Pulse or digital communications – Testing – Phase error or phase jitter
Patent
1996-04-12
1998-06-30
Tse, Young T.
Pulse or digital communications
Testing
Phase error or phase jitter
375371, 370468, 370516, 348464, 348500, H03B 346
Patent
active
057744971
ABSTRACT:
A method and a test instrument are provided for measuring program clock reference (PCR) jitter in a data stream, such as an MPEG-2 transport stream. The test instrument includes a line interface circuit for receiving the data stream, a digital computer for processing the data stream, a local clock for generating timestamps and a display unit. The digital computer extracts from the data stream a PCR sample which represents a count of a system time clock used to generate the data stream. The timestamp is obtained from the local clock and is associated with the PCR sample value. The digital computer determines a line of best fit to a set of values including the PCR sample value and the timestamp, and previously received PCR sample values and associated timestamps. The line of best fit represents a reconstructed system time clock. The digital computer determines a PCR jitter value for the PCR sample value by determining a distance between the line of best fit and the PCR sample value. The PCR jitter value may be displayed on the display unit, preferably in a histogram.
REFERENCES:
patent: 5533021 (1996-07-01), Branstad et al.
patent: 5537408 (1996-07-01), Branstad et al.
patent: 5640388 (1997-06-01), Woodhead et al.
Block Simon A.
Dyck Trevor S. R.
Hewlett-Packard Co
Tse Young T.
LandOfFree
Method and apparatus for PCR jitter measurement in an MPEG-2 tra does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for PCR jitter measurement in an MPEG-2 tra, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for PCR jitter measurement in an MPEG-2 tra will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1868140