DEVICE-TO-DEVICE (D2D) CROSS LINK POWER CONTROL

• US 20130324182A1
• Filed: 05/30/2013
• Published: 12/05/2013
• Est. Priority Date: 05/31/2012
• Status: Active Grant

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Inventors: Deng, Tao, Sternberg, Gregory S., Marinier, Paul, Poitau, Gwenael, Rudolf, Marian
• Granted Patent: US 9,807,709 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/281 taking into account user or data type priority
• CPC Class Codes: H04W 52/346 distributing total power among users or channels
• CPC Class Codes: H04W 52/365 Power headroom reporting
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/383 power control in peer-to-peer links
• CPC Class Codes: H04W 52/386 centralized, e.g. when the radio network controller or equivalent takes part in the power control
• CPC Class Codes: H04W 76/14 Direct-mode setup
• CPC Class Codes: H04W 76/15 Setup of multiple wireless link connections
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: H04W 92/18 between terminal devices

Abstract

Device-to-device (D2D) cross link power control systems and methods may be disclosed. For example, a device such as a UE or WTRU may determine whether it may have simultaneous transmissions where at least one of the transmissions may include a cross link transmission. The device may further determine whether a total transmit power of the simultaneous transmissions may exceed a maximum transmit power of the device. If the device may have simultaneous transmissions and such transmissions may exceed the maximum transmit power, the device may reallocate power based on a priority or priority setting. The device may further determine a maximum cross link power, a maximum device power, and a cross link transmit power level such that the device may further control the power for transmissions based thereon.

Claims

1. A wireless transmit and receive unit (WTRU), the WTRU configured to:

determine whether the WTRU has simultaneous transmissions, wherein at least one of the transmissions comprise a cross link transmission;

determine whether a total transmit power of the simultaneous transmissions exceeds a maximum transmit power of the WTRU; and

reallocate power based on a priority when the WTRU has simultaneous transmissions and the total transmit power exceeds a maximum transmit power of the WTRU.

2. The WTRU of claim 1, wherein the simultaneous transmissions comprise an uplink transmission and a cross link transmission.

3. The WTRU of claim 2, wherein the priority for reallocating the power comprises a combined uplink and crosslink channel power allocation in a priority order of transmissions on or with PUCCH, then PUSCH with L1 or L2 control signaling, then XPCCH, then PUSCH without the L1 or L2 control signaling, and then SRS.

4. The WTRU of claim 2, wherein the priority for reallocating the power comprises a combined uplink and cross link channel power allocation in a priority order of transmissions on or with PRACH and then XPCCH or XPDCH.

5. The WTRU of claim 2, wherein the priority for reallocating the power comprises a combined uplink and crosslink channel power allocation in a priority order of transmissions on or with PUCCH, then PUSCH with L1 or L2 control signaling, then PUSCH without the L1 or L2 control signaling, then XPDCH, and then SRS.

6. The WTRU of claim 2, wherein the simultaneous transmissions further comprise transmissions on a XPCCH and a XPDCH.

7. The WTRU of claim 6, wherein the priority for reallocating the power comprises a combined uplink and crosslink channel power allocation in a priority order of transmissions on or with PUCCH, then PUSCH with L1 or L2 control signaling, then XPCCH, then PUSCH without the L1 or L2 control signaling, then XPDCH and then SRS.

8. The WTRU of claim 6, wherein the priority for reallocating the power comprises a combined uplink and cross link channel power allocation in a priority order of transmissions on or with PRACH, then XPCCH, and then XPDCH.

9. The WTRU of claim 2, wherein the simultaneous transmissions further comprise transmissions with XPNDCH.

10. The WTRU of claim 9, wherein the priority for reallocating the power comprises a combined uplink and crosslink channel power allocation in a priority order of transmissions on or with XPNDCH, then PUCCH, then PUSCH with L1 or L2 control signaling, then PUSCH without the L1 or L2 control signaling, and then SRS.

11. The WTRU of claim 9, wherein the priority for reallocating the power comprises a combined uplink and cross link channel power allocation in a priority order of transmissions on or with XPNDCH and then PRACH.

12. A method for controlling power on a device supporting simultaneous transmissions, the method comprising:

determining, at the device, a cross link transmit power level; and

controlling a transmission power used for communicating to another device based on the determined cross link power level.

13. The method of claim 12, wherein the cross link transmit power level is determined based on cross link power headroom and signal and interference measurements.

14. The method of claim 12, wherein the transmission power is controlled on a per-transmission time interval (TTI) basis.

15. The method of claim 12, further comprising determining dynamic offsets to apply to the cross link power level based on transmission parameters.

16. The method of claim 15, wherein the transmission parameters comprise at least one of bandwidth, transport format, and transmit power control (TPC) commands.

17. The method of claim 16, wherein at least one TPC command is received from either a downlink channel or a cross link channel.

18. The method of claim 12, further comprising receiving the cross link transmit power level from a network component.

19. The method of claim 12, wherein the cross link transmit power level used is tied to at least one of the following:

a transmission power of an uplink (UL) channel or signal or a transmission power used for a latest transmission of a discovery signal.

20. The method of claim 12, wherein the cross link transmit power level is configured to be determined based on multiple power control modes.

21. A wireless transmit and receive unit (WTRU) configured to:

determine a maximum cross link power and a maximum WTRU power; and

control power for transmissions including at least one cross link transmission on the WTRU such that the power for the transmissions does not exceed the maximum WTRU power and the power for the at least one cross link transmission does not exceed the maximum cross-link power.

22. The WTRU of claim 21, wherein the at least one of the maximum cross link power or the maximum WTRU power is determined based on one or more of the following:

a power class associated with the WTRU, a signaled maximum power, MPR of an uplink or cross link band, AMPR of an uplink or cross link band, PMPR of an uplink or cross link band, or tolerances.

23. The WTRU of claim 21, wherein the maximum WTRU power is determined based on whether the simultaneous transmissions provided by the WTRU.

24. The WTRU of claim 21, wherein the WTRU is further configured to:

receive an updated maximum cross link power; and

adjust the maximum cross link power based on the received updated cross link power.

25. The WTRU of claim 24, wherein the updated maximum cross link power is received via at least one of the following:

a P-Max information element (IE), a semi-static grant, an RRC IE, RRC signaling, or a DCI format.