Grant-free uplink transmission in unlicensed spectrum

1. A method for an electronic device (ED) in a wireless communication network, the method comprising:

receiving, at an ED from a base station, grant-free (GF) resource configuration information to configure the ED for GF uplink transmission in unlicensed spectrum, the GF resource configuration information comprising GF ED group-specific resource configuration information indicating GF ED group-specific time-frequency (T/F) resources of the unlicensed spectrum for GF uplink transmission, wherein the GF resource configuration information is received in part via RRC signaling and in part via downlink control information (DCI) that is part of an ED-specific or a group common trigger; and

transmitting a grant-free uplink transmission over the unlicensed spectrum in accordance with the GF resource configuration information.

2. The method of claim 1 , wherein the GF resource configuration information further comprises a GF ED group-specific radio network temporary identifier (GFG-RNTI) for the ED to receive GFG common DCI messages from the base station.

3. The method of claim 1 , further comprising performing a clear channel assessment (CCA) in the unlicensed spectrum in accordance with the GF resource configuration information, wherein transmitting a GF uplink transmission over the unlicensed spectrum comprises starting the GF uplink transmission in accordance with the GF resource configuration information if the CCA is successful.

4. The method of claim 1 , wherein the GF uplink transmission of one ED or multiple ED of the group over the unlicensed spectrum is aligned to:

a common GF transmission cycle; and

a DL burst containing a Control Resource Set (CORESET) that includes ED-specific and/or group common DCI triggers.

5. The method of claim 1 , wherein the GF resource configuration information is received at least partially via at least one of:

a group-specific configuration message comprising the GF ED group-specific resource configuration information to configure the EDs in the group for GF uplink transmission in the unlicensed spectrum; and

an ED-specific configuration message.

6. The method of claim 1 , wherein the GF resource configuration information is received entirely via radio resource control (RRC) signaling.

7. The method of claim 1 , wherein the GF ED group-specific resource configuration information further comprises an indication of one or more occupational bandwidth-compliant (OCB-compliant) frequency hopping patterns to be used by one or more EDs in the group for grant-free uplink transmission within the T/F resources.

8. The method of claim 7 , wherein one or more of the OCB-compliant frequency hopping patterns comprises at least one of:

i) a sequence of frequency interlaces within the T/F resources;

ii) a sequence of unlicensed channels to occupy within the T/F resources; and

iii) a combination of i) and ii).

9. The method of claim 1 , wherein the GF ED group-specific resource configuration information further comprises an indication of an ED-specific field format for a grant-free group (GFG) common downlink control information (DCI) message.

10. The method of claim 1 , further comprising:

receiving a multi-cast group-specific grant-free group (GFG) feedback message on T/F resources of the unlicensed spectrum.

11. The method of claim 10 , wherein receiving a multi-cast group-specific grant-free group (GFG) feedback message comprises receiving the multi-cast GFG feedback message after a last grant-free uplink burst from one of the EDs in the group ends and within a maximum channel occupancy time (MCOT).

12. The method of claim 10 , wherein receiving the multi-cast GFG feedback message comprises receiving the multi-cast GFG feedback message as part of a GFG common time-alignment message, the GFG feedback message comprising, for each of one or more EDs in the group, an information field that includes Ack/Nack feedback related to one or more transport blocks transmitted by the ED within one or more most recent grant-free uplink bursts preceding the GFG Ack/Nack feedback message.

13. The method of claim 1 , further comprising:

receiving, over the unlicensed spectrum resources, a downlink burst from the base station containing a control resource set (CORESET) that includes an ED-specific downlink control information (DCI) trigger for the ED; and

timing the ED's group-aligned GF transmission in the unlicensed spectrum resources based on information in the ED-specific DCI trigger.

14. A method for an electronic device (ED) in a wireless communication network, the method comprising:

receiving, at an ED from a base station, grant-free (GF) resource configuration information to configure the ED for GF uplink transmission in unlicensed spectrum, the GF resource configuration information comprising: GF ED group-specific resource configuration information indicating GF ED group-specific time-frequency (T/F) resources of the unlicensed spectrum for GF uplink transmission; and information indicating a reference start time and a GF transmission cycle period;

performing a clear channel assessment (CCA) in the unlicensed spectrum in accordance with the GF resource configuration information; and

transmitting a grant-free uplink transmission over the unlicensed spectrum in accordance with the GF resource configuration information, wherein transmitting the GF uplink transmission comprises: starting the GF uplink transmission in accordance with the GF resource configuration information if the CCA is successful; and aligning the ED's GF uplink transmission in the T/F resources to the common GF transmission cycle defined by the common GF transmission cycle reference start time and the common GF transmission cycle period.

15. The method of claim 14 , wherein the GF resource configuration information is received in part via RRC signaling and in part via downlink control information (DCI) that is part of an ED-specific or a group common trigger.

16. The method of claim 14 , wherein the GF resource configuration information further comprises information indicating a plurality of potential GF occasions within a GF transmission cycle at which the ED could potentially start a GF uplink transmission.

17. The method of claim 14 , wherein the reference start time is an absolute start time expressed as the index of an alignment time unit (ATU).

18. The method of claim 14 , wherein the reference start time is a time offset relative to any one of:

radio resource control (RRC) signaling carrying at least part of the GF resource configuration information; and

downlink control information (DCI) carrying at least part of the GF resource configuration information.

19. The method of claim 14 , wherein the ED determines the reference start time based on the GF transmission cycle period and a current timer value of any one of: system frame number; subframe number; and slot number.

20. The method of claim 14 , wherein:

the GF ED group-specific resource configuration information further comprises information indicating a grant-free frame structure to be used by the group of EDs for grant-free uplink transmission in the unlicensed spectrum; and

transmitting a grant-free uplink transmission over the unlicensed spectrum comprises transmitting the grant-free uplink transmission in accordance with the grant-free frame structure indicated in the GF ED group-specific resource configuration information.

21. The method of claim 14 , further comprising:

receiving, over the unlicensed spectrum resources, a downlink burst from the base station containing a control resource set (CORESET) that includes an ED-specific downlink control information (DCI) trigger for the ED,

wherein at least part of the GF resource configuration information is received via the ED-specific downlink DCI trigger for the ED.

22. An electronic device (ED) comprising:

a memory storage comprising instructions; and

one or more processors in communication with the memory storage, wherein the one or more processors execute the instructions to:

configure the ED for grant-free (GF) uplink transmission in unlicensed spectrum in accordance with GF resource configuration information received from a base station, the GF resource configuration information comprising GF ED group-specific resource configuration information indicating GF ED group-specific time-frequency (T/F) resources of the unlicensed spectrum for GF uplink transmission, wherein the GF resource configuration information is received in part via RRC signaling and in part via downlink control information (DCI) that is part of an ED-specific or a group common trigger; and

transmit a grant-free uplink transmission over the unlicensed spectrum in accordance with the GF resource configuration information.

23. The ED of claim 22 , wherein the one or more processors execute the instructions to:

perform a clear channel assessment (CCA) in the unlicensed spectrum in accordance with the GF resource configuration information; and

start the GF uplink transmission in accordance with the GF resource configuration information if the CCA is successful.

24. The ED of claim 22 , wherein the one or more processors execute the instructions to start the GF uplink transmission in alignment with the GF uplink transmission of one or more EDs in the GF group.

25. The ED of claim 24 , wherein the GF uplink transmission of one ED or multiple ED of the group over the unlicensed spectrum is aligned to:

a common GF transmission cycle; and

a DL burst containing a Control Resource Set (CORESET) that includes ED-specific and/or group common DCI triggers.

26. The ED of claim 22 , wherein

the GF ED group-specific resource configuration information further comprises an indication of one or more occupational bandwidth-compliant (OCB-compliant) frequency hopping patterns to be used by one or more EDs in the group for grant-free uplink transmission within the T/F resources; and

one or more of the OCB-compliant frequency hopping patterns comprises at least one of:

i) a sequence of frequency interlaces within the T/F resources;

ii) a sequence of unlicensed channels to occupy within the T/F resources; and

iii) a combination of i) and ii).

27. The ED of claim 22 , wherein the one or more processors execute the instructions to:

receive a multi-cast group-specific grant-free group (GFG) feedback message on T/F resources of the unlicensed spectrum either

i) after a last grant-free uplink burst from one of the EDs in the group ends and within a maximum channel occupancy time (MCOT), or

ii) as part of a GFG common time-alignment message, the GFG feedback message comprising, for each of one or more EDs in the group, an information field that includes Ack/Nack feedback related to one or more transport blocks transmitted by the ED within one or more most recent grant-free uplink bursts preceding the GFG Ack/Nack feedback message.

28. The ED of claim 22 , wherein the one or more processors execute the instructions to:

receive, over the unlicensed spectrum resources, a downlink burst from the base station containing a control resource set (CORESET) that includes an ED-specific downlink control information (DCI) trigger for the ED; and

time the ED's group-aligned GF transmission in the unlicensed spectrum resources based on information in the ED-specific DCI trigger.

29. An electronic device (ED) comprising:

a memory storage comprising instructions; and

one or more processors in communication with the memory storage, wherein the one or more processors execute the instructions to:

configure the ED for grant-free (GF) uplink transmission in unlicensed spectrum in accordance with GF resource configuration information received from a base station, the GF resource configuration information comprising: GF ED group-specific resource configuration information indicating GF ED group-specific time-frequency (T/F) resources of the unlicensed spectrum for GF uplink transmission; and information indicating a reference start time and a GF transmission cycle period;

perform a clear channel assessment (CCA) in the unlicensed spectrum in accordance with the GF resource configuration information; and

transmit a grant-free uplink transmission over the unlicensed spectrum in accordance with the GF resource configuration information, wherein the one or more processors execute the instructions to: start the GF uplink transmission in accordance with the GF resource configuration information if the CCA is successful; and align the ED's GF uplink transmission in the T/F resources to the common GF transmission cycle defined by the common GF transmission cycle reference start time and the common GF transmission cycle period.

30. The ED of claim 29 , wherein the GF resource configuration information is received either:

entirely via radio resource control (RRC) signaling, or

in part via RRC signaling and in part via downlink control information (DCI) that is part of an ED-specific or a group common trigger.

31. The ED of claim 29 , wherein the GF resource configuration information further comprises information indicating a plurality of potential GF occasions within a GF transmission cycle at which the ED could potentially start a GF uplink transmission.