Processor based frequency selective jamming and communications system

• US 20060264168A1
• Filed: 05/19/2005
• Published: 11/23/2006
• Est. Priority Date: 05/19/2005
• Status: Active Grant

• Current Assignee: United States Department of the Navy
• Original Assignee: United States Department of the Navy
• Inventors: Corbett, Blaise L., Workman, Michael L.
• Granted Patent: US 7,483,671 B2
• Time in Patent Office: Days
• 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 all unauthorized devices within a broadband frequency spectrum within a jammed area, the system comprising:

a control node including a processor to determine RF channel information for one or more communications channels within the broadband frequency spectrum;

one or more authorized jamming nodes 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 the one more communications channels based on the RF channel information; and

one or more communications devices authorized by the control node to communicate using the one or more communications channels located within the notches.

2. The system of claim 1 wherein the communications channels include a caretaker channel to provide synchronization data and channel information to authorized jamming nodes and communications devices.

3. The system of claim 2 wherein the communications channels include a data channel for communications between authorized communications devices.

4. The system of claim 3 further comprising a future data communications channel wherein communications on the communications channels are frequency hopped under direction of the control node where the future data channel becomes a new data channel;

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

5. The system of claim 1 wherein the jamming node includes a processor to access noise data and apply a filter 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 the communication channels.

6. The system of claim 1 wherein the communications channels include a beacon channel monitored by the processor of the control node to authorize communication devices to use the communications channels and to provide the channel information to authorized communications devices allowing the communications devices to enter the jammed area and communicate using the communications channels.

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

8. A jamming node for jamming radio frequency (RF) communications of all unauthorized devices within a broadband frequency spectrum, the jamming node comprising:

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

a processor to access noise data and apply a filter based on the received channel data to determine jamming data 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 the processor to transmit signals to jam the broadband frequency spectrum; and

a notched spectrum transmitter under control of the processor to the create notches within the broadband frequency spectrum corresponding to the communications channels.

9. The jamming node of claim 8 wherein the communications channels include a caretaker channel to provide synchronization data and channel information to authorized jamming nodes and communications devices.

10. The jamming node of claim 9 wherein the communications channels include a data channel for communications between authorized communications devices.

11. The jamming node of claim 10 further comprising a future data communications channel wherein communications on the communications channels are frequency hopped under direction of the control node where the future data channel becomes a new data channel, the data channel becomes the caretaker channel, the notch corresponding to the caretaker channel is jammed, and a new future data and corresponding notch clear of RF energy are created.

12. A communications node for a jamming communications system that jams radio frequency (RF) communications of all unauthorized devices within a broadband frequency spectrum, the 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 the channel information to determine communications channels used by the communications system corresponding to the notches and to process a communication for transmission with the communications system; and

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

wherein the processor is configured to provide frequency hopping using the communications channels to provide secure communications with the jammed broadband frequency spectrum.

13. The communications node of claim 12 wherein the communications channels include a caretaker channel to provide synchronization data and channel information to the communications device.

14. The communications node of claim 13 wherein the communications channels include a data channel for communications between the communications device and another authorized communications device.

15. The communications node of claim 14 further comprising a future data communications channel wherein communications on the communications channels are frequency hopped under direction of the control node where the future data channel becomes a new data channel, the data channel becomes the caretaker channel, the notch corresponding to the caretaker channel is jammed, and a new future data and corresponding notch clear of RF energy are created.

16. The communications node of claim 12 wherein the communications channels include a beacon channel to transmit an authorization code by the transmitter under control of the processor to request authorization to communicate using the communications channels and to receive the channel information when authorized by the control node.

17. A method of jamming radio frequency (RF) communications of all unauthorized devices within a broadband frequency spectrum within a jammed area, the method comprising:

determining RF channel information for one or more communications channels within the broadband frequency spectrum;

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

creating notches in the broadband frequency spectrum clear of RF energy corresponding to the one more communications channels; and

communicating using the one or more communications channels located within the notches.

18. The method of claim 17 wherein determining the RF communications channels includes determining a caretaker channel to provide synchronization data and channel information to authorized devices.

19. The method of claim 18 wherein determining the RF communications channels includes determining a data channel for communications between authorized devices.

20. The method claim 19 further comprising:

determining a future data communications channel;

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

jamming the notch corresponding to the caretaker channel; and

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

21. The method of claim 17 further comprising:

determining a beacon communications channel;

monitoring the beacon channel for a device seeking authorization;

determining the devices is authorized; and

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