US5077754A
Expired / Lapsed
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Tau-dither circuit
Assignee: Kenwood KK
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Filing: 1990-03-20
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Granted: 1991-12-31
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Expires: 2010-03-20
Abstract
Abstract A tau-dither circuit in a spread spectrum communications system wherein a first PN code with a large phase change and a second PN code without a phase change are generated in the tau-dither circuit, and the first PN code is used as a PN code for synchronous tracking to a received signal whereas the second PN code is used as a PN code for despreading of the received signal.
Inventors
- 👤 Hirotaka Namioka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:21
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/69; H04B1/707; H04B1/7073; H04B1/7085
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
140 words
A tau-dither circuit in a spread spectrum communication system comprising: means (1, 2) for producing a first output representative of a correlation between a received spectrum spread signal and a first PN code sequence signal and demodulating said first output; means (3, 4, 5, 15) for producing a second output representative of a correlation between the received spectrum spread signal and a second PN code sequence signal and phase-detecting said second output; a PN code (9) sequence generator controlled by said phase-detected output for generating a PN code sequence signal; means (11) for generating said first PN code sequence signal by applying a first predetermined phase-delay to said PN code sequence signal; and means (11, 13, 14) for generating said second PN code sequence signal by applying a dithering to said PN code sequence signal with a second predetermined phase-delay.
Claim 2
Dependent Claim
140 words
A tau-dither circuit in a spread spectrum communication system comprising: means (1, 2) for producing a first output representative of a correlation between a received spectrum spread signal and a first PN code sequence signal and demodulating said first output; means (3, 4, 5, 15) for producing a second output representative of a correlation between the received spectrum spread signal and a second PN code sequence signal and phase-detecting said second output; a PN code (9) sequence generator controlled by said phase-detected output for generating a PN code sequence signal; means (11) for generating said first PN code sequence signal by applying a first predetermined phase-delay to said PN code sequence signal; and means (11, 13, 14) for generating said second PN code sequence signal by applying a dithering to said PN code sequence signal with a second predetermined phase-delay.
Claim 3
Dependent Claim
19 words
A tau-dither circuit according to claim 1, wherein said second predetermined phase-delay is larger than said first predetermined phase-delay.
Claim 4
Dependent Claim
30 words
A tau-dither circuit according to claim 2, wherein said phase-detecting means (3, 4, 5) performs the phase-detecting by taking a multiplication of a dithering period signal and said second output.
References Cited (Backward Citations)
USRE32905E
Cited
USRE32905F1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-30 | 1995-07-01 | 1995-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-30 | 1999-07-01 | 1999-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-30 | 2003-07-01 | 2003-12-31 | $7700.00 | Window Closed / Lapsed |