Demodulators – Frequency modulation demodulator – Input signal combined with local oscillator or carrier...
Patent
1993-07-14
1994-09-06
Grimm, Siegfried H.
Demodulators
Frequency modulation demodulator
Input signal combined with local oscillator or carrier...
329336, 329341, 329343, 455214, 455337, H03D 318
Patent
active
053451880
ABSTRACT:
Digital frequency demodulation is accomplished by monitoring similar transitions in an FM radio signal to determine frequency. Time intervals between similar transitions in the FM signal are established by selecting anticipated transition times and accumulating error values relative to actual transition times. Accumulated error values provide a basis for further selecting anticipated transition times in such manner that a reported sequence of anticipated transition times provides a basis for inferring signal frequency. In one illustrated embodiment, the chosen transition times are positive transitions in the FM signal and the anticipated times of transition are taken from a set of two time periods, an early transition and a late transition relative to a valid transition window. By reporting the selected anticipation times by associated values in a digital bit stream, frequency may be inferred by computing a ratio of given digital values in the bit stream relative to the total number of samples in the bit stream.
REFERENCES:
patent: 4368434 (1983-01-01), Miller et al.
patent: 4707666 (1987-11-01), Pfeifer et al.
patent: 5077538 (1991-12-01), Gehrt et al.
Two articles entitled "A Use of Limit Cycle Oscillations to Obtain Robust Analog-to-Digital Converters"and Table-Based Simulation of Delta-Sigma Modulators. Both articles are located in a manual entitled Oversampling Delta-Sigma Data Converters published by the Institute of Electrical and Electronics Engineers, Inc. in 1992 pp. 44-51, 163-167.
Galbi Elmer
Grimm Siegfried H.
Seiko Telecommunication Systems Inc.
LandOfFree
Sigma-delta digital FM demodulator does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sigma-delta digital FM demodulator, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sigma-delta digital FM demodulator will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1331940