Method and apparatus for downlink transmission in physical downlink control channel

Patent metadata

Field	Value
Publication number	US-2024015740-A1
Application number	US-202018018697-A
Country	US
Kind code	A1
Filing date	Jul 31, 2020
Priority date	Jul 31, 2020
Publication date	Jan 11, 2024
Grant date	—

Abstract

The present application relates to a method and an apparatus for downlink transmission in physical downlink control channel. The method includes: determining at least one transmission configuration indicator (TCI) state for receiving a physical down-link shared channel (PDSCH) or an aperiodic channel state information reference signal (AP CSI-RS), wherein multiple TCI states are activated for at least one control resource set (CORESET) in active bandwidth part (BWP) in serving cell; and receiving the PDSCH or the AP CSI-RS according to the determined at least one TCI state.

First claim

1 . A method of a user equipment (UE), comprising:
determining at least one transmission configuration indicator (TCI) state for receiving a physical downlink shared channel (PDSCH) or an aperiodic channel state information reference signal (AP CSI-RS), wherein multiple TCI states are activated for at least one control resource set (CORESET) in active bandwidth part (BWP) in serving cell.

2 . The method of claim 1 , wherein the at least one TCI state is determined for receiving the PDSCH , and the method further comprises:
calculating a time offset between a reception of a downlink control information (DCI) and a PDSCH corresponding to the DCI; wherein the time offset is less than a threshold, and determining the at least one TCI state for receiving the PDSCH comprises: determining one specific TCI state from a plurality of TCI states which is activated for a specific CORESET, which is associated with a monitored search space, with lowest identify number in latest slot within the active BWP of the serving cell monitored by the UE.

3 . (canceled)

4 . The method of claim 2 , wherein the UE is not configured with a parameter which indicates the UE to apply two default TCI states of single-DCI based multi- transmission reception point (TRP) transmission, or the UE is configured with the parameter and no TCI codepoint activated to the UE for PDSCH maps to two TCI states.

5 . The method of claim 1 , wherein the at least one TCI state is determined for receiving the AP CSI-RS , and the method further comprises:
calculating an offset between last symbol of last PDCCH and first symbol of AP CSI-RS resource, wherein the last PDCCH carries a DCI for triggering AP CSI-RS transmission, and the AP CSI-RS resource is in a non-zero power channel state information reference signal (NZP-CSI-RS) resource set configured without a parameter of tracking reference information; wherein the offset is less than a threshold, and determining the at least one TCI state for receiving the AP CSI-RS comprises: determining one specific TCI state from a plurality of TCI states which is activated for a specific CORESET associated with a monitored search space with lowest identify number in latest slot within the active BWP of the serving cell monitored by the UE.

6 . (canceled)

5 . The method of claim 5 , wherein in the same symbols of the AP CSI-RS resources are without any other downlink signal, which refers to a PDSCH scheduled with a time offset larger than or equal to another threshold, having an indicated TCI state.

8 . The method of claim 1 , wherein the at least one TCI state is determined for receiving the PDSCH, and the method further comprises:
calculating a time offset between a reception of a DCI and the PDSCH corresponding to the DCI; wherein the offset is equal to or greater than a threshold and a format of the DCI is without TCI field, and determining the at least one TCI state for receiving PDSCH comprises: determining a specific TCI state with lowest identity number from a plurality of TCI states which is activated for a specific CORESET used for transmitting a PDCCH.

9 . The method of claim 8 , wherein the UE is not configured with a parameter which indicates the UE to apply two default TCI states of single-DCI based multi-transmission reception point (TRP) transmission, or the UE is configured with the parameter and no TCI codepoint activated to the UE for PDSCH maps to two TCI states.

10 . The method of claim 1 , wherein the at least one TCI state is determined for receiving the PDSCH, and the method further comprises:
calculating a time offset between a reception of a DCI and the PDSCH corresponding to the DCI; wherein the offset is equal to or greater than a threshold and a format of the DCI is without TCI field, and determining the at least one TCI state for receiving the PDSCH comprises: determining two specific TCI states corresponding to lowest TCI codepoint among TCI codepoints, which are activated to the UE for PDSCH, containing two TCI states.

11 . The method of claim 10 , wherein the format of the DCI being without TCI field is configured by having no TCI present parameter for a specific CORESET used for transmitting the DCI, at least one TCI present parameter is configured for another CORESET configured in the active BWP of the serving cell, and the UE is configured with a parameter which indicates the UE to apply two default TCI states and at least one TCI codepoint activated to the UE for PDSCH maps to two TCI states.

12 . The method of claim 10 , wherein time domain resource assignment (TDRA) field in the DCI indicates an entry in a PDSCH time domain allocation list not containing a repetition number of PDSCH transmission and demodulation reference signal (DM-RS) ports indicated in the DCI are within two code division multiplexing (CDM) groups, and the method further comprises:
determining that a first TCI state of the two specific TCI states corresponds to one CDM group of a first DM-RS port indicated by the DCI, and a second TCI state of the two specific TCI states corresponds to the other CDM group.

13 . The method of claim 10 , wherein TDRA field in the DCI indicates an entry in a PDSCH time domain allocation list containing a repetition number of PDSCH transmission, or the UE is configured by a parameter of repetition scheme as for time division multiplexing scheme and DM-RS ports indicated in the DCI are within one CDM group, and the method further comprises:
determining that a first TCI state of the two specific TCI states corresponds to even PDSCH transmission occasions and a second TCI state of the two TCI specific states corresponds to odd PDSCH transmission occasions.

14 . The method of claim 10 , wherein the UE is configured by a parameter as first frequency division multiplexing scheme or second frequency division multiplexing scheme, DM-RS ports are indicated within a CDM group and precoding granularity is determined as wideband, and the method further comprises:
determining that first [n PRB/ 2] physical resource blocks (PRBs) correspond to a first TCI state of the two specific TCI states and remaining [n PRB/ 2] PRBs correspond to a second TCI state of the two TCI specific states, where [n PRB /2] PRB is the total number of allocated PRBs for the UE.

15 . The method of claim 10 , wherein the UE is configured by a parameter as first frequency division multiplexing scheme or second frequency division multiplexing scheme, DM-RS ports are indicated within a CDM group and P′ BWP.i is determined as one of the values among {2, 4}, and the method further comprises:
determining that even precoding resource block group (PRGs) within allocated frequency domain resources correspond to a first TCI state of the two specific TCI states and odd PRGs within allocated frequency domain resources correspond to a second TCI state of the two specific TCI states.

16 . The method of claim 1 , wherein the at least one TCI state is determined for receiving PDSCH, and the method further comprises:
calculating an offset between a reception of a DCI and the PDSCH corresponding to the DCI; wherein the offset is equal to or greater than a threshold and a DCI format is without TCI field and a plurality of TCI states is activated for the CORESET used for transmitting the DCI, and determining the at least one TCI state for receiving PDSCH comprises: determining two specific TCI states of a specific CORESET used for transmitting a PDCCH.

17 . The method of claim 16 , wherein TDRA field in the DCI indicates an entry in a PDSCH time domain allocation list not

Assignees

• Lenovo Beijing Ltd

Inventors

• Xiao Lingling
• Liu Bingchao
• Zhu Chenxi
• Ling Wei
• Zhang Yi

Classifications

• H04W72/1273 Primary

  of downlink data flows · CPC title

• H04W72/0457

  Variable allocation of band or rate · CPC title

• H04B7/0626

  Channel coefficients, e.g. channel state information [CSI] · CPC title

• H04W72/232

  the control data signalling from the physical layer, e.g. DCI signalling · CPC title

• H04L5/0044 Primary

  Allocation of payload; Allocation of data channels, e.g. PDSCH or PUSCH · CPC title