Accelerated cell activation in wireless communication

1. A method of wireless communication at a scheduling entity of a primary cell (PCell), comprising:

transmitting carrier aggregation (CA) capability information to a user equipment (UE);

transmitting, to the UE, secondary cell (SCell) pre-configuration information for facilitating an accelerated SCell activation procedure based on the CA capability information of the UE;

transmitting, to the UE, a control message to initiate the accelerated SCell activation procedure to establish a connection between the UE and one or more SCells;

controlling the one or more SCells to transmit respective UE-specific reference signals based on the SCell pre-configuration information; and

receiving, from the UE, a measurement report of the UE-specific reference signals indicating a preference of the one or more SCells for a CA configuration.

2. The method of claim 1 , wherein the SCell pre-configuration information comprises at least one of:

component carriers of the one or more SCells;

a timing offset between the PCell and each of the one or more SCells;

locations of synchronization signals of the one or more SCells;

UE-specific reference signal configuration information; or

SCell measurement object configuration for UE autonomous measurements.

3. The method of claim 1 , wherein transmitting the SCell pre-configuration information comprises:

transmitting the SCell pre-configuration information in a radio resource control (RRC) connection reconfiguration message.

4. The method of claim 1 , wherein controlling the one or more SCells comprises:

requesting each of the one or more SCells to transmit the respective UE-specific reference signal using time-frequency resources specified in the SCell pre-configuration information.

5. The method of claim 4 , wherein controlling the one or more SCells comprises:

controlling the one or more SCells to transmit the respective UE-specific reference signals at respective predetermined timing offsets based on the SCell pre-configuration information.

6. The method of claim 1 , further comprising selecting the respective UE-specific reference signals based on at least one of:

a previously requested reference signal; or

a predetermined active period in which UE synchronization is valid.

7. The method of claim 1 , wherein the CA capability information is configured to indicate the one or more SCells that are capable of performing the accelerated SCell activation procedure.

8. The method of claim 1 , further comprising:

communicating with the one or more SCells to determine the SCell pre-configuration information.

9. A method of wireless communication at a user equipment (UE), comprising:

receiving, from a primary cell (PCell), secondary cell (SCell) pre-configuration information specifying time-frequency resources allocated to reference signals of one or more secondary cells (SCells) for an accelerated SCell activation procedure;

receiving, from the PCell, a control message to initiate the accelerated SCell activation procedure to establish a connection with the one or more SCells in a carrier aggregation (CA) configuration;

measuring the reference signals received using the time-frequency resources specified in the SCell pre-configuration information; and

transmitting, to the PCell, a measurement report of the reference signals indicating a preference of the one or more SCells for the CA configuration.

10. The method of claim 9 , wherein the SCell pre-configuration information comprises at least one of:

channels of the one or more SCells;

a timing offset between the PCell and each of the one or more SCells;

locations of synchronization signals of the one or more SCells;

UE-specific reference signal configuration information; or

SCell measurement object configuration for UE autonomous measurements.

11. The method of claim 9 , wherein receiving the SCell pre-configuration information comprises:

receiving the SCell pre-configuration information in a radio resource control (RRC) connection reconfiguration message.

12. The method of claim 9 , wherein measuring the reference signals comprises:

receiving a UE-specific reference signal from each of the one or more SCells.

13. The method of claim 12 , wherein the UE-specific reference signal comprises at least one of:

a synchronization signal block (SS-block);

an alternate time-domain reference signal;

a channel state information reference signal (CSI-RS); or

a tracking reference signal.

14. The method of claim 9 , further comprising:

receiving carrier aggregation (CA) capability information from the PCell, the CA capability information indicating the one or more SCells that are capable of performing the accelerated SCell activation procedure.

15. The method of claim 9 , further comprising:

performing autonomous measurements of the reference signals; and

transmitting a measurement report of the autonomous measurements to the PCell.

16. A scheduling entity of a primary cell (PCell) for wireless communication, comprising:

a communication interface configured to communicate with user equipment (UE);

a memory; and

a processor operatively coupled with the memory and the communication interface,

wherein the processor and the memory are configured to:

transmit carrier aggregation (CA) capability information to the UE;

transmit, to the UE, secondary cell (SCell) pre-configuration information for facilitating an accelerated SCell activation procedure based on the CA capability information of the UE;

transmit, to the UE, a control message to initiate the accelerated SCell activation procedure to establish a connection between the UE and one or more SCells;

control the one or more SCells to transmit respective UE-specific reference signals based on the SCell pre-configuration information; and

receive, from the UE, a measurement report of the UE-specific reference signals indicating a preference of the one or more SCells for a CA configuration.

17. The scheduling entity of claim 16 , wherein the SCell pre-configuration information comprises at least one of:

component carriers of the one or more SCells;

a timing offset between the PCell and each of the one or more SCells;

locations of synchronization signals of the one or more SCells;

UE-specific reference signal configuration information; or

SCell measurement object configuration for UE autonomous measurements.

18. The scheduling entity of claim 16 , wherein the processor and the memory are further configured to:

transmit the SCell pre-configuration information in a radio resource control (RRC) connection reconfiguration message.

19. The scheduling entity of claim 16 , wherein the processor and the memory are further configured to:

control each of the one or more SCells to transmit the respective UE-specific reference signal using time-frequency resources specified in the SCell pre-configuration information.

20. The scheduling entity of claim 19 , wherein the processor and the memory are further configured to:

control the one or more SCells to transmit the respective UE-specific reference signals at respective predetermined timing offsets based on the SCell pre-configuration information.

21. The scheduling entity of claim 16 , wherein the processor and the memory are further configured to select the respective UE-specific reference signals based on at least one of:

a previously requested reference signal; or

a predetermined active period in which UE synchronization is valid.

22. The scheduling entity of claim 16 , wherein the CA capability information is configured to indicate the one or more SCells that are capable of performing the accelerated SCell activation procedure.

23. The scheduling entity of claim 16 , wherein the processor and the memory are further configured to:

communicate with the one or more SCells to determine the SCell pre-configuration information.

24. A user equipment (UE) for wireless communication, comprising:

a communication interface for wireless communication;

a memory; and

a processor operatively coupled with the memory and the communication interface,

wherein the processor and the memory are configured to:

receive, from a primary cell (PCell), secondary cell (SCell) pre-configuration information specifying time-frequency resources allocated to reference signals of one or more secondary cells (SCells) for an accelerated SCell activation procedure;

receive, from the PCell, a control message to initiate the accelerated SCell activation procedure to establish a connection with the one or more SCells in a carrier aggregation (CA) configuration;

measure the reference signals received using the time-frequency resources specified in the SCell pre-configuration information; and

transmit, to the PCell, a measurement report of the reference signals indicating a preference of the one or more SCells for the CA configuration.

25. The UE of claim 24 , wherein the SCell pre-configuration information comprises at least one of:

channels of the one or more SCells;

a timing offset between the PCell and each of the one or more SCells;

locations of synchronization signals of the one or more SCells;

UE-specific reference signal configuration information; or

SCell measurement object configuration for UE autonomous measurements.

26. The UE of claim 24 , wherein the processor and the memory are further configured to:

receive the SCell pre-configuration information in a radio resource control (RRC) connection reconfiguration message.

27. The UE of claim 24 , wherein the processor and the memory are further configured to receive the reference signals by:

receiving a UE-specific reference signal from each of the one or more SCells.

28. The UE of claim 27 , wherein the UE-specific reference signal comprises at least one of:

a synchronization signal block (SS-block);

an alternate time-domain reference signal;

a channel state information reference signal (CSI-RS); or

a tracking reference signal.

29. The UE of claim 24 , wherein the processor and the memory are further configured to:

receive carrier aggregation (CA) capability information from the PCell, the CA capability information indicating the one or more SCells that are capable of performing the accelerated SCell activation procedure.

30. The UE of claim 24 , wherein the processor and the memory are further configured to:

perform autonomous measurements of the reference signals; and

transmit a measurement report of the autonomous measurements to the PCell.