of Toens Generated by Squaring and by Fourth-Power Circuits”, The Bell System Technical Journal, vol. 57, No. 5, Jun. 1978, pp. 1489-1498.
Ungerboeck, Gottfried, “Fractional Tap-Spacing Equalizer and Consequences for Clock Recovery in Data Modems”, IEEE Transactions on Communications, vol. COM-24, No. 8, Aug. 1976, pp. 856-864.
Qureshi, Shahid U.H., “Adjustment of the Position of the Reference Tap of an Adaptive Equalizer”, IEEE Transactions on Communications, Sep. 1973, pp. 1046-1052.

Affiliated with

Also associated with

Rating

System and method for deriving symbol timing does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with System and method for deriving symbol timing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and System and method for deriving symbol timing will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3498664