Method and apparatus for controlling TPC command timing considering TDD-FDD carrier aggregation
One or more exemplary embodiments provide a TPC command timing by taking into consideration TDD-FDD CA and cross-carrier scheduling, and provide a PUSCH transmission power controlling method in a subframe i for an FDD-based scheduled cell, based on the TPC command timing. According to one or more exemplary embodiments, an uplink transmission power may be effectively controlled when TDD-FDD CA and cross-carrier scheduling is configured for a UE. A Physical Uplink Shared Channel (PUSCH) transmission power control timing may be optimized.
1. A User Equipment (UE) to receive a transmit power control (TPC) command in a wireless communication system supporting Time Division Duplex (TDD)-Frequency Division Duplex (FDD) Carrier Aggregation (CA), the UE comprising:
a processor to control a Radio Resource Control (RRC) connection with a base station through a first serving cell supporting a TDD mode, and to detect a Physical Downlink Control Channel (PDCCH) transmitted through the first serving cell, the PDCCH comprising a Transmit Power Control (TPC) command and being received in a subframe n−4;
a receiver to receive an RRC message through the first serving cell, the RRC message comprising carrier aggregation (CA) configuration information, the CA configuration information comprising information of a second serving cell supporting an FDD mode, and the first serving cell and the second serving cell being aggregated by a TDD-FDD CA scheme; and
a transmitter to transmit, from the UE, a Physical Uplink Shared Channel (PUSCH) associated with the TPC command through the second serving cell, the PUSCH being transmitted in a subframe n.
2. The UE of claim 1 , wherein:
the processor determines a transmit power of the PUSCH based on the TPC command; and
the TPC command indicates the transmit power of the PUSCH on the second serving cell.
3. The UE of claim 1 , wherein three subframes exist between the subframe n and the subframe n−4, and
wherein the three subframes include a subframe n−1, a subframe n−2, and a subframe n−3.
4. The UE of claim 1 , wherein the first serving cell is a primary serving cell (PCell), and the second serving cell is a secondary serving cell (SCell).
5. The UE of claim 1 , wherein:
the processor controls an establishment of a cross-carrier scheduling for the second serving cell; and
the second serving cell is a scheduled cell, which is scheduled by the first serving cell.
6. The UE of claim 1 , wherein the PDCCH corresponds to a PDCCH or an Enhanced PDCCH (EPDCCH).
7. The UE of claim 6 , wherein a cross-carrier scheduling between the first serving cell and the second serving cell is configured by an RRC signaling through the first serving cell.
8. The UE of claim 1 , wherein the subframe n−4 for the transmission of the PDCCH comprising the TPC command is determined based on a TDD Uplink(UL)/Downlink(DL) configuration of the first serving cell.
9. The UE of claim 1 , wherein:
in a radio frame, a number of subframes available for the transmission of the PDCCH comprising the TPC command is determined based on a TDD Uplink(UL)/Downlink(DL) configuration of the first serving cell; and
the subframe n−4 is determined from among the available subframes.
10. The UE of claim 1 , wherein regardless of a value of a TDD UL/DL configuration of the first serving cell, the PUSCH transmission on the second serving cell is available in subframe 0, subframe 4, subframe 5, and subframe 9, and
wherein for a PUSCH transmission in a subframe 6, the TPC command is not available.
11. The UE of claim 1 , wherein the PDCCH comprises a downlink control information (DCI) format 0 or a DCI format 4.
12. The UE of claim 11 , wherein the processor controls a transmit power of the PUSCH transmission based on a transmit power parameter included in the DCI format 0 or a transmit power parameter included in the DCI format 4.
13. A base station to control a transmit power control (TPC) command in a wireless communication system supporting Time Division Duplex (TDD)-Frequency Division Duplex (FDD) Carrier Aggregation (CA), the base station comprising:
a processor to control a Radio Resource Control (RRC) connection with a User Equipment (UE) through a first serving cell supporting a TDD mode, and to determine a transmit power of a Physical Uplink Shared Channel (PUSCH) transmission of the UE;
a transmitter to transmit, to the UE, an RRC message through the first serving cell, and to transmit, to the UE, a Physical Downlink Control Channel (PDCCH) through the first serving cell, the RRC message comprising carrier aggregation (CA) configuration information, the CA configuration information comprising information of a second serving cell supporting an FDD mode, the first serving cell and the second serving cell being aggregated by a TDD-FDD CA scheme, and the PDCCH comprising a TPC command and being transmitted in a subframe n−4; and
a receiver to receive, from the UE, the PUSCH associated with the TPC command through the second serving cell, the PUSCH being transmitted in a subframe n.
14. The base station of claim 13 , wherein:
the processor determines the transmit power of the PUSCH transmission based on a location of the UE; and
the TPC command indicates the transmit power of the PUSCH on the second serving cell.
15. The base station of claim 13 , wherein three subframes exist between the subframe n and the subframe n−4, and
wherein the three subframes include a subframe n−1, a subframe n−2, and a subframe n−3.
16. The base station of claim 13 , wherein the first serving cell is a primary serving cell (PCell), and the second serving cell is a secondary serving cell (SCell).
17. The base station of claim 13 , wherein:
the processor controls an establishment of a cross-carrier scheduling for the second serving cell; and
the second serving cell is a scheduled cell, which is scheduled by the first serving cell.
18. The base station of claim 13 , wherein the PDCCH corresponds to a PDCCH or an Enhanced PDCCH (EPDCCH).
19. The base station of claim 18 , wherein a cross-carrier scheduling between the first serving cell and the second serving cell is configured by an RRC signaling through the first serving cell.
20. The base station of claim 13 , wherein the subframe n−4 for the transmission of the PDCCH comprising the TPC command is determined based on a TDD Uplink(UL)/Downlink(DL) configuration of the first serving cell.
21. The base station of claim 13 , wherein:
in a radio frame, a number of subframes available for the transmission of the PDCCH comprising the TPC command is determined based on a TDD Uplink(UL)/Downlink(DL) configuration of the first serving cell; and
the subframe n−4 is determined from among the available subframes.
22. The base station of claim 13 , wherein regardless of a value of a TDD UL/DL configuration of the first serving cell, the PUSCH transmission on the second serving cell is available in subframe 0, subframe 4, subframe 5, and subframe 9, and
wherein for a PUSCH transmission in a subframe 6, the TPC command is not available.
23. A system for a User Equipment (UE) to receive a transmit power control (TPC) command in a wireless communication system supporting Time Division Duplex (TDD)-Frequency Division Duplex (FDD) Carrier Aggregation (CA), the system comprising:
a processor to control a Radio Resource Control (RRC) connection with a base station through a first serving cell supporting a TDD mode, and to detect a Physical Downlink Control Channel (PDCCH) transmitted through the first serving cell, the PDCCH comprising a Transmit Power Control (TPC) command and being received in a subframe n−4,
wherein the processor processes an RRC message received through the first serving cell, the RRC message comprising carrier aggregation (CA) configuration information, the CA configuration information comprising information of a second serving cell supporting an FDD mode, and the first serving cell and the second serving cell being aggregated by a TDD-FDD CA scheme, and
wherein the processor generates a Physical Uplink Shared Channel (PUSCH) associated with the TPC command to be transmitted through the second serving cell, the PUSCH being configured to be transmitted in a subframe n.