Processor based frequency selective jamming and communications system

• US 7,483,671 B2
• Filed: 05/19/2005
• Issued: 01/27/2009
• Est. Priority Date: 05/19/2005
• Status: Expired due to Fees

• Current Assignee: US Department of The Navy (U.S. Department Of Defense)
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Corbett, Blaise L., Workman, Michael L.
• Primary Examiner(s): GESESSE, TILAHUN
• Application Number:
  US11/134,608
• Publication Number:
  US 20060264168A1
• Time in Patent Office: 1,349 Days
• Field of Search: 455/1, 455/404.1, 455/404.2, 455/410, 455/411, 340/539.1, 340/568.1, 375/130, 342/14, 342/13
• US Class Current: 455/1
• CPC Class Codes: H04K 3/226 Selection of non-jammed channel for communication spectrum sharing arrangements H04W16/14; selection of wireless resources by user or terminal H04W72/02
• CPC Class Codes: H04K 3/25 based on characteristics of target signal or of transmission as countermeasure against surveillance H04K3/827, e.g. using direct sequence spread spectrum or fast frequency hopping spread spectrum techniques H04B1/69
• CPC Class Codes: H04K 3/28 with jamming and anti-jamming mechanisms both included in a same device or system, e.g. wherein anti-jamming includes prevention of undesired self-jamming resulting from jamming
• CPC Class Codes: H04K 3/42 characterized by the control of the jamming frequency or wavelength
• CPC Class Codes: H04K 3/827 using characteristics of target signal or of transmission as countermeasure against jamming H04K3/25, e.g. using direct sequence spread spectrum or fast frequency hopping spread spectrum techniques H04B1/69

Abstract

In one general aspect, a communications system as described herein provides a wide-band jamming signal that is digitally created, conditioned, and modified by a processing based system to provide open data channels to authorized parties within a jammed communications band. The communications system modifies and maintains the open data channels to sustain communications between authorized devices. In addition, the communications system provides frequency hopping using the open data channels to supply secure data links to authorized devices within the jammed communications band while denying service to unauthorized communication nodes or devices.

Claims

1. A communications system for jamming radio frequency (RF) communications of an unauthorized device within a broadband frequency spectrum within a jammed area, the system comprising:

a control node including a processor to determine RF channel information for at least one communications channel within the broadband frequency spectrum;

at least one authorized jamming node to transmit RF signals to jam RF communications within the broadband frequency spectrum and to create notches within the broadband frequency spectrum clear of RF energy corresponding to said communications channel based on said RF channel information; and

at least one communications device authorized by said control node to communicate using said communications channel located within said notches, wherein said communications channel includes a caretaker channel to provide synchronization data and said channel information to authorized jamming nodes and communications devices.

2. The system of claim 1 wherein said communications channel includes a data channel for communications between authorized communications devices.

3. The system of claim 2 further comprising a future data communications channel wherein communications on said communications channels are frequency hopped under direction of said control node such that said future data channel becomes a new data channel;

said data channel becomes said caretaker channel, said notch corresponding to said caretaker channel is jammed, and a new future data and corresponding notch clear of RF energy are created.

4. The system of claim 1 wherein said jamming node includes a processor to filter noise data based on the communications channel data to determine jamming data to create a jammed broadband frequency spectrum with notches clear of RF energy corresponding to said communication channel.

5. The system of claim 1 wherein said communications channel includes a beacon channel monitored by the processor of said control node to authorize said communication device to use said communications channel and to provide said channel information to said authorized communications device allowing said communications said to enter the jammed area and communicate using said communications channel.

6. The system of claim 1 wherein said communications channel includes a beacon channel monitored by the processor of said control node to authorize jamming nodes to use said communications channel and to provide said channel information to authorized jamming nodes allowing said jamming node to enter the jammed area and begin jamming of the broadband frequency spectrum.

7. A jamming node for jamming radio frequency (RF) communication channels of an unauthorized device within a broadband frequency spectrum, said jamming node comprising;

a receiver to receive channel information from a control node for communication channels within the broadband frequency spectrum;

a processor to filter noise data based on, said channel information and to determine jamming data from which to create a jammed broadband frequency spectrum with notches clear of RF energy corresponding to the communication channels;

a broadband frequency transmitter under control of said processor to transmit signals for jamming the broadband frequency spectrum; and

a notched spectrum transmitter under control of said processor to create said notches within the broadband frequency spectrum corresponding to the communication channels, wherein the communication channels include a caretaker channel to provide synchronization data and said channel information to authorized jamming nodes and communications devices.

8. The jamming node of claim 7 wherein the communication channels include an authorized data channel for communications between authorized communications devices.

9. A jamming node for jamming radio frequency (RF) communication channels of an unauthorized device within a broadband frequency spectrum, said jamming node comprising:

a receiver to receive channel information from a control node for communication channels within the broadband frequency spectrum;

a processor to filter noise data based on said channel information and to determine jamming data from which to create a jammed broadband frequency spectrum with notches clear of RF energy corresponding to the communication channels;

a broadband frequency transmitter under control of said processor to transmit signals for jamming the broadband frequency spectrum; and

a notched spectrum transmitter under control of said processor to create said notches within the broadband frequency spectrum corresponding to the communication channels;

a future data communications channel wherein communications on the communication channels are frequency hopped under direction of said control node such that said future data channel becomes a new data channel, said data channel becomes said caretaker channel, said notch corresponding to said caretaker channel is jammed, and a new future data and corresponding notch clear of RF energy are created.

10. A communications node for a jamming communications system that jams radio frequency (RF) communications of an unauthorized device within a broadband frequency spectrum, said communications node comprising:

a receiver to receive channel information from a control node corresponding to notches within the jammed broadband frequency spectrum that are clear of RF energy;

a processor to process said channel information from which to determine a communications channel used by the communications system corresponding to said notches and to process a communication for transmission with the communications system; and

a transmitter under control of said processor to transmit said communication using said determined channel identified by said channel information,

wherein said processor provides frequency hopping using said communications channels for producing secure communications within the jammed broadband frequency spectrum, said communications channels include a caretaker channel to provide synchronization data and said channel information to an authorized communications device.

11. The communications node of claim 10 wherein paid communications channels include a data channel for communications between said authorized communications device and another authorized communications device.

12. The communications node of claim 11 further comprising a future data communications channel wherein communications on said communications channels are frequency hopped under direction of said control node where said future data channel becomes a new data channel, said data channel becomes said caretaker channel, said notch corresponding to said caretaker channel that jammed, and a new future data channel and corresponding notch clear of RF energy are created.

13. The communications node of claim 10 wherein said communications channels include a beacon channel to transmit an authorization code by said transmitter under control of said processor to request authorization to communicate using said communications channels and to receive said channel information when authorized by said control node.

14. A method of jamming radio frequency (RF) communications of an unauthorized device within a broadband frequency spectrum within a jammed area, said method comprising:

determining RF channel information for at least one communications channel within the broadband frequency spectrum;

transmitting RF signals to jam the RF communications within the broadband frequency spectrum based on said RF channel information;

creating notches in the broadband frequency spectrum clear of RF energy corresponding to said communications channel; and

communicating through said communications channel located within said notches, wherein determining said RF communications channel includes determining a caretaker channel to provide synchronization data and said RF channel information to authorized devices.

15. The method of claim 14 wherein determining said RF communications channel includes determining a data channel for communications between authorized devices.

16. of claim 15 further comprising:

determining a future data communications channel;

frequency hopping said communications channel where said future data channel becomes a new data channel and said data channel becomes said caretaker channel;

jamming said notch corresponding to said caretaker channel; and

creating a new future data and corresponding notch clear of RF energy.

17. A method of jamming radio frequency (RF) communications of an unauthorized device within a broadband frequency spectrum within a jammed area, said method comprising:

determining RF channel information for at least one communications channel within the broadband frequency spectrum;

transmitting RF signals to jam the RF communications within the broadband frequency spectrum based on said RF channel information;

creating notches in the broadband frequency spectrum clear of RF energy corresponding to said communications channel;

communicating through said communications channel located within said notches;

determining a beacon communications channel;

.

monitoring said beacon channel for a device seeking authorization;

determining said device is authorized as an authorized device; and

providing synchronization and said channel information to said authorized device to allow said device to enter the jammed area and communicate within the jammed broadband frequency spectrum.