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EP-3906749-B1 - SINGLE TRANSMITTER SWITCHING FOR DUAL CONNECTIVITY

EP3906749B1EP 3906749 B1EP3906749 B1EP 3906749B1EP-3906749-B1

Inventors

  • HOSSEINI, Seyedkianoush
  • RICO ALVARINO, ALBERTO
  • CHEN, WANSHI
  • GAAL, PETER

Dates

Publication Date
20260506
Application Date
20200102

Claims (16)

  1. A method for wireless communication at a user equipment, UE, configured for single transmitter operation, comprising: identifying (1305), for a carrier aggregation configuration comprising a primary cell and one or more secondary cells, a first frame structure configuration for the primary cell and a second frame structure configuration for a secondary cell of the one or more secondary cells, the first frame structure configuration for the primary cell being different from the second frame structure configuration for the secondary cell; receiving (1310), from a base station, a downlink communication on the secondary cell; determining (1315) a feedback timing for the secondary cell based at least in part on the first frame structure configuration for the primary cell and the second frame structure configuration for the secondary cell, wherein determining the feedback timing comprises: identifying a third frame structure configuration based at least in part on the first frame structure configuration and the second frame structure configuration, the third frame structure configuration identifying at least one uplink Transmission Time Interval, TTI, of the primary cell for feedback in response to downlink communications from the base station; and determining the feedback timing according to the identified third frame structure configuration; and transmitting, (1320) in response to the received downlink communication, feedback to the base station according to the determined feedback timing.
  2. The method of claim 1, further comprising: receiving, from a base station, an indication of the first frame structure configuration for the primary cell, the received indication of the first frame structure configuration identifying at least one uplink TTI of the primary cell for feedback in response to downlink communications from the base station, wherein the first frame structure configuration is identified based at least in part on the received indication of the first frame structure configuration.
  3. The method of claim 2, wherein receiving the indication of the first frame structure configuration comprises: receiving radio resource control signaling comprising the indication of the first frame structure configuration.
  4. The method of claim 2, wherein the secondary cell operates according to a frequency division duplexing mode.
  5. The method of claim 4, wherein the primary cell operates according to a time division duplexing mode.
  6. The method of claim 1, wherein identifying the third frame structure configuration comprises: mapping a first indicator of the first frame structure configuration and a second indicator of the second frame structure configuration to a third indicator of the third frame structure configuration.
  7. The method of claim 1, wherein the third frame structure configuration is a different frame structure configuration than the first frame structure configuration and the second frame structure configuration.
  8. The method of claim 1, wherein the third frame structure configuration is a same frame structure configuration as the first frame structure configuration or the second frame structure configuration.
  9. The method of claim 1, further comprising: receiving, from a base station, an indication of the second frame structure configuration for the secondary cell, the received indication of the second frame structure configuration identifying at least one uplink transmission time interval, TTI, of the secondary cell for the downlink communication from the base station, wherein the second frame structure configuration is identified based at least in part on the received indication of the second frame structure configuration.
  10. The method of claim 1, wherein: the primary cell operates according to a frequency division duplexing mode or a time division duplexing mode; and the secondary cell operates according to the time division duplexing mode.
  11. The method of claim 1, wherein the carrier aggregation configuration comprises a dual connectivity configuration comprising a master cell group and a secondary cell group, the primary cell in the master cell group and the secondary cell in the secondary cell group.
  12. The method of claim 1, further comprising: receiving an indication of a time division multiplexing pattern; and transmitting, according to the time division multiplexing pattern, an uplink transmission using a shortened TTI on the secondary cell, the secondary cell configured to operate according to a frequency division duplexing mode.
  13. A method for wireless communication at a base station, comprising: identifying (1705) a carrier aggregation configuration comprising a primary cell and one or more secondary cells, a first frame structure configuration for the primary cell being different from a second frame structure configuration for a secondary cell of the one or more secondary cells; determining (1710) a feedback timing for the secondary cell based at least in part on the first frame structure configuration for the primary cell and the second frame structure configuration for the secondary cell, wherein determining the feedback timing comprises: identifying a third frame structure configuration based at least in part on the first frame structure configuration and the second frame structure configuration, the third frame structure configuration identifying at least one uplink Transmission Time Interval, TTI, of the primary cell for feedback in response to downlink communications from the base station; and determining the feedback timing according to the identified third frame structure configuration; transmitting,(1715) to a user equipment, UE, a downlink communication on the secondary cell; and receiving (1720), in response to the transmitted downlink communication, feedback from the UE according to the determined feedback timing.
  14. An apparatus for wireless communication at a user equipment, UE, configured for single transmitter operation comprising: means for identifying (1305), for a carrier aggregation configuration comprising a primary cell and one or more secondary cells, a first frame structure configuration for the primary cell and a second frame structure configuration for a secondary cell of the one or more secondary cells, the first frame structure configuration for the primary cell being different from the second frame structure configuration for the secondary cell; means for receiving (1310), from a base station, a downlink communication on the secondary cell; means for determining (1315) a feedback timing for the secondary cell based at least in part on the first frame structure configuration for the primary cell and the second frame structure configuration for the secondary cell, wherein determining the feedback timing comprises: identifying a third frame structure configuration based at least in part on the first frame structure configuration and the second frame structure configuration, the third frame structure configuration identifying at least one uplink, Transmission Time Interval, TTI, of the primary cell for feedback in response to downlink communications from the base station; and determining the feedback timing according to the identified third frame structure configuration; and means for transmitting (1320), in response to the received downlink communication, feedback to the base station according to the determined feedback timing.
  15. An apparatus for wireless communication at a base station, comprising: means for identifying (1705) a carrier aggregation configuration comprising a primary cell and one or more secondary cells, a first frame structure configuration for the primary cell being different from a second frame structure configuration for a secondary cell of the one or more secondary cells; means for determining (1710) a feedback timing for the secondary cell based at least in part on the first frame structure configuration for the primary cell and the second frame structure configuration for the secondary cell, wherein determining the feedback timing comprises: identifying a third frame structure configuration based at least in part on the first frame structure configuration and the second frame structure configuration, the third frame structure configuration identifying at least one uplink, Transmission Time Interval, TTI, of the primary cell for feedback in response to downlink communications from the base station; and determining the feedback timing according to the identified third frame structure configuration; means for transmitting (1715), to a user equipment, UE, a downlink communication on the secondary cell; and means for receiving (1720), in response to the transmitted downlink communication, feedback from the UE according to the determined feedback timing.
  16. A computer-readable medium comprising instructions which, when executed by a computer associated to a user equipment or a base station, cause respectively the user equipment or the base station to carry out the method of any of claims 1 to 12 or claim 13.

Description

BACKGROUND The following relates generally to wireless communications, and to single transmitter switching for dual connectivity. Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as NR systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple-access communications system may include a number of base stations or network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE). US 2014/092786 describes hybrid automatic repeat request (harq) mapping for carrier aggregation. 3GPP document R1- 1712163 of Huawei describes TDM of LTE and NR uplinks for LTE-NR dual connectivity. SUMMARY The described techniques relate to improved methods, systems, devices, and apparatuses that support single transmitter switching for dual connectivity. Generally, the described techniques provide for a user equipment (UE) to receive system information block (SIB)-configured primary cell (PCell) and/or secondary cell (SCell) time division duplexing (TDD) uplink-downlink configurations that indicate frame structure configurations for a first base station serving a PCell (and zero or more SCells), and a second base station serving the SCell (and zero or more additional SCells), respectively. Additionally, a UE may receive a radio resource control (RRC)-configured PCell TDD uplink-downlink reference configuration which may indicate which uplink subframes of the SIB-configured PCell frame structure configuration are usable for hybrid automatic repeat request (HARQ)-related transmissions (e.g., transmission of acknowledgements (ACKs) and/or non-acknowledgements (NACKs)). The UE may compare (e.g., via a table or index pairs) an index of the SIB-configured SCell TDD uplink-downlink configuration with the RRC-configured PCell TDD uplink-downlink reference configuration, and may determine a SCell TDD uplink-downlink reference configuration. The UE may use the SCell uplink-downlink reference configuration to determine which uplink subframes of the SIB-configured SCell frame structure configuration are usable for HARQ-related transmissions (e.g., transmission of ACKs and/or NACKs). The invention is defined by the appended independent claims. Any example below not falling within the scope defined by the wording of the appended claims is provided as example, useful for the understanding of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates an example of a wireless communications system that supports single transmitter switching for dual connectivity in accordance with aspects of the present disclosure.FIG. 2 illustrates an example of a wireless communications system that supports single transmitter switching for dual connectivity in accordance with aspects of the present disclosure.FIGs. 3A and 3B illustrate an example of a secondary cell (SCell) hybrid automatic repeat request (HARQ) procedure that supports single transmitter switching for dual connectivity in accordance with aspects of the present disclosure.FIG. 4 illustrates an example of a process flow that supports single transmitter switching for dual connectivity in accordance with aspects of the present disclosure.FIGs. 5 and 6 show block diagrams of devices that support single transmitter switching for dual connectivity in accordance with aspects of the present disclosure.FIG. 7 shows a block diagram of a communications manager that supports single transmitter switching for dual connectivity in accordance with aspects of the present disclosure.FIG. 8 shows a diagram of a system including a device that supports single transmitter switching for dual connectivity in accordance with aspects of the present disclosure.FIGs. 9 and 10 show block diagrams of devices that support single transmitter switching for dual connectivity in accordance with aspects of the present disclosure.FIG. 11 shows a block diagram of a communications manager that supports single transmitter switching for dual connectivity in accordance with aspects of the present disclosure.FIG. 12 shows a diagram of a system including a device that supports single transmitter switching for dual connectivity in accordance with aspects of the presen