US3584309A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and means for compensating amplitude and time drifts in sampled waveform systems
Assignee: Unisys Corp
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Filing: 1969-07-23
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Granted: 1971-06-08
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Expires: 1989-07-23
Abstract
Abstract Method and means for compensating amplitude and time drifts in sampled waveform systems utilizing a nonsequential scanning pattern of the sampling gate thereby achieving long term averaging for noise reduction. A first sample of the magnitude of the waveform is obtained at a sampling time established with respect to a time base synchronized to the waveform, which sample is taken on a portion of the waveform having zero slope. A second sample thereof is obtained with respect to the time base on a portion of the waveform having a slope of relatively large magnitude with respect to zero slope. The difference between the magnitudes of the waveform obtained during the two sampling times is stored thereby providing a reference by which subsequently occurring time drifts may be compensated. Prior to obtaining each subsequent sample of the waveform, samples are obtained at the two reference sampling times and the difference is obtained between the magnitudes sampled thereat and compared to the stored reference. The error signal provided thereby is utilized to compensate the sampling time of the subsequent sample for time drift. The subsequent sample is compensated for amplitude drift by subtracting the magnitude of the waveform obtained at the zero slope reference sampling time from the magnitude obtained during the subsequent sampling time. The timing drift error signal obtained is also utilized to compensate the two reference sampling times when obtaining subsequent reference samples of the waveform.
Inventors
- 👤 Alexander M Nicolson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:35
CPC Classifications
G; G01; G01R; G01R13/00; G01R13/20; G01R13/22; G01R13/34; G01R13/342
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
198 words
Apparatus for compensating amplitude and time drifts in sampled waveform systems having a time base established with respect to said waveform, said apparatus comprising first, second and third sampling means responsive to said waveform for providing samples of the magnitude of said waveform at first, second and third sampling times with respect to said time base, respectively, first subtraction means responsive to said first and second sampling means for providing a first signal representative of the difference between said magnitudes sampled at said first and second sampling times, reference means for storing an initail value of said first signal, second subtraction means responsive to said first subtraction means and said reference means for providing an error signal representative of the difference between said first signal and said stored initial value thereof, adjusting means responsive to said second subtraction means for adjusting said first, second and third sampling times, in accordance with said error signal, and third subtraction means responsive to said first and third sampling means for providing a signal representative of the difference between said magnitudes sampled at said first and third adjusted sampling times thereby providing a signal representative of a compensated sample of said waveform.
Claim 2
Dependent Claim
198 words
Apparatus for compensating amplitude and time drifts in sampled waveform systems having a time base established with respect to said waveform, said apparatus comprising first, second and third sampling means responsive to said waveform for providing samples of the magnitude of said waveform at first, second and third sampling times with respect to said time base, respectively, first subtraction means responsive to said first and second sampling means for providing a first signal representative of the difference between said magnitudes sampled at said first and second sampling times, reference means for storing an initail value of said first signal, second subtraction means responsive to said first subtraction means and said reference means for providing an error signal representative of the difference between said first signal and said stored initial value thereof, adjusting means responsive to said second subtraction means for adjusting said first, second and third sampling times, in accordance with said error signal, and third subtraction means responsive to said first and third sampling means for providing a signal representative of the difference between said magnitudes sampled at said first and third adjusted sampling times thereby providing a signal representative of a compensated sample of said waveform.
Claim 3
Dependent Claim
50 words
Apparatus of the character recited in claim 1 further including first, second and third positioning means for providing first, second and third positioning signals respectively whose respective coactions with said time base provide signals determinant respectively of said first, second and third sampling times with respect to said time base.
Claim 4
Dependent Claim
51 words
Apparatus of the character recited in claim 2 further including switching means for sequentially coupling said first, second and third positioning signals into coaction with said time base, and triggering means synchronized with said switching means for sequentially providing actuating trigger signals to said first, second and third sampling means respectively.
Claim 5
Dependent Claim
25 words
Apparatus of the character recited in claim 2 further including means for incrementing said third positioning signal thereby to provide adjacent samples of said waveform.
Claim 6
Dependent Claim
58 words
Apparatus of the character recited in claim 2 in which said adjusting means includes integrating means responsive to said error signal for integrating said error signal thereby providing a feedback signal, and combining means responsive to said feedback signal and said positioning signals for combining said feedback signal with said positioning signals thereby to reduce said error signal.
Claim 7
Dependent Claim
42 words
Apparatus of the character recited in claim 5 in which said adjusting means further includes inverting means for selectively inverting the polarity of said feedback signal in accordance with the polarity of the slope of said waveform at said second sampling time.
Claim 8
Independent Claim
214 words
A method for compensating amplitude and time drifts in sampled waveform systems having a time base with respect to said waveform, said method comprising the steps of sampling the magnitude of said waveform at a first sampling time with respect to said time base, sampling the magnitude of said waveform at a second sampling time with respect to said time base, obtaining the difference between said magnitudes sampled at said first and second sampling times respectively thereby providing a first signal representative of the difference therebetween, resampling the magnitudes of said waveform at said first and second sampling times, respectively, obtaining the difference between said magnitude resampled at said first and second sampling times, respectively, thereby providing a second signal representative of the difference therebetween, obtaining the difference between said first and second signals thereby providing an error signal representative of the difference therebetween, generating a feedback signal in accordance with said error signal, sampling the magnitude of said waveform at a third sampling time with respect to said time base, said third sampling time being adjusted in accordance with said feedback signal, and obtaining the difference between said magnitude sampled at said third sampling time and said magnitude resampled at said first sampling time thereby providing a first compensated sample of said waveform.
Claim 9
Independent Claim
214 words
A method for compensating amplitude and time drifts in sampled waveform systems having a time base with respect to said waveform, said method comprising the steps of sampling the magnitude of said waveform at a first sampling time with respect to said time base, sampling the magnitude of said waveform at a second sampling time with respect to said time base, obtaining the difference between said magnitudes sampled at said first and second sampling times respectively thereby providing a first signal representative of the difference therebetween, resampling the magnitudes of said waveform at said first and second sampling times, respectively, obtaining the difference between said magnitude resampled at said first and second sampling times, respectively, thereby providing a second signal representative of the difference therebetween, obtaining the difference between said first and second signals thereby providing an error signal representative of the difference therebetween, generating a feedback signal in accordance with said error signal, sampling the magnitude of said waveform at a third sampling time with respect to said time base, said third sampling time being adjusted in accordance with said feedback signal, and obtaining the difference between said magnitude sampled at said third sampling time and said magnitude resampled at said first sampling time thereby providing a first compensated sample of said waveform.
Claim 10
Dependent Claim
162 words
A method of the character recited in claim 7 further including the steps of sampling the magnitudes of said waveform at adjusted first and second sampling times, respectively, said first and second sampling times being adjusted in accordance with said feedback signal, obtaining the difference between said magnitudes sampled at said adjusted first and second sampling times respectively thereby providing a new second signal representative of the difference therebetween, obtaining the difference between said first signal and said new second signal thereby providing a new error signal representative of the difference therebetween, combining said new error signal with said feedback signal, sampling the magnitude of said waveform at a fourth sampling time with respect to said time base, said fourth sampling time being adjusted in accordance with said feedback signal, and obtaining the difference between said magnitude sampled at said fourth sampling time and said magnitude sampled at said adjusted first sampling time thereby providing a second compensated sample of said waveform.
Claim 11
Dependent Claim
96 words
A method of the character recited in claim 7 in which said step of sampling the magnitude of said waveform at a first sampling time includes the step of selecting said first sampling time whereby said waveform is sampled on a portion thereof having a slope of small magnitude, and said step of sampling the magnitude of said waveform at a second sampling time includes the step of selecting said second sampling time whereby said waveform is sampled on a portion thereof having a slope of large magnitude with respect to said slope of small magnitude.
Claim 12
Dependent Claim
43 words
A method of the character recited in claim 9 in which said step of selecting said first sampling time comprises the step of selecting said first sampling time whereby said waveform is sampled on a portion thereof having a slope of zero magnitude.
Claim 13
Dependent Claim
60 words
A method of the character recited in claim 8 in which said step of sampling the magnitudes of said waveform at adjusted first and second sampling times comprises the step of sampling the magnitudes of said waveform at adjusted first second sampling times respectively wherein said first and second sampling times are adjusted thereby to reduce said new error signal.
Claim 14
Dependent Claim
31 words
A method of the character recited in claim 7 in which said step of generating a feedback signal comprises the step of integrating said error signal thereby providing said feedback signal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-07 | 1974-12-07 | 1975-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-07 | 1978-12-07 | 1979-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-07 | 1982-12-07 | 1983-06-08 | $7700.00 | Window Closed / Lapsed |