US4221005A
Expired / Lapsed
US
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Pseudonoise code tracking loop
Assignee: National Aeronautics and Space Administration
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Filing: 1979-05-21
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Granted: 1980-09-02
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Expires: 1999-05-21
Abstract
Abstract A delay-locked loop is provided for tracking a pseudonoise (PN) reference code in an incoming communication signal. The loop is less sensitive to gain imbalances, which can otherwise introduce timing errors in the PN reference code formed by the loop.
Inventors
- 👤 with respect to an invention of Frosch Robert A. Administrator of the National Aeronautics and Space Administration
- 👤 David T. La Flame
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:04
CPC Classifications
H; H04; H04L; H04L7/00; H04L7/04; H04L7/041; H04L7/043
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
114 words
A tracking apparatus for forming a pseudonoise reference code from an incoming signal, comprising: (a) pseudonoise code generating means for forming a multiple bit pseudonoise reference code in response to a loop error signal; (b) means for forming signals representing the sum and the difference between two selected bits of the pseudonoise reference code; (c) first multiplier means for forming a first product signal from the sum signal and the incoming signal; (d) second multiplier means for forming a second product signal from the difference signal and the incoming signal; (e) means for forming the loop error signal from the first and second product signals to cause operation of said pseudonoise code generating means.
Claim 2
Dependent Claim
114 words
A tracking apparatus for forming a pseudonoise reference code from an incoming signal, comprising: (a) pseudonoise code generating means for forming a multiple bit pseudonoise reference code in response to a loop error signal; (b) means for forming signals representing the sum and the difference between two selected bits of the pseudonoise reference code; (c) first multiplier means for forming a first product signal from the sum signal and the incoming signal; (d) second multiplier means for forming a second product signal from the difference signal and the incoming signal; (e) means for forming the loop error signal from the first and second product signals to cause operation of said pseudonoise code generating means.
Claim 3
Dependent Claim
16 words
The tracking apparatus of claim 1, wherein said means for forming comprises: summing function circuit means.
Claim 4
Dependent Claim
54 words
The tracking apparatus of claim 2, wherein said summing function circuit means comprises: (a) a first summing function circuit for forming the sum of the two selected bits of the pseudonoise reference code; and (b) a second summing function circuit for forming the difference between the two selected bits of the pseudonoise reference code.
Claim 5
Dependent Claim
20 words
The tracking apparatus of claim 1, wherein said pseudonoise code generating means comprises: a multiple stage digital signal storage means.
Claim 6
Dependent Claim
31 words
The tracking apparatus of claim 4, wherein said multiple stage digital storage means comprises: a multiple stage shift register having n stages, wherein n is a positive integer greater than one.
Claim 7
Dependent Claim
34 words
The tracking apparatus of claim 5, wherein said means for forming comprises: means for forming signals representing the sum and the difference between the contents of stages n and n-1 of said shift register.
Claim 8
Dependent Claim
42 words
The tracking apparatus of claim 6, wherein said means for forming comprises: means for forming signals representing the sum and the difference between the contents of stages n and n-y, wherein y is an integer greater than 1 but less than n.
Claim 9
Dependent Claim
39 words
The tracking apparatus of claim 1, further including: (a) loop filter means for receiving the loop error signal and forming therefrom an output signal whose voltage varies in accordance with the error signal; and (b) voltage controlled oscillator means.
Claim 10
Dependent Claim
29 words
The tracking apparatus of claim 1, further including: band pass filter means electrically connected at the output of each of said first multiplier means and said second multiplier means.
Claim 11
Dependent Claim
32 words
The tracking apparatus of claim 1, wherein said means for forming the loop error signal comprises: means for multiplying the first and second products signals together to form the loop error signal.
Claim 12
Independent Claim
93 words
A method of forming a pseudonoise reference code from an incoming signal, comprising: (a) generating a multiple bit pseudonoise reference code in response to a loop error signal; (b) forming signals representing the sum and the difference between two selected bits of the pseudonoise reference code; (c) forming a first product signal from the sum signal and the incoming signal; (d) forming a second product signal from the difference signal and the incoming signal; (e) forming the loop error signal from the first and second product signals to cause said step of generating.
Claim 13
Independent Claim
93 words
A method of forming a pseudonoise reference code from an incoming signal, comprising: (a) generating a multiple bit pseudonoise reference code in response to a loop error signal; (b) forming signals representing the sum and the difference between two selected bits of the pseudonoise reference code; (c) forming a first product signal from the sum signal and the incoming signal; (d) forming a second product signal from the difference signal and the incoming signal; (e) forming the loop error signal from the first and second product signals to cause said step of generating.
Claim 14
Dependent Claim
47 words
The tracking apparatus of claim 1, wherein said step of forming signals representing the sum and difference comprises: (a) forming the sum of the two selected bits of the pseudonoise reference code; and (b) forming the difference between the two selected bits of the pseudonoise reference code.
Claim 15
Dependent Claim
50 words
The method of claim 12, wherein the pseudonoise code is a sequence of n bits, n being a positive integer, and said step of forming sum and difference signals comprises: forming signals representing the sum and the difference between the contents of stages n and n-1 of said shift register.
Claim 16
Dependent Claim
39 words
The method of claim 13, wherein said step of forming comprises: forming signals representing the sum and the difference between the contrents of stages n and n-y, wherein y is an integer greater than 1 but less than n.
Claim 17
Dependent Claim
29 words
The method of claim 11, wherein said step of forming the loop error signal comprises: multiplying the first and second products signals together to form the loop error 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) | 1983-09-02 | 1984-03-03 | 1984-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-02 | 1988-03-03 | 1988-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-02 | 1992-03-03 | 1992-09-02 | $7700.00 | Window Closed / Lapsed |