Frequency detector device and method

Oscillators – Automatic frequency stabilization using a phase or frequency... – With reference oscillator or source

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

331 1R, H03L 700

Patent

active

043085059

ABSTRACT:
A frequency detector and method for use in timing and carrier recovery applications. In a timing recovery application, the circuit includes means for generating a variable frequency periodic clock signal corresponding to an input data signal, means for determining whether successive data transitions of the data signal occur during first and second predetermined portions of successive cycles of the clock signal and means for changing the frequency of the clock signal when successive data transitions occur during different ones of the predetermined portions. For carrier recovery applications, the circuit includes means responsive to an input signal for generating a timing recovery signal, means for generating a local carrier signal having in-phase and quadrature axis components, means responsive to the local carrier signal and to the input signal for forming a baseband signal having in-phase and quadrature axis components, means responsive to the timing recovery signal for sampling the baseband signal at timing intervals corresponding to the timing recovery signal thereby forming a sample baseband signal, means for determining when the sample baseband signal occurs within a predetermined region of the in-phase axis or quadrature axis and means for changing the frequency of the carrier signal if successive samples are on opposite sides of the in-phase axis or quadrature axis.

REFERENCES:
patent: 3840821 (1974-10-01), Conway
patent: 4100503 (1978-07-01), Lindsey et al.
Axelsson, E., "Analysis of the Quantizing Error of a Zero-Counting Frequency Estimator", IEEE Trans. Information Thy., vol. IT-22, p. 596, 9/76.
Park, Jr., G., "An FM Detector for Low S/N", IEEE Trans. Comm., vol. Com-18, p. 110, Apr. 1970.
Runge, J., "Phase Locked Loops with Signal Injection for Increased Pull-In Range and Reduced Output Phase Jitter", IEEE Trans. Comm., vol. 4, 6/76.
Penwarden et al., "Improving Digital Radio Efficiency", Telephony, pp. 42-47, Jun. 6, 1977.
Richman, D., "Color-Carrier Reference Phase Synchronization Accuracy in NTSC Color Television", Proc. Ire., vol. 42, p. 106, 1/54.
Pickard, T., "The Effects of Noise on a Method of Frequency Measurement", Ire Trans. Information Thy., vol. IT-4, p. 83, 6/58.
Pawula, Robert, "Analysis of an Estimator of the Center Frequency of a Power Spectrum", IEEE Trans. Information Thy., vol. IT-14, p. 669, 9/68.
Cahn, C., "Improving Freq. Aquisition of a Costas Loop", IEEE Trans. on Comm., vol. Com-25, p. 1453, 12/77.
Oberst, J. F., "Generalized Phase Comparators for Improved PLL Aquisition", IEEE Trans. on Comm. Tech., vol. Com-19, p. 1142, 12/71.
Duttweiler, D., "The Jitter Performance of Phase Locked Loops", The Bell System Technical Journal, pp. 37-58, 1/76.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Frequency detector device 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 Frequency detector device and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Frequency detector device and method will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-1020260

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.