Downlink signal reception with antenna panel switching

1. A cellular base station, comprising:

at least one antenna;

at least one radio coupled to the at least one antenna; and

a processor coupled to the at least one radio;

wherein the at least one antenna, the at least one radio, and the processor are configured to cause the cellular base station to:

receive an indication of a delay from a wireless device;

select a scheduling offset for a transmission to the wireless device large enough for beam switching at the wireless device based at least in part on the delay, wherein the scheduling offset is an offset between a physical downlink control channel (PDCCH) transmission and an aperiodic channel state information reference signal (A-CSI-RS) transmission that is triggered by the PDCCH, wherein:

when the delay is one of 224 or 336 symbols, the A-CSI-RS is configured for repetitions and a number of beam groups is greater than 1, select the scheduling offset to be at least the delay, and otherwise select the scheduling offset to be a value lower than 224 or 336 symbols;

transmit the PDCCH triggering the A-CSI-RS transmission at the scheduling offset; and

transmit the A-CSI-RS CSI RS based on the scheduling offset.

2. The cellular base station of claim 1 ,

wherein the value lower than 224 or 336 symbols is one of 48 or 24 symbols.

3. The cellular base station of claim 1 , wherein the A-CSI-RS transmission is for beam management, wherein the at least one antenna, the at least one radio, and the processor are further configured to cause the cellular base station to:

receive an indication of a number of beams per beam group supported by the wireless device;

determine whether a number of scheduled channel state information reference signal (CSI-RS) resources of the A-CSI-RS transmission is above the number of beams per beam group supported by the wireless device; and

select a value of at least the antenna panel activation delay for the scheduling offset when the number of scheduled CSI-RS resources of the A-CSI-RS transmission is above the number of beams per beam group supported by the wireless device and when repetition is configured to be on for the scheduled CSI-RS resources.

4. The cellular base station of claim 3 , wherein the at least one antenna, the at least one radio, and the processor are further configured to cause the cellular base station to:

select a value of less than the antenna panel activation delay for the scheduling offset when the number of scheduled CSI-RS resources of the A-CSI-RS transmission is not greater than the number of beams per beam group supported by the wireless device.

5. The cellular base station of claim 1 , wherein the A-CSI-RS transmission is for beam management, wherein the at least one antenna, the at least one radio, and the processor are further configured to cause the cellular base station to:

receive an indication of a number of beams per beam group supported by the wireless device;

determine whether a number of scheduled channel state information reference signals (CSI-RS) resources of the A-CSI-RS transmission is above the number of beams per beam group supported by the wireless device; and

select a scheduling offset such that at least the antenna panel activation delay passes before the end of the transmission to the wireless device when the number of scheduled CSI-RS resources of the A-CSI-RS transmission is above the number of beams per beam group supported by the wireless device.

6. The cellular base station of claim 1 , wherein the A-CSI-RS transmission is for tracking, an A-CSI-RS transmission for channel state information acquisition, or a physical downlink shared channel (PDSCH) transmission, wherein the at least one antenna, the at least one radio, and the processor are further configured to cause the cellular base station to:

determine whether a transmission configuration indicator (TCI) state for the transmission is stale;

select a value of at least the antenna panel activation delay for the scheduling offset when the TCI state for the transmission is stale.

7. The cellular base station of claim 6 , wherein the at least one antenna, the at least one radio, and the processor are further configured to cause the cellular base station to:

select a value of less than the antenna panel activation delay for the scheduling offset when the TCI state for the transmission is not stale.

8. The cellular base station of claim 6 , wherein the cellular base station is further configured to determine that a TCI state for a transmission is stale when at least one of:

a downlink reference signal in the TCI state or quasi-co-located with a reference signal in the TCI state has not been reported by the wireless device within a threshold amount of time;

a downlink reference signal in the TCI state is not configured in a TCI state for a control resource set or quasi-co-located with a downlink reference signal that is configured in a TCI state for a control resource set for the wireless device;

a PDSCH transmission with the TCI state has not been transmitted to the wireless device within a threshold amount of time; or

a periodic CSI-RS or semi-persistent CSI-RS with the TCI state has not been transmitted to the wireless device within a threshold amount of time.

9. An apparatus, comprising:

a processor configured to cause a cellular base station to:

receive an indication of a delay from a wireless device;

select a scheduling offset for a transmission to the wireless device large enough for beam switching at the wireless device based at least in part on the delay, wherein the scheduling offset is an offset between a physical downlink control channel (PDCCH) transmission and an aperiodic channel state information reference signal (A-CSI-RS) transmission that is triggered by the PDCCH, wherein:

when the delay is one of 224 or 336 symbols, the A-CSI-RS is configured for repetitions and a number of beam groups is greater than 1, select the scheduling offset to be at least the delay, and otherwise select the scheduling offset to be a value lower than 224 or 336 symbols;

transmit the PDCCH triggering the A-CSI-RS transmission at the scheduling offset; and

transmit the A-CSI-RS to the wireless device based on the scheduling offset.

10. The apparatus of claim 9 , wherein the processor is further configured to cause the cellular base station to:

receive an indication of a number of beams per beam group supported by the wireless device;

determine whether a number of scheduled channel state information reference signal (CSI-RS) resources of the transmission is above the number of beams per beam group supported by the wireless device; and

select the scheduling offset further based at least in part on whether the number of scheduled CSI-RS resources transmission is above the number of beams per beam group supported by the wireless device.

11. The apparatus of claim 9 , wherein the processor is further configured to cause the cellular base station to:

determine whether a transmission configuration indicator (TCI) state for the transmission is out-of-date; and

select the scheduling offset further based at least in part on whether the TCI state for the transmission is out-of-date.

12. The apparatus of claim 11 , wherein the processor is further configured to cause the cellular base station to:

determine that the TCI state for the transmission is out-of-date when a downlink reference signal in the TCI state or quasi-co-located with a reference signal in the TCI state has not been reported by the wireless device within a threshold amount of time.

13. The apparatus of claim 11 , wherein the processor is further configured to cause the cellular base station to:

determine that the TCI state for the transmission is out-of-date when a downlink reference signal in the TCI state is not configured in a TCI state for a control resource set for the wireless device or quasi-co-located with a downlink reference signal that is configured in a TCI state for a control resource set for the wireless device.

14. The apparatus of claim 11 , wherein the processor is further configured to cause the cellular base station to:

determine that the TCI state for the transmission is out-of-date when a physical downlink shared channel (PDSCH) transmission with the TCI state has not been transmitted to the wireless device within a threshold amount of time.

15. The apparatus of claim 11 , wherein the processor is further configured to cause the cellular base station to:

determine that the TCI state for the transmission is out-of-date when a periodic channel state information reference signal (CSI-RS) or semi-persistent CSI-RS with the TCI state has not been transmitted to the wireless device within a threshold amount of time.

16. The apparatus of claim 9 ,

wherein the value lower than 224 or 336 symbols is one of 48 or 24 symbols.

17. A method, comprising:

by a base station:

receiving an indication of a delay from a wireless device;

selecting a scheduling offset for a transmission to the wireless device large enough for beam switching at the wireless device based at least in part on the delay, wherein the scheduling offset is an offset between a physical downlink control channel (PDCCH) transmission and an aperiodic channel state information reference signal (A-CSI-RS) transmission that is triggered by the PDCCH, wherein:

when the delay is one of 224 or 336 symbols, the A-CSI-RS is configured for repetitions and a number of beam groups is greater than 1, select the scheduling offset to be at least the delay, and otherwise select the scheduling offset to be a value lower than 224 or 336 symbols;

transmitting the PDCCH triggering the A-CSI-RS transmission at the scheduling offset; and

transmitting the A-CSI-RS CSI RS based on the scheduling offset.

18. The method of claim 17 , wherein the value lower than 224 or 336 symbols is one of 48 or 24 symbols.

19. The method of claim 17 , further comprising:

receiving an indication of a number of beams per beam group supported by the wireless device;

determining whether a number of scheduled channel state information reference signal (CSI-RS) resources of the transmission is above the number of beams per beam group supported by the wireless device; and

selecting the scheduling offset further based at least in part on whether the number of scheduled CSI-RS resources transmission is above the number of beams per beam group supported by the wireless device.

20. The method of claim 17 , further comprising:

determining whether a transmission configuration indicator (TCI) state for the transmission is out-of-date; and

selecting the scheduling offset further based at least in part on whether the TCI state for the transmission is out-of-date.