Methods and apparatuses for multi-TRP transmission

1. A method performed by a User Equipment (UE), the method comprising:

receiving Transmission/Reception Point (TRP) information from a base station;

communicating with a plurality of TRPs based on the TRP information;

receiving Downlink Control Information (DCI) comprising a rate matching indicator indicating a particular one of a plurality of rate match pattern configurations contained in a Radio Resource Control (RRC) message;

identifying a particular TRP transmitting the DCI based on the TRP information; and

performing a rate matching procedure, based on the particular one of the plurality of rate match pattern configurations, to identify at least one radio resource unavailable for a Physical Downlink Shared Channel (PDSCH) on which a DL signal is transmitted by the particular TRP;

wherein the TRP information identifies a correspondence between the plurality of TRPs and a plurality of Downlink (DL) Reference Signal (RS) resources;

wherein the TRP information comprises at least one of:

a plurality of TRP Identifiers (IDs);

a plurality of Control Resource Set (CORESET) IDs; and

a TRP mapping table comprising a plurality of TRP indices and a plurality of DL RS resource indices.

2. The method of claim 1 , further comprising:

receiving the DCI from the particular TRP, wherein the DCI further comprises a DL preemption indicator containing the TRP information;

identifying the particular TRP associated with the DL preemption indicator based on the TRP information; and

preempting a DL transmission from the particular TRP by another transmission.

3. The method of claim 1 , further comprising:

determining whether a total number of Physical Downlink Control Channel (PDCCH) candidates of the plurality of TRPs for Blind Decoding (BD), or a total number of Control Channel Elements (CCEs) of the plurality of TRPs for PDCCH estimation, exceeds a threshold; and

dropping at least part of the PDCCH candidates, or at least part of the CCEs, when the total number of the PDCCH candidates for BD or the total number of the CCEs for PDCCH estimation exceeds the threshold.

4. The method of claim 3 , wherein at least one dropped PDCCH candidate or at least one dropped CCE is determined based on an order of signal quality values of CORESETs of PDCCHs, or a type of a search space associated with the at least one dropped PDCCH candidate or the at least one dropped CCE.

5. The method of claim 3 , wherein at least one dropped PDCCH candidate or at least one dropped CCE is transmitted from one of the plurality of TRPs.

6. The method of claim 1 , further comprising:

transmitting Uplink Control Information (UCI) comprising a Channel State Information (CSI) report to the base station;

wherein the CSI report comprises a plurality of measurement results, and each of the plurality of measurement results comprises a CSI-RS Resource Indicator (CRI) and a measurement parameter set corresponding to the CRI.

7. The method of claim 6 , wherein each of the measurement parameter set comprises at least one of a Precoding Matrix Indicator (PMI), a Channel Quality Indicator (CQI), a Rank Indication (RI), and a Layer Indication (LI).

8. The method of claim 1 , further comprising:

receiving a Medium Access Control (MAC) Control Element (CE) from the base station, the MAC CE comprising a plurality of spatial relation information indicators, more than one of the plurality of spatial relation information indicators activated for a Physical Uplink Control Channel (PUCCH) transmission; and

performing the PUCCH transmission using at least one spatial filter that is determined from the activated more than one of the plurality of spatial relation information indicators.

9. The method of claim 8 , further comprising:

selecting at least one particular spatial relation information indicator from the activated more than one of the plurality of spatial relation information indicators, according to signal quality values of DL signals associated with the activated more than one of the plurality of spatial relation information indicators;

wherein the at least one spatial filter used for the PUCCH transmission is associated with the at least one particular spatial relation information indicator.

10. The method of claim 9 , wherein a number of the at least one particular spatial relation information indicator is greater than one when the UE supports a simultaneous transmission function.

11. A User Equipment (UE) comprising:

one or more non-transitory computer-readable media having computer-executable instructions embodied thereon;

at least one processor coupled to the one or more non-transitory computer-readable media, and configured to execute the computer-executable instructions to:

receive Transmission/Reception Point (TRP) information from a base station;

communicate with a plurality of TRPs based on the TRP information;

receive Downlink Control Information (DCI) comprising a rate matching indicator indicating a particular one of a plurality of rate match pattern configurations contained in a Radio Resource Control (RRC) message;

identify a particular TRP transmitting the DCI based on the TRP information; and

perform a rate matching procedure, based on the particular rate match pattern configuration, to identify at least one radio resource unavailable for a Physical Downlink Shared Channel (PDSCH) on which a DL signal is transmitted by the particular TRP;

wherein the TRP information identifies a correspondence between the plurality of TRPs and a plurality of Downlink (DL) Reference Signal (RS) resources;

wherein the TRP information comprises at least one of:

a plurality of TRP Identifiers (IDs);

a plurality of Control Resource Set (CORESET) IDs; and

a TRP mapping table comprising a plurality of TRP indices and a plurality of DL RS resource indices.

12. The UE of claim 11 , wherein the at least one processor is further configured to execute the computer-executable instructions to:

receive the DCI from the particular TRP, wherein the DCI further comprises a DL preemption indicator containing the TRP information;

identify the particular TRP associated with the DL preemption indicator based on the TRP information; and

preempt a DL transmission from the particular TRP by another transmission.

13. The UE of claim 11 , wherein the at least one processor is further configured to execute the computer-executable instructions to:

determine whether a total number of Physical Downlink Control Channel (PDCCH) candidates of the plurality of TRPs for Blind Decoding (BD), or a total number of Control Channel Elements (CCEs) of the plurality of TRPs for PDCCH estimation, exceeds a threshold; and

drop at least part of the PDCCH candidates, or at least part of the CCEs, when the total number of the PDCCH candidates for BD or the total number of the CCEs for PDCCH estimation exceeds the threshold.

14. The UE of claim 13 , wherein at least one dropped PDCCH candidate or at least one dropped CCE is determined based on an order of signal quality values of CORESETs of PDCCHs, or a type of a search space associated with the at least one dropped PDCCH candidate or the at least one dropped CCE.

15. The UE of claim 13 , wherein at least one dropped PDCCH candidate or at least one dropped CCE is transmitted from one of the plurality of TRPs.

16. The UE of claim 11 , wherein the at least one processor is further configured to execute the computer-executable instructions to:

transmit Uplink Control Information (UCI) comprising a Channel State Information (CSI) report to the base station;

wherein the CSI report comprises a plurality of measurement results, and each of the plurality of measurement results comprises a CSI-RS Resource Indicator (CRI) and a measurement parameter set corresponding to the CRI.

17. The UE of claim 16 , wherein each measurement parameter set comprises at least one of a Precoding Matrix Indicator (PMI), a Channel Quality Indicator (CQI), a Rank Indication (RI), and a Layer Indication (LI).

18. The UE of claim 11 , wherein the at least one processor is further configured to execute the computer-executable instructions to:

receive a Medium Access Control (MAC) Control Element (CE) from the base station, the MAC CE comprising a plurality of spatial relation information indicators, more than one of the plurality of spatial relation information indicators activated for a Physical Uplink Control Channel (PUCCH) transmission; and

perform the PUCCH transmission using at least one spatial filter that is determined from the activated more than one of the plurality of spatial relation information indicators.

19. The UE of claim 18 , wherein the at least one processor is further configured to execute the computer-executable instructions to:

select at least one particular spatial relation information indicator from the activated more than one of the plurality of spatial relation information indicators, according to signal quality values of DL signals associated with the activated more than one of the plurality of spatial relation information indicators;

wherein the at least one spatial filter used for the PUCCH transmission is associated with the at least one particular spatial relation information indicator.

20. The UE of claim 19 , wherein a number of the at least one particular spatial relation information indicator is greater than one when the UE supports a simultaneous transmission function.