COMBINED OPEN LOOP/CLOSED LOOP (CQI-BASED) UPLINK TRANSMIT POWER CONTROL WITH INTERFERENCE MITIGATION FOR E-UTRA

• US 20150195793A1
• Filed: 03/20/2015
• Published: 07/09/2015
• Est. Priority Date: 10/03/2006
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Shin, Sung-Hyuk, Grieco, Donald M., Olesen, Robert L.
• Granted Patent: US 10,070,397 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 5/0057 Physical resource allocation for CQI
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/10 Open loop power control
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
• 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 52/262 taking into account adaptive modulation and coding [AMC] scheme AMC per se H04L1/0001
• CPC Class Codes: H04W 52/265 taking into account the quality of service QoS
• CPC Class Codes: H04W 52/286 during data packet transmission, e.g. high speed packet access [HSPA]

Abstract

A combined open loop and closed loop (channel quality indicator (CQI)-based) transmit power control (TPC) scheme with interference mitigation for a long term evolution (LTE) wireless transmit/receive unit (WTRU) is disclosed. The transmit power of the WTRU is derived based on a target signal-to-interference noise ratio (SINR) and a pathloss value. The pathloss value pertains to the downlink signal from a serving evolved Node-B (eNodeB) and includes shadowing. An interference and noise value of the serving eNodeB is included in the transmit power derivation, along with an offset constant value to adjust for downlink (DL) reference signal power and actual transmit power. A weighting factor is also used based on the availability of CQI feedback.

Claims

1. A wireless transmit/receive unit (WTRU) configured to:

receive a downlink control message, the downlink control message comprising uplink scheduling information, wherein the uplink scheduling information comprises modulation and coding set (MCS) information and transmit power control (TPC) information;

measure a pathloss based on a received signal;

determine a transmit power level for a uplink shared channel transmission using a combined open loop and closed loop power control scheme, wherein an open loop power control parameter for the combined open loop and closed loop power control scheme comprises the measured pathloss, and a closed loop power correction factor for the combined open loop and closed loop power control scheme is based on at least the TPC information and the MCS information; and

transmit the uplink shared channel transmission at the determined transmit power level in accordance with the uplink scheduling information.

2. The WTRU of claim 1, wherein the determined transmit power level is further based on a predetermined weighting factor, and the predetermined weighting factor has a value from 0 to 1.

3. The WTRU of claim 1, wherein the WTRU being configured to determine the transmit power level for the uplink shared channel transmission using the combined open loop and closed loop power control scheme comprises the WTRU being configured to:

set an initial transmit power level for the uplink shared channel transmission using an open loop portion of the combined open loop and closed loop power control scheme; and

adjust the initial transmit power level to the determined transmit power level using a closed loop portion of the combined open loop and closed loop power control scheme.

4. The WTRU according to claim 3, wherein the open loop portion of the combined open loop and closed loop power control scheme is based on at least the measured pathloss.

5. The WTRU according to claim 3, wherein the closed loop portion of the combined open loop and closed loop power control scheme is based on the closed loop power correction factor determined based on at least the TPC information and the MCS information.

6. The WTRU according to claim 3, wherein at least one parameter of the open loop portion of the combined open loop and closed loop power control scheme is based on a target signal-to-interference and noise ratio (SINR).

7. The WTRU according to claim 1, wherein the determined transmit power level is further based on a maximum transmit power level.

8. A method implemented by a wireless transmit/receive unit (WTRU), the method comprising:

the WTRU receiving a downlink control message, the downlink control message comprising uplink scheduling information, wherein the uplink scheduling information comprises modulation and coding set (MCS) information and transmit power control (TPC) information;

the WTRU measuring a pathloss based on a received signal;

the WTRU determining a transmit power level for a uplink shared channel transmission using a combined open loop and closed loop power control scheme, wherein an open loop power control parameter for the combined open loop and closed loop power control scheme comprises the measured pathloss, and a closed loop power correction factor for the combined open loop and closed loop power control scheme is based on at least the TPC information and the MCS information; and

the WTRU transmitting the uplink shared channel transmission at the determined transmit power level in accordance with the uplink scheduling information.

9. The method of claim 8, wherein the determined transmit power level is further based on a predetermined weighting factor, and the predetermined weighting factor has a value from 0 to 1.

10. The method of claim 8, wherein the WTRU determining the transmit power level for the uplink shared channel transmission using the combined open loop and closed loop power control scheme comprises:

the WTRU setting an initial transmit power level for the uplink shared channel transmission using an open loop portion of the combined open loop and closed loop power control scheme; and

the WTRU adjusting the initial transmit power level to the determined transmit power level using a closed loop portion of the combined open loop and closed loop power control scheme.

11. The method of claim 10, wherein the open loop portion of the combined open loop and closed loop power control scheme is based on at least the measured pathloss.

12. The method of claim 10, wherein the closed loop portion of the combined open loop and closed loop power control scheme is based on the closed loop power correction factor determined based on at least the TPC information and the MCS information.

13. The method of claim 10, wherein at least one parameter of the open loop portion of the combined open loop and closed loop power control scheme is based on a target signal-to-interference and noise ratio (SINR).

14. The method of claim 8, wherein the determined transmit power level is further based on a maximum transmit power level.