Method and apparatus for transmission power control for a sounding reference signal

Abstract

A method and apparatus for transmitting a reference signal from a User Equipment (UE) are provided. The method includes transmitting a first reference signal using a sequence determined from an identity of the at least one transmission point and transmitting a second reference signal with a transmission power having an offset with a first maximum value configured by higher layer signaling from the at least one transmission point; and transmitting a first reference signal using a sequence configured to the UE by higher layer signaling from the at least one transmission point and transmitting a second reference signal with a transmission power having an offset with a second maximum value configured by higher layer signaling from the at least one transmission point, wherein the second maximum value is larger than the first maximum value, and the first reference signal and the second reference signal are either identical or non-identical.

What is claimed is: 
     
       1. A method for transmitting signals from a user equipment (UE) that receives signaling from at least one transmission point and transmits signaling to at least one reception point, the method comprising the steps of:
 transmitting a first reference signal using a sequence determined from an identity of the at least one transmission point;   transmitting a second reference signal with a first transmission power having an offset with a first maximum value configured using first higher layer signaling received from the at least one transmission point;   transmitting a third reference signal using a sequence configured to the UE using second higher layer signaling received from the at least one transmission point; and   transmitting a fourth reference signal with a second transmission power having an offset with a second maximum value configured using third higher layer signaling received from the at least one transmission point,   wherein the second maximum value is larger than the first maximum value.   
     
     
       2. The method of  claim 1 , wherein each of the first reference signal and the third reference signal is one of a demodulation reference signal that is associated with a physical it uplink shared channel or with a physical uplink control channel, and a sounding reference signal, and
 wherein each of the second reference signal and the fourth reference signal is a sounding reference signal, and   wherein the transmission power offset of the second reference signal is relative to a transmission power of a signal, other than sounding reference signals, in the physical uplink shared channel.   
     
     
       3. The method of  claim 2 , wherein the sounding reference signal is transmitted periodically or dynamically. 
     
     
       4. The method of  claim 1 , further comprising:
 determining the first transmission power for the second reference signal by applying a first compensation factor to a first path loss estimate, the second reference signal including a sounding reference signal; and   determining the second transmission power for the fourth reference signal by applying a second compensation factor to a second path loss estimate, the fourth reference signal including a sounding, reference signal.   
     
     
       5. The method of  claim 1 , wherein the sequence configured to the UE is a Zadoff-Chu sequence. 
     
     
       6. The method of  claim 1 , wherein at least one among the first reference signal, second reference signal, third reference signal, and fourth reference signal is a sounding reference signal, the transmissions power of the sounding reference signal is adjusted by a transmission power control (TPC) command provided by a downlink control information (DCI) format that includes cyclic redundancy check (CRC) bits that are scrambled by a radio network temporary identifier (RNTI). 
     
     
       7. A method for transmitting signals from a user equipment (UE) in response to an indication by a field included in a downlink control information (DCI) format conveyed to the UE in a physical downlink control channel transmitted from at least one transmission point, the method comprising the steps of:
 transmitting a sounding reference signal with a first power determined from a first set of parameters, if the DCI format schedules data transmission to the UE; and   transmitting signals on a physical uplink shared channel with a second power determined from a second set of parameters, if the DCI format schedules data transmission from the UE.   
     
     
       8. The method of  claim 7 , wherein each of the first and second sets of parameters includes a power control command. 
     
     
       9. The method of  claim 7 , wherein each of the first and second sets of parameters includes a power offset. 
     
     
       10. The method of  claim 7 , wherein the sounding reference signal reports channel state information (CSI) of the UE. 
     
     
       11. A user equipment (UE) for transmitting signals, the UE receiving signaling from at least one transmission point and transmitting signaling to at least one reception point, the UE comprising:
 a receiver configured to receive higher layer signaling from the at least one transmission point; and   a transmitter configured to:
 transmit a first reference signal using a sequence determined from an identity of the at least one transmission point, 
 transmit a second reference signal with a first transmission power having an offset with a first maximum value configured using first higher layer signaling received from the at least one transmission point, 
 transmit a third reference signal using a sequence configured by second higher layer signaling received from the at least one transmission point, and 
 transmit a fourth reference signal with a second transmission power having an offset with a second maximum value configured using third higher layer signaling received from the at least one transmission point, 
   wherein the second maximum value is larger than the first maximum value.   
     
     
       12. The UE of  claim 11 , wherein each of the first reference signal and the third reference signal is one of a demodulation reference signal that is associated with a physical uplink shared channel or with a physical uplink control channel, and a sounding reference signal, and
 wherein each of the second reference signal and the fourth reference signal is a sounding reference signal and the transmission power offset of the second reference signal is relative to a transmission power of a signal, other than sounding reference signals, in the physical uplink shared channel.   
     
     
       13. The UE of  claim 12 , wherein the sounding reference signals are transmitted periodically or dynamically. 
     
     
       14. The UE of  claim 11 , further comprising:
 a controller configured to determine the first transmission power for the second reference signal by applying a first compensation factor to a first path loss estimate, and   to determine the second transmission power for the fourth reference signal by applying a second compensation factor to a second path loss estimate, the fourth reference signal including a sounding reference signal.   
     
     
       15. The UE of  claim 11 , wherein the sequence configured by the second higher layer signaling is a Zadoff-Chu sequence. 
     
     
       16. The of  claim 11 , wherein at least one among the first reference signal, second reference signal, third reference signal, and fourth reference signal is a sounding reference signal, the transmission power of the sounding reference signal is adjusted by a transmission power control (TPC) command provided by a downlink control information (DCI) format that includes cyclic redundancy check (CRC) bits that are scrambled by a radio network temporary identifier (RNTI). 
     
     
       17. A user equipment (UE) for transmitting signals in response to an indication by a field included in a downlink control information (DCI) format conveyed in a physical downlink control channel transmitted from at least one transmission point, the UE comprising:
 a receiver configured to receive DCI formats is respective physical downlink control channels; and   a transmitter configured to transmit a sounding reference signal with a first power determined from a first set of parameters, if a first DCI format from among tile DCI formats schedules data transmission to the UE apparatus, and to transmit signals on a physical uplink shared channel with a second power determined from a second set of parameters, if a second DCI format from among the DCI formats schedules data transmission from the UE.   
     
     
       18. The UE of  claim 17 , wherein each of the first and second sets of parameters includes a power control command. 
     
     
       19. The UE of  claim 17 , wherein each of the first and second sets of parameters includes a power offset. 
     
     
       20. The UE of  claim 17 , wherein the sounding reference signal reports channel state information (CSI) of the UE. 
     
     
       21. A method for a user equipment (UE) to determine power for signal transmission, the method comprising:
 receiving first information about a first configuration for a first set of parameters associated with transmission of a sounding reference signal (SRS) and second information about a second configuration for a second set of parameters associated with transmission of a physical uplink shared channel (PUSCH);   receiving at least one of a first downlink control information (DCI) format associated with a first power control for an SRS transmission or a second DCI format associated with a second power control for a PUSCH transmission;   performing the first power control for the SRS transmission using the first set of parameters and a first transmission power control (TPC) command in the first DCI format, in case that the UE transmits the SRS; and   performing the second power control for the PUSCH transmission using the second set of parameters and a second TPC command in the second DCI format, in case that the UE transmits data on the PUSCH,   wherein the first set of parameters includes a first path-loss compensation factor for the first power control, and the second set of parameters includes a second path-loss compensation factor for the second power control, and   wherein the first DCI format includes a first cyclic redundancy check (CRC) field scrambled by a TPC-SRS-radio network temporary identifier (RNTI), and the second DCI format includes a second CRC field scrambled by a TPC-PUSCH-RNTI.    
     
     
       22. The method of  claim 21 , wherein the first set of parameters includes the first path-loss compensation factor which is multiplied with a first downlink path-loss factor used in the first power control, and
 wherein the second set of parameters includes the second path-loss compensation factor which is multiplied with a second downlink path-loss factor used in the second power control.    
     
     
       23. The method of  claim 21 , wherein the first TPC command is used for a first closed-loop TPC process in the first power control, and the second TPC command is used for a second closed-loop TPC process in the second power control.  
     
     
       24. A user equipment (UE), comprising:
 a transceiver; and   a processor configured to:
 receive, through the transceiver, first information about a first configuration for a first set of parameters associated with transmission of a sounding reference signal (SRS) and second information about a second configuration for a second set of parameters associated with transmission of a physical uplink shared channel (PUSCH), 
 receive, through the transceiver, at least one of a first downlink control information (DCI) format associated with a first power control for an SRS transmission or a second DCI format associated with a second power control for a PUSCH transmission, 
 perform the first power control for the SRS transmission using the first set of parameters and a first transmission power control (TPC) command in the first DCI format, in case that the UE transmits the SRS, and 
 perform the second power control for the PUSCH transmission using the second set of parameters and a second TPC command in the second DCI format, in case that the UE transmits data on the PUSCH, 
   wherein the first set of parameters includes a first path-loss compensation factor for the first power control, and the second set of parameters includes a second path-loss compensation factor for the second power control, and   wherein the first DCI format includes a first cyclic redundancy check (CRC) field scrambled by a TPC-SRS-radio network temporary identifier (RNTI), and the second DCI format includes a second CRC field scrambled by a TPC-PUSCH-RNTI.    
     
     
       25. The UE of  claim 24 , wherein the first set of parameters includes the first path-loss compensation factor which is multiplied with a first downlink path-loss factor used in the first power control, and
 wherein the second set of parameters includes the second path-loss compensation factor which is multiplied with a second downlink path-loss factor used in the second power control.    
     
     
       26. The UE of  claim 24 , wherein the first TPC command is used for a first closed-loop TPC process in the first power control, and the second TPC command is used for a second closed-loop TPC process in the second power control.  
     
     
       27. A base station, comprising:
 a transceiver; and   a processor configured to:
 transmit, through the transceiver, first information about a first configuration for a first set of parameters associated with transmission of a sounding reference signal (SRS) and second information about a second configuration for a second set of parameters associated with transmission of a physical uplink shared channel (PUSCH), 
 transmit, through the transceiver, a first downlink control information (DCI) format associated with a first power control for an SRS transmission or a second DCI format associated with a second power control for a PUSCH transmission, 
 receive, through the transceiver, the SRS by using the first set of parameters and a first transmission power control (TPC) command in the first DCI format, in case that a user equipment (UE) transmits the SRS, and 
 receive, through the transceiver, data on the PUSCH by using the second set of parameters and a second TPC command in the second DCI format, in case that the UE transmits the data on the PUSCH, 
   wherein the first set of parameters includes a first path-loss compensation factor for the first power control, and the second set of parameters includes a second path-loss compensation factor for the second power control, and   wherein the first DCI format includes a first cyclic redundancy check (CRC) field scrambled by a TPC-SRS-radio network temporary identifier (RNTI), and the second DCI format includes a second CRC field scrambled by a TPC-PUSCH-RNTI.    
     
     
       28. The base station of  claim 27 , wherein the first set of parameters includes the first path-loss compensation factor which is multiplied with a first downlink path-loss factor used in the first power control, and
 wherein the second set of parameters includes the second path-loss compensation factor which is multiplied with a second downlink path-loss factor used in the second power control.    
     
     
       29. The base station of  claim 27 , wherein the first TPC command is used for a first closed-loop TPC process in the first power control, and the second TPC command is used for a second closed-loop TPC process in the second power control.  
     
     
       30. A method for a base station, the method comprising:
 transmitting first information about a first configuration for a first set of parameters associated with transmission of a sounding reference signal (SRS) and second information about a second configuration for a second set of parameters associated with transmission of a physical uplink shared channel (PUSCH);   transmitting a first downlink control information (DCI) format associated with a first power control for an SRS transmission or a second DCI format associated with a second power control for a PUSCH transmission;   receiving the SRS by using the first set of parameters and a first transmission power control (TPC) command in the first DCI format, in case that a user equipment (UE) transmits the SRS; and   receiving data on the PUSCH by using the second set of parameters and a second TPC command in the second DCI format, in case that the UE transmits the data on the PUSCH,   wherein the first set of parameters includes a first path-loss compensation factor for the first power control, and the second set of parameters includes a second path-loss compensation factor for the second power control, and   wherein the first DCI format includes a first cyclic redundancy check (CRC) field scrambled by a TPC-SRS-radio network temporary identifier (RNTI), and the second DCI format includes a second CRC field scrambled by a TPC-PUSCH-RNTI.    
     
     
       31. The method of  claim 30 , wherein the first set of parameters includes the first path-loss compensation factor which is multiplied with a first downlink path-loss factor used in the first power control, and
 wherein the second set of parameters includes the second path-loss compensation factor which is multiplied with a second downlink path-loss factor used in the second power control.    
     
     
       32. The method of  claim 30 , wherein the first TPC command is used for a first closed-loop TPC process in the first power control, and the second TPC command is used for a second closed-loop TPC process in the second power control.