US5057795A
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Digital gaussian white noise generation system and method of use
Assignee: ERIC MANDELBAUM ESQ
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Filing: 1990-10-25
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Granted: 1991-10-15
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Expires: 2010-10-25
Abstract
Abstract Apparatus for digitally synthesizing substantially Gaussian white noise of an adjustable bandwidth but of substantially constant amplitude. The apparatus comprises a pair of pseudorandom sequence generators, plural delay circuits, plural finite impulse response filters, and a summing network. The pseudorandom sequence generators are made up of a pair of shift registers having a large plurality of output stages to provide a first digital electrical signal representing a pseudorandom number sequence of a long repetition rate at the output stages. The delay circuits are coupled to selected output stages of the pseudorandom sequence generators for providing second respective digital electrical signals representing respective uncorrelated pseudorandom number sequences whose spectrum is a predetermined function, e.g., (sine X)/X. The finite impulse response filters are binary weighted and coupled to respective ones of the delay circuits for cancelling the predetermined function spectrum of the pseudorandom number sequence of the second electrical signals to produce respective first analog electrical signals of substantially uniform amplitude distribution. The summing network is coupled to the finite impulse response filters to sum the first analog electrical signals to produce an analog white noise signal of substantially Gaussian distribution.
Inventors
- 👤 Thomas M. Napier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:04
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/84
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
182 words
Apparatus for digitally synthesizing substantially Gaussian white noise of an adjustable, wide bandwidth but of substantially constant amplitude, said apparatus comprising pseudorandom sequence generation means, delay generation means, finite impulse response filter means, and summing means, said pseudorandom sequence generation means having a large plurality of output stages and being arranged for providing first digital electrical signals representing a pseudorandom number sequence of a long repetition rate at said output stages, said delay generation means being coupled to selected output stages of said pseudorandom sequence generation means for providing second respective digital electrical signals representing respective uncorrelated pseudorandom number sequences whose spectrum is a predetermined function, said finite impulse response filter means being weighted and coupled to respective ones of said delay generation means for altering the predetermined function spectrum of the pseudorandom number sequences of said second electrical signals to produce respective first analog electrical signals of substantially uniform amplitude distribution, said summing means being coupled to said finite impulse response filter means for summing said first analog electrical signals to produce an analog white noise signal of substantially Gaussian distribution.
Claim 2
Dependent Claim
182 words
Apparatus for digitally synthesizing substantially Gaussian white noise of an adjustable, wide bandwidth but of substantially constant amplitude, said apparatus comprising pseudorandom sequence generation means, delay generation means, finite impulse response filter means, and summing means, said pseudorandom sequence generation means having a large plurality of output stages and being arranged for providing first digital electrical signals representing a pseudorandom number sequence of a long repetition rate at said output stages, said delay generation means being coupled to selected output stages of said pseudorandom sequence generation means for providing second respective digital electrical signals representing respective uncorrelated pseudorandom number sequences whose spectrum is a predetermined function, said finite impulse response filter means being weighted and coupled to respective ones of said delay generation means for altering the predetermined function spectrum of the pseudorandom number sequences of said second electrical signals to produce respective first analog electrical signals of substantially uniform amplitude distribution, said summing means being coupled to said finite impulse response filter means for summing said first analog electrical signals to produce an analog white noise signal of substantially Gaussian distribution.
Claim 3
Dependent Claim
18 words
The apparatus of claim 1 wherein said finite impulse response filter means comprises a plurality of weighted filters.
Claim 4
Dependent Claim
26 words
The apparatus of claim 2 wherein said filters are weighted in a manner to substantially cancel the predetermined function spectrum of said second digital electrical signals.
Claim 5
Dependent Claim
11 words
The apparatus of claim 3 wherein said function is (sine X)/X.
Claim 6
Dependent Claim
99 words
The apparatus of claim 2 wherein each of said finite impulse response filters comprises a digital shift register and an associated digital-to-analog converter, said digital shift register having a plurality of output stages, said digital to analog converter having a plurality of input stages, and whereupon selected ones of said output stages of said shift register are connected to respective ones of the input stages of said digital-to-analog converter to effect a predetermined weighting of said second digital electrical signals to cancel the function of the second digital electrical signal provided thereto to produce said first analog electrical signal.
Claim 7
Dependent Claim
11 words
The apparatus of claim 5 wherein said function is (sine X)/X.
Claim 8
Dependent Claim
19 words
The apparatus of claim 1 wherein said pseudorandom sequence generation means comprises at least one multistage digital shift register.
Claim 9
Dependent Claim
19 words
The apparatus of claim 3 wherein said pseudorandom sequence generation means comprises at least one multistage digital shift register.
Claim 10
Dependent Claim
19 words
The apparatus of claim 5 wherein said pseudorandom sequence generation means comprises at least one multistage digital shift register.
Claim 11
Dependent Claim
16 words
The apparatus of claim 1 wherein said delay generation means comprises a plurality of exclusive-OR gates.
Claim 12
Dependent Claim
11 words
The apparatus of claim 1 wherein said weighting is binary related.
Claim 13
Dependent Claim
11 words
The apparatus of claim 3 wherein said weighting is binary related.
Claim 14
Dependent Claim
11 words
The apparatus of claim 5 wherein said weighting is binary related.
Claim 15
Dependent Claim
11 words
The apparatus of claim 7 wherein said weighting is binary related.
Claim 16
Dependent Claim
40 words
The apparatus of claim 1 wherein said pseudorandom sequence generation means is clocked at a preselected frequency, with said frequency being selectable to vary the bandwidth of said noise signal produced by said apparatus while maintaining said substantially Gaussian distribution.
Claim 17
Dependent Claim
38 words
The apparatus of claim 7 wherein said shift register is clocked at a preselected frequency, with said frequency being selectable to vary the bandwidth of said noise signal produced by said apparatus while maintaining said substantially Gaussian distribution.
Claim 18
Dependent Claim
38 words
The apparatus of claim 8 wherein said shift register is clocked at a preselected frequency, with said frequency being selectable to vary the bandwidth of said noise signal produced by said apparatus while maintaining said substantially Gaussian distribution.
Claim 19
Dependent Claim
11 words
The apparatus of claim 15 wherein said weighting is binary related.
Claim 20
Dependent Claim
11 words
The apparatus of claim 16 wherein said weighting is binary related.
Claim 21
Dependent Claim
11 words
The apparatus of claim 17 wherein said weighting is binary related.
Claim 22
Dependent Claim
37 words
The apparatus of claim 2 wherein said second digital signals comprise at least three signals, each being uncorrelated to the others, with a respective one of each of said second signals being provided to a respective filter.
Claim 23
Dependent Claim
62 words
The apparatus of claim 2 wherein said second digital signals comprise at least nine signals, each being uncorrelated to the others, with a respective one of each of said second signals being provided to a respective filter, whereupon the ratio of the peak amplitude of the noise produced by said apparatus to the rms value of said noise is at least five.
Claim 24
Dependent Claim
62 words
The apparatus of claim 2 wherein said second digital signals comprise at least twelve signals, each being uncorrelated to the others, with a respective one of each of said second signals being provided to a respective filter, whereupon the ratio of the peak amplitude of the noise produced by said apparatus to the rms value of said noise is at least six.
Claim 25
Independent Claim
108 words
A method for digitally synthesizing substantially Gaussian white noise of an adjustable, wide bandwidth but of substantially constant amplitude, said method comprising providing first digital electrical signals representing pseudorandom number sequences of a long repetition rate, delaying selected ones of said first digital signals for providing second respective digital electrical signals representing respective uncorrelated pseudorandom number sequences whose spectrum is a predetermined function, altering the predetermined function spectrum of the pseudorandom number sequence of said second electrical signals to produce respective first analog electrical signals of substantially uniform amplitude distribution, and summing said first analog electrical signals to produce an analog white noise signal of substantially Gaussian distribution.
Claim 26
Independent Claim
108 words
A method for digitally synthesizing substantially Gaussian white noise of an adjustable, wide bandwidth but of substantially constant amplitude, said method comprising providing first digital electrical signals representing pseudorandom number sequences of a long repetition rate, delaying selected ones of said first digital signals for providing second respective digital electrical signals representing respective uncorrelated pseudorandom number sequences whose spectrum is a predetermined function, altering the predetermined function spectrum of the pseudorandom number sequence of said second electrical signals to produce respective first analog electrical signals of substantially uniform amplitude distribution, and summing said first analog electrical signals to produce an analog white noise signal of substantially Gaussian distribution.
Claim 27
Dependent Claim
30 words
The method of claim 24 wherein said first analog electrical signals are produced by weighted filters which are binary related to cancel the function of the second digital electrical signals.
Claim 28
Dependent Claim
39 words
The method of claim 24 wherein said first digital electrical signals are produced in response to a preselected clock frequency, with said frequency being selectable to vary the bandwidth of said noise signal while maintaining said substantially Gaussian distribution.
Claim 29
Dependent Claim
39 words
The method of claim 25 wherein said first digital electrical signals are produced in response to a preselected clock frequency, with said frequency being selectable to vary the bandwidth of said noise signal while maintaining said substantially Gaussian distribution.
Claim 30
Dependent Claim
47 words
The method of claim 24 wherein said second digital signals comprise at least three signals, each being uncorrelated to the others, with a respective one of each of said second signals being provided to a respective filter for producing respective ones of said first analog electrical signals.
Claim 31
Dependent Claim
69 words
The method of claim 24 wherein said second digital signals comprise at least nine signals, each being uncorrelated to the others, with a respective one of each of said second signals being provided to a respective filter for producing respective ones of said first analog electrical signals, whereupon the ratio of the peak amplitude of the noise produced to the rms value of said noise is at least five.
Claim 32
Dependent Claim
69 words
The method of claim 24 wherein said second digital signals comprise at least twelve signals, each being uncorrelated to the others, with a respective one of each of said second signals being provided to a respective filter for producing respective ones of said first analog electrical signals, whereupon the ratio of the peak amplitude of the noise produced to the rms value of said noise is at least six.
Claim 33
Dependent Claim
47 words
The method of claim 25 wherein said second digital signals comprise at least three signals, each being uncorrelated to the others, with a respective one of each of said second signals being provided to a respective filter for producing respective ones of said first analog electrical signals.
Claim 34
Dependent Claim
69 words
The method of claim 25 wherein said second digital signals comprise at least nine signals, each being uncorrelated to the others, with a respective one of each of said second signals being provided to a respective filter for producing respective ones of said first analog electrical signals, whereupon the ratio of the peak amplitude of the noise produced to the rms value of said noise is at least five.
Claim 35
Dependent Claim
69 words
The method of claim 25 wherein said second digital signals comprise at least twelve signals, each being uncorrelated to the others, with a respective one of each of said second signals being provided to a respective filter for producing respective ones of said first analog electrical signals, whereupon the ratio of the peak amplitude of the noise produced to the rms value of said noise is at least six.
Claim 36
Dependent Claim
24 words
The method of claim 24 wherein said delaying of selected one of said first digital signals is accomplished by use of respective exclusive-OR gates.
References Cited (Backward Citations)
US3742381A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-10-14 | 1995-04-15 | 1995-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-10-14 | 1999-04-15 | 1999-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-10-14 | 2003-04-15 | 2003-10-15 | $7700.00 | Window Closed / Lapsed |