US4755795A
Expired / Lapsed
US
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Adaptive sample rate based on input signal bandwidth
Assignee: HP Inc
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Filing: 1986-10-31
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Granted: 1988-07-05
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Expires: 2006-10-31
Abstract
Abstract A method and apparatus selects an appropriate sampling rate for an input signal based on a dynamic measurement of the bandwidth of the signal. In the preferred embodiment, the bandwidth of the input signal is determined by comparing the power of the entire input signal with the power of the input signal within a selected bandwidth. A discrete Fourier transform is used to perform the bandwidth analysis.
Inventors
- 👤 Richard W. Page
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:45
CPC Classifications
H; H03; H03H; H03H17/00; H03H17/02; H03H17/0294; G; G01; G01R; G01R23/00; G01R23/16; G01R23/165; H03H17/04; H03H17/0416; H03H17/0427; H03H17/0438; H03H17/045
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
157 words
Apparatus for compressing a digital input signal by sampling the signal at a variable rate based on the bandwidth of the signal, comprising: means for receiving the digital input signal and sampling the digital input signal at one of a plurality of sampling rates; means responsive to the digital input signal for making a sample by sample estimate of the instantaneous bandwidth of the signal, by comparing the power of the entire input signal with the power of the input signal within a selected bandwidth by applying a short-time discrete Fourier transform to the digital input signal, and for producing an output signal if the power of the entire input signal is greater than the power of the input signal within the selected bandwidth by more than a predetermined amount; means responsive to the output signal of the power comparing means for causing the sampling means to sample the digital input signal at a lower sampling rate.
Claim 2
Dependent Claim
157 words
Apparatus for compressing a digital input signal by sampling the signal at a variable rate based on the bandwidth of the signal, comprising: means for receiving the digital input signal and sampling the digital input signal at one of a plurality of sampling rates; means responsive to the digital input signal for making a sample by sample estimate of the instantaneous bandwidth of the signal, by comparing the power of the entire input signal with the power of the input signal within a selected bandwidth by applying a short-time discrete Fourier transform to the digital input signal, and for producing an output signal if the power of the entire input signal is greater than the power of the input signal within the selected bandwidth by more than a predetermined amount; means responsive to the output signal of the power comparing means for causing the sampling means to sample the digital input signal at a lower sampling rate.
Claim 3
Dependent Claim
51 words
The apparatus of claim 1 wherein the digital input signal comprises the output data stream from an analog to digital converter, and the sampling means resamples the output signal at one of a plurality of sampling rates, lower than or equal to the sampling rate of the analog to digital converter.
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) | 1991-07-05 | 1992-01-04 | 1992-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-05 | 1996-01-04 | 1996-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-05 | 2000-01-04 | 2000-07-05 | $7700.00 | Window Closed / Lapsed |