EP4620149A1

EP4620149A1 - Methods and apparatuses for csi computation and reporting for coherent joint transmission

Info

Publication number: EP4620149A1
Application number: EP23881181.4A
Authority: EP
Inventors: Yi Zhang; Chenxi Zhu; Wei Ling; Bingchao LIU; Lingling Xiao
Original assignee: Lenovo Beijing Ltd
Current assignee: Lenovo Beijing Ltd
Priority date: 2023-05-15
Filing date: 2023-05-15
Publication date: 2025-09-24
Also published as: GB202509535D0; GB2640103A; KR20260011126A; AU2023370455A1; MX2025008104A; CN120457654A; WO2024087587A1

Abstract

The present application relates to methods and apparatuses for channel state information (CSI) computation and reporting for coherent joint transmission (CJT). An embodiment of the present disclosure provides a user equipment (UE), comprising: a transceiver; and a processor coupled with the transceiver and configured to: receive, via the transceiver, configuration information indicating a number of channel state information-reference signal (CSI-RS) resource in a CSI-RS resource set as channel measurement resources; determine a first symbol associated with a first additional time duration and a second symbol associated with a second additional time duration; and transmit, via the transceiver, a CSI report in the case that an uplink transmission carrying the CSI report is later than or at the same time with the first symbol after an end of a last symbol of a physical downlink control channel (PDCCH) which triggers the CSI report; and in the case that uplink transmission carrying the CSI report is later than or at the same time with the second symbol after an end of a last symbol of an aperiodic CSI-RS resource for channel measurements, an aperiodic channel measurement-interference measurement (CSI-IM) used for an interference measurement, and an aperiodic non zero power (NZP) CSI-RS for an interference measurement.

Description

METHODS AND APPARATUSES FOR CSI COMPUTATION AND REPORTING FOR COHERENT JOINT TRANSMISSION

TECHNICAL FIELD

The present disclosure relates to wireless communications, and particularly relates to methods and apparatuses for channel state information (CSI) computation and reporting for coherent joint transmission (CJT) .

BACKGROUND OF THE INVENTION

The continuing evolution of multiple inputs multiple outputs (MIMO) may be the most important part of 3^rd generation partnership project (3GPP) physical layer. It is important to identify and specify necessary enhancements for both downlink and uplink MIMO for facilitating the use of large antenna array, not only for frequency range 1 (FR1) but also for FR2 to fulfil the request for evolution of new radio (NR) deployments in 3GPP Release 18.
As CJT improves coverage and average throughput in commercial deployments with high-performance backhaul and synchronization, enhancements on channel state information (CSI) acquisition for frequency division duplex (FDD) and time division duplex (TDD) , targeting FR1, can be beneficial in expanding the utility of multiple transmission or reception points (TRPs) deployments.
With increasing CSI-RS resources for CJT, TRP selection and beam number combination selection, processing complexity may be increased remarkably, and correspondingly, the CSI computation time may be increased remarkably. Accordingly, it is advantageous to provide solutions for methods and apparatuses for CSI reporting for CJT considering the CSI computation time.
For CJT mTRP with N_TRP TRPs or TRP-groups (where N_TRP may be an integer with a value equal to or larger than one) , the channel measurement resource (CMR) may include K NZP CSI-RS resources (where K may be an integer with a value equal to or larger than one) , where one resource corresponds to one TRP or TRP-group (i.e. K = N_TRP) . Thus, CJT may be implicitly indicated by the configuration information indicating a number of channel state information-reference signal (CSI-RS) resources in a CSI-RS resource set as channel measurement resources in the present disclosure. Hereinafter in the present disclosure, the expression "receiving the configuration information indicating a number of CSI-RS resources in a CSI-RS resource set as channel measurement resources" (or similar expressions) and the expression "CJT" may be interchangeably used in the description.

SUMMARY

An embodiment of the present disclosure provides a user equipment (UE) , comprising: a transceiver; and a processor coupled with the transceiver and configured to: receive, via the transceiver, configuration information indicating a number of channel state information-reference signal (CSI-RS) resource in a CSI-RS resource set as channel measurement resources; determine a first symbol associated with a first additional time duration and a second symbol associated with a second additional time duration; and transmit, via the transceiver, a CSI report in the case that an uplink transmission carrying the CSI report is later than or at the same time with the first symbol after an end of a last symbol of a physical downlink control channel (PDCCH) which triggers the CSI report; and in the case that uplink transmission carrying the CSI report is later than or at the same time with the second symbol after an end of a last symbol of an aperiodic CSI-RS resource for channel measurements, an aperiodic channel measurement-interference measurement (CSI-IM) used for an interference measurement, and an aperiodic non zero power (NZP) CSI-RS for an interference measurement.
In some embodiments, the first symbol is determined by a third symbol defined by the specification and the first additional time duration, and the second symbol is determined by a fourth symbol defined by the specification and the second additional time duration.
In some embodiments, in the case that a total number of CSI-RS ports per CSI-RS resource exceeds a threshold, the first additional time duration or the second additional time duration includes a first time period.
In some embodiments, a value of the threshold is 8 in the case that 3 transmission or reception points (TRPs) or 4 TRPs are configured; or a value of the threshold is 16 in the case that 2 TRPs are configured.
In some embodiments, in the case that the UE supports TRP selection, the first additional time duration or the second additional time duration includes a second time period.
In some embodiments, in the case that the UE supports a selection of beam number combination, the first additional time duration or the second additional time duration includes a third time period.
In some embodiments, the processor is further configured to: transmit, via the transceiver, UE capability information indicating one or more additional time durations, wherein the one or more additional time durations includes a first time period, a second time period or a third time period .
In some embodiments, the first additional time duration or the second additional time duration is determined from one or more additional time durations reported by the UE, predetermined by a specification, or configured by a base station (BS) based on the one or more additional time durations reported by the UE.
In some embodiments, the first additional time duration or the second additional time duration is associated with a minimum subcarrier spacing (SCS) of the following: an SCS of a PDCCH carrying downlink control information (DCI) which triggers the SCI report; an SCS of the uplink transmission carrying the CSI report; or a minimum SCS of an aperiodic CSI-RS triggered by the DCI.
In some embodiments, the first additional time duration or the second additional time duration includes a number of orthogonal frequency division multiplexing (OFDM) symbols.
In some embodiments, the first additional time duration and the second additional time duration have the same value.
In some embodiments, the first additional time duration and the second additional time duration are scalable based on different SCSs.
Another embodiment of the present disclosure provides a UE, comprising: a transceiver; and a processor coupled with the transceiver and configured to: receive, via the transceiver, configuration information indicating a number of CSI-RS resources in a CSI-RS resource set and configuration information of discontinuous reception (DRX) ; and transmit, via the transceiver, a CSI report based on time relation between the number of CSI-RS resources in the CSI-RS resource set and a CSI reference resource, wherein at least one CSI-RS resource in the CSI-RS resource set is within the DRX active time duration.
In some embodiments, the CSI report is only transmitted in the case that a CSI-RS transmission occasion for each CSI-RS resource in the CSI-RS resource set is earlier than or at the same time with the CSI reference resource in the time domain.
In some embodiments, the CSI report is transmitted in the case that a first CSI-RS transmission occasion for a first CSI-RS resource (s) in the CSI-RS resource set is earlier than or at the same time with the CSI reference resource in the time domain, and wherein a second CSI-RS transmission occasion for a second CSI-RS resource (s) in the CSI-RS resource set is later than the CSI reference resource in the time domain; or in the case that a first CSI-RS transmission occasion for a first CSI-RS resource (s) in the CSI-RS resource set is earlier than or at the same time with the CSI reference resource in the time domain, and a second CSI-RS transmission occasion for a second CSI-RS resource (s) in the CSI-RS resource set is earlier than or at the same time with the CSI reference resource in the time domain.
In some embodiments, the CSI report is based on the first CSI-RS resource in the CSI-RS resource set.
In some embodiments, the CSI report is based on the first CSI-RS resource in the CSI-RS resource set, or both the first CSI-RS resource and the second CSI-RS resource in the CSI-RS resource set.
Yet another embodiment of the present disclosure provides a BS, comprising: a transceiver; and a processor coupled with the transceiver and configured to: transmit, via the transceiver, configuration information indicating a number of CSI-RS resources in a CSI-RS resource set as channel measurement resources; determine a first symbol associated with a first additional time duration and a second symbol associated with a second additional time duration; and receive, via the transceiver, a CSI report in the case that an uplink transmission carrying the CSI report is later than or at the same time with the first symbol after an end of a last symbol of a PDCCH which triggers the CSI report; and in the case that uplink transmission carrying the CSI report is later than or at the same time with the second symbol after an end of a last symbol of an aperiodic CSI-RS resource for channel measurements, an aperiodic CSI-IM used for an interference measurement, and an aperiodic NZP CSI-RS for an interference measurement.
In some embodiments, the first symbol is determined by a third symbol defined by the specification and the first additional time duration, and the second symbol is determined by a fourth symbol defined by the specification and the second additional time duration.
In some embodiments, in the case that a total number of CSI-RS ports per CSI-RS resource exceeds a threshold, the first additional time duration or the second additional time duration includes a first time period.
In some embodiments, a value of the threshold is 8 in the case that 3 TRPs or 4 TRPs are configured; or a value of the threshold is 16 in the case that 2 TRPs are configured.
In some embodiments, in the case that the UE supports TRP selection, the first additional time duration or the second additional time duration includes a second time period.
In some embodiments, in the case that the UE supports a selection of beam number combination, the first additional time duration or the second additional time duration includes a third time period.
In some embodiments, the processor is further configured to: transmit, via the transceiver, UE capability information indicating one or more additional time durations, wherein the one or more additional time durations includes a first time period, a second time period or a third time period.
In some embodiments, the first additional time duration or the second additional time duration is determined from one or more additional time durations reported by the UE, predetermined by a specification, or configured by the BS based on the one or more additional time durations reported by the UE.
In some embodiments, the first additional time duration or the second additional time duration is associated with a minimum SCS of the following: an SCS of a PDCCH carrying DCI which triggers the SCI report; an SCS of the uplink transmission carrying the CSI report; or a minimum SCS of an aperiodic CSI-RS triggered by the DCI.
In some embodiments, the first additional time duration or the second additional time duration includes a number of orthogonal frequency division multiplexing (OFDM) symbols.
In some embodiments, the first additional time duration and the second additional time duration have the same value.
In some embodiments, the first additional time duration and the second additional time duration are scalable based on different SCSs.
Still another embodiment of the present disclosure provides a BS, comprising: a transceiver; and a processor coupled with the transceiver and configured to: transmit, via the transceiver, configuration information indicating a number of CSI-RS resources in a CSI-RS resource set and configuration information of DRX; and receive, via the transceiver, a CSI report based on time relation between the number of CSI-RS resources in the CSI-RS resource set and a CSI reference resource, wherein at least one CSI-RS resource in the CSI-RS resource set is within the DRX active time duration.
In some embodiments, the CSI report is only received in the case that a CSI-RS transmission occasion for each CSI-RS resource in the CSI-RS resource set is earlier than or at the same time with the CSI reference resource in the time domain.
In some embodiments, the CSI report is received in the case that a first CSI-RS transmission occasion for a first CSI-RS resource (s) in the CSI-RS resource set is earlier than or at the same time with the CSI reference resource in the time domain, and wherein a second CSI-RS transmission occasion for a second CSI-RS resource (s) in the CSI-RS resource set is later than the CSI reference resource in the time domain; or in the case that a first CSI-RS transmission occasion for a first CSI-RS resource (s) in the CSI-RS resource set is earlier than or at the same time with the CSI reference resource in the time domain, and a second CSI-RS transmission occasion for a second CSI-RS resource (s) in the CSI-RS resource set is earlier than or at the same time with the CSI reference resource in the time domain.
In some embodiments, the CSI report is based on the first CSI-RS resource in the CSI-RS resource set.
In some embodiments, the CSI report is based on the first CSI-RS resource in the CSI-RS resource set, or both the first CSI-RS resource and the second CSI-RS resource in the CSI-RS resource set.
Still another embodiment of the present disclosure provides a method performed by a UE, comprising: receiving configuration information indicating a number of CSI-RS resource in a CSI-RS resource set as channel measurement resources; determining a first symbol associated with a first additional time duration and a second symbol associated with a second additional time duration; and transmitting a CSI report in the case that an uplink transmission carrying the CSI report is later than or at the same time with the first symbol after an end of a last symbol of a PDCCH which triggers the CSI report; and in the case that uplink transmission carrying the CSI report is later than or at the same time with the second symbol after an end of a last symbol of an aperiodic CSI-RS resource for channel measurements, an aperiodic CSI-IM used for an interference measurement, and an aperiodic NZP CSI-RS for an interference measurement.
Still another embodiment of the present disclosure provides a method performed by a BS, comprising: transmitting configuration information indicating a number of CSI-RS resources in a CSI-RS resource set as channel measurement resources; determining a first symbol associated with a first additional time duration and a second symbol associated with a second additional time duration; and receiving a CSI report in the case that an uplink transmission carrying the CSI report is later than or at the same time with the first symbol after an end of a last symbol of a PDCCH which triggers the CSI report; and in the case that uplink transmission carrying the CSI report is later than or at the same time with the second symbol after an end of a last symbol of an aperiodic CSI-RS resource for channel measurements, an aperiodic CSI-IM used for an interference measurement, and an aperiodic NZP CSI-RS for an interference measurement.
Still another embodiment of the present disclosure provides a method performed by a UE, comprising receiving configuration information indicating a number of CSI-RS resources in a CSI-RS resource set and configuration information of DRX; and transmitting a CSI report based on time relation between the number of CSI-RS resources in the CSI-RS resource set and a CSI reference resource, wherein at least one CSI-RS resource in the CSI-RS resource set is within the DRX active time duration.
Still another embodiment of the present disclosure provides a method performed by a BS, comprising transmitting configuration information indicating a number of CSI-RS resources in a CSI-RS resource set and configuration information of DRX; and receiving a CSI report based on time relation between the number of CSI-RS resources in the CSI-RS resource set and a CSI reference resource, wherein at least one CSI-RS resource in the CSI-RS resource set is within the DRX active time duration.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which advantages and features of the application can be obtained, a description of the application is rendered by reference to specific embodiments thereof, which are illustrated in the appended drawings. These drawings depict only example embodiments of the application and are not therefore to be considered limiting of its scope.
Fig. 1 depicts a schematic diagram illustrating a wireless communication system 100 according to some embodiments of the present application.
Fig. 2 illustrates time durations for CSI computation according to some embodiments of the present disclosure.
Fig. 3 illustrates a method performed by a UE for CJT according to some embodiments of the present disclosure.
Fig. 4 illustrates a method performed by a BS for CJT according to some embodiments of the present disclosure.
Fig. 5 illustrates a method performed by a UE for CJT according to some embodiments of the present disclosure.
Fig. 6 illustrates a method performed by a BS for CJT according to some embodiments of the present disclosure.
Fig. 7 illustrates a simplified block diagram of an apparatus according to some embodiments of the present disclosure.

DETAILED DESCRIPTION

The detailed description of the appended drawings is intended as a description of the currently preferred embodiments of the present invention, and is not intended to represent the only form in which the present invention may be practiced. It should be understood that the same or equivalent functions may be accomplished by different embodiments that are intended to be encompassed within the spirit and scope of the present invention.
While operations are depicted in the drawings in a particular order, persons skilled in the art will readily recognize that such operations need not be performed in the particular order as shown or in a sequential order, or that all illustrated operations need be performed, to achieve desirable results; sometimes one or more operations can be skipped. Further, the drawings can schematically depict one or more example processes in the form of a flow diagram. However, other operations that are not depicted can be incorporated in the example processes that are schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the illustrated operations. In certain circumstances, multitasking and parallel processing can be advantageous.
Reference will now be made in detail to some embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. To facilitate understanding, embodiments are provided under specific network architecture and new service scenarios, such as a cellular telephone network, a time division multiple access (TDMA) -based network, a code division multiple access (CDMA) -based network, an orthogonal frequency division multiple access (OFDMA) -based network, a LTE network, a 3^rd generation partnership project (3GPP) -based network, LTE, LTE-Advanced (LTE-A) , 3GPP 4G, 3GPP 5G NR, 3GPP Release 16 and onwards, a satellite communications network, a high altitude platform network, and so on. It is contemplated that along with the developments of network architectures and new service scenarios, all embodiments in the present disclosure are also applicable to similar technical problems; and moreover, the terminologies recited in the present disclosure may change, which should not affect the principle of the present disclosure.
Fig. 1 depicts a schematic diagram illustrating an exemplary wireless communication system 100 according to some embodiments of the present application.
Referring to FIG. 1, the wireless communication system 100 may include a BS 101, TRPs 103 (e.g., TRP 103a and TRP 103b) , and UEs 105 (e.g., UE 105a, UE 105b, and UE 105c) . Although only one BS 101, two TRPs 103 and three UEs 105 are shown for simplicity, it should be noted that the wireless communication system 100 may include more or less communication device (s) , apparatus, or node (s) in accordance with some other embodiments of the present application.
The wireless communication system 100 may be compatible with any type of network that may be capable of sending and receiving wireless communication signals. For example, the wireless communication system 100 may be compatible with a wireless communication network, a cellular telephone network, a time division multiple access (TDMA) based network, a code division multiple access (CDMA) based network, an orthogonal frequency division multiple access (OFDMA) based network, an LTE network, a 3GPP-based network, a 3GPP 5G network, a satellite communications network, a high-altitude platform network, and/or other communications networks.
The BS 101 may also be referred to as an access point, an access terminal, a base, a macro cell, a node-B, an enhanced or evolved node B (eNB) , a generalized node B (gNB) , a home node-B, a relay node, or a device, or described using other terminology used in the art. The BS 101 is generally part of a radio access network that may include a controller communicably coupled to the BS 101.
The TRPs 103, for example, the TRP 103a and the TRP 103b, can communicate with the BS 101 via, for example, a backhaul link. Each of TRPs 103 can serve some or all of the UEs 105. As shown in FIG. 1, the TRP 103a can serve some mobile stations (which include the UE 105a, the UE 105b, and the UE 105c) within a serving area or region (e.g., a cell or a cell sector) . The TRP 103b can serve some mobile stations (which include the UE 105a, the UE 105b, and the UE 105c) within a serving area or region (e.g., a cell or a cell sector) . In some other embodiments, the TRP 103a and the TRP 103b may serve different UEs. The TRP 103a and the TRP 103b can communicate with each other via, for example, a backhaul link.
In some embodiments of the present application, the TRPs may perform CJT with the UE 105. All the TRPs involved in the CJT may have the same antenna configuration but are at different locations. In the CJT, each TRP may transmit the same data to the UE 105. Each TRP may be configured and transmit with a CSI-RS resource for channel measurement with the same number of antenna ports. In other words, one TRP may correspond to one CSI-RS resource. Therefore, in the present disclosure, the expressions "per TRP" and "per CSI-RS resource" may be used interchangeably, the expressions "across TRPs" and "across CSI-RS resources" may be used interchangeably, or the like.
According to some embodiments of the present application, the UE (s) 105 may include computing devices, such as desktop computers, laptop computers, personal digital assistants (PDAs) , tablet computers, smart televisions (e.g., televisions connected to the Internet) , set-top boxes, game consoles, security systems (including security cameras) , vehicle on-board computers, network devices (e.g., routers, switches, and modems) , or the like.
According to some embodiments of the present application, the UE (s) 105 may include a portable wireless communication device, a smart phone, a cellular telephone, a flip phone, a device having a subscriber identity module, a personal computer, a selective call receiver, or any other device that is capable of sending and receiving communication signals on a wireless network.
According to some embodiments of the present application, the UE (s) 105 may include wearable devices, such as smart watches, fitness bands, optical head-mounted displays, or the like.
Moreover, the UE (s) 105 may be referred to as a subscriber unit, a mobile, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a fixed terminal, a subscriber station, a user terminal, or a device, or described using other terminology used in the art.
In 3GPP Release 16 (Rel-16) or Release 17 (Rel-16) , features for facilitating multi-TRP deployments have been introduced focusing on non-coherent joint transmission (NC-JT) . In 3GPP Release 18 (Rel-18) , it is important to identify and specify necessary enhancements for both downlink and uplink multiple input multiple output (MIMO) for facilitating the use of large antenna array, not only for frequency range 1 (FR1) (e.g., 450MHz-6GHz) but also for frequency range 2 (FR2) (e.g., 24.25GHz-52.6GHz) to fulfil the requirement for evolution of NR deployments.
CJT may improve coverage and cell average throughput and cell edge throughput in commercial deployments with high-performance backhaul and synchronization, and provide enhancement on channel state information (CSI) acquisition for frequency division duplex (FDD) and time division duplex (TDD) , which can be beneficial in expanding the utility of multi-TRP deployments. Accordingly, In Rel-18, CJT may be further studied.
With continuing evolution of MIMO, currently, it is agreed to specify enhancements of CSI acquisition for CJT targeting FR1 and up to 4 TRPs, assuming ideal backhaul and synchronization as well as the same number of antenna ports across TRPs. The maximum number of CSI-RS ports per CSI-RS resource may be 32. As the TRP number configured for CJT may be 2, 3, and 4, the maximum number of CSI-RS ports across CSI-RS resources may be 128. Each CSI-RS resource may have the same number of CSI-RS ports.
On the Type-II codebook refinement for multiple TRPs for CJT, regarding the spatial domain (SD) basis (i.e., beam) selection, in the case that N_TRP candidate TRPs (or candidate CSI-RS resources) are configured by a BS, the BS may configure N_L combinations of values from a beam number set, i.e., {L₁, ..., L_NTRP} , via higher-layer (e.g., radio link control (RRC) ) signaling, wherein L_i is a beam number for TRP_i, i = 1, …, N_TRP.
In some embodiments, the selection of N CSI-RS resources from N_TRP candidate CSI-RS resources may be performed by a UE for CJT. That is, the UE may support TRP selection dynamically and indicate the selected TRP (s) (or TRP selection) in a CSI report. In some other embodiments, the selection of a beam number combination from N_L (N_L>1) configured combinations can be performed by a UE for CJT. In other words, the UE may support beam number combination selection and indicate the selected beam number combination in a CSI report. With increasing CSI-RS resources for CJT, TRP selection, and beam number combination selection, the UE processing complexity for CSI in CJT scenarios is increased remarkably.
Regarding legacy CSI calculation and measurement, when a field (e.g. the CSI request field) included in a DCI triggers a CSI report (s) on PUSCH, the UE may provide a valid CSI report for a triggered report (e.g. the n-th triggered report) in the case that the following two conditions are fulfilled:
1. the first uplink symbol to carry the corresponding CSI report (s) including the effect of the timing advance, starts no earlier than at symbol Z_ref, and
2. the first uplink symbol to carry the n-th CSI report including the effect of the timing advance, starts no earlier than at symbol Z'_ref (n) ,
Where Z_ref is defined as the next uplink symbol with its CP starting T_proc, CSI= (Z) (2048+144) ·κ2^-μ·T_C+T_switch after the end of the last symbol of the PDCCH triggering the CSI report (s) , and where Z'_ref (n) , is defined as the next uplink symbol with its CP starting T'_proc, CSI= (Z') (2048+144) ·κ2^-μ·T_C after the end of the last symbol in time of the latest of: aperiodic CSI-RS resource for channel measurements, aperiodic CSI-IM used for interference measurements, and aperiodic NZP CSI-RS for interference measurement, when aperiodic CSI-RS is used for channel measurement for the n-th triggered CSI report. The detailed CP starting of Z_ref and Z'_ref (n) may be found in 3GPP documents, for example, in TS 38.214, and details are omitted here.
The above time durations, e.g. Z_ref, and Z'_ref (n) , do not take the increasing CSI-RS resources for CJT, TRP selection, and beam number combination selection into consideration, thus may no longer be suitable for the UE to provide the CSI report. The present disclosure proposes to introduce one or more additional time durations for some UEs, which may be used by the UE for performing CSI computation.
Fig. 2 illustrates time durations for CSI computation according to some embodiments of the present disclosure.
In Fig. 2, the UE may receive a DCI which may trigger one or more CSI reports, and the UE may provide a valid CSI report on PUSCH. The UE may receive a set of CSI-RS resource including Ks CSI-RS resources for channel measurement, where Ks may be the total number of CSI-RS resources in the CSI-RS resource set for channel measurement. For different values of K_s, different numbers of CSI-RS ports per CSI-RS resource may be configured as follows:
○ Ks = 1, at most 32 CSI-RS ports per CSI-RS resource may be configured.
○ Ks = 2, at most 16 CSI-RS ports per CSI-RS resource may be configured.
○ 2 < Ks <= 8, at most 8 CSI-RS ports per CSI-RS resource may be configured.
For a CSI report of the one or more CSI reports, for example, the n-th triggered report, the UE may determine the valid time for providing for proving the CSI report, which is associated with two symbols, and the two symbols are denoted with Z₄ and Z₄' for simplicity.
Z₄ may be defined as the next uplink symbol with its CP starting T_proc, CSI= (Z) (2048+144) ·κ2^-μ·T_C+T_switch after the end of the last symbol of the PDCCH. The CP starting may be the same as defined in in 3GPP documents, for example, in TS 38.214, and details are omitted here.
The UE may also receive one or more aperiodic CSI-RS resources for channel measurements, one or more aperiodic CSI-IMs used for interference measurements, and/or one or more aperiodic NZP CSI-RSs for interference measurement. The aperiodic CSI-RS resources, the aperiodic CSI-IMs, and the aperiodic NZP CSI-RSs may not be received at the same time, and one of them may be received last in time.
Z₄' may be defined as the next uplink symbol with its CP starting T'_proc, CSI= (Z') (2048+144) ·κ2^-μ·T_C after the end of the last symbol in time of the latest of: an aperiodic CSI-RS resource for channel measurements, aperiodic CSI-IM used for interference measurements, and aperiodic NZP CSI-RS for interference measurement. The CP starting may be the same as defined in in 3GPP documents, for example, in TS 38.214, and details are omitted here.
For example, in Fig. 2, the CSI-RS may be received last in time. Accordingly, Z₄' may be defined as the next uplink symbol with its CP starting T'_proc, CSI= (Z') (2048+144) ·κ2^-μ·T_C after the end of the last symbol in time of the CSI-RS.
The UE may prepare the n-th triggered CSI report before the starting of the PUSCH.
In the present disclosure, the time durations Z₄ and Z₄' may be associated with additional time durations depending on different UE capabilities (or different UE behaviors) , the detailed time durations may be further described in the following four cases.
Case 1
In case 1, the UE may not support TRP selection or beam number combination selection; or the UE may support TRP selection and beam number combination selection, but may not perform the TRP selection or beam number combination selection.
Based on different total numbers of CSI-RS ports (the maximum number of CSI-RS ports across N CSI-RS may be 128) and the different total numbers of TRPs, there may be the following scenarios:
1. Scenario 1: for 3 TRPs or 4 TRPs, the total number of CSI-RS ports per CSI-RS resource may be less than or equal to 8, ; and
2. Scenario 2: for 2 TRPs, the total number of CSI-RS ports per CSI-RS resource may be less than or equal to 16, .
For the above two scenarios, the legacy CSI computation table may be reused and details are omitted here. For scenario 1 and 3, parallel CPUs may be used for the 3 TRPs and 4 parallel CPUs may be used for the 4 TRPs. For scenario 2, 2 parallel CPUs can be used for 2 TRPs.
There may also be the following scenarios:
1. Scenario 3: for 3 CSI-RS resources in one CSI-RS resource set or 4 CSI-RS resources in one CSI-RS resource set, the total number of CSI-RS ports per CSI-RS resource may be larger than 8; and
2. Scenario 4: for 2 CSI-RS resources in one CSI-RS resource set, the total number of CSI-RS ports per CSI-RS resource may be larger than 16.
For the above two scenarios, the time for performing the CSI report (i.e. CSI computation time) may be longer than the above scenario 1 and scenario 2, and the currently configured CSI computation time may not be sufficient for the UE to prepare the CSI report.
Accordingly, in order to prepare the CSI report, the present disclosure proposes to introduce one or more additional time durations for some UEs, which may be used by the UE for performing CSI computation.
In some embodiments, the one or more additional time durations may be determined by the UE, and reported to the BS or to the network, such as by UE capability infomration. In some other embodiments, the one or more additional time durations may be determined by the BS or by the network based on the one or more additional time durations reported by the UE. For example, the BS or the network may determine one or more additional time durations based on one or more additional time durations reported from multiple UEs. In still some embodiments, the one or more additional time durations may be specified in the specification. In still some embodiments, one or more longer time durations (such as the sums of the currently used time durations plus additional time durations) may be defined.
In some embodiments, the one or more time durations (which may be represented by Z₄ and Z'₄) with additional time durations (which may be represented by x7, x7', x8, x8', x9, and x9') may be represented as the following table:
Table 1: CSI computation delay requirement for CJT
wherein μ corresponds to the minimum of μ_PDCCH, μ_CSI-RS, and μ_UL, wherein μ_PDCCH corresponds to the subcarrier spacing of the PDCCH with which the DCI was transmitted, μ_CSI-RS corresponds to the minimum subcarrier spacing of the aperiodic CSI-RS triggered by the DCI, and μ_UL corresponds to the subcarrier spacing of the PUSCH with which the CSI report is to be transmitted.
Z₄ [symbols] may correspond to an additional time duration for a CSI report, wherein Z₄ may be defined as the next uplink symbol with its CP starting T_proc, CSI= (Z) (2048+144) ·κ2^-μ·T_C+T_switch after the end of the last symbol of the PDCCH. For example, the value such as "40 + x7" in the third row may correspond to the next uplink symbol with the CP starting after the end of the last symbol of the PDCCH. It should be noted that the value such as "40" , "72" and "141" are just for illustrating, not limiting, other values may also be applied to the solutions of the present disclosure.
Z'₄ may be defined as the next uplink symbol with its CP starting T'_proc, CSI= (Z') (2048+144) ·κ2^-μ·T_C after the end of the last symbol in time of the latest of: an aperiodic CSI-RS resource for channel measurements, aperiodic CSI-IM used for interference measurements, and aperiodic NZP CSI-RS for interference measurement. For example, the value such as "37 + x7'" in the third row may correspond to the next uplink symbol with the CP starting after the end of the last symbol in time of the latest of:an aperiodic CSI-RS resource for channel measurements, aperiodic CSI-IM used for interference measurements, and aperiodic NZP CSI-RS for interference measurement. It should be noted that the value such as "37" , "69" and "140" are just for illustrating, not limiting, other values may also be applied to the solutions of the present disclosure.
The additional time durations x7, x7', x8, x8', x9, or x9'may include a number of OFDM symbols. For example, the value of x7 may include an integral number of OFDM symbols, such as 0 OFDM symbol, 10 OFDM symbols, 18 OFDM symbols, or 37 OFDM symbols, or the like. For 0 OFDM symbol, it means no additional time duration is needed. Similarly, the value of x7', x8, x8', x9, and x9' may also include an integral number of OFDM symbols. In some embodiments, for a UE with lower procession capability, the value of x7 may be 37 OFDM symbols. For a UE with higher procession capability, the value of x7 may be 18 OFDM symbols.
In some embodiments, the additional time durations for Z₄ and Z₄' corresponding to the same SCS may be the same or different. That is, parameters x7 and x7' may have the same value, or may have different values. Similarly, the parameters x8 and x8' may have the same value, or may have different values, and the parameters x9 and x9' may have the same value, or may have different values.
In some embodiments, the additional time duration may be scalable for different SCSs, for example, x9 may have twice (or around two times, three times, four times, etc. ) the value of x8, and x8 may have twice (or around two times, three times, four times, etc. ) the value of x7, in other words: x9 = 2 × x8 = 4 × x7. Similarly, x9' may have twice (or around two times, three times, four times, etc. ) the value of x8', and x8 may have twice (or around two times, three times, four times, etc. ) the value of x7'.
The above table may have more rows, for example, the value of μ may be 3, 4, etc., correspondingly, the time durations (e.g. Z₄ and Z₄') with the additional time durations (e.g. x7, x7', x8, x8', x9, and x9') may be configured in a similar way.
Case 2
In case 2, the UE may support TRP selection but not beam number combination selection. Alternatively, the UE may also support both TRP selection and beam number combination selection, but may only perform TRP selection but not perform the beam number combination selection.
Denote the total number of TRPs as N_TRP for simplicity, and the total number of selected TRP with N for simplicity, the UE may select N TRPs from the N_TRP TRPs. In other words, the UE may select N CSI-RS resources from N_TRP CSI-RS resources configured by the BS, and may transmit the N selected CSI-RS resources to the BS or the network (or transmit the TRP selection) as a part of the CSI report. That is, the CSI report may include the selection of N CSI-RS resources from N_TRP candidate CSI-RS resources.
The UE may need additional time duration for TRP selection, which may be related with the TRP selection algorithm.
In some embodiments, the optimum selection schemes may be used for TRP selection, and the additional time duration may be related with possible candidate number of TRP selection (e.g. N_TRP) and the total number of supported simultaneous CSI calculations (i.e. the total number of CSI processing units (CPUs) ) . The actual value may be variable because of different UE implementation, such as the processing capability allocation in parallel or in serial, and/or because of different UE capabilities or UE behaviors. The UE may report one or more additional time durations (for example, one or more of the above additional time durations x7, x7', x8, x8', x9, or x9' in table 1) for TRP selection to the BS (or the network) based on realization schemes (which may be adopted by the UE or configured by the BS) and/or the UE capabilities. It should be noted that the values for the additional time durations, such as x7, x7', x8, x8', x9, or x9', may be the same or different from the values in case 1.
In some other embodiments, the sub-optimum selection schemes may be used for TRP selection, for example, the TRPs may be selected based on the RSRP value. In this case, there may be no need to increase the CSI computation time for TRP selection compared with the CSI computation time for CJT not supporting TRP selection. In some embodiment, in the case the one or more additional time durations for CJT supporting TRP selection are not reported, the value for the additional time durations for CJT supporting TRP selection may be 0, and the CSI computation time for CJT supporting TRP selection may be the same with the CSI computation time for CJT not supporting TRP selection.
Case 3
In case 3, the UE may support beam number combination selection but not TRP selection. Alternatively, the UE may also support both TRP selection and beam number combination selection, but may only perform beam number combination selection but may not perform the TRP selection.
For a configured value of N_TRP, a set of N_L combinations of values for {L₁, ..., L_NTRP} may be configured by the BS via a higher-layer signaling, (e.g. an RRC signaling) . When the beam number combination number N_L > 1, the selected combination of values for {L₁, ..., L_NTRP} may be reported by an indicator in a CSI report. For example, N_TRP configured for CJT may be 2, 3, or 4, and the candidate beam number combination N_L may be 1, 2, or 4. In such case, additional UE realization complexity is related with the beam selection algorithm. The additional time duration may be used for beam combination selection and the actual time may be related with beam selection algorithm.
In some embodiments, the optimum beam selection schemes may be used, additional CSI computation time is related with beam combination number N_L and CPU number used for beam number combination selection. The actual value may be variable because of different UE implementation, and/or because of different UE capabilities. In some embodiments, the UE may report one or more additional time durations (for example, one or more of the above additional time durations x7, x7', x8, x8', x9, or x9' in table 1) based on the realization schemes (which may be adopted by the UE or configured by the BS) and/or the UE capabilities. It should be noted that the values for the additional time durations, such as x7, x7', x8, x8', x9, or x9', may be the same or different from the values in case 1 or case 2.
In some embodiments, the sub-optimum beam number combination selection schemes may be used. For example, the beam number combination may be selected based on the singular value corresponding beam. In this case, there may be no need to increase CSI computation time for beam number combination selection compared with the CSI computation time for CJT not supporting beam number combination selection. In some embodiment, in the case the one or more additional time durations for CJT supporting beam number combination selection are not reported, the value for the additional time durations for CJT supporting beam number combination selection may be 0, and the CSI computation time for CJT supporting beam number combination selection may be the same with the CSI computation time for CJT not supporting beam number combination selection.
Case 4
In case 4, the UE may perform both TRP selection and beam number combination selection. In such case, the designs for additional time durations described in case 2 and case 3 may be combined.
Similarly, the additional time durations (such as one or more of the above additional time durations x7, x7', x8, x8', x9, or x9' in table 1) may be reported by the UE in the case that the UE may support both TRP selection and beam number combination selection.
The additional time durations may be value 0 for special sub-optimum realization schemes. In some embodiment, in the case the one or more additional time durations for CJT supporting both TRP selection and beam number combination selection are not reported, the value for the additional time durations for CJT supporting both TRP selection and beam number combination selection may be 0, and the CSI computation time for CJT supporting both TRP selection and beam number combination selection may be the same with the CSI computation time for CJT not supporting beam number combination selection.
For the above cases, it should be noted that additional time durations x7, x7', x8, x8', x9, or x9' in table 1, for example, for different UE capabilities and/or different UE behaviors. For the same UE, the additional time duration x7 for case 1 may be with the smallest value, and the additional time duration x7 for case 4 may be with the largest value. There may also be other additional time durations corresponding to other SCSs. These additional time durations may be determined by the UE, and reported to the BS or to the network, such as by UE capability, or may be determined by the BS or by the network based on the one or more additional time durations reported by the UE, or may be specified in the specification. One or more additional time durations may be reported to BS, such as UE capability, corresponding one or more aspects including a TRP number, a CSI-RS port number, a TRP selection, or a beam number combination selection, respectively.
For non-coherent joint transmission (NCJT) , the UE may be configured to perform discontinuous reception (i.e. the UE may receive configuration information of DRX) . The CSI-RS resource set for non-CJT may be configured with two resource groups and a number of resource pairs, the UE may transmit a CSI report only if receiving at least one CSI-RS transmission occasion for each CSI-RS resource in a resource pair within the same DRX active time no later than CSI reference resource and drops the report otherwise.
For CJT, there may be maximum 4 NZP CSI-RS for channel measurement resource (CMR) in the one CSI-RS resource set. In some cases, the configured N_TRP CSI-RS resources may be located in two consecutive slots, for example slot n and slot n+1.
It is possible that some CSI-RS resources (e.g. in slot n) may be received no later than CSI reference resource and other CSI-RS resources (e.g. in slot n+1) may be received later than CSI reference resource.
The present disclosure proposes some solutions for the UE to perform the CSI report as follows:
Embodiment 1:
In this embodiment, when at least one CSI-RS transmission occasion for each CSI-RS resource in the CSI-RS resource set for CMR is within the same DRX active time no later than the CSI reference resource, the UE may transmit a CSI report. In other words, when at least one CSI-RS transmission occasion for each CSI-RS resource in slot n and each CSI-RS resource in slot n+1 if existed is within the same DRX active time earlier than or at the same time as the CSI reference resource, the UE may transmit the CSI report. Otherwise, the UE may not transmit the CSI report. The transmission occasion may be defined based on each CSI-RS resource in this embodiment. Also, it may be defined based on CSI-RS resource set, where all the CSI-RS resources in one CSI-RS resource set share the same transmission occasion.
For example, there is the CSI-RS resource set including a CSI-RS resource 1 in slot n and a CSI-RS resource 2 in slot n+1. There is a CSI-RS transmission occasion 1 for CSI-RS resource 1 is within the same DRX active time no later than CSI reference resource, and a CSI-RS transmission occasion 2 for CSI-RS resource 2 is also within the same DRX active time no later than CSI reference resource, and the UE may transmit the CSI report.
Embodiment 2:
In this embodiment, when at least one CSI-RS transmission occasion for any CSI-RS resource in the CSI-RS resource set for CMR is within the same DRX active time no later than CSI reference resource, the UE may transmit a CSI report. For example, there is a CSI-RS resource 1 in the CSI-RS resource set that is in slot n, and/or a CSI-RS resource 2 in the CSI-RS resource set that is in slot n+1, there is a CSI-RS transmission occasion 1 for CSI-RS resource 1 is within the same DRX active time no later than CSI reference resource, and a CSI-RS transmission occasion 2 for CSI-RS resource 1 is within the same DRX active time later than CSI reference resource, and the UE may transmit the CSI report. The TRP selection may be performed among the CSI-RS resource no later than CSI reference resources. That is, the TRP selection may be performed among the CSI-RS resources including CSI-RS resource 1, but not including CSI-RS resource 2.
Put it in another way, when there is no CSI-RS transmission occasion for any CSI-RS resource in the CSI-RS resource set for CMR that is within the same DRX active time no later than CSI reference resource, the UE may not transmit a CSI report.
Embodiment 3:
In this embodiment, when at least one CSI-RS transmission occasion for any CSI-RS resource in the CSI-RS resource set for CMR is within the same DRX active time no later than CSI reference resource, the UE may transmit a CSI report. There is no restriction for the CSI report. In other words, there is no restriction for the CSI-RS resources in the CSI-RS resource set used for CSI report updating and the UE may use all the CSI-RS resources in the case that the UE is able to finish CSI calculation based on these CSI-RS resources. Compared with embodiment 2, the UE may perform the TRP selection with no restriction, which means the TRP selection may be performed among the CSI-RS resources later or no later than the CSI reference resource. The TRP selection may be performed among the CSI-RS resources including both CSI-RS resource 1 (no later than the CSI reference resource) and CSI-RS resource 2 (later than the CSI reference resource) .
Fig. 3 illustrates a method performed by a UE for CJT according to some embodiments of the present disclosure. Fig. 4 illustrates a method performed by a BS for CJT corresponding to the method performed by the UE as shown in Fig. 3 according to some embodiments of the present disclosure.
In operation 301, the UE may receive configuration information indicating a number of CSI-RS resource in a CSI-RS resource set as channel measurement resources, that is, the UE may be configured to perform CJT; in operation 302, the UE may determine a first symbol associated with a first additional time duration and a second symbol associated with a second additional time duration; and in operation 303, the UE may transmit, via the transceiver, a CSI report in the case that an uplink transmission carrying the CSI report is later than or at the same time with the first symbol after an end of a last symbol of a PDCCH which triggers the CSI report; and in the case that uplink transmission carrying the CSI report is later than or at the same time with the second symbol after an end of a last symbol of an aperiodic CSI-RS resource for channel measurements, an aperiodic CSI-IM used for an interference measurement, and an aperiodic NZP CSI-RS for an interference measurement.
Correspondingly, in operation 401, the BS may transmit configuration information indicating a number of CSI-RS resource in a CSI-RS resource set as channel measurement resources; in operation 402, the BS may determine a first symbol associated with a first additional time duration and a second symbol associated with a second additional time duration; and in operation 403, the BS may receive, via the transceiver, a CSI report in the case that an uplink transmission carrying the CSI report is later than or at the same time with the first symbol after an end of a last symbol of a PDCCH which triggers the CSI report; and in the case that uplink transmission carrying the CSI report is later than or at the same time with the second symbol after an end of a last symbol of an aperiodic CSI-RS resource for channel measurements, an aperiodic CSI-IM used for an interference measurement, and an aperiodic NZP CSI-RS for an interference measurement.
In some embodiments, the first symbol is determined by a third symbol defined by the specification and the first additional time duration, and the second symbol is determined by a fourth symbol defined by the specification and the second additional time duration. For example, as shown in table 1, the first symbol may be "40+x7" as shown in the third row, it is determined by the third symbol (with a value 40, which may be defined by the specification) and the first additional time duration (which may be x7) . The second symbol may be "37+x7" as shown in the third row, it is determined by the fourth symbol (with a value 37, which may be defined by the specification) and the second additional time duration (which may be x7') .
In some embodiments, in the case that a total number of CSI-RS ports per CSI-RS resource exceeds a threshold, the first additional time duration or the second additional time duration includes a first time period. In some embodiments, a value of the threshold is 8 in the case that 3 TRPs or 4 TRPs are configured; or a value of the threshold is 16 in the case that 2 TRPs are configured.
In some embodiments, in the case that the UE supports TRP selection, the first additional time duration or the second additional time duration includes a second time period.
In some embodiments, in the case that the UE supports a selection of beam number combination, the first additional time duration or the second additional time duration includes a third time period.
In some embodiments, the UE may transmit UE capability information, to the BS, which may indicate one or more additional time durations, wherein the one or more additional time durations includes a first time period, a second time period or a third time period. For example, the UE may transmit the UE capability information which may indicate one of more of the above x7, x7', x8, x8', x9, and x9'.
In some embodiments, the first additional time duration or the second additional time duration is determined from one or more additional time durations reported by the UE, predetermined by a specification, or configured by a base station (BS) based on the one or more additional time durations reported by the UE.
In some embodiments, the first additional time duration or the second additional time duration is associated with a minimum SCS of the following:
an SCS of a PDCCH carrying DCI which triggers the SCI report;
an SCS of the uplink transmission carrying the CSI report; or
a minimum SCS of an aperiodic CSI-RS triggered by the DCI.
In some embodiments, the first additional time duration or the second additional time duration includes a number of OFDM symbols. For example, 10 OFDM symbols, 18 OFDM symbols, etc.
In some embodiments, the first additional time duration and the second additional time duration have the same value.
In some embodiments, the first additional time duration and the second additional time duration are scalable based on different SCSs.
Fig. 5 illustrates a method performed by a UE for CJT according to some embodiments of the present disclosure. Fig. 6 illustrates a method performed by a BS for CJT corresponding to the method performed by the UE as shown in Fig. 5 according to some embodiments of the present disclosure.
In operation 501, the UE may receive configuration information indicating a number of CSI-RS resources in a CSI-RS resource set and configuration information of DRX; and in operation 502, the UE may transmit a CSI report based on time relation between the number of CSI-RS resources in the CSI-RS resource set and a CSI reference resource, wherein at least one CSI-RS resource in the CSI-RS resource set is within the DRX active time duration.
Correspondingly, at the BS side, in operation 601, the BS may transmit configuration information indicating a number of CSI-RS resources in a CSI-RS resource set and configuration information of DRX; and in operation 602, the BS may receive a CSI report based on time relation between the number of CSI-RS resources in the CSI-RS resource set and a CSI reference resource, wherein at least one CSI-RS resource in the CSI-RS resource set is within the DRX active time duration.
In some embodiments, the CSI report is only transmitted in the case that a CSI-RS transmission occasion for each CSI-RS resource in the CSI-RS resource set is earlier than or at the same time with the CSI reference resource in the time domain.
In some embodiments, the CSI report is transmitted in the case that a first CSI-RS transmission occasion for a first CSI-RS resource (s) in the CSI resource-RS set is earlier than or at the same time with the CSI reference resource in the time domain, and wherein a second CSI-RS transmission occasion for a second CSI-RS resource (s) in the CSI-RS resource set is later than the CSI reference resource in the time domain; or in the case that a first CSI-RS transmission occasion for a first CSI-RS resource (s) in the CSI-RS resource set is earlier than or at the same time with the CSI reference resource in the time domain, and a second CSI-RS transmission occasion for a second CSI-RS resource (s) in the CSI-RS resource set is earlier than or at the same time with the CSI reference resource in the time domain.
In some embodiments, the CSI report is based on the first CSI-RS resource in the CSI resource set.
In some embodiments, the CSI report is based on the first CSI-RS resource in the CSI resource set, or both the first CSI-RS resource and the second CSI-RS resource in the CSI resource set.
Fig. 7 illustrates a simplified block diagram of an apparatus according to some embodiments of the present disclosure.
As shown in Fig. 7, an example of the apparatus 700 may include at least one processor 704 and at least one transceiver 702 coupled to the processor 704. The apparatus 700 may be a UE, a BS, or any other device with similar functions.
Although in this figure, elements such as the at least one transceiver 702 and processor 704 are described in the singular, the plural is contemplated unless a limitation to the singular is explicitly stated. In some embodiments of the present disclosure, the transceiver 702 may be divided into two devices, such as a receiving circuitry and a transmitting circuitry. In some embodiments of the present disclosure, the apparatus 700 may further include an input device, a memory, and/or other components.
In some embodiments of the present disclosure, the apparatus 700 may be a UE. The transceiver 702 and the processor 704 may interact with each other so as to perform the operations of the UE described in any of Figs. 1-6. In some embodiments of the present disclosure, the apparatus 700 may be a BS. The transceiver 702 and the processor 704 may interact with each other so as to perform the operations of the BS described in any of Figs. 1-6.
In some embodiments of the present disclosure, the apparatus 700 may further include at least one non-transitory computer-readable medium.
For example, in some embodiments of the present disclosure, the non-transitory computer-readable medium may have stored thereon computer-executable instructions to cause the processor 704 to implement the method with respect to the UE as described above. In some embodiments of the present disclosure, the non-transitory computer-readable medium may have stored thereon computer-executable instructions to cause the processor 704 to implement the method with respect to the BS as described above.
The method of the present disclosure can be implemented on a programmed processor. However, controllers, flowcharts, and modules may also be implemented on a general purpose or special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit elements, an integrated circuit, a hardware electronic or logic circuit such as a discrete element circuit, a programmable logic device, or the like. In general, any device that has a finite state machine capable of implementing the flowcharts shown in the figures may be used to implement the processing functions of the present disclosure.
While the present disclosure has been described with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. For example, various components of the embodiments may be interchanged, added, or substituted in other embodiments. Also, all of the elements shown in each Fig. are not necessary for operation of the disclosed embodiments. For example, one skilled in the art of the disclosed embodiments would be capable of making and using the teachings of the present disclosure by simply employing the elements of the independent claims. Accordingly, the embodiments of the present disclosure as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the present disclosure.
In this disclosure, relational terms such as "first, " "second, " and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms "comprises, " "comprising, " or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "a, " "an, " or the like does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element. Also, the term "another" is defined as at least a second or more. The terms "including, " "having, " and the like, as used herein, are defined as "comprising. "

Claims

A user equipment (UE) , comprising:

a transceiver; and

a processor coupled with the transceiver and configured to:

receive, via the transceiver, configuration information indicating a number of channel state information-reference signal (CSI-RS) resource in a CSI-RS resource set as channel measurement resources;

determine a first symbol associated with a first additional time duration and a second symbol associated with a second additional time duration; and

transmit, via the transceiver, a CSI report in the case that an uplink transmission carrying the CSI report is later than or at the same time with the first symbol after an end of a last symbol of a physical downlink control channel (PDCCH) which triggers the CSI report; and in the case that uplink transmission carrying the CSI report is later than or at the same time with the second symbol after an end of a last symbol of an aperiodic CSI-RS resource for channel measurements, an aperiodic channel measurement-interference measurement (CSI-IM) used for an interference measurement, and an aperiodic non zero power (NZP) CSI-RS for an interference measurement.
The UE of Claim 1, wherein the first symbol is determined by a third symbol defined by the specification and the first additional time duration, and the second symbol is determined by a fourth symbol defined by the specification and the second additional time duration.
The UE of Claim 1, wherein in the case that a total number of channel state information-reference signal (CSI-RS) ports per CSI-RS resource exceeds a threshold, the first additional time duration or the second additional time duration includes a first time period.
The UE of Claim 3, wherein a value of the threshold is 8 in the case that 3 transmission or reception points (TRPs) or 4 TRPs are configured; or a value of the threshold is 16 in the case that 2 TRPs are configured.
The UE of Claim 1, wherein in the case that the UE supports TRP selection, the first additional time duration or the second additional time duration includes a second time period, or wherein in the case that the UE supports a selection of beam number combination, the first additional time duration or the second additional time duration includes a third time period.
The UE of Claim 1, wherein the processor is further configured to:

transmit, via the transceiver, UE capability information indicating one or more additional time durations, wherein the one or more additional time durations includes a first time period, a second time period or a third time period .
The UE of Claim 1, wherein the first additional time duration or the second additional time duration is determined from one or more additional time durations reported by the UE, predetermined by a specification, or configured by a base station (BS) based on the one or more additional time durations reported by the UE.
The UE of Claim 1, wherein the first additional time duration or the second additional time duration is associated with a minimum subcarrier spacing (SCS) of the following:

an SCS of a physical downlink control channel (PDCCH) carrying downlink control information (DCI) which triggers the SCI report;

an SCS of the uplink transmission carrying the CSI report; or

a minimum SCS of an aperiodic CSI-RS triggered by the DCI.
The UE of Claim 8, wherein the first additional time duration or the second additional time duration includes a number of orthogonal frequency division multiplexing (OFDM) symbols.
The UE of Claim 8, wherein the first additional time duration and the second additional time duration have the same value.
The UE of Claim 8, wherein the first additional time duration and the second additional time duration are scalable based on different SCSs.
A user equipment (UE) , comprising:

a transceiver; and

a processor coupled with the transceiver and configured to:

receive, via the transceiver, configuration information indicating a number of channel state information-reference signal (CSI-RS) resources in a CSI-RS resource set and configuration information of discontinuous reception (DRX) ; and

transmit, via the transceiver, a channel state information (CSI) report based on time relation between the number of CSI-RS resources in the CSI-RS resource set and a CSI reference resource, wherein at least one CSI-RS resource in the CSI-RS resource set is within the DRX active time duration.
The UE of Claim 12, wherein the CSI report is only transmitted in the case that a CSI-RS transmission occasion for each CSI-RS resource in the CSI-RS resource set is earlier than or at the same time with the CSI reference resource in the time domain.
The UE of Claim 12, wherein the CSI report is transmitted in the case that a first CSI-RS transmission occasion for a first CSI-RS resource (s) in the CSI-RS resource set is earlier than or at the same time with the CSI reference resource in the time domain, and wherein a second CSI-RS transmission occasion for a second CSI-RS resource (s) in the CSI-RS resource set is later than the CSI reference resource in the time domain; or in the case that a first CSI-RS transmission occasion for a first CSI-RS resource (s) in the CSI-RS resource set is earlier than or at the same time with the CSI reference resource in the time domain, and a second CSI-RS transmission occasion for a second CSI-RS resource (s) in the CSI-RS resource set is earlier than or at the same time with the CSI reference resource in the time domain.
A base station (BS) , comprising:

a transceiver; and

a processor coupled with the transceiver and configured to:

transmit, via the transceiver, configuration information indicating a number of channel state information-reference signal (CSI-RS) resources in a CSI-RS resource set as channel measurement resources;

determine a first symbol associated with a first additional time duration and a second symbol associated with a second additional time duration; and

receive, via the transceiver, a CSI report in the case that an uplink transmission carrying the CSI report is later than or at the same time with the first symbol after an end of a last symbol of a physical downlink control channel (PDCCH) which triggers the CSI report; and in the case that uplink transmission carrying the CSI report is later than or at the same time with the second symbol after an end of a last symbol of an aperiodic CSI-RS resource for channel measurements, an aperiodic channel measurement-interference measurement (CSI-IM) used for an interference measurement, and an aperiodic non zero power (NZP) CSI-RS for an interference measurement.