Combined open loop/closed loop (CQI-based) uplink transmit power control with interference mitigation for E-UTRA
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.
1. A wireless transmit/receive unit (WTRU) comprising:
circuitry 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;
the circuitry further configured to measure pathloss based on a received signal;
the circuitry further configured to determine a transmit power level for a physical uplink channel based on at least the measured pathloss, the TPC information, the MCS information, and a predetermined weighting factor, wherein the predetermined weighting factor has a value from 0 to 1; and
the circuitry further configured to output a signal based on the uplink scheduling information and the determined transmit power level for transmission on a physical uplink channel.
2. The WTRU of claim 1 , wherein the predetermined weighting factor has a value of 0 or 1.
3. The WTRU of claim 1 , wherein the predetermined weighting factor is multiplied to the measured pathloss.
4. The WTRU according to claim 1 , wherein the physical uplink channel is a physical uplink shared channel (PUSCH).
5. The WTRU according to claim 1 , wherein the determined transmit power level is based at least in part on a closed loop power control factor.
6. The WTRU according to claim 1 , wherein the determined transmit power level is based on a maximum transmit power level.
7. The WTRU according to claim 1 , wherein the physical uplink channel is a physical uplink control channel (PUCCH) and the determined transmit power level is further based on a quality factor associated with channel quality indication (CQI) information of the PUCCH.
8. The WTRU of claim 1 , wherein the measured pathloss corresponds to a parameter associated with an open loop potion of a power control scheme for the physical uplink channel.
9. The WTRU of claim 8 , wherein the TPC information and the MCS information correspond to parameters associated with a closed loop portion of the power control scheme for the physical uplink channel.
10. The WTRU of claim 8 , wherein a target signal-to-interference and noise ratio (SINR) is used as a basis to determine a parameter of the open loop portion of the power control scheme for the physical uplink channel.
11. A method, implemented in 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 pathloss based on a received signal;
the WTRU determining a transmit power level for a physical uplink channel based on at least the measured pathloss, the TPC information, the MCS information, and a predetermined weighting factor, wherein the predetermined weighting factor has a value from 0 to 1; and
the WTRU outputting a signal based on the uplink scheduling information and the determined transmit power level for transmission on a physical uplink channel.
12. The method of claim 11 , wherein the predetermined weighting factor has a value of 0 or 1.
13. The method of claim 11 , wherein the predetermined weighting factor is multiplied to the measured pathloss.
14. The method of claim 11 , wherein the physical uplink channel is a physical uplink shared channel (PUSCH).
15. The method of claim 11 , wherein the determined transmit power level is based at least in part on a closed loop power control factor.
16. The method of claim 11 , wherein the determined transmit power level is based on a maximum transmit power level.
17. The method of claim 11 , wherein the physical uplink channel is a physical uplink control channel (PUCCH) and the determined transmit power level is further based on a quality factor associated with channel quality indication (CQI) information of the PUCCH.
18. The method of claim 11 , wherein the TPC information and the MCS information correspond to parameters associated with a closed loop portion of a power control scheme for the physical uplink channel.
19. The method of claim 18 , wherein the measured pathloss corresponds to a parameter associated with an open loop potion of the power control scheme for the physical uplink channel.
20. The method of claim 11 , wherein the TPC information is associated with an outer loop closed loop transmit power control scheme controlled by an evolved Node B (eNodeB).