TRANSMIT POWER ADJUSTMENT FOR INTER-DEVICE COMMUNICATION IN WIRELESS COMMUNICATION SYSTEMS

• US 20140086157A1
• Filed: 09/26/2012
• Published: 03/27/2014
• Est. Priority Date: 09/26/2012
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Bontu, Chandra Sekhar, Song, Yi, Cai, Zhijun
• Granted Patent: US 10,154,467 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/383 power control in peer-to-peer links

Abstract

Systems and methods for user equipment (UE) transmit power adjustment for inter-device communication in wireless communication systems are provided. A UE may communicate directly with another UE over a direct inter-device communication link when they are located in proximity. The UE may adjust its transmit power for the inter-device communication during a device handshake/discovery procedure. For example, the UE may adjust its transmit power for the inter-device communication based on a data exchange between the UE and the other UE over the inter-device communication link. Long term evolution (LTE) downlink or uplink radio resources may be used for the data exchange over the inter-device communication link.

Claims

1. A method for wireless communication, comprising:

determining whether to adjust a transmit power level associated with a user equipment (UE) based on a data exchange between the UE and at least one other UE over an inter-device communication link; and

adjusting the transmit power level based on the determination.

2. The method of claim 1, further comprising:

transmitting a first sequence to the at least one other UE over an inter-device communication link;

receiving the first sequence from the at least one other UE over the inter-device communication link;

increasing a transmit power level of the UE; and

using the increased transmit power level of the UE for a next transmission to the at least one other UE over the inter-device communication link.

3. The method of claim 2, further comprising:

receiving a second sequence from the at least one other UE over the inter-device communication link, the second sequence being different from the first sequence; and

maintaining the transmit power level of the UE for subsequent transmissions to the at least one other UE over the inter-device communication link.

4. The method of claim 3, further comprising:

sending a response message to a base station indicating a completion of a device handshake procedure, in response to receiving the second sequence.

5. The method of claim 2, wherein the increased transmit power level of the UE does not exceed a maximum transmit power level of the UE.

6. The method of claim 2, wherein the transmit power level of the UE is greater than a minimum transmit power level of the UE.

7. The method of claim 2, wherein the transmit power level of the UE is increased by a predetermined transmit power increment value.

8. The method of claim 2, further comprising:

determining whether signal quality of the received first sequence is above a predetermined threshold; and

transmitting a second sequence to the at least one other UE over the inter-device communication link, using the increased transmit power level of the UE, when the signal quality of the received first sequence is above a predetermined threshold.

9. The method of claim 8, further comprising:

transmitting the first sequence to the at least one other UE over the inter-device communication link, using the increased transmit power level of the UE, when the signal quality of the received first sequence is below a predetermined threshold.

10. The method of claim 2, further comprising:

determining that the increased transmit power level of the UE exceeds a maximum transmit power of the UE; and

sending a response message to a base station indicating a failure of a device handshake procedure.

11. The method of claim 2, further comprising:

receiving an initiation message from a base station for initiating a device handshake procedure, prior to transmitting the first sequence to the at least one other UE.

12. The method of claim 11, wherein the initiation message from the base station includes resource allocation for the transmission of the first sequence to the at least one other UE over the inter-device communication link.

13. The method of claim 11, wherein the initiation message from the base station is received using a device-to-device radio network temporary identity (DD-RNTI).

14. The method of claim 11, wherein the initiation message from the base station is received using a downlink control information (DCI) format which includes a field indicating that the initiation message is for the inter-device communication link.

15. The method of claim 11, wherein the initiation message from the base station includes a transmit point identification of the UE.

16. The method of claim 11, further comprising:

receiving a radio resource control (RRC) inter-device connection setup message from the base station; and

sending a RRC inter-device connection setup response message to the base station.

17. The method of claim 16, wherein the RRC inter-device connection setup message includes at least one of:

a cell radio network temporary identity (C-RNTI) of the at least one other UE;

a temporary transmit point identification of the UE;

a minimum and/or maximum transmit power level for the UE transmitting over the inter-device communication link;

a device-to-device radio network temporary identity (DD-RNTI);

a set of predefined sequences;

a channel quality indicator (CQI) threshold;

a transmit power incremental value for the UE; and

a guard time.

18. The method of claim 11, wherein the at least one other UE receives the initialization message from the base station and detects the first sequence in response to receiving the initialization message.

19. The method of claim 2, wherein the UE transmits the first sequence using long term evolution (LTE) downlink resources.

20. The method of claim 2, wherein the UE transmits the first sequence using long term evolution (LTE) uplink resources.

21. A user equipment (UE) configured to:

determine whether to adjust a transmit power level associated with the UE based on a data exchange between the UE and at least one other UE over an inter-device communication link; and

adjust the transmit power level based on the determination.

22. The user equipment of claim 21, further configured to:

transmit a first sequence to the at least one other UE over an inter-device communication link;

receive the first sequence from the at least one other UE over the inter-device communication link;

increase a transmit power level of the UE; and

use the increased transmit power level of the UE for a next transmission to the at least one other UE over the inter-device communication link.

23. The user equipment of claim 22, further configured to:

receive a second sequence from the at least one other UE over the inter-device communication link, the second sequence being different from the first sequence; and

maintain the transmit power level of the UE for subsequent transmissions to the at least one other UE over the inter-device communication link.

24. The user equipment of claim 23, further configured to:

send a response message to a base station indicating a completion of a device handshake procedure, in response to receiving the second sequence.

25. The user equipment of claim 22, wherein the increased transmit power level of the UE does not exceed a maximum transmit power level of the UE.

26. The user equipment of claim 22, wherein the transmit power level of the UE is greater than a minimum transmit power level of the UE.

27. The user equipment of claim 22, wherein the transmit power level of the UE is increased by a predetermined transmit power increment value.

28. The user equipment of claim 22, further configured to:

determine whether signal quality of the received first sequence is above a predetermined threshold; and

transmit a second sequence to the at least one other UE over the inter-device communication link, using the increased transmit power level of the UE, when the signal quality of the received first sequence is above a predetermined threshold.

29. The user equipment of claim 28, further configured to:

transmit the first sequence to the at least one other UE over the inter-device communication link, using the increased transmit power level of the UE, when the signal quality of the received first sequence is below a predetermined threshold.

30. The user equipment of claim 22, further configured to:

determine that the increased transmit power level of the UE exceeds a maximum transmit power of the UE; and

send a response message to a base station indicating a failure of a device handshake procedure.

31. The user equipment of claim 22, further configured to:

receive an initiation message from a base station for initiating a device handshake procedure, prior to transmitting the first sequence to the at least one other UE.

32. The user equipment of claim 31, wherein the initiation message from the base station includes resource allocation for the transmission of the first sequence to the at least one other UE over the inter-device communication link.

33. The user equipment of claim 31, wherein the initiation message from the base station is received using a device-to-device radio network temporary identity (DD-RNTI).

34. The user equipment of claim 31, wherein the initiation message from the base station is received using a downlink control information (DCI) format which includes a field indicating that the initiation message is for the inter-device communication link.

35. The user equipment of claim 31, wherein the initiation message from the base station includes a transmit point identification of the UE.

36. The user equipment of claim 31, further configured to:

receive a radio resource control (RRC) inter-device connection setup message from the base station; and

send a RRC inter-device connection setup response message to the base station.

37. The user equipment of claim 36, wherein the RRC inter-device connection setup message includes at least one of:

a cell radio network temporary identity (C-RNTI) of the at least one other UE;

a temporary transmit point identification of the UE;

a minimum and/or maximum transmit power level for the UE transmitting over the inter-device communication link;

a device-to-device radio network temporary identity (DD-RNTI);

a set of predefined sequences;

a channel quality indicator (CQI) threshold;

a transmit power incremental value for the UE; and

a guard time.

38. The user equipment of claim 31, wherein the at least one other UE receives the initialization message from the base station and detects the first sequence in response to receiving the initialization message.

39. The user equipment of claim 22, wherein the UE transmits the first sequence using long term evolution (LTE) downlink resources.

40. The user equipment of claim 22, wherein the UE transmits the first sequence using long term evolution (LTE) uplink resources.