Power control in cognitive radio systems based on spectrum sensing side information

• US 8,315,663 B2
• Filed: 08/31/2011
• Issued: 11/20/2012
• Est. Priority Date: 04/26/2007
• Status: Active Grant

• Current Assignee: Lingna Holdings Pte LLC (Intellectual Ventures LLC)
• Original Assignee: Lingna Holdings Pte LLC (Intellectual Ventures LLC)
• Inventors: Hamdi, Karama, Zhang, Wei, Ben Letaief, Khaled
• Primary Examiner(s): Sobutka, Philip
• Application Number:
  US13/223,120
• Publication Number:
  US 20110312368A1
• Time in Patent Office: 447 Days
• Field of Search: None
• US Class Current: 455/522
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/243 taking into account interferences
• CPC Class Codes: H04W 52/246 where the output power of a terminal is based on a path parameter calculated in said terminal
• CPC Class Codes: H04W 52/26 using transmission rate or quality of service QoS [Quality of Service]
• CPC Class Codes: H04W 52/265 taking into account the quality of service QoS
• CPC Class Codes: H04W 52/283 Power depending on the position of the mobile
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

For cognitive radio systems, the transmit power of a cognitive radio device is controlled so that the cognitive, unlicensed radio device does not interfere with the use of a shared spectrum by a primary, licensed device. Controlling the transmit power includes determining a distance, or a function of the distance, between a primary transmitter of the primary device and the cognitive radio device based on sensing information from a spectrum sensing process. The maximum transmit power of the cognitive radio device is then dynamically controlled based on the distance, or the function of the distance, while considering a worst case scenario of an underlying cognitive radio model, to guarantee a quality of service requirement of the primary device.

Claims

1. A method, comprising:

determining a parameter relating to a distance between a primary transmitter of a primary device and a cognitive radio device including determining a function of an average probability of a missing energy detection of the primary transmitter of the primary device based on sensing information from a spectrum sensing process that senses a presence of the primary device on a spectrum based on signals emitted from the primary transmitter.

2. The method according to claim 1, further comprising:

dynamically controlling a transmit power of the cognitive radio device based on the parameter to meet a quality of service (QoS) requirement for the primary device, wherein the dynamically controlling includes maintaining a predetermined ratio between the transmit power of the cognitive radio device and a transmit power of the primary device.

3. The method according to claim 1, wherein the determining the parameter includes determining the distance between the primary transmitter and the cognitive radio device based on the sensing information.

4. The method according to claim 1, wherein the determining the parameter includes determining a path loss between the primary transmitter and the cognitive radio device based on the sensing information.

5. The method according to claim 1, wherein the determining the parameter includes determining the distance between the primary transmitter and the cognitive radio device based on the average probability of the missing energy detection.

6. The method according to claim 1, wherein the determining the parameter includes determining the parameter as a function of the distance based on the average probability of the missing energy detection.

7. The method according to claim 6, wherein the determining the parameter includes determining the parameter as a path loss function of the distance based on the average probability of the missing energy detection.

8. The method according to claim 1, further comprising increasing the transmit power of the cognitive radio device in response to a decrease in a signal to noise ratio of a transmission between the primary device and the cognitive radio device.

9. A cognitive radio device, comprising:

a spectrum sensing component configured to sense presence information about utilization of a designated portion of a network spectrum by a primary device, wherein the cognitive radio device shares the designated portion of the network spectrum with the primary device; and

a power control component configured to control a transmission power of the cognitive radio device based on a function of an average probability of a missing energy detection of a primary transmitter of the primary device output from the spectrum sensing component.

10. The cognitive radio device according to claim 9, wherein the cognitive radio device is configured to limit interference with the primary device on the designated portion of the network spectrum.

11. The cognitive radio device according to claim 9, wherein the power control component is further configured to control the transmission power of the cognitive radio device based on the primary device being located in a pre-defined location or area in order to satisfy a quality of service (QoS) requirement of the primary device.

12. The cognitive radio device according to claim 9, wherein the power control component is further configured to determine a distance between the primary transmitter of the primary device and the cognitive radio device based on the presence information.

13. The cognitive radio device according to claim 9, wherein the power control component is further configured to determine a path loss characteristic between the primary transmitter of the primary device and the cognitive radio device based on the presence information.

14. The cognitive radio device according to claim 9, wherein the power control component is further configured to control the transmission power of the cognitive radio device based on a distance between the primary device and the cognitive radio device, wherein the distance is calculated based on the average probability of the missing energy detection.

15. The cognitive radio device according to claim 9, wherein the power control component is further configured to control the transmission power of the cognitive radio device based on a path loss function that is mathematically related to a distance between the primary device and the cognitive radio device, wherein the distance is calculated based on a function of probability of the missing energy detection.

16. The cognitive radio device according to claim 9, wherein the transmission power of the cognitive radio device is indirectly proportional to a signal to noise ratio of a transmission between the cognitive radio device and the primary device.

17. A non-transitory computer readable storage medium comprising computer executable instructions that, in response to execution, cause a computing device to perform operations, comprising:

deriving a set of candidate distances between a cognitive radio device and at least one licensed device based on at least one function of average probability of at least one missing energy detection of the at least one licensed device determined from spectrum sensing side information including, determining a shortest distance of the set of candidate distances.

18. The non-transitory computer readable storage medium device of claim 17, the operations further comprising:

dynamically controlling transmit power of the cognitive radio based on the shortest distance to limit interference by the cognitive radio device with the at least one licensed device.

19. The non-transitory computer readable storage medium device of claim 17, wherein the deriving includes deriving, for the at least one licensed device, at least one range of possible distances to the at least one licensed device from the cognitive radio device from the spectrum sensing side information received from the at least one licensed device and the determining includes selecting a closest distance of the at least one range.

20. The non-transitory computer readable storage medium device according to claim 17, wherein the deriving includes deriving at least one path loss characteristic of at least one channel between the at least one licensed device and the cognitive radio device based on the spectrum sensing side information.

21. The non-transitory computer readable storage medium device of claim 17, the operations further comprising:

dynamically increasing the transmit power of the cognitive radio device in response to increasing path loss on the at least channel between the at least one licensed device and the cognitive radio device.

22. A system, comprising:

means for determining a distance, or a function related to the distance, between a primary transmitter of a primary device and a cognitive radio device as a function of average probability of a missing energy detection of the primary transmitter of the primary device from a spectrum sensing means for sensing a presence of the primary device on a shared spectrum based on signals emitted from the primary transmitter; and

means for dynamically controlling a transmit power of the cognitive radio device based on the distance, or the function related to the distance, output from the means for determining to assist in meeting a quality of service (QoS) requirement of the primary device while the cognitive radio device shares the shared spectrum with the primary device.