Method and apparatus for applying slot format indication (SFI) to a cell in unlicensed spectrum in a wireless communication system
A method and apparatus are disclosed. In an example from the perspective of a User Equipment (UE), a Slot Format Indication (SFI) is received within a first Channel Occupancy Time (COT) of a serving cell. The SFI is indicative of one or more slot formats of one or more slots of the serving cell. A first signal indicative of an ending position of the first COT is received. A beginning of at least one slot of the one or more slots is after the ending position. The UE determines whether to apply a slot format, of a slot of the one or more slots, to the slot based upon whether the slot is within the first COT, wherein the slot format of the slot is indicated by the SFI.
1. A method of a User Equipment (UE), comprising:
determining whether a slot of a serving cell is within a first Channel Occupancy Time (COT) of the serving cell; and
determining whether to apply a slot format to the slot of the serving cell based upon the determination of whether the slot is within the first COT of the serving cell, wherein an indication of the slot format is received within the first COT.
2. The method of claim 1 , comprising:
applying a slot format of a slot to the slot responsive to a determination that the slot is within the first COT, wherein the slot format is indicated by the indication.
3. The method of claim 1 , comprising:
applying a partial slot format of a slot to a portion of the slot responsive to a determination that the portion of the slot is within the first COT, wherein the partial slot format of the slot corresponds to the portion of the slot and the partial slot format of the slot is indicated by the indication.
4. The method of claim 1 , comprising:
at least one of discarding a partial slot format of a slot or not applying the partial slot format of the slot to a portion of the slot responsive to at least one of:
a determination that the portion of the slot is outside the first COT; or
a determination that the portion of the slot is not within a COT of the serving cell, wherein the partial slot format of the slot corresponds to the portion of the slot and the partial slot format of the slot is indicated by the indication.
5. The method of claim 1 , comprising:
deriving a slot format of a portion of the slot based upon at least a semi-static slot structure responsive to at least one of:
a determination that the portion of the slot is outside the first COT;
a determination that the portion of the slot is not within a COT of the serving cell; or
a determination that the portion of the slot is within a second COT of the serving cell, wherein the second COT is after the first COT.
6. The method of claim 1 , comprising:
at least one of discarding or not applying a slot format of the slot responsive to at least one of:
a determination that the slot is outside the first COT; or
a determination that the slot is not within a COT of the serving cell, wherein the slot format of the slot is indicated by the indication.
7. The method of claim 1 , comprising:
deriving a slot format of the slot based upon at least a semi-static slot structure responsive to at least one of:
a determination that the slot is outside the first COT;
a determination that the slot is not within a COT of the serving cell; or
a determination that the slot is within a second COT of the serving cell, wherein the second COT is after the first COT.
8. The method of claim 1 , wherein the UE does not receive a second indication for the serving cell between a time corresponding to reception of the indication and a time corresponding to a symbol of the slot.
9. The method of claim 1 , comprising:
determining that at least one of a slot format, a transmission direction or a functionality of one or more orthogonal frequency-division multiplexing (OFDM) symbols of the slot are flexible if a slot format of the slot is at least one of discarded or not applied, wherein the slot format of the slot is indicated by the indication.
10. The method of claim 1 , comprising:
responsive to at least one of discarding or not applying a slot format of the slot:
not performing reception of at least one of a configured physical channel or a reference signal, wherein the slot format of the slot is indicated by the indication.
11. A communication device, comprising:
a processor; and
memory comprising processor-executable instructions that when executed by the processor cause performance of operations, the operations comprising:
determining whether a slot of a serving cell is within a first Channel Occupancy Time (COT) of the serving cell; and
determining whether to apply a slot format to the slot of the serving cell based upon the determination of whether the slot is within the first COT of the serving cell, wherein an indication of the slot format is received within the first COT.
12. The communication device of claim 11 , the operations comprising:
applying a slot format of a slot to the slot responsive to a determination that the slot is within the first COT, wherein the slot format is indicated by the indication.
13. The communication device of claim 11 , the operations comprising:
applying a partial slot format of a slot to a portion of the slot responsive to a determination that the portion of the slot is within the first COT, wherein the partial slot format of the slot corresponds to the portion of the slot and the partial slot format of the slot is indicated by the indication.
14. The communication device of claim 11 , the operations comprising:
at least one of discarding a partial slot format of a slot or not applying the partial slot format of the slot to a portion of the slot responsive to at least one of:
a determination that the portion of the slot is outside the first COT; or
a determination that the portion of the slot is not within a COT of the serving cell, wherein the partial slot format of the slot corresponds to the portion of the slot and the partial slot format of the slot is indicated by the indication.
15. The communication device of claim 11 , the operations comprising:
deriving a slot format of a portion of the slot based upon at least a semi-static slot structure responsive to at least one of:
a determination that the portion of the slot is outside the first COT;
a determination that the portion of the slot is not within a COT of the serving cell; or
a determination that the portion of the slot is within a second COT of the serving cell, wherein the second COT is after the first COT.
16. The communication device of claim 11 , the operations comprising:
at least one of discarding or not applying a slot format of the slot responsive to at least one of:
a determination that the slot is outside the first COT; or
a determination that the slot is not within a COT of the serving cell, wherein the slot format of the slot is indicated by the indication.
17. The communication device of claim 11 , the operations comprising:
deriving a slot format of the slot based upon at least a semi-static slot structure responsive to at least one of:
a determination that the slot is outside the first COT;
a determination that the slot is not within a COT of the serving cell; or
a determination that the slot is within a second COT of the serving cell, wherein the second COT is after the first COT.
18. The communication device of claim 11 , wherein the communication device does not receive a second indication for the serving cell between a time corresponding to reception of the indication and a time corresponding to a symbol of the slot.
19. The communication device of claim 11 , the operations comprising:
determining that at least one of a slot format, a transmission direction or a functionality of one or more orthogonal frequency-division multiplexing (OFDM) symbols of the slot are flexible if a slot format of the slot is at least one of discarded or not applied, wherein the slot format of the slot is indicated by the indication.
20. A method of a User Equipment (UE), comprising:
applying a slot format, of a first slot of a serving cell, to the first slot, wherein the first slot is within a first Channel Occupancy Time (COT) of the serving cell, and an indication of the slot format of the first slot is received within the first COT; and
not performing reception of at least one of a configured physical channel or a reference signal on a second slot if the second slot is outside the first COT, wherein an indication of a second slot format of the second slot is received within the first COT.