Methods and apparatus for supporting transmission bursts
Methods and apparatus for supporting transmission bursts in unlicensed spectrum are described. Different sets of sub-bands within a downlink bandwidth portion of unlicensed spectrum can be, and sometimes are, occupied during different DL transmission bursts depending on channel availability. A user device is configured with channel usage information, e.g. N bitmaps, each bitmap indicating a different control channel resource allocation that may be used for communication with the UE, and/or reference signal information. The UE determines the occupied sub-bands in a DL transmission burst over the bandwidth portion, and determines control channel resource information based on the determined occupied sub-channels. The UE determines CSI-RS measurement locations based on determined sub-band occupancy. In some embodiments, the UE performs in-sync and out-of-sync evaluations based BLER threshold scaling factors, which are based on sub-band occupancy.
1. A communications method, the method comprising:
operating a user equipment (UE) device to receive from a base station information relating to communications channel usage, said information including reference signal information indicating time and frequency resources used for different sub-band occupancies;
operating the UE device to determine which sub-bands of a downlink (DL) band being used by the UE device are occupied, said determination being a sub-band occupancy determination where a sub-band occupancy indicates which sub-bands of a communications band are being used to communicate with the UE device; and
operating the UE device to determine channel state information-reference signal (CSI-RS) measurement locations based on the determined sub-band occupancy.
2. The method of claim 1 , further comprising:
operating the UE device to monitor the determined channel state information-reference signal (CSI-RS) measurement locations of the DL for reference signals.
3. The method of claim 2 , wherein operating the UE device to determine which sub-bands of a DL band being used by the UE are occupied includes:
operating the UE device to determine based on signals received during said monitoring which sub-bands of the DL band are occupied.
4. The method of claim 1 , wherein operating the UE device to determine CSI-RS measurement locations based on determined sub-band occupancy includes operating the UE to use the determined sub-band occupancy to determine from the received reference signal information CSI-RS measurement locations.
5. The method of claim 4 , further comprising:
operating the UE device to perform CSI-RS measurements on the time and frequency resources indicated by the determined CSI-RS measurement locations.
6. The method of claim 4 , further comprising:
performing in-sync evaluations based on the sub-band occupancy.
7. The method of claim 4 , wherein performing in-sync evaluations is further based on a BLER threshold scaling factor.
8. The method of claim 6 , further comprising:
operating the UE device to determine the BLER threshold scaling factor to use to perform said in-sync evaluation based on the determined sub-band occupancy.
9. The method of claim 4 , where each sub-band occupancy corresponds to a different set of sub-bands which are used by the base station for communication with the UE device.
10. The method of claim 4 , wherein operating the UE device to receive from the base station information relating to communications channel, usage includes receiving information indicating a control resource allocation.
11. The method of claim 4 , wherein the DL band corresponds to unlicensed spectrum.
12. A user equipment (UE) device comprising:
a receiver; and
a processor configured to:
operate the user equipment (UE) device to:
receive from a base station information relating to communications channel usage, said information including reference signal information indicating time and frequency resources used for different sub-band occupancies;
determine which sub-bands of a downlink (DL) band being used by the UE device are occupied, said determination being a sub-band occupancy determination where a sub-band occupancy indicates which sub-bands of a communications band are being used to communicate with the UE device; and
determine channel state information—reference signal (CSI-RS) measurement locations based on the determined sub-band occupancy.
13. The UE device of claim 12 , wherein the processor is further configured to:
operate the UE device to monitor the determined channel state information-reference signal (CSI-RS) measurement locations of the DL for reference signals.
14. The UE device of claim 13 , wherein the processor is configured, as part of being configured to operate the UE device to determine which sub-bands of a DL band being used by the UE device are occupied:
to determine based on signals received during said monitoring which sub-bands of the DL band are occupied.
15. The UE device of claim 12 , wherein said processor is configured, as part of being configured to operate the UE to determine channel state information-reference signal (CSI-RS) measurement locations, to control the UE device to:
use the determined sub-band occupancy to determine from the received reference signal information CSI-RS measurement locations.
16. The UE device of claim 15 , wherein said processor is configured to control the UE device to:
perform CSI-RS measurements on the time and frequency resources indicated by the determined CSI-RS measurement locations.
17. The UE device of claim 15 , wherein said processor is configured to control the UE device to:
perform in-sync evaluations based on the sub-band occupancy.
18. The UE device of claim 15 , wherein performing in-sync evaluations is based on a BLER threshold scaling factor.
19. The UE device of claim 18 , wherein said processor is configured, to control the UE device to:
determine the BLER threshold scaling factor to use to perform said in-sync evaluation based on the determined sub-band occupancy.
20. A non-transitory computer readable medium including computer executable instructions which when executed by a processor control a user equipment (UE) device using unlicensed spectrum to perform the steps of:
operating the UE device to receive from a base station information relating to communications channel usage, said information including reference signal information indicating time and frequency resources used for different sub-band occupancies;
operating the UE device to determine which sub-bands of a downlink (DL) band being used by the UE device are occupied, said determination being a sub-band occupancy determination where a sub-band occupancy indicates which sub-bands of a communications band are being used to communicate with the UE device; and
operating the UE device to determine channel state information-reference signal (CSI-RS) measurement locations based on the determined sub-band occupancy.