Timing recovery system

Details Timing recovery system Timing recovery system

1998-03-31

2000-10-17

Chin, Stephen

Pulse or digital communications

Receivers

Angle modulation

375327, H04L 2714

Patent

active

061342769

ABSTRACT:
A digital timing recovery system advantageously employs both demodulated I-phase and Q-phase components to more accurately locate the synchronization signal of an incoming VSB signal. The Q-phase component is advantageously employed to detect the phase error. The use of the Q-phase component provides a more accurate measure of the phase error and results in a larger (wider) acquisition range for timing frequency offset. More specifically, the timing recovery system of this invention performs symbol clock recovery based on the VSB signal segment synchronization (sync) signal and generates a pulse density modulated (PDM) phase difference signal that controls a voltage controlled crystal oscillator (VCXO) in the phase-locked loop. This is realized, in one embodiment of the invention, by correlating received sync segment data with the known sync signal pattern and searching for "peaks" in the correlation values that are periodic at the known sync segment data rate. Once the sync pattern is found, the correlation values for adjacent samples are advantageously employed to generate the necessary feedback control signal value for the VCXO. Technical advantages of applicants' unique invention are that the need for an analog synchronous detector is eliminated, a more accurate measure than that obtained by prior known systems is obtained and a wider acquisition range is obtained for timing frequency offset.

REFERENCES:
patent: 4849991 (1989-07-01), Arnold et al.
patent: 5703905 (1997-12-01), Langberg
patent: 5796786 (1998-08-01), Lee
patent: 5809009 (1998-09-01), Matsuoka et al.

Affiliated with

Also associated with

Rating

Timing 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 Timing recovery system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Timing recovery system will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-476736