Method and apparatus for controlling TPC command timing considering TDD-FDD carrier aggregation
View Patent ↗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. An apparatus 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 apparatus comprising:
a processor; and
a non-transitory computer readable memory storing computer executable instructions, that when executed by the processor cause the apparatus to perform the following steps:
controlling 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;
receiving 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
transmitting, from the apparatus, 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 apparatus of claim 1 , the steps further comprising:
determining a transmit power of the PUSCH based on the TPC command; and
wherein the TPC command indicates the transmit power of the PUSCH on the second serving cell.
3. The apparatus 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 apparatus 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 apparatus of claim 1 , the steps further comprising:
controlling an establishment of a cross-carrier scheduling for the second serving cell; and wherein
the second serving cell is a scheduled cell, which is scheduled by the first serving cell.
6. The apparatus of claim 1 , wherein the PDCCH corresponds to a PDCCH or an Enhanced PDCCH (EPDCCH).
7. The apparatus of claim 6 , wherein the 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 apparatus 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 apparatus 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 the 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 apparatus of claim 1 , wherein regardless of a value of the 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 apparatus of claim 1 , wherein the PDCCH comprises a downlink control information (DCI) format 0 or a DCI format 4.
12. The apparatus 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 method for receiving a transmit power control (TPC) command in a wireless communication system supporting Time Division Duplex (TDD)-Frequency Division Duplex (FDD) Carrier Aggregation (CA), the method comprising:
controlling 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;
receiving 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
transmitting, from a 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.
14. The method of claim 13 , further comprising:
determining a transmit power of the PUSCH based on the TPC command; and wherein the TPC command indicates the transmit power of the PUSCH on the second serving cell.
15. The method 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 method 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 method of claim 13 , the steps further comprising:
controlling an establishment of a cross-carrier scheduling for the second serving cell; and
wherein the second serving cell is a scheduled cell, which is scheduled by the first serving cell.
18. An apparatus 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 apparatus 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 apparatus, a Physical Uplink Shared Channel (PUSCH) associated with the TPC command through the second serving cell, the PUSCH being transmitted in a subframe n.