US5239555A
Expired / Lapsed
US
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Frequency hopping signal interceptor
Assignee: United States Department of the Army
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Filing: 1991-11-04
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Granted: 1993-08-24
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Expires: 2011-11-04
Abstract
Abstract An FH interceptor for determining bandwidth, hop number, dwell time, hop rate, channel spacing and hop frequencies. A compressive receiver, having a passband greater than the bandwidth, samples received signals at a scan rate greater than the hop rate. On each scan, the receiver separates the received signal into its frequency components. A histogram memory, connected to the receiver, stores a frequency distribution of the frequency components including the scan periods. A data processor uses the histogram memory to determine the FH parameters.
Inventors
- 👤 Charles E. Konig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 00:58
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/69; H04B1/713; H04B1/7156; H04B2001/71563
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
213 words
A frequency hopping interceptor system for intercepting a frequency hopping signal which includes determining the frequency hopping parameters of bandwidth, hop number, dwell time, hop rate, minimum channel spacing, and a set of hop frequencies containing at least a minimum and a maximum frequencies comprising: a compressive receiver means having a passband that includes the bandwidth for sampling a received signal at a scan rate that is greater than the hop rate and for separating said received signal into its frequency components over a plurality of scan periods; a memory means connected to said compressive receiver means for storing the number occurrences of each of said frequency components and its scan period; and a data processor means connected to said memory means for determining the hop frequencies, the number of frequencies from the total number of different frequency components, the bandwidth from the difference between the maximum frequency and the minimum frequency, the hop rate from the ratio of the number of frequencies to the minimum time required to receive two successive ones of the same frequence component, dwell time from the minimum time between successively occurring frequency components, the channel spacing from the minimum difference between adjacent frequency components, and the hop number from the time of occurrence of a frequency component.
Claim 2
Dependent Claim
213 words
A frequency hopping interceptor system for intercepting a frequency hopping signal which includes determining the frequency hopping parameters of bandwidth, hop number, dwell time, hop rate, minimum channel spacing, and a set of hop frequencies containing at least a minimum and a maximum frequencies comprising: a compressive receiver means having a passband that includes the bandwidth for sampling a received signal at a scan rate that is greater than the hop rate and for separating said received signal into its frequency components over a plurality of scan periods; a memory means connected to said compressive receiver means for storing the number occurrences of each of said frequency components and its scan period; and a data processor means connected to said memory means for determining the hop frequencies, the number of frequencies from the total number of different frequency components, the bandwidth from the difference between the maximum frequency and the minimum frequency, the hop rate from the ratio of the number of frequencies to the minimum time required to receive two successive ones of the same frequence component, dwell time from the minimum time between successively occurring frequency components, the channel spacing from the minimum difference between adjacent frequency components, and the hop number from the time of occurrence of a frequency component.
Claim 3
Dependent Claim
20 words
The system of claim 1 wherein said memory means stores at least two occurrences of each of said frequency components.
Claim 4
Dependent Claim
35 words
The system of claim 1 wherein said memory means has a plurality of storage cells with the number of occurrences of each of said frequency components being stored in a different one of said cells.
Claim 5
Dependent Claim
29 words
The system of claim 3 wherein at least seventy percent of the number of said cells have the number of occurrences of each of said frequency components stored therein.
Claim 6
Dependent Claim
23 words
The system of claim 4 further including a frequency hopping receiver connected to said data processor means for receiving said frequency hopping signal.
Claim 7
Independent Claim
185 words
A method of intercepting a frequency hopping signal including determining the frequency hopping parameters of bandwidth, hop number, dwell time, hop rate, minimum channel spacing, and a set of hop frequencies containing at least a minimum and a maximum frequencies comprising: sampling said frequency hopping signal at a scan rate that is greater than the hop rate to obtain a sampled signal over a plurality of scan periods; separating said sampled signal into its frequency components over said scan periods; storing the number of occurrences of each of said frequency components and its scan period; and determining the hop frequencies, the number of frequencies from the total number of different frequency components, the bandwidth from the difference between the maximum frequency and the minimum frequency, the hop rate from the ratio of the number of frequencies to the minimum time required to receive two successive ones of the same frequency component, dwell time from the minimum time between successively occurring frequency components, the channel spacing from the minimum difference between adjacent components, and the hop number from the time of occurrence of a frequency component.
Claim 8
Independent Claim
185 words
A method of intercepting a frequency hopping signal including determining the frequency hopping parameters of bandwidth, hop number, dwell time, hop rate, minimum channel spacing, and a set of hop frequencies containing at least a minimum and a maximum frequencies comprising: sampling said frequency hopping signal at a scan rate that is greater than the hop rate to obtain a sampled signal over a plurality of scan periods; separating said sampled signal into its frequency components over said scan periods; storing the number of occurrences of each of said frequency components and its scan period; and determining the hop frequencies, the number of frequencies from the total number of different frequency components, the bandwidth from the difference between the maximum frequency and the minimum frequency, the hop rate from the ratio of the number of frequencies to the minimum time required to receive two successive ones of the same frequency component, dwell time from the minimum time between successively occurring frequency components, the channel spacing from the minimum difference between adjacent components, and the hop number from the time of occurrence of a frequency component.
Claim 9
Dependent Claim
22 words
The method of claim 6 wherein said storing step includes storing the number of each of said frequency components at least twice.
Claim 10
Dependent Claim
25 words
The method of claim 6 wherein the number of occurrences of each of said frequency components are stored in a plurality of different memory cells.
Claim 11
Dependent Claim
26 words
The method of claim 8 wherein at least seventy percent of said cells have the number of occurrences of each of said frequency components stored therein.
Claim 12
Dependent Claim
24 words
The method of claim 9 further including receiving said frequency hopping signal with a frequency hopping receiver in accordance with said frequency hopping parameters.
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) | 1996-08-23 | 1997-02-22 | 1997-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-23 | 2001-02-22 | 2001-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-23 | 2005-02-22 | 2005-08-24 | $7700.00 | Window Closed / Lapsed |