Device to-device (D2D) cross link power control

• US 9,807,709 B2
• Filed: 05/30/2013
• Issued: 10/31/2017
• 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
• Primary Examiner(s): Sorowar, Golam
• Application Number:
  US13/906,063
• Publication Number:
  US 20130324182A1
• Time in Patent Office: 1,615 Days
• 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 method for controlling a cross link transmit power level on a wireless transmit/receive unit (WTRU), the method comprising:

receiving an explicit indication from a network entity;

selecting a cross link transmit power control (TPC) formula for a transmission from the WTRU to another WTRU, wherein the cross link TPC formula is selected from a plurality of cross link TPC formulas based at least on the received explicit indication;

determining a cross link transmit power level in accordance with at least the selected cross link TPC formula; and

sending the transmission to the other WTRU using the determined cross link transmit power level, wherein a first cross link TPC formula is semi-statically configured and a second cross link TPC formula is calculated based on at least a path loss.

2. The method of claim 1, wherein the cross link transmit power level is further determined in accordance with at least one of:

a path loss or a cross link bandwidth.

3. The method of claim 1, wherein the cross link transmit power level is controlled on a per-transmission time interval (TTI) basis.

4. The method of claim 1, wherein the explicit indication is included in downlink control information (DCI).

5. The method of claim 4, wherein the DCI includes a TPC command and the explicit indication is included in the TPC command.

6. The method of claim 1, wherein the cross link transmit power level is determined in connection with a transmission power level of an uplink (UL) channel between the WTRU and the network entity.

7. The method of claim 1, further comprising determining a cross link power control mode on which the WTRU is operating, wherein the cross link power control mode is associated with the received explicit indication.

8. The method of claim 7, wherein the cross link TPC formula is selected on a condition that the WTRU operates on the cross link power control mode.

9. The method of claim 1, wherein:

a first cross link TPC formula is selected from first and second cross link TPC formulas and is associated with a first one of a plurality of cross link power control modes such that the second crosslink TPC formula, as a non-selected cross link TPC formula, is associated with a second one of the plurality of cross link power control modes.

10. A wireless transmit/receive unit (WTRU) comprising:

a receiver configured to receive an explicit indication from a network entity;

a processor configured to;

select a cross link transmit power control (TPC) formula for a transmission from the WTRU to another WTRU, wherein the cross link TPC formula is selected from a plurality of cross link TPC formulas based at least on the received explicit indication; and

determine a cross link transmit power level in accordance with at least the selected cross link TPC formula; and

a transmitter configured to send the transmission to the other WTRU using the determined cross link transmit power level, wherein a first cross link TPC formula is semi-statically configured and a second cross link TPC formula is calculated based on at least a path loss.

11. The WTRU of claim 10, wherein the processor is configured to determine the cross link transmit power level further in accordance with at least one of:

a path loss or a cross link bandwidth.

12. The WTRU of claim 10, wherein the processor is configured to control the cross link transmit power level on a per-transmission time interval (TTI) basis.

13. The WTRU of claim 10, wherein the explicit indication is included in downlink control information (DCI).

14. The WTRU of claim 13, wherein the DCI includes a TPC command and the explicit indication is included in the TPC command.

15. The WTRU of claim 10, wherein the processor is configured to determine the cross link transmit power level in connection with a transmission power level of an uplink (UL) channel between the WTRU and the network entity.

16. The WTRU of claim 10, wherein the processor is configured to determine a cross link power control mode on which the WTRU is operating, wherein the cross link power control mode is associated with the received explicit indication.

17. The WTRU of claim 16, wherein the cross link TPC formula is selected on a condition that the WTRU operates on the cross link power control mode.

18. The WTRU of claim 10, wherein:

a first cross link TPC formula is selected from first and second cross link TPC formulas and is associated with a first one of a plurality of cross link power control modes such that the second crosslink TPC formula, as a non-selected cross link TPC formula, is associated with a second one of the plurality of cross link power control modes.