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

• US 8,521,094 B2
• Filed: 10/11/2012
• Issued: 08/27/2013
• 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:
  US13/649,875
• Publication Number:
  US 20130035133A1
• Time in Patent Office: 320 Days
• Field of Search: None
• US Class Current: 455/67.11
• 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, by a computing device including a processor, an average probability of a missing energy detection of a primary transmitter of a primary device based on sensing information associated with a cognitive radio device; and

determining, by the computing device, a distance parameter between the primary transmitter and the cognitive radio device based upon the average probability of the missing energy detection.

2. The method of claim 1, further comprising:

controlling, by the computing device, a transmit power of the cognitive radio device based on the distance parameter to meet a quality of service requirement for the primary device.

3. The method of claim 2, wherein the controlling the transmit power comprises:

determining a maximum transmit power that meets the quality of service requirement based upon a path loss function of the distance parameter; and

limiting the transmit power to the maximum transmit power.

4. The method of claim 1, wherein the determining the distance parameter comprises:

determining a plurality of candidate distances between the primary transmitter and the cognitive radio device based upon the average probability of the missing energy detection; and

setting the distance parameter to a shortest distance of the plurality of candidate distances.

5. The method of claim 1, further comprising:

determining, by the computing device, the sensing information by monitoring energy of a signal received by the cognitive radio device in a predetermined bandwidth for predetermined period of time.

6. A cognitive radio device, comprising:

a spectrum sensing component configured to;

estimate an average probability of a missing energy detection of a primary transmitter of a primary device based on sensing information associated with a cognitive radio device; and

estimate a distance parameter between the primary transmitter and the cognitive radio device based upon the average probability of the missing energy detection.

7. The cognitive radio device of claim 6, further comprising:

a power control component configured to adjust a transmit power of the cognitive radio device based on the distance parameter to meet a quality of service requirement for the primary device.

8. The cognitive radio device of claim 7, wherein the power control component is further configured to:

determine a maximum transmit power that meets the quality of service requirement based upon a path loss function of the distance parameter; and

prevent the transmit power from exceeding the maximum transmit power.

9. The cognitive radio device of claim 6, wherein the spectrum sensing component is further configured to:

identify a plurality of candidate distances between the primary transmitter and the cognitive radio device based upon the average probability of the missing energy detection; and

set the distance parameter to a shortest distance of the plurality of candidate distances.

10. The cognitive radio device of claim 6, wherein the spectrum sensing component is further configured to determine the sensing information by monitoring energy of a signal received by the cognitive radio device in a predetermined spectrum for at least one predetermined time slot.

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

approximating an average probability of a missing energy detection of a primary transmitter of a primary device based on sensing information associated with a cognitive radio device; and

identifying a distance parameter between the primary transmitter and the cognitive radio device based upon the average probability of the missing energy detection.

12. The non-transitory computer readable storage medium of claim 11, wherein the operations further comprise modifying a transmit power of the cognitive radio device based on the distance parameter to meet a quality of service requirement for the primary device.

13. The non-transitory computer readable storage medium of claim 12, wherein the operations further comprise:

identifying a maximum transmit power that meets the quality of service requirement based upon a path loss function of the distance parameter; and

inhibiting the transmit power from exceeding the maximum transmit power.

14. The non-transitory computer readable storage medium of claim 11, wherein the identifying the distance parameter comprises:

estimating a plurality of candidate distances between the primary transmitter and the cognitive radio device based upon the average probability of the missing energy detection; and

selecting a distance as a function of a shortest distance of the plurality of candidate distances as the distance parameter.

15. The non-transitory computer readable storage medium of claim 11, wherein the operations further comprise obtaining the sensing information by monitoring energy of a signal received by the cognitive radio device in a predetermined bandwidth for one or more predetermined time intervals.

16. A system, comprising:

means for calculating an average probability of a missing energy detection of a primary transmitter of a primary device based on sensing information associated with a cognitive radio device; and

means for determining a distance parameter between the primary transmitter and the cognitive radio device based upon the average probability of the missing energy detection.

17. The system of claim 16, further comprising:

means for setting a transmit power of the cognitive radio device based on the distance parameter to meet a quality of service requirement for the primary device.

18. The system of claim 17, further comprising:

means for determining a maximum transmit power that meets the quality of service requirement based upon a path loss function of the distance parameter; and

means for blocking the transmit power from exceeding the maximum transmit power.

19. The system of claim 16, wherein the means for determining the distance parameter comprises:

means for identifying a plurality of candidate distances between the primary transmitter and the cognitive radio device based upon the average probability of the missing energy detection; and

means for setting the distance parameter to a shortest distance of the plurality of candidate distances.

20. The system of claim 16, further comprising:

means for determining the sensing information by monitoring energy of a signal received by the cognitive radio device in at least one predetermined spectrum for at least one predetermined time period.