Half-duplex user equipment operation in new radio frequency division duplexed bands

1. A method of wireless communication performed by a user equipment (UE), comprising:

determining a guard period associated with switching from a first communication mode to a second communication mode,

wherein the UE is operating in a half-duplex frequency division duplexing (FDD) mode of operation,

wherein the guard period associated with switching from the first communication mode to the second communication mode is different than a guard period associated with switching from the second communication mode to the first communication mode, and

wherein the guard period is determined based at least in part on at least one of:

a determination of whether a number of phase locked loops (PLLs) associated with the UE to be used for the first communication mode is less than a number of PLLs associated with the UE to be used for the second communication mode, or

a determination of whether a particular subcarrier spacing corresponds to a first particular subcarrier spacing associated with the UE or a second particular subcarrier spacing associated with the UE, wherein the first particular subcarrier spacing is associated with the first communication mode and operates at a different kilohertz (kHz) subcarrier spacing relative to the second particular subcarrier spacing associated with the second communication mode;

providing an indication of the guard period; and

switching from the first communication mode to the second communication mode based at least in part on the guard period.

2. The method of claim 1 , wherein the UE is to use a single PLL for both the first communication mode and the second communication mode.

3. The method of claim 1 , wherein the UE is to use a first PLL for the first communication mode and a second PLL for the second communication mode.

4. The method of claim 1 , further comprising:

providing an indication of whether the UE supports a first guard period type or supports a second guard period type.

5. The method of claim 1 , further comprising: providing an indication that the UE supports operation in the half-duplex FDD mode of operation.

6. The method of claim 1 , wherein the guard period is a function of the particular subcarrier spacing over a fixed time duration.

7. The method of claim 1 , wherein the particular subcarrier spacing is a subcarrier spacing associated with receiving a downlink communication or is a subcarrier spacing associated with transmitting an uplink communication.

8. The method of claim 1 , wherein the particular subcarrier spacing is a fixed reference subcarrier spacing.

9. The method of claim 1 , wherein the particular subcarrier spacing is based at least in part on the first communication mode being downlink reception and the second communication mode being uplink transmission.

10. The method of claim 1 , wherein the particular subcarrier spacing is based at least in part on the first communication mode being uplink transmission and the second communication mode being downlink reception.

11. The method of claim 1 , wherein, when the first communication mode is downlink reception and the second communication mode is uplink transmission, the guard period is shorter than a guard period associated with a switch from the second communication mode to the first communication mode.

12. The method of claim 1 , wherein, when the first communication mode is uplink transmission and the second communication mode is downlink reception, the guard period is longer than a guard period associated with a switch from the second communication mode to the first communication mode.

13. The method of claim 1 , further comprising:

providing guard period support information associated with the UE, the guard period support information including information that identifies a reference subcarrier spacing corresponding to the guard period support information,

wherein a resolution of the guard period support information is in terms of symbols, slots, or subframes.

14. The method of claim 1 , wherein the guard period is a function of a numerology associated with the first communication mode or the second communication mode.

15. The method of claim 1 , further comprising:

determining a collision rule associated with managing a potential collision involving an uplink communication or the guard period; and

managing the potential collision based at least in part on the collision rule.

16. The method of claim 15 , wherein the potential collision is between a synchronization signal block (SSB) or a channel state information reference signal (CSI-RS) and at least one of:

the uplink communication, or

the guard period.

17. The method of claim 16 , wherein the collision rule indicates one of:

that the UE is to perform a radio resource management (RRM) measurement and drop the uplink communication,

that the UE is to skip the RRM measurement and transmit the uplink communication,

that the UE is not to expect a collision involving an SSB or CSI-RS for mobility, or

that the UE is to manage the potential collision based at least in part on a service type of the uplink communication.

18. The method of claim 15 , wherein the potential collision is between the guard period and a pre-scheduled or pre-configured resource associated with the uplink communication.

19. The method of claim 18 , wherein the collision rule indicates one of:

that the UE is to drop the uplink communication, or

that the UE is to puncture a portion of the uplink communication that collides with the guard period.

20. The method of claim 18 , wherein the pre-scheduled or pre-configure resource is associated with at least one of:

a random access channel (RACH) occasion,

a physical uplink shared channel (PUSCH) occasion associated with a RACH procedure, or

a grant-free uplink transmission.

21. The method of claim 15 , wherein the potential collision is between a downlink communication and at least one of the uplink communication or the guard period.

22. The method of claim 21 , wherein the collision rule indicates one of:

that the UE is to drop the uplink communication and receive the downlink communication,

that the UE is to drop the downlink communication and transmit the uplink communication, or

that the UE is not to expect collisions between downlink communications and uplink communications.

23. The method of claim 21 , wherein the downlink communication is at least one of:

a paging physical downlink control channel (PDCCH),

a paging physical downlink shared channel (PDSCH),

a system information PDCCH, or

a system information PDSCH.

24. The method of claim 15 , wherein the collision rule indicates that the UE is to manage the potential collision based at least in part on a configuration of the UE.

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

a memory; and

one or more processors coupled to the memory, the one or more processors configured to:

determine a guard period associated with switching from a first communication mode to a second communication mode,

wherein the UE is operating in a half-duplex frequency division duplexing (FDD) mode of operation,

wherein the guard period associated with switching from the first communication mode to the second communication mode is different than a guard period associated with switching from the second communication mode to the first communication mode, and

wherein the guard period is determined based at least in part on at least one of:

a determination of whether a number of phase locked loops (PLLs) associated with the UE to be used for the first communication mode is less than a number of PLLs associated with the UE to be used for the second communication mode, or

a determination of whether a particular subcarrier spacing corresponds to a first particular subcarrier spacing associated with the UE or a second particular subcarrier spacing associated with the UE, wherein the first particular subcarrier spacing is associated with the first communication mode and operates at a different kilohertz (kHz) subcarrier spacing relative to the second particular subcarrier spacing associated with the second communication mode;

provide an indication of the guard period; and

switch from the first communication mode to the second communication mode based at least in part on the guard period.

26. A non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions comprising:

one or more instructions that, when executed by one or more processors of a user equipment (UE), cause the one or more processors to:

determine a guard period associated with switching from a first communication mode to a second communication mode,

wherein the UE is operating in a half-duplex frequency division duplexing (FDD) mode of operation,

wherein the guard period associated with switching from the first communication mode to the second communication mode is different than a guard period associated with switching from the second communication mode to the first communication mode, and

wherein the guard period is determined based at least in part on at least one of:

a determination of whether a number of phase locked loops (PLLs) associated with the UE to be used for the first communication mode is less than a number of PLLs associated with the UE to be used for the second communication mode, or

a determination of whether a particular subcarrier spacing corresponds to a first particular subcarrier spacing associated with the UE or a second particular subcarrier spacing associated with the UE, wherein the first particular subcarrier spacing is associated with the first communication mode and operates at a different kilohertz (kHz) subcarrier spacing relative to the second particular subcarrier spacing associated with the second communication mode; and

switch from the first communication mode to the second communication mode based at least in part on the guard period.

27. An apparatus for wireless communication, comprising:

means for determining a guard period associated with switching from a first communication mode to a second communication mode,

wherein the apparatus is operating in a half-duplex frequency division duplexing (FDD) mode of operation,

wherein the guard period associated with switching from the first communication mode to the second communication mode is different than a guard period associated with switching from the second communication mode to the first communication mode, and

wherein the guard period is determined based at least in part on at least one of:

a determination of whether a number of phase locked loops (PLLs) associated with the apparatus to be used for the first communication mode is less than a number of PLLs associated with the apparatus to be used for the second communication mode, or

a determination of whether a particular subcarrier spacing corresponds to a first particular subcarrier spacing associated with the apparatus or a second particular subcarrier spacing associated with the apparatus, wherein the first particular subcarrier spacing is associated with the first communication mode and operates at a different kilohertz (kHz) subcarrier spacing relative to the second particular subcarrier spacing associated with the second communication mode;

means for providing an indication of the guard period; and

means for switching from the first communication mode to the second communication mode based at least in part on the guard period.

28. The method of claim 1 , further comprising:

providing the indication of the guard period in a capability report.

29. The UE of claim 25 , wherein the one or more processors, to provide the indication of the guard period, are further configured to:

provide the indication of the guard period in a capability report.

30. A method of wireless communication performed by a network entity, comprising:

receiving an indication of a guard period associated with a user equipment (UE) for switching from a first communication mode to a second communication mode,

wherein the guard period associated with switching from the first communication mode to the second communication mode is different than a guard period associated with switching from the second communication mode to the first communication mode;

determining, based on the indication that the UE is operating in a half-duplex frequency division duplexing (FDD) mode of operation,

wherein the guard period corresponds to at least one of:

a determination of whether a number of phase locked loops (PLLs) associated with the UE to be used for the first communication mode is less than a number of PLLs associated with the UE to be used for the second communication mode, or

a determination of whether a particular subcarrier spacing corresponds to a first particular subcarrier spacing associated with the UE or a second particular subcarrier spacing associated with the UE, wherein the first particular subcarrier spacing is associated with the first communication mode and operates at a different kilohertz (kHz) subcarrier spacing relative to the second particular subcarrier spacing associated with the second communication mode; and

communicating with the UE based at least in part on the guard period.

31. A base station for wireless communication, comprising:

a memory; and

one or more processors coupled to the memory, the one or more processors configured to:

receive an indication of a guard period associated with a user equipment (UE) for switching from a first communication mode to a second communication mode,

wherein the guard period associated with switching from the first communication mode to the second communication mode is different than a guard period associated with switching from the second communication mode to the first communication mode;

determine, based on the indication, that the UE is operating in a half-duplex frequency division duplexing (FDD) mode of operation,

wherein the guard period corresponds to at least one of:

a determination of whether a number of phase locked loops (PLLs) associated with the UE to be used for the first communication mode is less than a number of PLLs associated with the UE to be used for the second communication mode, or

a determination of whether a particular subcarrier spacing corresponds to a first particular subcarrier spacing associated with the UE or a second particular subcarrier spacing associated with the UE, wherein the first particular subcarrier spacing is associated with the first communication mode and operates at a different kilohertz (kHz) subcarrier spacing relative to the second particular subcarrier spacing associated with the second communication mode; and

communicate with the UE based at least in part on the guard period.

32. The base station of claim 31 , wherein the one or more processors are further configured to:

receive an indication of whether the UE supports a first guard period type or supports a second guard period type.

33. The base station of claim 31 , wherein the guard period is a function of the particular subcarrier spacing over a fixed time duration.

34. The base station of claim 31 , wherein the particular subcarrier spacing is a fixed reference subcarrier spacing.