Spectrum sharing system and method thereof

Patent metadata

Field	Value
Publication number	US-10812985-B2
Application number	US-201816224253-A
Country	US
Kind code	B2
Filing date	Dec 18, 2018
Priority date	Mar 12, 2015
Publication date	Oct 20, 2020
Grant date	Oct 20, 2020

Abstract

A spectrum sharing system includes an advanced beacon (e.g. a low latency RF link) as part of an information sharing subsystem. The advanced beacon signal carries radar spectrum transmission schedule in an obfuscated way such as not to reveal the geolocation of the radar. The information sharing subsystem directs nodes, such as cell phones, to share spectrum based on spectrum sharing instructions contained in the advanced beacon. The spectrum sharing system permits out-of-band sharing of spectrum white space, as well as sharing of in-band spectrum gray space.

First claim

What is claimed:

1. A method of sharing radar spectrum of one or more radars, comprising:
providing at least part of a radar schedule for at least a portion of the radar spectrum to a beacon transmitter without providing a geolocation of the radars;
sending a beacon signal from the beacon transmitter, wherein the beacon signal is a radio frequency (RF) link and carries spectrum sharing instructions to at least one communications node desiring to share the portion of the radar spectrum, wherein the sharing instructions comprises an in-band spectrum sharing instructions and an out-of-band spectrum sharing instructions;
receiving the beacon signal at a beacon receiver, wherein the beacon receiver is operatively coupled to the at least one communications node and a network;
directing the at least one communications node to occupy the portion of the radar spectrum based on the spectrum sharing instructions, wherein if the sharing instructions includes in-band sharing instructions, then the beacon receiver directs the at least one communications node to occupy a spectrum gray space within the portion of the radar spectrum and directs the at least one communications node to exit the portion of the radar spectrum when the portion of the radar spectrum needs to be re-occupied by the radars; and wherein,
if the sharing instructions include out-of-band sharing instructions, then the beacon receiver directs the at least one communications node to occupy a spectrum white space adjacent the portion of the radar spectrum that are unoccupied by the radars; and
wherein the method of sharing radar spectrum is adapted to prevent signal interference by requiring the at least one communications node to exit the portion of the radar spectrum desired to be re-occupied by the radars before any interference can occur.

2. The method of claim 1 , wherein a frame structure comprises a plurality of request to send (RTS) spectrum slots and a plurality of clear to send (CTS) spectrum slots; and randomly selecting a RTS spectrum slot by one of the radars and announcing itself to another of the radars over the beacon signal, wherein the announcing is accomplished by establishing a training sequence enabling the other radars and the beacon receiver to synchronize and estimate channel functions.

3. The method of claim 2 , wherein within the RTS spectrum slot, one of the radars informs other radars of an intended use code.

4. The method of claim 2 , further comprising:
acknowledging the presence of one of the radars announcing itself nearby to the other radars; and
sending a CTS message at a lower power than that for an inter-radar coordination.

5. The method of claim 2 , further comprising:
transmitting heartbeat messages from the radars simultaneously during a heartbeat data portion of the frame structure as part of the information sharing subsystem; and
decoding the heartbeat messages simultaneously.

6. The method of claim 1 , further comprising:
hopping, at the radars, between different radar transmission frequencies in the first portion of the spectrum;
adapting, at the information sharing subsystem, to the hopping;
adjusting, at the information sharing subsystem, free spectrum parameters and notifying the nodes to occupy those empty white spaces or gray spaces.

7. The method of claim 1 , further comprising computing available time-frequency slots in a radar local coordinator to pre-compute the time-frequency slots that are available at a particular azimuth location.

8. The method of claim 1 , wherein hierarchy monitoring dictates the spectrum sharing relationship such that:
if the radars requires more isolation, then less spectrum is available for the node; and
if the radars requires less isolation, then more spectrum is available for the node.

9. The method of claim 1 , further comprising:
registering the communications node with at least one of a government spectrum access system and a commercial spectrum access system, prior to the start of spectrum sharing;
exchanging the credentials of the communications node for authentication and security;
providing an encryption key from the government spectrum access system and/or the commercial spectrum access system, to the communications node; and
decrypting encrypted information included in the beacon signal.

10. The method of claim 1 , further comprising aligning the beacon signal with a global positioning system (GPS).

11. The method of claim 10 , further comprising establishing a frame structure when aligning the beacon signal with the GPS.

12. A spectrum sharing system, comprising:
at least one radar providing a radar schedule;
a beacon receiver configured to receive a beacon signal generated from a beacon transmitter, the beacon signal being a low latency radio frequency (RF) link carrying information that identifies the radar schedule and the beacon signal carrying spectrum sharing instructions carried by a heartbeat message comprising at least one of in-band spectrum sharing instructions and out-of-band spectrum sharing instructions; and
a communications node operatively coupled with the beacon receiver and configured to receive the spectrum sharing instructions, wherein if the sharing instructions include in-band sharing instructions, then the node is directed to occupy spectrum gray space in a portion of the spectrum and the node exits the gray space when the portion of the spectrum needs to be re-occupied by the radar; and if the sharing instructions include out-of-band sharing instructions, then the node occupies spectrum white space adjacent the portion of the spectrum that is not occupied by the radar and the node exits the white space adjacent the portion of the spectrum when the portion of the spectrum needs to be re-occupied by the radar.

13. The system of claim 12 , wherein a location of the radar is obfuscated.

14. The system of claim 12 , wherein the radar schedule is encrypted.

15. The system of claim 12 , wherein an Urgent Co-existence Signaling (UCS) message is used by the radar to take control of the spectrum.

16. The system of claim 12 , wherein the communications node is commercial and/or military.

Assignees

• Bae Sys Inf & Elect Sys Integ

Inventors

• Mody Apurva N
• Carrigan Kenneth
• Chuang Jack
• Lackpour Alex
• Sherman Matthew J
• Rosenwinkel Alan M

Classifications

• G01S7/023

  Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile communication or other radar systems, e.g. using electro-magnetic interference [EMI] reduction techniques (auxiliary means for detecting or identifying radar signals or the like G01S7/021; means for anti-jamming G01S7/36) · CPC title

• H04K3/226

  Selection of non-jammed channel for communication (spectrum sharing arrangements H04W16/14; selection of wireless resources by user or terminal H04W72/02) · CPC title

• H04L5/0091

  Signalling for the administration of the divided path, e.g. signalling of configuration information · CPC title

• H04J13/0062

  Zadoff-Chu · CPC title

• H04L5/0051

  of dedicated pilots, i.e. pilots destined for a single user or terminal · CPC title