US4985899A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Intercept detector for spread-spectrum signals
Assignee: Boeing Co
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Filing: 1989-10-05
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Granted: 1991-01-15
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Expires: 2009-10-05
Abstract
Abstract A device for intercepting and decoding spread-spectrum frequency-hopped signals. A bank of frequency domain filters contains a filter for each expected bandwidth in the frequency-hopped signal. Each detector of a bank of detectors detects a pulse and noise in the bandwidth of the pulse from a corresponding filter. A bank of thresholding devices differentiates a pulse from the surrounding noise in accordance with a power level threshold value. The device achieves an improvement of approximately the square root of n, where n is the number of frequency domain filters in the apparatus.
Inventors
- 👤 John B. Walsh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:47
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/69; H04B1/713; H04B1/7136; H04B2001/71362
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
132 words
An apparatus for decoding a spread-spectrum frequency hopped signal having pulses in a plurality of different bands, the apparatus comprising: means for receiving the frequency hopped signal; means, coupled to the receiving means, for filtering a pulse in each of the plurality of different bands and for filtering the corresponding background noise in each of the plurality of different bands; means, coupled to the filtering means, for detecting the filtered pulses and the corresponding background noise of each pulse; thresholding means, coupled to the detecting means, for differentiating the filtered pulses from the background noise, each differentiated pulse having a power level greater than a threshold power level corresponding to the bandwidth of the pulse; and means, coupled to the thresholding means, for summing the differentiated pulses to produce a decoded signal.
Claim 2
Independent Claim
132 words
An apparatus for decoding a spread-spectrum frequency hopped signal having pulses in a plurality of different bands, the apparatus comprising: means for receiving the frequency hopped signal; means, coupled to the receiving means, for filtering a pulse in each of the plurality of different bands and for filtering the corresponding background noise in each of the plurality of different bands; means, coupled to the filtering means, for detecting the filtered pulses and the corresponding background noise of each pulse; thresholding means, coupled to the detecting means, for differentiating the filtered pulses from the background noise, each differentiated pulse having a power level greater than a threshold power level corresponding to the bandwidth of the pulse; and means, coupled to the thresholding means, for summing the differentiated pulses to produce a decoded signal.
Claim 3
Dependent Claim
15 words
The apparatus of claim 1, wherein the receiving means includes: an antenna; and an amplifier.
Claim 4
Dependent Claim
63 words
The apparatus of claim 1, wherein the filtering means further includes: a plurality of filters, each of the plurality of filters for filtering a different one of the plurality of bands; and a plurality of detectors, coupled to corresponding ones of the plurality of filters, each of the plurality of detectors detecting an output of a corresponding one of the plurality of filters.
Claim 5
Dependent Claim
51 words
The apparatus of claim 3, wherein the thresholding means includes a plurality of threshold devices, each of the threshold devices connected to a corresponding one of the plurality of detectors and having a power level threshold value corresponding to the bandwidth detected by a corresponding one of the plurality of filters.
Claim 6
Independent Claim
144 words
An apparatus for decoding a spread-spectrum frequency hopped signal having pulses in a plurality of different bands, the apparatus comprising: means for receiving the frequency hopped signal; a bank of filters, each filter filtering a signal pulse and corresponding background noise in one of the plurality of different bands; a bank of detectors, each detector coupled to one corresponding filter in the bank of filters, for detecting a filtered pulse and its corresponding background noise; a bank of threshold devices, each threshold device coupled to one corresponding detector in the bank of detectors and having a power level threshold value corresponding to the bandwidth of one of the plurality of bands, for differentiating the detected signal pulse from its corresponding background noise; and a summing circuit, coupled to the bank of threshold devices, for summing the differentiated signals to create a decoded output signal.
Claim 7
Independent Claim
144 words
An apparatus for decoding a spread-spectrum frequency hopped signal having pulses in a plurality of different bands, the apparatus comprising: means for receiving the frequency hopped signal; a bank of filters, each filter filtering a signal pulse and corresponding background noise in one of the plurality of different bands; a bank of detectors, each detector coupled to one corresponding filter in the bank of filters, for detecting a filtered pulse and its corresponding background noise; a bank of threshold devices, each threshold device coupled to one corresponding detector in the bank of detectors and having a power level threshold value corresponding to the bandwidth of one of the plurality of bands, for differentiating the detected signal pulse from its corresponding background noise; and a summing circuit, coupled to the bank of threshold devices, for summing the differentiated signals to create a decoded output signal.
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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) | 1994-01-14 | 1994-07-16 | 1995-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-14 | 1998-07-16 | 1999-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-14 | 2002-07-16 | 2003-01-15 | $7700.00 | Window Closed / Lapsed |