US3875328A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for measuring the signal to noise ratio for a periodic signal
Assignee: RCA Corp
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Filing: 1973-08-03
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Granted: 1975-04-01
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Expires: 1993-08-03
Abstract
Abstract Apparatus for measuring the signal-to-noise ratio of a television signal wherein the noise and signal level of the signal are derived from the on-the-air television signal horizontal sync pulses. The noise is derived by sampling the sync pulses and bandpass filtering the samples, while the signal level is derived by D.C. filtering the sync pulse samples. The signalto-noise ratio is the ratio between the derived signals which ratio is provided by a suitably calibrated meter.
Inventors
- 👤 John James Gibson
- 👤 Hans George Schwarz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:42
CPC Classifications
H; H04; H04N; H04N17/00; G; G01; G01R; G01R29/00; G01R29/26
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
163 words
An apparatus for measuring the signal to noise ratio of a periodic input signal, comprising: cycle sampling means for sampling solely the same certain portion of each cycle of a sufficient number of cycles of said input signal to thereby provide as an output thereof a signal comprising a plurality of input signal samples whose average value manifests the average peak level of said input signal and whose standard deviation value manifests the magnitude of the noise in said input signal, means for deriving from said output signal applied as an input thereto a first D.C. signal having a value manifesting said average value and a second D.C. signal having a value manifesting said standard deviation value, and means responsive to said first and second signals applied as respective inputs thereto for comparing the value of said first signal to the value of said second signal to thereby provide an output signal therefrom manifesting the signal to noise ratio of said input signal.
Claim 2
Independent Claim
163 words
An apparatus for measuring the signal to noise ratio of a periodic input signal, comprising: cycle sampling means for sampling solely the same certain portion of each cycle of a sufficient number of cycles of said input signal to thereby provide as an output thereof a signal comprising a plurality of input signal samples whose average value manifests the average peak level of said input signal and whose standard deviation value manifests the magnitude of the noise in said input signal, means for deriving from said output signal applied as an input thereto a first D.C. signal having a value manifesting said average value and a second D.C. signal having a value manifesting said standard deviation value, and means responsive to said first and second signals applied as respective inputs thereto for comparing the value of said first signal to the value of said second signal to thereby provide an output signal therefrom manifesting the signal to noise ratio of said input signal.
Claim 3
Dependent Claim
28 words
The apparatus of claim 1 wherein said deriving means includes a low pass filter for deriving said first signal and a bandpass filter for deriving said second signal.
Claim 4
Dependent Claim
27 words
The apparatus of claim 1 wherein said input signal has a timing portion and an information portion, said cycle sampling means being synchronized with said timing portion.
Claim 5
Dependent Claim
26 words
The apparatus of claim 1 wherein said input signal is a television signal and said certain portion is the horizontal synchronizing portion of said television signal.
Claim 6
Dependent Claim
45 words
The apparatus of claim 1 wherein said input signal includes a timing portion, SAID cycle sampling means including means for deriving said timing portion from said input signal and means responsive to said derived timing portion for synchronizing said sampling means to said input signal.
Claim 7
Independent Claim
156 words
An apparatus for measuring the signal to noise ratio of a television signal including a timing portion and a video portion comprising: cycle sampling means for sampling solely the timing portion of each cycle of a sufficient proportion of cycles of said television signal to thereby provide as an output thereof a signal comprising a plurality of timing portion samples whose average value manifests the average peak level of said television signal and whose standard deviation value manifests the magnitude of the noise in said television signal, means for deriving from said output signal a first signal having a value proportional ot said average value and a second signal having a value proportional to said standard deviation value, and means responsive to said first and second signals for comparing the value of first signal to said second signal, the ratio between said first and second signals manifesting the signal to noise ratio of said television signal.
Claim 8
Independent Claim
156 words
An apparatus for measuring the signal to noise ratio of a television signal including a timing portion and a video portion comprising: cycle sampling means for sampling solely the timing portion of each cycle of a sufficient proportion of cycles of said television signal to thereby provide as an output thereof a signal comprising a plurality of timing portion samples whose average value manifests the average peak level of said television signal and whose standard deviation value manifests the magnitude of the noise in said television signal, means for deriving from said output signal a first signal having a value proportional ot said average value and a second signal having a value proportional to said standard deviation value, and means responsive to said first and second signals for comparing the value of first signal to said second signal, the ratio between said first and second signals manifesting the signal to noise ratio of said television signal.
Claim 9
Dependent Claim
28 words
The apparatus of claim 6 wherein said cycle sampling means includes detecting means responsive to said television signal applied thereto for detecting the envelope of said television signal.
Claim 10
Dependent Claim
42 words
The apparatus of claim 6 wherein said cycle sampling means includes means for deriving a timing signal from said television signal, cycle said sampling means being responsive to said derived timing signal for synchronously sampling said timing portion of said television signal.
Claim 11
Dependent Claim
48 words
The apparatus of claim 6 wherein said second signal deriving means includes a bandpass filter and means for providing as an output signal therefrom a signal having a D.C. level manifesting the rms noise level of said sampled timing portion applied as an input to said bandpass filter.
Claim 12
Dependent Claim
26 words
The apparatus of claim 6 wherein said first signal deriving means includes a low pass filter having said timing portion samples applied as an input thereto.
Claim 13
Independent Claim
212 words
An apparatus for measuring the signal to noise ratio of a television signal including a timing portion having a given repetition rate and information portion, comprising: detecting means for detecting said television signal to produce as an output thereof a signal manifesting the envelope of said television signal, timing signal generating means for generating a timing signal having a repetition rate the same as said given repetition rate, cycle sampling means responsive to said detected television signal and said timing signal applied as inputs thereto for sampling the timing portion of said detected television signal, filter means, means for applying said sampled timing portion of said television signal to said filter means, said filter means providing at an ouput thereof in response to said detected signal applied as an input thereto a first signal having a value manifesting the average peak level of said timing portion of said television signal and a second signal having a value manifesting the magnitude of the noise in said timing portion of said television signal, and comparision means responsive to said first and second signals applied as input signals thereto for providing a third signal at an output thereof having a value manifesting the ratio of the value of said first signal to said second signal.
Claim 14
Independent Claim
212 words
An apparatus for measuring the signal to noise ratio of a television signal including a timing portion having a given repetition rate and information portion, comprising: detecting means for detecting said television signal to produce as an output thereof a signal manifesting the envelope of said television signal, timing signal generating means for generating a timing signal having a repetition rate the same as said given repetition rate, cycle sampling means responsive to said detected television signal and said timing signal applied as inputs thereto for sampling the timing portion of said detected television signal, filter means, means for applying said sampled timing portion of said television signal to said filter means, said filter means providing at an ouput thereof in response to said detected signal applied as an input thereto a first signal having a value manifesting the average peak level of said timing portion of said television signal and a second signal having a value manifesting the magnitude of the noise in said timing portion of said television signal, and comparision means responsive to said first and second signals applied as input signals thereto for providing a third signal at an output thereof having a value manifesting the ratio of the value of said first signal to said second signal.
Claim 15
Dependent Claim
73 words
The apparatus of claim 11 wherein said filter means includes a D. C. filter and a bandpass filter and; said comparison means includes a D.C. meter selectively coupled to said D.C. filter and said bandpass filter, said apparatus further includes means for selectively setting the value of said first signal to a certain value, said meter providing an indication of the ratio of the value of said second signal to said certain value.
Claim 16
Dependent Claim
33 words
The apparatus of claim 11 having a certain noise FIGURE and further including noisE compensation means coupled to said detecting means to compensate for the value of said certain noise in said apparatus.
Claim 17
Dependent Claim
210 words
In combination: An input terminal for receiving a transmitted television signal, signal detecting means for detecting said television signal, a settable attenuator connected between said input terminal and said detecting means, cycle sampling means for sampling solely the same certain portion of each cycle of a sufficient proportion of cycles of said television signal to thereby provide as an output thereof a signal having an average value manifesting the average peak level of said television signal and a standard deviation value manifesting the magnitude of the noise in said television signal, a low pass filter, a bandpass filter, a pulse stretch circuit coupled between said sampling means and said filters for stretching each of said sample portions and applying said stretched portions to said filters, means responsive to a signal passed to said bandpass filter for producing a D.C. signal having a value manifesting the magnitude of the standard deviation of said sampled portion when said bandpassed signal is applied thereto, and indicating means coupled to the last mentioned means and to said low pass filter for providing an indication of the signal to noise ratio of said television signal by comparing the value of the signal passed by said low pass filter and the value of said D.C. signal.
Claim 18
Dependent Claim
210 words
In combination: An input terminal for receiving a transmitted television signal, signal detecting means for detecting said television signal, a settable attenuator connected between said input terminal and said detecting means, cycle sampling means for sampling solely the same certain portion of each cycle of a sufficient proportion of cycles of said television signal to thereby provide as an output thereof a signal having an average value manifesting the average peak level of said television signal and a standard deviation value manifesting the magnitude of the noise in said television signal, a low pass filter, a bandpass filter, a pulse stretch circuit coupled between said sampling means and said filters for stretching each of said sample portions and applying said stretched portions to said filters, means responsive to a signal passed to said bandpass filter for producing a D.C. signal having a value manifesting the magnitude of the standard deviation of said sampled portion when said bandpassed signal is applied thereto, and indicating means coupled to the last mentioned means and to said low pass filter for providing an indication of the signal to noise ratio of said television signal by comparing the value of the signal passed by said low pass filter and the value of said D.C. signal.
Claim 19
Independent Claim
140 words
A method for measuring the signal to noise ratio of a periodic input signal, comprising: sampling solely the same certain portion of each cycle of a sufficient proportion of cycles of said input signal to thereby provide as an output thereof a signal comprising a plurlity of input signal samples whose average value manifests the average peak level of said input signal and whose standard deviation value manifests the magnitude of the noise of the input signal, deriving from said output signal applied as an input thereto a first signal having a value manifesting said average value and a second signal having a value manifesting said standard deviation value, and comparing the value of said first signal to the value of said second signal to thereby provide an output signal manifesting the signal to noise ratio of said input signal.
Claim 20
Independent Claim
140 words
A method for measuring the signal to noise ratio of a periodic input signal, comprising: sampling solely the same certain portion of each cycle of a sufficient proportion of cycles of said input signal to thereby provide as an output thereof a signal comprising a plurlity of input signal samples whose average value manifests the average peak level of said input signal and whose standard deviation value manifests the magnitude of the noise of the input signal, deriving from said output signal applied as an input thereto a first signal having a value manifesting said average value and a second signal having a value manifesting said standard deviation value, and comparing the value of said first signal to the value of said second signal to thereby provide an output signal manifesting the signal to noise ratio of said input signal.
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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) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |