US4297533A
Expired / Lapsed
US
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Detector to determine the presence of an electrical signal in the presence of noise of predetermined characteristics
Assignee: Siemens Building Technologies AG
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Filing: 1979-06-07
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Granted: 1981-10-27
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Expires: 1999-06-07
Abstract
Abstract A detector for determining the presence of an electrical signal in the presence of noise, the electrical signal having at least two predetermined characteristics, includes a signal transforming device for obtaining a plurality of independent estimates of each characteristic, a classification device connected to the signal transforming device for sorting the plurality of independent estimates into at least two classes, and a counting device for signaling the presence of the electrical signal, when the number of the estimates within one class exceeds a predetermined number.
Inventors
- 👤 Jean-Gabriel Gander
- 👤 Ralph Aubert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:36
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/0038; G01R19/165; G01R19/17
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
95 words
A detector for determining the presence of an electrical signal in the form of a tone in the presence of noise, said electrical signal having at least two predetermined characteristics, comprising in combination: signal transforming means for obtaining a plurality of independent estimates of each of said characteristics, classification means connected to said signal transforming means for sorting said plurality of independent estimates into at least two classes, respectively, and counting means for signaling the presence of said electrical signal when the number of said estimates within one of said classes exceeds a predetermined number.
Claim 2
Dependent Claim
95 words
A detector for determining the presence of an electrical signal in the form of a tone in the presence of noise, said electrical signal having at least two predetermined characteristics, comprising in combination: signal transforming means for obtaining a plurality of independent estimates of each of said characteristics, classification means connected to said signal transforming means for sorting said plurality of independent estimates into at least two classes, respectively, and counting means for signaling the presence of said electrical signal when the number of said estimates within one of said classes exceeds a predetermined number.
Claim 3
Dependent Claim
122 words
A detector for determining the presence of an electrical signal in the form of a tone in the presence of noise, said electrical signal having at least two predetermined characteristics, comprising in combination: signal transforming means for obtaining a plurality of independent estimates of each of said characteristics, classification means connected to said signal transforming means for sorting said plurality of independent estimates into at least two classes, respectively, and counting means for signaling the presence of said electrical signal when the number of said estimates within one of said classes exceeds a first predetermined number, and for signaling the absence of said electrical signal when the number of said estimates within the other of said classes exceeds a second predetermined number.
Claim 4
Dependent Claim
122 words
A detector for determining the presence of an electrical signal in the form of a tone in the presence of noise, said electrical signal having at least two predetermined characteristics, comprising in combination: signal transforming means for obtaining a plurality of independent estimates of each of said characteristics, classification means connected to said signal transforming means for sorting said plurality of independent estimates into at least two classes, respectively, and counting means for signaling the presence of said electrical signal when the number of said estimates within one of said classes exceeds a first predetermined number, and for signaling the absence of said electrical signal when the number of said estimates within the other of said classes exceeds a second predetermined number.
Claim 5
Dependent Claim
61 words
A detector as claimed in claim 1 or 2, wherein said electrical signal includes a tone signal, and said characteristics include the three characteristic features of output level, frequency, and power spectrum of said tone signal, and said classification means sorts said plurality of independent estimates of at least two of said three characteristic features into said at least two classes.
Claim 6
Dependent Claim
61 words
A detector as claimed in claim 1 or 2, wherein said electrical signal includes an input signal having a DC component, and wherein said predetermined characteristics include the three characteristic features of output level, bandwidth, and time derivative of said input signal, and wherein said signal transforming means obtains at least two of said three characteristic features of said predetermined characteristics.
Claim 7
Dependent Claim
30 words
A detector as claimed in claim 1 or 2, further comprising a microprocessor, said microprocessor forming at least a portion of said signal transforming means, and of said classification means.
Claim 8
Dependent Claim
87 words
A detector as claimed in claim 3, wherein said tone signal includes a tone frequency having a complex envelope Z(t), and wherein Z(t) is the time derivative of said complex envelope, and wherein said signal transforming means obtains said frequency from the imaginary portion of the quotient of the time derivative of said complex envelope divided by said complex envelope ##EQU8## and obtains said spectral density from the real portion of the quotient of the time derivative of said complex envelope divided by said complex envelope ##EQU9##
Claim 9
Dependent Claim
102 words
A detector as claimed in claim 6, wherein said signal transforming means includes a first multiplier means for forming a product of said frequency of said tone signal z(t) and a first sinusoidal reference frequency, (cos ω o t) and a second multiplier means for forming a product of said frequency of said tone signal z(t) and a second sinusoidal reference frequency (sin ω o t) shifted by 90° with respect to said first sinusoidal reference frequency, and further comprising means postcoupled to each of said multiplier means for de-emphasizing high frequencies in the output of each of said multiplier means, respectively.
Claim 10
Dependent Claim
22 words
A detector as claimed in claim 7, wherein the means postcoupled to each of said multiplier means include a low-pass frequency filter.
Claim 11
Dependent Claim
20 words
A detector as claimed in claim 7, wherein the means postcoupled to each of said multiplier means include an integrator.
Claim 12
Dependent Claim
27 words
A detector as claimed in claim 7, wherein said multiplier means are digital multiplier means, and further comprising digital signal generating means for generating said reference frequencies.
Claim 13
Dependent Claim
76 words
A detector as claimed in claim 1 or 2, for determining the presence of, and differentiating between at least two electrical signals having different respective characteristics, and wherein said classification means sorts said plurality of estimates into at least two classes corresponding to said different respective characteristics, and whereby, when the number of said estimates with a respective class exceeds a predetermined number, said detector signals the presence of the signal corresponding to said respective class.
Claim 14
Dependent Claim
87 words
A detector as claimed in claim 2, wherein said tone signal includes a tone frequency having a complex envelope Z(t), and wherein Z(t) is the time derivative of said complex envelope, and wherein said signal transforming means obtains said frequency from the imaginary portion of the quotient of the time derivative of said complex envelope divided by said complex envelope ##EQU10## and obtains said power spectrum from the real portion of the quotient of the time derivative of said complex envelope divided by said complex envelope ##EQU11##
Claim 15
Dependent Claim
102 words
A detector as claimed in claim 12, wherein said signal transforming means includes a first multiplier means for forming a product of said frequency of said tone signal z(t) and a first sinusoidal reference frequency, (cos w o t) and a second multiplier means for forming a product of said frequency of said tone signal z(t) and a second sinusoidal reference frequency (sin w o t) shifted by 90° with respect to said first sinusoidal reference frequency, and further comprising means postcoupled to each of said multiplier means for de-emphasizing high frequencies in the output of each of said multiplier means, respectively.
Claim 16
Dependent Claim
22 words
A detector as claimed in claim 13, wherein the means postcoupled to each of said multiplier means include a low-pass frequency filter.
Claim 17
Dependent Claim
20 words
A detector as claimed in claim 13, wherein the means postcoupled to each of said multiplier means include an integrator.
Claim 18
Dependent Claim
27 words
A detector as claimed in claim 13, wherein said multiplier means are digital multiplier means, and further comprising digital signal generating means for generating said reference frequencies.
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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) | 1984-10-26 | 1985-04-27 | 1985-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-26 | 1989-04-27 | 1989-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-26 | 1993-04-27 | 1993-10-27 | $7700.00 | Window Closed / Lapsed |