US5161185A
Expired / Lapsed
US
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Method and apparatus for reducing noise in a digital voltage signal
Assignee: Texas Instruments Inc
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Filing: 1992-03-11
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Granted: 1992-11-03
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Expires: 2012-03-11
Abstract
Abstract A method and circuitry for reducing noise is provided. The circuit receives a digital data signal at its input (26). The signal is input to a magnitude evaluator (28) and a pass/squelch circuit (30). Magnitude evaluator (28) samples the digital signal and controls an integrator (36) according to the magnitude of each of the samples. Integrator (36) averages the magnitudes over time. If the signal is a noise signal, integrator (36) toggles a switch (40) to activate pass/squelch circuit (30) to squelch the digital data at its input (29). If the signal is a valid signal, then integrator (36) toggles switch (40) to deactivate pass/squelch circuit (30) to allow the digital data to pass therethrough to destination device (44).
Inventors
- 👤 James R. Hochschild
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 00:32
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/20; H03G3/30; H03G3/34; H03G3/344; H03M; H03M1/00; H03M1/06; H03M1/08; H04; H04B; H04B1/00; H04B1/06; H04B1/10; H04B1/1027; H03M1/12
Claims Analysis
Total Claims: 63
Claim 1
Independent Claim
77 words
A method of reducing noise in a digital voltage signal directed to a destination device, comprising: digitally evaluating the magnitude of the digital voltage signal to obtain an evaluated magnitude; digitally integrating the evaluated magnitude at an integration frequency and over a predetermined time period to generate an average value; and substituting a null voltage signal for the digital voltage signal to the destination device if the average value is within a first predetermined range of magnitude.
Claim 2
Independent Claim
77 words
A method of reducing noise in a digital voltage signal directed to a destination device, comprising: digitally evaluating the magnitude of the digital voltage signal to obtain an evaluated magnitude; digitally integrating the evaluated magnitude at an integration frequency and over a predetermined time period to generate an average value; and substituting a null voltage signal for the digital voltage signal to the destination device if the average value is within a first predetermined range of magnitude.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein the first predetermined range of magnitude is any magnitude range below approximately -6 0 dBm.
Claim 4
Dependent Claim
30 words
The method of claim 1 and further comprising outputting the digital voltage signal to the destination device if the average value is not within the first predetermined range of magnitude.
Claim 5
Dependent Claim
20 words
The method of claim 3 wherein the first predetermined range of magnitude is any magnitude range below approximately -60 dBm.
Claim 6
Dependent Claim
44 words
The method of claim 1 and further comprising: disabling said integrating step if the value of said evaluated magnitude exceeds the value of a predetermined threshold; and coupling the digital voltage signal to the destination device without the passage of said predetermined time period.
Claim 7
Dependent Claim
13 words
The method of claim 5 wherein the predetermined threshold is approximately -52 dBm.
Claim 8
Dependent Claim
15 words
The method of claim 1 wherein said integrating step is synchronous with said evaluating step.
Claim 9
Dependent Claim
15 words
The method of claim 3 wherein said substituting step is synchronous with said integrating step.
Claim 10
Dependent Claim
15 words
The method of claim 3 wherein said connecting step is synchronous with said integrating step.
Claim 11
Dependent Claim
19 words
The method of claim 3 wherein said integrating step occurs at a sufficient delay time following said evaluating step.
Claim 12
Dependent Claim
33 words
The method of claim 1 wherein the digital voltage signal comprises a plurality of bits and said evaluating step comprises evaluating a selected group of most significant bits of the digital voltage signal.
Claim 13
Dependent Claim
21 words
The method of claim 11 wherein said selected group of most significant bits comprises bits 2-7 of the digital voltage signal.
Claim 14
Dependent Claim
42 words
The method of claim 3 wherein said integrating step comprises: incrementing a counter when an evaluated magnitude is within the first predetermined range of magnitude; and decrementing the counter when an evaluated magnitude is not within the first predetermined range of magnitude.
Claim 15
Dependent Claim
26 words
The method of claim 13 wherein the average value is within the first predetermined range of magnitude if the counter is within a first count range.
Claim 16
Dependent Claim
16 words
The method of claim 14 wherein the first count range is from six to seven counts.
Claim 17
Dependent Claim
30 words
The method of claim 13 wherein the counter is a three bit counter, and the average value is within the first predetermined range of magnitude if the count equals seven.
Claim 18
Dependent Claim
27 words
The method of claim 13 wherein the average value is not within the first predetermined range of magnitude if the counter is within a second count range.
Claim 19
Dependent Claim
16 words
The method of claim 17 wherein the second count range is from zero to one counts.
Claim 20
Dependent Claim
31 words
The method of claim 13 wherein the counter is a three bit counter, and the average value is not within the first predetermined range of magnitude if the count equals zero.
Claim 21
Independent Claim
127 words
A method of reducing noise in a telephone communications channel voltage signal, the voltage signal passing through an amplifier, filter and an A/D converter to obtain a digital voltage signal directed to a destination device, comprising: digitally evaluating the magnitude of the digital voltage signal to obtain an evaluated magnitude; digitally integrating the evaluated magnitude at an integration frequency and over a predetermined time period to generate an average value; coupling a null voltage signal to the destination device if the average value is within a first predetermined range of magnitude, the null voltage signal being generated over a second predetermined range of magnitude; and coupling the digital voltage signal to the destination device if the average value is not within the first predetermined range of magnitude.
Claim 22
Independent Claim
127 words
A method of reducing noise in a telephone communications channel voltage signal, the voltage signal passing through an amplifier, filter and an A/D converter to obtain a digital voltage signal directed to a destination device, comprising: digitally evaluating the magnitude of the digital voltage signal to obtain an evaluated magnitude; digitally integrating the evaluated magnitude at an integration frequency and over a predetermined time period to generate an average value; coupling a null voltage signal to the destination device if the average value is within a first predetermined range of magnitude, the null voltage signal being generated over a second predetermined range of magnitude; and coupling the digital voltage signal to the destination device if the average value is not within the first predetermined range of magnitude.
Claim 23
Dependent Claim
20 words
The method of claim 20 wherein the first predetermined range of magnitude is any magnitude less than approximately -60 dBm.
Claim 24
Dependent Claim
45 words
The method of claim 20 and further comprising disabling said integrating step if the value of said evaluated magnitude exceeds the value of a predetermined threshold so that the digital voltage signal will reach the destination device without the passage of said predetermined time period.
Claim 25
Dependent Claim
13 words
The method of claim 22 wherein the predetermined threshold is approximately -52 dBm.
Claim 26
Dependent Claim
16 words
The method of claim 20 wherein said integrating step is synchronous with said evaluating step .
Claim 27
Dependent Claim
34 words
The method of claim 20 wherein the digital voltage signal is provided by an analog-to-digital converter, and said evaluating step comprises evaluating a selected group of most significant bits of the digital voltage signal.
Claim 28
Dependent Claim
21 words
The method of claim 25 wherein the selected group of most significant bits comprises bits 2-7 of the digital voltage signal.
Claim 29
Dependent Claim
42 words
The method of claim 20 wherein said integrating step comprises: incrementing a counter when an evaluated magnitude is within the first predetermined range of magnitude; and decrementing the counter when an evaluated magnitude is not within the first predetermined range of magnitude.
Claim 30
Dependent Claim
31 words
The method of claim 27 wherein the average value is within the first predetermined range of magnitude if the counter is within a first count range from six to seven counts.
Claim 31
Dependent Claim
30 words
The method of claim 27 wherein the counter is a three bit counter, and the average value is within the first predetermined range of magnitude if the count equals seven.
Claim 32
Dependent Claim
32 words
The method of claim 27 wherein the average value is not within the first predetermined range of magnitude if the counter is within a second count range from zero to one counts.
Claim 33
Dependent Claim
31 words
The method of claim 27 wherein the counter is a three bit counter, and the average value is not within the first predetermined range of magnitude if the count equals zero.
Claim 34
Independent Claim
103 words
A method of forming circuitry for reducing noise in a digital voltage signal directed to a destination device, comprising: forming a digital magnitude evaluator for evaluating the magnitude of a digital voltage signal; forming a digital integrator for integrating the evaluated magnitude at an integration frequency and over a predetermined time period to generate an average value; and forming a digital squelch circuit for substituting a null voltage signal for the digital voltage signal to the destination device if the average value is within a first predetermined range of magnitude, the null voltage signal being generated over a second predetermined range of magnitude.
Claim 35
Independent Claim
103 words
A method of forming circuitry for reducing noise in a digital voltage signal directed to a destination device, comprising: forming a digital magnitude evaluator for evaluating the magnitude of a digital voltage signal; forming a digital integrator for integrating the evaluated magnitude at an integration frequency and over a predetermined time period to generate an average value; and forming a digital squelch circuit for substituting a null voltage signal for the digital voltage signal to the destination device if the average value is within a first predetermined range of magnitude, the null voltage signal being generated over a second predetermined range of magnitude.
Claim 36
Dependent Claim
29 words
The method of claim 32 wherein said step of forming a squelch circuit comprises forming the first predetermined range of magnitude is any magnitude less than approximately -60 dBm.
Claim 37
Dependent Claim
35 words
The method of claim 32 and further comprising forming a pass circuit for connecting the digital voltage signal to the destination device if the average value is not within the first predetermined range of magnitude.
Claim 38
Dependent Claim
29 words
The method of claim 34 wherein said step of forming a squelch circuit comprises forming the first predetermined range of magnitude is any magnitude less than approximately -60 dBm.
Claim 39
Dependent Claim
45 words
The method of claim 32 and further comprising disabling said integrating step if the value of said evaluated magnitude exceeds the value of a predetermined threshold so that the digital voltage signal will reach the destination device without the passage of said predetermined time period.
Claim 40
Dependent Claim
20 words
The method of claim 36 wherein wherein said forming a circuit comprises setting the predetermined threshold at approximately -52 dBm.
Claim 41
Dependent Claim
41 words
The method of claim 32 wherein the digital voltage signal is provided by an analog-to-digital converter, and said step of forming the evaluator comprises forming an evaluator for evaluating a selected group of most significant bits of the digital voltage signal.
Claim 42
Dependent Claim
25 words
The method of claim 38 wherein said step of forming the evaluator comprises forming an evaluator for evaluating bits 2-7 of the digital voltage signal.
Claim 43
Dependent Claim
46 words
The method of claim 32 wherein said step of forming the integrator comprises forming a counter for incrementing when an evaluated magnitude is within the first predetermined range of magnitude and for decrementing when an evaluated magnitude is not within the first predetermined range of magnitude.
Claim 44
Dependent Claim
18 words
The method of claim 40 wherein said step of forming the counter comprises forming a three bit counter.
Claim 45
Dependent Claim
91 words
A circuit for reducing noise in a digital voltage signal directed to a destination device, comprising: circuitry for digital evaluating the magnitude of a digital voltage signal; circuitry for digitally integrating the evaluated magnitude at an integration frequency and over a predetermined time period to generate an average value; and circuitry for substituting a null voltage signal for the digital voltage signal to the destination device if the average value is within a first predetermined range of magnitude, the null voltage signal being generated over a second predetermined range of magnitude.
Claim 46
Dependent Claim
91 words
A circuit for reducing noise in a digital voltage signal directed to a destination device, comprising: circuitry for digital evaluating the magnitude of a digital voltage signal; circuitry for digitally integrating the evaluated magnitude at an integration frequency and over a predetermined time period to generate an average value; and circuitry for substituting a null voltage signal for the digital voltage signal to the destination device if the average value is within a first predetermined range of magnitude, the null voltage signal being generated over a second predetermined range of magnitude.
Claim 47
Dependent Claim
20 words
The circuit of claim 42 wherein the first predetermined range of magnitude is any magnitude less than approximately -60 dBm.
Claim 48
Dependent Claim
32 words
The circuit of claim 42 and further comprising circuitry for connecting the digital voltage signal to the destination device if the average value is not within the first predetermined range of magnitude.
Claim 49
Dependent Claim
20 words
The circuit of claim 44 wherein the first predetermined range of magnitude is any magnitude less than approximately -60 dBm.
Claim 50
Dependent Claim
45 words
The method of claim 42 and further comprising disabling said integrating step if the value of said evaluated magnitude exceeds the value of a predetermined threshold so that the digital voltage signal will reach the destination device without the passage of said predetermined time period.
Claim 51
Dependent Claim
13 words
The circuit of claim 46 wherein the predetermined threshold is approximately -52 dBm.
Claim 52
Dependent Claim
19 words
The circuit of claim 42 wherein said circuitry for integrating is for operating synchronous with said circuitry for evaluating.
Claim 53
Dependent Claim
23 words
The circuit of claim 44 wherein either said circuitry for substituting or said circuitry for connecting operates synchronous with said circuitry for integrating.
Claim 54
Dependent Claim
21 words
The circuit of claim 42 wherein said circuitry for integrating operates at a sufficient delay time following said circuitry for evaluating.
Claim 55
Dependent Claim
37 words
The circuit of claim 42 wherein the digital voltage signal is provided by an analog-to-digital converter, and said circuitry for evaluating comprises circuitry for evaluating a selected group of most significant bits of the digital voltage signal.
Claim 56
Dependent Claim
21 words
The circuit of claim 51 wherein the selected group of most significant bits comprises bits 2-7 of the digital voltage signal.
Claim 57
Dependent Claim
43 words
The circuit of claim 44 wherein said circuitry for integrating comprises a counter for incrementing when an evaluated magnitude is within the first predetermined range of magnitude and for decrementing when an evaluated magnitude is not within the first predetermined range of magnitude.
Claim 58
Dependent Claim
26 words
The circuit of claim 53 wherein the average value is within the first predetermined range of magnitude if the counter is within a first count range.
Claim 59
Dependent Claim
16 words
The circuit of claim 54 wherein the first count range is from six to seven counts.
Claim 60
Dependent Claim
30 words
The circuit of claim 53 wherein the counter is a three bit counter, and the average value is within the first predetermined range of magnitude if the count equals seven.
Claim 61
Dependent Claim
27 words
The circuit of claim 53 wherein the average value is not within the first predetermined range of magnitude if the counter is within a second count range.
Claim 62
Dependent Claim
16 words
The circuit of claim 57 wherein the second count range is from zero to one counts.
Claim 63
Dependent Claim
31 words
The circuit of claim 53 wherein the counter is a three bit counter, and the average value is not within the first predetermined range of magnitude if the count equals zero.
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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) | 1995-11-03 | 1996-05-04 | 1996-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-03 | 2000-05-04 | 2000-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-11-03 | 2004-05-04 | 2004-11-03 | $7700.00 | Window Closed / Lapsed |