US5146471A
Expired / Lapsed
US
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Correlator for spread spectrum communications systems
Assignee: NWF INDUSTRIES
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Filing: 1991-04-11
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Granted: 1992-09-08
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Expires: 2011-04-11
Abstract
Abstract An improved correlator for use in a spread spectrum communications system which operates with a predetermined chip sequence includes an N-stage correlation register, wherein each stage corresponds to a signal chip in the sequence, an a means for autocorrelating each of the N stages with the corresponding chips in the sequence. The correlator further includes a means for modifying the sequence to accomodate multiple communication channels.
Inventors
- 👤 Brooks E. Cowart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:09
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/69; H04B1/707; H04B1/7073; H04B1/7075; H04B1/70755; H04B1/709; H04B1/70757; H04B1/708; H04B2201/00; H04B2201/69; H04B2201/707; H04B2201/70703
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
87 words
In a communications system wherein data is recovered by correlating a received spread spectrum signal with a known predetermined chip sequence, an improved correlator comprising: a correlation register having N stages, where N is an integer greater than zero, with each stage corresponding to a signal chip in said sequence, said correlation register being coupled to receive said spread spectrum signal; means for autocorrelating each of said N stages with the corresponding chips of said sequence; and means for modifying said sequence to accommodate multiple communication channels.
Claim 2
Dependent Claim
87 words
In a communications system wherein data is recovered by correlating a received spread spectrum signal with a known predetermined chip sequence, an improved correlator comprising: a correlation register having N stages, where N is an integer greater than zero, with each stage corresponding to a signal chip in said sequence, said correlation register being coupled to receive said spread spectrum signal; means for autocorrelating each of said N stages with the corresponding chips of said sequence; and means for modifying said sequence to accommodate multiple communication channels.
Claim 3
Dependent Claim
51 words
The improvement of claim 1 wherein said modifying means comprises: an additional N-stage register receiving code sequence data which defines a weighting value for each of said N-stages of said correlation register; and logic means for combining the Nth stage of additional register with the Nth stage of said correlation register.
Claim 4
Dependent Claim
35 words
The improvement of claim 2 further comprising means for loading said correlation register with the contents of said additional register to allow a selected sequence to be applied to a data stream for subsequent transmission.
Claim 5
Dependent Claim
19 words
The improvement of claim 2 wherein said correlation register and said additional register each comprise a linear shift register.
Claim 6
Dependent Claim
42 words
The improvement of claim 4 wherein said logic means comprises N 2-input XOR/XNOR logic gates, each gate receiving one of its inputs from said Nth stage of said correlation register and its other input from said Nth stage of said additional register.
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) | 1995-09-08 | 1996-03-09 | 1996-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-08 | 2000-03-09 | 2000-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-08 | 2004-03-09 | 2004-09-08 | $7700.00 | Window Closed / Lapsed |