Combined open loop/closed loop method for controlling uplink power of a mobile station
A method and apparatus are disclosed comprising a combined open loop/closed loop uplink power control scheme for E-UTRA. The combined open and closed loop method for UL intra-cell PC controls the wireless transmit receive unit (WTRU) transmit power spectral density (PSD), PSD Tx , (e.g. power per RB).
1. A method for controlling transmit power of a wireless transmit/receive unit (WTRU) comprising:
determining an open loop uplink (UL) power control (PC) component based on pathloss measurement;
determining a closed loop PC component including a correction factor, wherein the correction factor is based on a PC correction command signaled in a UL grant associated with a hybrid automatic repeat request (HARQ) process;
combining the open loop component and the closed loop PC component with a delta factor related to an offset value to determine a transmit power, wherein the offset value is related to a modulation coding set (MCS); and
applying the transmit power in accordance with a timing of the HARQ process.
2. The method of claim 1 , further comprising:
receiving the PC correction command.
3. The method of claim 2 , wherein the PC correction command is received in a pre-configured signaling time.
4. The method of claim 1 , wherein the open loop PC component is based on the pathloss variation.
5. The method of claim 4 , wherein the pathloss variation is a variation between the pathloss prior to a discontinuous transmission and a time before resuming an UL transmission.
6. The method of claim 1 , wherein the PC correction command comprises multiple command bits determined based on link quality.
7. The method of claim 1 , wherein applying the transmit power in accordance with a timing of the HARQ process comprises:
applying the transmit power to the beginning of a next uplink transmit time interval (TTI) until a next transmit power update.
8. The method of claim 1 , wherein the correction factor is zero (0) in an initial uplink transmission.
9. The method of claim 1 , further comprising:
determining an interference load indicator the interference loud indicator determined from a strongest neighboring cell.
10. The method of claim 9 , wherein the transmit power is based on a downlink reference signal wherein the interference load indicator is used to mitigate inter-cell interference.
11. A wireless transmit/receive unit (WTRU) comprising a processor, wherein the processor is configured to:
determine an open loop uplink (UL) power control (PC) component based on pathloss measurement;
determine a closed loop PC component including a correction factor, wherein the correction factor is based on a PC correction command signaled in a UL grant associated with a hybrid automatic repeat request (HARQ) process;
combine the open loop component and the closed loop PC component with a delta factor related to offset value to determine a WTRU transmit power, wherein the offset value is related to a modulation coding set (MCS); and
apply the transmit power in accordance with a timing of the HARQ process.
12. The WTRU of claim 11 , further comprising:
a receiver for receiving the PC correction.
13. The WTRU of claim 12 , wherein the PC correction command is received in a pre-configured signaling time.
14. The WTRU of claim 11 , wherein the open loop PC component is based on a pathloss variation.
15. The WTRU of claim 14 , wherein the pathloss variation is a variation between the pathloss prior to a discontinuous transmission (DTX) and a time before resuming an UL transmission.
16. The WTRU of claim 11 , wherein the PC correction command comprises multiple command bits determined based on link quality.
17. The WTRU of claim 11 , wherein:
the transmit power is applied to the beginning of a next uplink transmit time interval (TTI) until a next transmit power update.
18. The WTRU of claim 11 , wherein the correction factor is zero (0) in an initial uplink transmission.
19. The WTRU of claim 11 , wherein the processor determines an interference load indicator the interference load indicator determined from a strongest neighboring cell.
20. The WTRU of claim 19 , wherein the transmit power is based on a downlink reference signal wherein the interference loud indicator is used to mitigate inter-cell interference.
21. The method of claim 2 , wherein the open loop PC component comprises a cell-specific parameter.
22. The method of claim 21 , wherein the cell-specific parameter is provided from higher layers.
23. The method of claim 21 , wherein the open loop PC component comprises a WTRU-specific parameter.
24. The method of claim 23 , wherein the WTRU-specific parameter is provided from higher layers.
25. The method of claim 2 , wherein the open loop PC component comprises a WTRU-specific parameter.
26. The method of claim 25 , wherein the WTRU-specific parameter is provided from higher layers.
27. The method of claim 1 , wherein applying the transmit power in accordance with a timing of the HARQ process comprises: applying the transmit power after one HARQ cycle time.
28. The WTRU of claim 12 , wherein the open loop PC component comprises a cell-specific parameter.
29. The WTRU of claim 28 , wherein the cell-specific parameter is provided from higher layers.
30. The WTRU of claim 28 , wherein the open loop PC component comprises a WTRU-specific parameter.
31. The WTRU of claim 30 , wherein the WTRU-specific parameter is provided from higher layers.
32. The WTRU of claim 12 , wherein the open loop PC component comprises a WTRU-specific parameter.
33. The WTRU of claim 32 , wherein the WTRU-specific parameter is provided from higher layers.
34. The WTRU of claim 12 , wherein the transmit power is applied after one HARQ cycle time.
35. A method implemented by an eNode-B for use with controlling transmit power of a wireless transmit/receive unit (WTRU), the method comprising:
transmitting any of a cell-specific parameter and WTRU-specific parameter for determining an open loop uplink (UL) power control (PC) component as a function of pathloss;
transmitting a PC correction command; and
receiving, from the WTRU, a transmission having an applied transmit power, wherein the applied transmit power comprises a combination of the open loop PC component, a closed loop PC component and a delta factor related to an offset value, wherein the offset value is related to a modulation coding set (MCS), wherein the closed loop PC component includes a correction factor, and wherein the correction factor is based on the PC correction command.
36. The method of claim 35 , wherein the PC correction command is transmitted in a UL grant associated with a hybrid automatic repeat request (HARQ) process.
37. The method of claim 36 , wherein the received transmission with applied transmission power is received in accordance with a timing of the HARQ process.
38. The method of claim 35 , wherein the PC correction command is transmitted at a pre-configured signaling time.
39. The method of claim 35 , wherein the cell-specific parameter is provided from higher layers.
40. The method of claim 35 , wherein the WTRU-specific parameter is provided from higher layers.
41. An eNode-B for use with controlling transmit power of a wireless transmit/receive unit (WTRU), the eNode-B comprising a transmitter and a receiver, wherein:
the transmitter is configured to transmit any of a cell-specific parameter and WTRU-specific parameter for determining an open loop uplink (UL) power control (PC) component as a function of pathloss;
the transmitter is configured to transmit a PC correction command; and
the receiver is configured to receive, from the WTRU, a transmission having an applied transmit power, wherein the applied transmit power comprises a combination of the open loop PC component, a closed loop PC component and a delta factor related to an offset value, wherein the offset value is related to a modulation coding set (MCS), wherein the closed loop PC component includes a correction factor, and wherein the correction factor is based on the PC correction command.
42. The eNode-B of claim 41 , wherein the transmitter is configure to transmit the PC correction command in a UL grant associated with a hybrid automatic repeat request (HARQ) process.
43. The eNode-B of claim 42 , wherein the receiver is configured to receive the transmission with applied transmission power in accordance with a timing of the HARQ process.
44. The eNode-B of claim 41 , wherein the transmitter is configured to transmit the PC correction command at a pre-configured signaling time.
45. The eNode-B of claim 41 , wherein the cell-specific parameter is provided from higher layers.
46. The eNode-B of claim 41 , wherein the WTRU-specific parameter is provided from higher layers.