Method and Device for Controlling Power of Cognitive Radio System

• US 20140038659A1
• Filed: 10/25/2010
• Published: 02/06/2014
• Est. Priority Date: 09/03/2010
• Status: Active Grant

• Current Assignee: Guangdong OPPO Mobile Telecommunications Corporation Limited
• Original Assignee: ZTE Corporation
• Inventors: Wei, Min, Zhao, Nan, Li, Feng, Tian, Kaibo, Li, Yan
• Granted Patent: US 9,173,173 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04B 17/354 Adjacent channel leakage power
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/243 taking into account interferences
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range

Abstract

The disclosure provides a method and a device for controlling power of a cognitive radio system. The method comprises: measuring a system parameter of a cognitive radio system and a system parameter of a TV system located in an adjacent channel of the cognitive radio system; determining a maximum transmission power of the cognitive radio system according to the system parameter of the cognitive radio system and the system parameter of the TV system; controlling an actual transmission power of the cognitive radio system to be less than the maximum transmission power. In the disclosure, interference to the TV system can be reduced maximally, so that the sensitivity of a receiver inside the TV system is guaranteed.

Claims

1. A method for controlling power of a cognitive radio system, comprising:

measuring a system parameter of a cognitive radio system and a system parameter of a television (TV) system located in an adjacent channel of the cognitive radio system;

determining a maximum transmission power of the cognitive radio system according to the system parameter of the cognitive radio system and the system parameter of the TV system; and

controlling an actual transmission power of the cognitive radio system to be less than the maximum transmission power.

2. The method according to claim 1, wherein according to the system parameter of the cognitive radio system and the system parameter of the TV system, the maximum transmission power P_TX of the cognitive radio system is determined via a following formula:

P_TX=P<sub>RX—

TV</sub>−

R_D/U−

G+ACIR+max{MCL,PL(d)}−

A

wherein P<sub>RX—

TV</sub> refers to a reception power of a place in which a receiver of the TV system locates, R_D/U refers to an expected useful-signal-to-interference-signal power ratio of the receiver of the TV system, G refers to a sum of a gain of a transmitting antenna of the cognitive radio system and a gain of a receiving antenna of the TV system, ACIR refers to an adjacent channel interference ratio of a coexistence system formed by the cognitive radio system and the TV system, MCL refers to a minimum coupling loss of the coexistence system, d refers to a distance between the receiver of the TV system and a transmitter of the cognitive radio system, PL(d) refers to a path loss between the cognitive radio system and the TV system, and A refers to an effective output power activity factor of the transmitting antenna of the cognitive radio system.

3. The method according to claim 2, wherein the reception power P_RX—

_TV of the place in which the receiver of the TV system locates is determined via a following formula;

R<sub>RX—

TV</sub>=min{P<sub>RX—

TV—

L</sub>,P<sub>RX—

TV—

R</sub>}

wherein P<sub>RX—

TV—

L</sub> refers to a TV reception power of a left adjacent channel of a TV white space occupied by the cognitive radio system, and P<sub>RX—

TV—

R</sub> refers to a TV reception power of a right adjacent channel of the TV white space occupied by the cognitive radio system.

4. The method according to claim 3, wherein when there is no signal of the TV system in the right adjacent channel, P_RX—

_TV=P<sub>RX—

TV—

L</sub>;

when there is no signal of the TV system in the left adjacent channel, P<sub>RX—

TV</sub>=P<sub>RX—

TV—

R</sub>.

5. The method according to claim 1, wherein

the system parameter of the cognitive radio system comprises at least one of:

a gain of a transmitting antenna of the cognitive radio system, an adjacent channel interference ratio of a coexistence system formed by the cognitive radio system and the TV system, a minimum coupling loss of the coexistence system, and an effective output power activity factor of the transmitting antenna of the cognitive radio system;

the system parameter of the TV system comprises at least one of;

a gain of a receiving antenna of the TV system, a reception power of a place in which a receiver of the TV system locates, an expected useful-signal-to-interference-signal power ratio of the receiver of the TV system, a distance between the receiver of the TV system and a transmitter of the cognitive radio system, and a path loss between the cognitive radio system and the TV system.

6. The method according to claim 1, wherein the actual transmission power of the cognitive radio system is controlled to be less than the maximum transmission power in at least one of the following ways:

increase of filters, increase of spectrum isolation belts, and increase of a space interval between a receiver and a transmitter.

7. The method according to claim 1, wherein after controlling the actual transmission power of the cognitive radio system to be less than the maximum transmission power, the method further comprises:

determining a maximum value of an interference power received by the cognitive radio system;

judging whether the maximum value is less than a maximum interference power allowable in the cognitive radio system;

if it is judged that the maximum value is less than the maximum interference power allowable in the cognitive radio system, determining that the cognitive radio system and the TV system coexist.

8. The method according to claim 7, wherein the maximum value I of the interference power received by the cognitive radio system is determined via a following formula:

I=P<sub>TX—

TV</sub>+G+A_TV−

ACIR_TV−

PL(d)

wherein P<sub>TX—

TV</sub> refers to a transmission power of a transmitter of the TV system, G refers to a sum of a gain of a transmitting antenna of the TV system and a gain of a receiving antenna of the cognitive radio system, A_TV refers to an activity factor, ACIR_TV refers to an adjacent channel leakage ratio, d refers to a distance between the transmitter of the TV system and a receiver of the cognitive radio system, and PL(d) refers to a path loss between the cognitive radio system and the TV system.

9. The method according to claim 7, wherein if it is judged that the maximum value is not less than the maximum interference power allowable in the cognitive radio system, an out-of-band leakage of the TV system is reduced in at least one of the following ways:

increase of filters, increase of spectrum isolation belts, increase of a space interval between a receiver and a transmitter, and a pre-distortion.

12. The method according to claim 2, wherein after controlling the actual transmission power of the cognitive radio system to be less than the maximum transmission power, the method further comprises:

determining a maximum value of an interference power received by the cognitive radio system;

judging whether the maximum value is less than a maximum interference power allowable in the cognitive radio system;

if it is judged that the maximum value is less than the maximum interference power allowable in the cognitive radio system, determining that the cognitive radio system and the TV system coexist.

13. The method according to claim 3, wherein after controlling the actual transmission power of the cognitive radio system to be less than the maximum transmission power, the method further comprises:

determining a maximum value of an interference power received by the cognitive radio system;

judging whether the maximum value is less than a maximum interference power allowable in the cognitive radio system;

if it is judged that the maximum value is less than the maximum interference power allowable in the cognitive radio system, determining that the cognitive radio system and the TV system coexist.

14. The method according to claim 4, wherein after controlling the actual transmission power of the cognitive radio system to be less than the maximum transmission power, the method further comprises:

determining a maximum value of an interference power received by the cognitive radio system;

judging whether the maximum value is less than a maximum interference power allowable in the cognitive radio system;

if it is judged that the maximum value is less than the maximum interference power allowable in the cognitive radio system, determining that the cognitive radio system and the TV system coexist.

15. The method according to claim 12, wherein the maximum value I of the interference power received by the cognitive radio system is determined via a following formula:

I=P<sub>TX—

TV</sub>+G+A_TV−

ACIR_TV−

PL(d)

wherein P<sub>TX—

TV</sub> refers to a transmission power of a transmitter of the TV system, G refers to a sum of a gain of a transmitting antenna of the TV system and a gain of a receiving antenna of the cognitive radio system, A_TV refers to an activity factor, ACIR_TV refers to an adjacent channel leakage ratio, d refers to a distance between the transmitter of the TV system and a receiver of the cognitive radio system, and PL(d) refers to a path loss between the cognitive radio system and the TV system.

16. The method according to claim 13, wherein the maximum value I of the interference power received by the cognitive radio system is determined via a following formula:

I=P<sub>TX—

TV</sub>+G+A_TV−

ACIR_TV−

PL(d)

wherein P<sub>TX—

TV</sub> refers to a transmission power of a transmitter of the TV system, G refers to a sum of a gain of a transmitting antenna of the TV system and a gain of a receiving antenna of the cognitive radio system, A_TV refers to an activity factor, ACIR_TV refers to an adjacent channel leakage ratio, d refers to a distance between the transmitter of the TV system and a receiver of the cognitive radio system, and PL(d) refers to a path loss between the cognitive radio system and the TV system.

17. The method according to claim 14, wherein the maximum value I of the interference power received by the cognitive radio system is determined via a following formula:

I=P<sub>TX—

TV</sub>+G+A_TV−

ACIR_TV−

PL(d)

wherein P<sub>TX—

TV</sub> refers to a transmission power of a transmitter of the TV system, G refers to a sum of a gain of a transmitting antenna of the TV system and a gain of a receiving antenna of the cognitive radio system, A_TV refers to an activity factor, ACIR_TV refers to an adjacent channel leakage ratio, d refers to a distance between the transmitter of the TV system and a receiver of the cognitive radio system, and PL(d) refers to a path loss between the cognitive radio system and the TV system.

18. The method according to claim 12, wherein if it is judged that the maximum value is not less than the maximum interference power allowable in the cognitive radio system, an out-of-band leakage of the TV system is reduced in at least one of the following ways:

increase of filters, increase of spectrum isolation belts, increase of a space interval between a receiver and a transmitter, and a pre-distortion.

19. The method according to claim 13, wherein if it is judged that the maximum value is not less than the maximum interference power allowable in the cognitive radio system, an out-of-band leakage of the TV system is reduced in at least one of the following ways:

increase of filters, increase of spectrum isolation belts, increase of a space interval between a receiver and a transmitter, and a pre-distortion.

20. The method according to claim 14, wherein if it is judged that the maximum value is not less than the maximum interference power allowable in the cognitive radio system, an out-of-band leakage of the TV system is reduced in at least one of the following ways:

increase of filters, increase of spectrum isolation belts, increase of a space interval between a receiver and a transmitter, and a pre-distortion.

10. A device for controlling power of a cognitive radio system, comprising:

a measurement module, configured to measure a system parameter of a cognitive radio system and a system parameter of a TV system located in an adjacent channel of the cognitive radio system;

a determination module, configured to determine a maximum transmission power of the cognitive radio system according to the system parameter of the cognitive radio system and the system parameter of the TV system; and

a control module, configured to control an actual transmission power of the cognitive radio system to be less than the maximum transmission power.

11. The device according to claim 10, wherein the determination module is further configured to determine the maximum transmission power P_TX of the cognitive radio system via a following formula:

P_TX=P<sub>RX—

TV</sub>−

R_D/U−

G+ACIR+max{MCL,PL(d)}−

A

wherein P<sub>RX—

TV</sub> refers to a reception power of a place in which a receiver of the TV system locates, R_D/U refers to an expected useful-signal-to-interference-signal power ratio of the receiver of the TV system, G refers to a sum of a gain of a transmitting antenna of the cognitive radio system and a gain of a receiving antenna of the TV system, ACIR refers to an adjacent channel interference ratio of a coexistence system formed by the cognitive radio system and the TV system, MCL refers to a minimum coupling loss of the coexistence system, d refers to a distance between the receiver of the TV system and a transmitter of the cognitive radio system, PL(d) refers to a path loss between the cognitive radio system and the TV system, and A refers to an effective output power activity factor of the transmitting antenna of the cognitive radio system.