Pulse or digital communications – Synchronizers – Frequency or phase control using synchronizing signal
Patent
1997-01-30
1999-09-07
Bocure, Tesfaldet
Pulse or digital communications
Synchronizers
Frequency or phase control using synchronizing signal
H04L 700
Patent
active
059498340
ABSTRACT:
A symbol sync acquisition circuit for a digital VSB signal finds sync pattern correlations in the incoming signal. Initially both positive and negative sync pattern correlations are accorded equal weight, with non sync pattern correlations being accorded a negative weight. Values are accumulated in a segment integrator and stored in a FIFO having a location for each symbol position in a segment. A comparator initially produces an output when sync pattern correlations are found that add to a given value. After a relatively small number of correlations, as tabulated in a confidence counter, a VCO is enabled to change its frequency under control of error pulses based upon the symbol sync. After a greater number of sync pattern correlations, the symbol position in the segment is fixed, sliding to a new symbol location in the FIFO is precluded, the signal polarity is determined and changed, if necessary, and a higher threshold is established for the comparator. The confidence counter continues to build after lock is attained. Should confidence be lost, the system resets and acquisition is started from the beginning.
REFERENCES:
patent: 5444743 (1995-08-01), Scarpa
patent: 5621483 (1997-04-01), Krishnamurthy et al.
patent: 5745528 (1998-04-01), Fimoff et al.
patent: 5751774 (1998-05-01), Wang
Laud Timothy G.
Mutzabaugh Dennis M.
Bocure Tesfaldet
Zenith Electronics Corporation
LandOfFree
VSB symbol sync recovery system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with VSB symbol sync recovery system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and VSB symbol sync recovery system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1811848