System and method of implementing a cognitive radio device with enhanced spectrum sensing

• US 8,928,759 B2
• Filed: 06/05/2012
• Issued: 01/06/2015
• Est. Priority Date: 06/08/2011
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Aurora Wireless Inc (RCC Holdings Corp.)
• Inventors: Li, Lingjie, Yee, Jung
• Primary Examiner(s): Harold, Jefferey
• Assistant Examiner(s): HAIEM, SEAN N
• Application Number:
  US13/489,078
• Publication Number:
  US 20120315855A1
• Time in Patent Office: 945 Days
• Field of Search: None
• US Class Current: 348/192
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A cognitive radio band device uses information gleaned from a database inquiry based on geo-location information in combination with spectrum sensing to determine if cognitive radio channels are available for unlicensed use.

Claims

1. A system for implementing a cognitive radio band device with enhanced spectrum sensing, comprising:

a variable resolution geo-location server configured to receive geo-location information from the cognitive radio band device, translate the geo-location information into a location indicator, assign a location accuracy function to the location indicator, and return the location indicator to the cognitive radio band device;

a cognitive radio band spectrum data_base front end configured to receive the location indicator from the cognitive radio band device and use the location indicator to compile an available spectrum map that is returned to the cognitive radio band device; and

a spectrum sensor available to the cognitive radio band device, the spectrum sensor being adapted to detect certain cognitive radio band signal types.

2. The system as claimed in claim 1 further comprising a database of location indicator/cognitive radio channel table information that is used by the cognitive radio band spectrum data base front end to compile the available spectrum map.

3. The system as claimed in claim 1 further comprising a database of cognitive radio band device registration information that is maintained by the cognitive radio spectrum data base front end and used by the cognitive radio spectrum data base front end to communicate with the cognitive radio band device when required.

4. The system as claimed in claim 1 further comprising a database of geo-location interpretation information that is used by the variable resolution geo-location server to translate the geo-location information into the location indicator.

5. The system as claimed in claim 4 wherein the location accuracy function being expressed in a format that can be used by the cognitive radio spectrum data base to compile the available spectrum map that is returned to the cognitive radio band device.

6. A cognitive radio band device, comprising:

a spectrum sensor adapted to sense certain cognitive radio band signal types based on a sensing map to produce a sensor map;

memory for storing geo-location information and

an operating/backup channel list; and

cognitive radio spectrum management logic configured to

provide a variable resolution geo-location server with the geo-location information;

receive a location indicator from the variable resolution geo-location server;

pass the location indicator to a cognitive radio spectrum database front end to request an available spectrum map from the cognitive radio spectrum database front end;

inspect the available spectrum map to prepare the sensing map for the spectrum sensor;

combine the available spectrum map and the sensor map using predetermined combination rules to produce a combined spectrum map; and

select operating and backup channels for the operating/backup channel list from the combined spectrum map based in at least in part on sensing requirements.

23. The cognitive radio band device as claimed in claim 6, wherein the predetermined combination rules include weightings based on a probability of false alarm and a probability of detection.

24. The cognitive radio band device as claimed in claim 6, wherein the cognitive radio spectrum management logic is further configured to determine whether a current available spectrum map has expired.

25. The cognitive radio band device as claimed in claim 24, wherein the cognitive radio spectrum management logic is further configured, if the current available spectrum map has expired, to:

pass the location indicator to the cognitive radio spectrum database front end and request a new available spectrum map from the cognitive radio spectrum database front end; and

inspect the new available spectrum map to create a new sensing map for the spectrum sensor.

26. The cognitive radio band device as claimed in claim 6, wherein the cognitive radio spectrum management logic is further configured to:

start sensing timers for the channels in the combined spectrum map; and

determine whether one of the sensing timers has expired.

27. The cognitive radio band device as claimed in claim 26, wherein the cognitive radio spectrum management logic is further configured to:

in the case that one of the sensing timers has expired, cause the spectrum sensor to sense the channel associated with the expired sensing timer to determine if a signal can be detected; and

if a signal cannot be detected on the channel, reset the sensing timer associated with that channel.

28. The cognitive radio band device as claimed in claim 27, wherein the cognitive radio spectrum management logic is further configured to, in the case that the channel associated with the expired sensing timer is an operating channel, inspect the operating/backup channel list to determine if at least one backup channel is available.

29. The cognitive radio band device as claimed in claim 28, wherein the cognitive radio spectrum management logic is further configured to, in the case that at least one backup channel is available, select one of the at least one backup channels as a new operating channel.

30. The cognitive radio band device as claimed in claim 29, wherein the cognitive radio spectrum management logic is further configured to compute a sensing timer adjustment for the new operating channel based on the time remaining on the sensing timer associated with the channel selected as the new operating channel and a default operating channel sensing time.

31. The cognitive radio band device as claimed in claim 6, wherein the cognitive radio spectrum management logic is further configured to determine whether the geo-location information has changed.

32. The cognitive radio band device as claimed in claim 31, wherein the cognitive radio spectrum management logic is further configured to, if the geo-location information has changed:

provide the variable resolution geo-location server with the changed geo-location information;

receive a new location indicator from the variable resolution geo-location server;

pass the new location indicator to the cognitive radio spectrum database front end and request a new available spectrum map from the cognitive radio spectrum database front end; and

inspect the new available spectrum map to prepare the sensing map for the spectrum sensor.

33. The cognitive radio band device as claimed in claim 6, wherein the cognitive radio spectrum management logic is further configured to determine whether movement of the cognitive radio band device that exceeds a predetermined threshold has been detected.

34. The cognitive radio band device as claimed in claim 33, wherein the cognitive radio spectrum management logic is further configured to, if the movement of the cognitive radio band device that exceeds the predetermined threshold has been detected:

provide the variable resolution geo-location server with geo-location information associated with a new location of the cognitive radio band device;

receive a new location indicator from the variable resolution geo-location server;

pass the new location indicator to the cognitive radio spectrum database front end and request a new available spectrum map from the cognitive radio spectrum database front end; and

inspect the new available spectrum map to prepare a new sensing map for the spectrum sensor.

35. The cognitive radio band device as claimed in claim 27, wherein sensing timers associated with operating and backup channels have different timer values.

36. The cognitive radio band device as claimed in claim 35, wherein the timer values are chosen so that an operating channel is sensed more frequently than a backup channel.

37. The cognitive radio band device as claimed in claim 36, wherein the timer values are chosen so that a backup channel is sensed more frequently than a channel that is neither a backup channel nor an operating channel.

7. A method for use in operating a cognitive radio band device, the method comprising:

providing a variable resolution geo-location server with geo-location information available to the cognitive radio band device;

receiving a location indicator from the variable resolution geo-location server;

passing the location indicator to a cognitive radio spectrum database front end to request a available spectrum map from the cognitive radio spectrum database front end;

inspecting the available spectrum map to prepare a sensing map for a spectrum sensor of the cognitive radio band device;

sensing cognitive radio spectrum based on the sensing map to produce a sensor map;

combining the available spectrum map and the sensor map using predetermined combination rules to produce a combined spectrum map; and

selecting operating and backup channels for an operating/backup channel list from the combined spectrum map based in at least in part on sensing requirements.

8. The method as claimed in claim 7, wherein

the predetermined combination rules include weightings based on a probability of false alarm and a probability of detection.

9. The method as claimed in claim 7 further comprising determining whether a current available spectrum map has expired.

10. The method as claimed in claim 9, wherein if the current available spectrum map has expired, the method further comprises:

passing the location indicator to the cognitive radio spectrum database front end and requesting a new available spectrum map from the cognitive radio spectrum database front end; and

inspecting the new available spectrum map to create a new sensing map for use in sensing cognitive radio spectrum.

11. The method as claimed in claim 7, further comprising:

starting sensing timers for the channels in the combined spectrum map; and

determining whether one of the sensing timers has expired.

12. The method as claimed in claim 11 further comprising:

in the case that one of the sensing timers has expired, sensing the channel associated with the expired sensing timer to determine if a signal can be detected; and

if a signal cannot be detected on the channel, resetting the sensing timer associated with that channel.

13. The method as claimed in claim 12, further comprising in the case that the channel associated with the expired sensing timer is an operating channel, inspecting the operating/backup channel list to determine if at least one backup channel is available.

14. The method as claimed in claim 13, further comprising in the case that at least one backup channel is available, selecting one of the at least one backup channels as a new operating channel.

15. The method as claimed in claim 14 further comprising computing a sensing timer adjustment for the new operating channel based on the time remaining on the sensing timer associated with the channel selected as the new operating channel and a default operating channel sensing time.

16. The method as claimed in claim 7 further comprising determining whether the geo-location information has changed.

17. The method as claimed in claim 16 wherein if the geo-location information has changed the method further comprises:

providing the variable resolution geo-location server with the changed geo-location information;

receiving a new location indicator from the variable resolution geo-location server;

passing the new location indicator to the cognitive radio spectrum database front end and requesting a new available spectrum map from the cognitive radio spectrum database front end; and

inspecting the new available spectrum map to prepare the sensing map for the spectrum sensor.

18. The method as claimed in claim 7 wherein the method further comprises determining whether movement of the cognitive radio band device that exceeds a predetermined threshold has been detected.

19. The method as claimed in claim 18 wherein if the movement of the cognitive radio band device that exceeds the predetermined threshold has been detected, the method further comprises:

providing the variable resolution geo-location server with geo-location information associated with a new location of the cognitive radio band device;

receiving a new location indicator from the variable resolution geo-location server;

passing the new location indicator to the cognitive radio spectrum database front end and requesting a new available spectrum map from the cognitive radio spectrum database front end; and

inspecting the new available spectrum map to prepare a new sensing map for the spectrum sensor.

20. The method as claimed in claim 12, wherein sensing timers associated with operating and backup channels have different timer values.

21. The method as claimed in claim 20, wherein the timer values are chosen so that an operating channel is sensed more frequently than a backup channel.

22. The method as claimed in claim 21, wherein the timer values are chosen so that a backup channel is sensed more frequently than a channel that is neither a backup channel nor an operating channel.