US4759079A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Random noise detecting system and method
Assignee: Pioneer Corp
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Filing: 1984-12-27
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Granted: 1988-07-19
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Expires: 2004-12-27
Abstract
Abstract A system and method for detecting the level of random noise contained in a band-limited amplitude-modulated signal. A sychronizing signal is produced which is π/2 out of phase with respect to the carrier of the amplitude-modulated signal. The amplitude-modulated signal and the synchronizing signal are multiplied together. Only a low frequency component is extracted from the multiplication output, and the low frequency component is taken as an indication of the level of the random noise contained in the amplitude-modulated signal.
Inventors
- 👤 Toshihito Ichikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:21
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/06; H04B1/10; H04B1/1027
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
95 words
A random noise detecting method for detecting a random noise level in an amplitude-modulated signal which is band limited and which contains random noise, comprising the steps of: producing a synchronizing signal π/2 out of phase with a carrier of said amplitude-modulated signal; multiplying said amplitude-modulated signal and said synchronizing signal to provide a multiplication output; and extracting only a low frequency component from said multiplication output, said low frequency component being below twice a frequency of said carrier of said amplitude-modulated signal, and said low frequency component being indicative of said ramdom noise level.
Claim 2
Dependent Claim
95 words
A random noise detecting method for detecting a random noise level in an amplitude-modulated signal which is band limited and which contains random noise, comprising the steps of: producing a synchronizing signal π/2 out of phase with a carrier of said amplitude-modulated signal; multiplying said amplitude-modulated signal and said synchronizing signal to provide a multiplication output; and extracting only a low frequency component from said multiplication output, said low frequency component being below twice a frequency of said carrier of said amplitude-modulated signal, and said low frequency component being indicative of said ramdom noise level.
Claim 3
Dependent Claim
44 words
The random noise detecting method of claim 1, wherein said step of producing said synchronizing signal comprises applying said amplitude-modulated signal to a bandpass filter whose passband is extremely narrow, and subjecting the signal thus obtained by 90° to thereby produce said synchronizing signal.
Claim 4
Dependent Claim
36 words
The random noise detecting method of claim 1, for the case of a double-sideband suppressed carrier signal, further comprising the step of producing said carrier by passing said amplitude-modulated signal through a Costas-loop phase-locked loop circuit.
Claim 5
Dependent Claim
26 words
The random noise detecting method of claim 1, wherein said step of producing said synchronizing signal comprises passing said amplitude-modulated signal through a phase-locked loop circuit.
Claim 6
Dependent Claim
98 words
A random noise detecting system for detecting a random noise level in an amplitude-modulated signal which is band limited and which contains random noise, comprising: means for producing a synchronizing signal π/2 out of phase with a carrier of the amplitude-modulated signal; means for multiplying the amplitude-modulated signal and the synchronizing signal to provide a multiplication output; and means for extracting only a low frequency component from said multiplication output, said low frequency component being below twice a frequency of said carrier of said amplitude-modulated signal, and said low frequency component being indicative of said random noise level.
Claim 7
Dependent Claim
98 words
A random noise detecting system for detecting a random noise level in an amplitude-modulated signal which is band limited and which contains random noise, comprising: means for producing a synchronizing signal π/2 out of phase with a carrier of the amplitude-modulated signal; means for multiplying the amplitude-modulated signal and the synchronizing signal to provide a multiplication output; and means for extracting only a low frequency component from said multiplication output, said low frequency component being below twice a frequency of said carrier of said amplitude-modulated signal, and said low frequency component being indicative of said random noise level.
Claim 8
Dependent Claim
20 words
The random noise detecting system of claim 5, wherein said means for producing said synchronizing signal comprises a phase-locked loop.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-07-19 | 1992-01-18 | 1992-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-19 | 1996-01-18 | 1996-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-19 | 2000-01-18 | 2000-07-19 | $7700.00 | Window Closed / Lapsed |