Boots – shoes – and leggings
Patent
1996-09-10
1998-05-19
Trammell, James P.
Boots, shoes, and leggings
3647241, 364487, 375371, 375373, 375376, 375375, 327156, 327159, 370516, 315226, H04L 700, H04L 2536
Patent
active
057544379
ABSTRACT:
A phase measurement apparatus and method for measuring electrical signal jitter and wander operates in real time and digitally controls bandwidths over which the measurements are performed. The apparatus includes a digital phase-lock loop (PLL) for generating phase difference signal data having first and second frequency components above and below the loop bandwidth of the phase locked loop. An analog-to-digital converter digitizes the analog phase difference signal from the phase detector. A digital signal processor (DSP) receives the digital data and performs a loop filter function for generating frequency update values to the DDS for phase locking the PLL to an incoming signal. The DSP performs an integration function on the loop filter function output to generate the second frequency components. The first and second frequency components are combined in a summing circuit and filtered in digitally programmable low and high pass filters for establishing measurement bands for measuring the phase difference. A measurement processor measures peak-to-peak minimum and maximum values and generates RMS values of the phase difference signal over a selected time interval and generating an output in unit intervals for jitter and time for wander. The DSP further includes low and high pass filter functions and an accumulator for summing filtered second frequency components to generate wander data. The DSP processes the frequency update values to generate frequency drift data.
REFERENCES:
patent: 4718074 (1988-01-01), Mannas et al.
patent: 4811359 (1989-03-01), Nakajima et al.
patent: 5010403 (1991-04-01), Wardzala
patent: 5012494 (1991-04-01), Lai et al.
patent: 5036249 (1991-07-01), McCaslin
patent: 5241285 (1993-08-01), Jackson
patent: 5373255 (1994-12-01), Bray et al.
patent: 5402443 (1995-03-01), Wong
patent: 5406592 (1995-04-01), Baumert
patent: 5425060 (1995-06-01), Roberts et al.
patent: 5493243 (1996-02-01), Ghoshal
patent: 5506627 (1996-04-01), Ciardi
patent: 5517685 (1996-05-01), Aoyama et al.
patent: 5579351 (1996-11-01), Kim
patent: 5608761 (1997-03-01), Opas et al.
"Broadcast Quality Video Over SDH Networks; Eradicating Sub Carrier Corruption Due To pointers," J.A. Shields et al., IBC 95 Intl. Broadcasting Convention Pub. No. 413, pp. 269-273, Sep. 1995, IEEE, London, U.K.
"Automate Your Field Testing with the CTS 750 SDH Test Set," Tektronix, Inc., Pub. No. 2GW-9139-0, 1993, Beaverton, Oregon.
"SDH/SONET Telecommunications Standards Primer," Tektronix, Inc., Pub. No. 3SW-8085-1, 1994, Beaverton, Oregon.
"PM6431 E1XC Features, Applications, Receiver Section, and Transmit Section" by PMC-Sierra, Inc., http://www.pmc-sierra.bc.ca/apdh/e1xc.html., Jan. 24, 1997.
"Communication Integrated Circuits-ISDN Data Access/Digital Terminal ICs Data Communication ICs Wireless Communication ICs Exchange ICs PRI/Switching ICs ISDN Data", http://www.allianet.com/siemens/Catalog/01.html., 1996.
Mark Haas, "Modulation Domain Analysis -A New Method for Measuring Jitter on Digital Devices" by Tom Carrico of HP Co., http://www.haas.com/doc/jitter.htm.
"DSP CARD 4 User Manual and Application Software", http://www.daisy.cheque.uq.edu.au/vk4yeq/DSP$/manual/manual.html, and http://www.trap.org/dsp/dsp4/application.html., Apr. 1995.
Bucher William K.
Nguyen Cuong H.
Tektronix Inc.
Trammell James P.
LandOfFree
Phase measurement apparatus and method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Phase measurement apparatus and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Phase measurement apparatus and method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1859440