Slot format indicator (SFI) and slot aggregation level indication in group common PDCCH and SFI conflict handling

1. A method for wireless communications by a user equipment (UE), comprising:

receiving a downlink control channel carrying a slot format indicator (SFI) that indicates whether one or more symbols in at least a current slot are for uplink or for downlink;

determining a scheduled transmission that conflicts with the SFI;

determining a direction of the one or more symbols as uplink or downlink based on the received SFI or based on a direction of the scheduled transmission; and

transmitting or receiving in the one or more symbols based on the determined direction for the one or more symbols.

2. The method of claim 1 , wherein the downlink control channel comprises a group common physical downlink control channel (GC PDCCH).

3. The method of claim 1 , wherein:

the transmission is scheduled by a received downlink control information (DCI); and

determining the direction of the one or more symbols comprises giving priority to the direction of the transmission scheduled by the DCI.

4. The method of claim 1 , wherein:

the transmission is scheduled by a received downlink control information (DCI); and

determining the direction of the one or more symbols comprises:

giving priority to the SFI if the DCI was received in a previous slot, and

giving priority to the DCI if the DCI was received in the current slot.

5. The method of claim 1 , wherein:

the scheduled transmission comprises at least one of a downlink periodic signal in one of the symbols indicated as uplink, reserved, or empty by the SFI or an uplink periodic signal in one of the symbols indicated as downlink, reserved, or empty by the SFI.

6. The method of claim 3 , wherein:

the transmission is scheduled by at least one of a grant in the DCI or ACK/NACK timing information in the DCI scheduling the UE to transmit in a symbol indicated as non-uplink by the SFI or scheduling the UE to receive in a symbol indicated as non-downlink by the SFI.

7. The method of claim 5 , wherein the periodic signal comprises at least one of: a channel state information reference signal (CSI-RS), a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), semi-persistent scheduling (SPS), a sounding reference signal (SRS), or a physical uplink control channel (PUCCH) carrying channel state information (CSI).

8. The method of claim 5 , further comprising:

receiving downlink control information (DCI) containing a grant for the symbol scheduled for the periodic signal, wherein

determining the direction of the one or more symbols comprises determining the direction of the symbol based on the grant in the DCI.

9. The method of claim 5 , wherein determining the direction of the one or more symbols comprises determining the direction of the symbol based on the SFI if the SFI indicates a direction for that symbol.

10. The method of claim 5 , wherein determining the direction of the one or more symbols comprises determining the direction of the symbol based on the periodic signal if the SFI indicates the symbol as empty.

11. The method of claim 5 , wherein determining the direction of the one or more symbols comprises determining the direction of the symbol based on the SFI if the SFI indicates the symbol as reserved.

12. An apparatus for wireless communications, comprising:

means for receiving a downlink control channel carrying a slot format indicator (SFI) that indicates whether one or more symbols in at least a current slot are for uplink or for downlink;

means for determining a scheduled transmission that conflicts with the SFI;

means for determining a direction of the one or more symbols as uplink or downlink based on the received SFI or based on a direction of the scheduled transmission; and

means for transmitting or receiving in the one or more symbols based on the determined direction for the one or more symbols.

13. The apparatus of claim 12 , wherein the downlink control channel comprises a group common physical downlink control channel (GC PDCCH).

14. The apparatus of claim 12 , wherein:

the transmission is scheduled by a received downlink control information (DCI); and

means for determining the direction of the one or more symbols comprises means for giving priority to the direction of the transmission scheduled by the DCI.

15. The apparatus of claim 12 , wherein:

the transmission is scheduled by a received downlink control information (DCI); and

means for determining the direction of the one or more symbols comprises:

means for giving priority to the SFI if the DCI was received in a previous slot, and

means for giving priority to the DCI if the DCI was received in the current slot.

16. The apparatus of claim 12 , wherein:

the scheduled transmission comprises at least one of a downlink periodic signal in one of the symbols indicated as uplink, reserved, or empty by the SFI or an uplink periodic signal in one of the symbols indicated as downlink, reserved, or empty by the SFI.

17. The apparatus of claim 14 , wherein:

the transmission is scheduled by at least one of a grant in the DCI or ACK/NACK timing information in the DCI scheduling the UE to transmit in a symbol indicated as non-uplink by the SFI or scheduling the UE to receive in a symbol indicated as non-downlink by the SFI.

18. The apparatus of claim 16 , wherein the periodic signal comprises at least one of: a channel state information reference signal (CSI-RS), a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), semi-persistent scheduling (SPS), a sounding reference signal (SRS), or a physical uplink control channel (PUCCH) carrying channel state information (CSI).

19. The apparatus of claim 16 , further comprising:

means for receiving downlink control information (DCI) containing a grant for the symbol scheduled for the periodic signal, wherein

means for determining the direction of the one or more symbols comprises means for determining the direction of the symbol based on the grant in the DCI.

20. The apparatus of claim 16 , wherein means for determining the direction of the one or more symbols comprises means for determining the direction of the symbol based on the SFI if the SFI indicates a direction for that symbol.

21. The apparatus of claim 16 , wherein means for determining the direction of the one or more symbols comprises means for determining the direction of the symbol based on the periodic signal if the SFI indicates the symbol as empty.

22. The apparatus of claim 16 , wherein means for determining the direction of the one or more symbols comprises means for determining the direction of the symbol based on the SFI if the SFI indicates the symbol as reserved.

23. An apparatus for wireless communications, comprising:

a transceiver configured to receive a downlink control channel carrying a slot format indicator (SFI) that indicates whether one or more symbols in at least a current slot are for uplink or for downlink; and

at least one processor coupled with a memory and configured to:

determine a scheduled transmission that conflicts with the SFI; and

determine a direction of the one or more symbols as uplink or downlink based on the received SFI or based on a direction of the scheduled transmission; wherein

the transceiver is further configured to transmit or receive in the one or more symbols based on the determined direction for the one or more symbols.

24. The apparatus of claim 23 , wherein the downlink control channel comprises a group common physical downlink control channel (GC PDCCH).

25. The apparatus of claim 23 , wherein:

the transmission is scheduled by a received downlink control information (DCI); and

the at least one processor is configured to determine the direction of the one or more symbols by giving priority to the direction of the transmission scheduled by the DCI.

26. The apparatus of claim 23 , wherein:

the transmission is scheduled by a received downlink control information (DCI); and

the at least one processor is configured to determine the direction of the one or more symbols by:

giving priority to the SFI if the DCI was received in a previous slot, and

giving priority to the DCI if the DCI was received in the current slot.

27. The apparatus of claim 23 , wherein:

the scheduled transmission comprises at least one of a downlink periodic signal in one of the symbols indicated as uplink, reserved, or empty by the SFI or an uplink periodic signal in one of the symbols indicated as downlink, reserved, or empty by the SFI.

28. The apparatus of claim 25 , wherein:

the transmission is scheduled by at least one of a grant in the DCI or ACK/NACK timing information in the DCI scheduling the UE to transmit in a symbol indicated as non-uplink by the SFI or scheduling the UE to receive in a symbol indicated as non-downlink by the SFI.

29. The apparatus of claim 27 , wherein the periodic signal comprises at least one of: a channel state information reference signal (CSI-RS), a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), semi-persistent scheduling (SPS), a sounding reference signal (SRS), or a physical uplink control channel (PUCCH) carrying channel state information (CSI).

30. The apparatus of claim 27 , wherein:

the transceiver is configured to receive a downlink control information (DCI) containing a grant for the symbol scheduled for the periodic signal, wherein

the at least one processor is configured to determine the direction of the symbol based on the grant in the DCI.

31. The apparatus of claim 27 , wherein the at least one processor is configured to determine the direction of the one or more symbols by determining the direction of the symbol based on the SFI if the SFI indicates a direction for that symbol.

32. The apparatus of claim 27 , wherein the at least one processor is configured to determine the direction of the one or more symbols by determining the direction of the symbol based on the periodic signal if the SFI indicates the symbol as empty.

33. The apparatus of claim 27 , wherein the at least one processor is configured to determine the direction of the one or more symbols by determining the direction of the symbol based on the SFI if the SFI indicates the symbol as reserved.