Method and apparatus for transmitting and receiving uplink channel

Abstract

A method according to an embodiment of the present specification comprises the steps of: receiving DCI for scheduling of a PUSCH; and transmitting the PUSCH on the basis of a precoder. A TPMI and / or an SRI for determining the precoder are indicated on the basis of the DCI. The TPMI is indicated on the basis of a first field indicating one of first indices. The precoder is associated with one or more resource blocks (RBs) from among scheduled resource blocks (RBs). The first indices are characterized by being related to TPMIs based on the same PTRS port.

Description

Method and device for transmitting and receiving an uplink channel

[0001] This specification relates to a method and device for transmitting and receiving an uplink channel.

[0002] Mobile communication systems were developed to provide voice services while ensuring user activity. However, they have expanded beyond voice to include data services. Currently, explosive growth in traffic is leading to resource shortages and users are demanding faster services, necessitating a more advanced mobile communication system.

[0003] Next-generation mobile communication systems must support explosive data traffic growth, dramatically increasing data rates per user, a vastly increased number of connected devices, ultra-low end-to-end latency, and high energy efficiency. To achieve these goals, various technologies are being studied, including dual connectivity, massive multiple input multiple output (MIMO), in-band full duplex, non-orthogonal multiple access (NOMA), super wideband support, and device networking.

[0004] According to existing operation, the same precoding is applied to scheduled RBs for PUSCH (wideband precoding). In the future, precoding for each subband may be supported in a frequency-selective channel environment (subband precoding).

[0005] As described above, when the precoder is different for each subband, the precoder applied to the DMRS port(s) of each subband is different. That is, the order of DMRS ports with good channel quality is different for each subband, and thus the PTRS port combination for each subband may be different. For example, as the PTRS port combination is different for each subband, multiple beams (panels) may be used for some subband(s). When the beam (panel) combination is different for each subband, the UL power control and beam management (BM) operations must also be different. That is, the UL power control and beam management operations must be performed differently for each subband(s) where different beam (panel) combinations are applied / used.

[0006] Setting / defining UL power control and beam management operations for each beam (panel) combination per subband to support frequency-segmented precoding as described above may be inefficient in terms of implementation complexity.

[0007] The purpose of this specification is to minimize implementation complexity in supporting frequency-specific precoding.

[0008] The technical problems to be achieved in this specification are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0009] A method according to one embodiment of the present disclosure includes the steps of receiving downlink control information (DCI) for scheduling a physical uplink shared channel (PUSCH) and transmitting the PUSCH based on a precoder.

[0010] The precoder is determined based on the above DCI.

[0011] A Transmit Precoding Matrix Index (TPMI) and / or a Sounding Reference Signal Resource Indicator (SRI) for determining the above precoder are indicated based on the DCI.

[0012] The TPMI is indicated based on a first field indicating one of the first indices. The precoder is associated with one or more scheduled resource blocks (RBs). The first indices are characterized in that they are associated with TPMIs based on the same phase tracking reference signal (PTRS) port.

[0013] The above PUSCH may be associated with four antenna ports 1000 to 1003. The same PTRS port may be PTRS port 0 or PTRS port 1 associated with two of the four antenna ports.

[0014] The TPMIs based on the same PTRS port may be associated with precoding matrices whose elements are 0 for the remaining two antenna ports among the four antenna ports.

[0015] Based on the above same PTRS port being PTRS port 0 associated with antenna ports 1000 and 1002, the TPMIs based on the above same PTRS port can be associated with the precoding matrices whose second and fourth elements are 0 associated with antenna ports 1001 and 1003.

[0016] Based on the above same PTRS port being PTRS port 1 associated with antenna ports 1001 and 1003, the TPMIs based on the above same PTRS port can be associated with the above precoding matrices having the first element and the third element being 0 associated with antenna ports 1000 and 1002.

[0017] The above first field may be a precoding information and number of layers field.

[0018] The above first indexes may be indexes of a table defined based on the TPMIs based on the same PTRS port.

[0019] The above SRI may be indicated based on an SRI field indicating one of the second indices. The second indices may be associated with SRIs based on the same PTRS port.

[0020] The SRIs based on the same PTRS port may be associated with SRS resources in which the same PTRS port is set among SRS resources within the SRS resource set.

[0021] i) the number of SRS resources in the SRS resource set is 4, and ii) based on the same PTRS port being set for two SRS resources among the four SRS resources: the SRIs based on the same PTRS port may be two SRIs related to the two SRS resources among the four SRIs.

[0022] A terminal according to another embodiment of the present disclosure includes one or more transceivers, one or more processors, and one or more memories connected to the one or more processors and storing instructions.

[0023] The instructions are characterized in that, based on being executed by the one or more processors, the one or more processors are set to perform all steps of any one of the methods.

[0024] A device according to another embodiment of the present disclosure comprises one or more memories and one or more processors functionally connected to the one or more memories.

[0025] Said one or more memories are characterized in that they store instructions that cause said one or more processors to perform all steps of any one of said methods based on what is executed by said one or more processors.

[0026] In another embodiment of the present disclosure, one or more non-transitory computer-readable media store instructions.

[0027] The instructions executable by one or more processors are characterized by configuring the one or more processors to perform all steps of any one of the methods.

[0028] A method according to another embodiment of the present disclosure includes the steps of transmitting downlink control information (DCI) for scheduling a physical uplink shared channel (PUSCH), and receiving the PUSCH based on a precoder.

[0029] The precoder is determined based on the above DCI.

[0030] A Transmit Precoding Matrix Index (TPMI) and / or a Sounding Reference Signal Resource Indicator (SRI) for determining the above precoder are indicated based on the DCI.

[0031] The TPMI is indicated based on a first field mapped to one of the defined indices. The precoder is associated with one or more scheduled resource blocks (RBs). The defined indices are characterized in that they are associated with TPMIs based on the same phase tracking reference signal (PTRS) port.

[0032] A base station according to another embodiment of the present disclosure includes one or more transceivers, one or more processors, and one or more memories coupled to the one or more processors and storing instructions.

[0033] The instructions are characterized in that they are executed by the one or more processors, and the one or more processors are set to perform all steps of the method.

[0034] According to an embodiment of the present specification, 1) a Transmit Precoding Matrix Index (TPMI) for determining a precoder is indicated among TPMIs based on the same PTRS port. This can reduce the DCI overhead for indicating a precoder compared to a case where a precoder for each subband (e.g., one or more RBs) is indicated based on the entire TPMIs.

[0035] 2) In addition, since only TPMIs based on the same PTRS port are utilized, operations based on subband-specific precoding can be simplified. That is, as subband-specific precoding is supported, the increase in implementation complexity of UL power control and beam management-related operations can be minimized.

[0036] The effects that can be obtained from this specification are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by those skilled in the art to which the present invention pertains from the description below.

[0037] Figure 1 is a diagram showing an example of uplink transmission and reception operation.

[0038] FIG. 2 is a flowchart illustrating a method according to one embodiment of the present specification.

[0039] FIG. 3 is a flowchart illustrating a method according to another embodiment of the present specification.

[0040] FIG. 4 is a drawing showing the configuration of a first device and a second device according to an embodiment of the present specification.

[0041] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The detailed description set forth below, together with the accompanying drawings, is intended to illustrate exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced. The following detailed description includes specific details to provide a thorough understanding of the present invention. However, those skilled in the art will appreciate that the present invention may be practiced without these specific details.

[0042] In some cases, to avoid obscuring the concept of the present invention, well-known structures and devices may be omitted or illustrated in block diagram form focusing on the core functions of each structure and device.

[0043] Hereinafter, downlink (DL) refers to communication from a base station to a terminal, and uplink (UL) refers to communication from a terminal to a base station. In downlink, a transmitter may be part of a base station, and a receiver may be part of a terminal. In uplink, a transmitter may be part of a terminal, and a receiver may be part of a base station. A base station may be expressed as a first communication device, and a terminal may be expressed as a second communication device. A base station (BS) may be replaced by terms such as a fixed station, Node B, eNB (evolved-NodeB), gNB (Next Generation NodeB), BTS (base transceiver system), access point (AP: Access Point), network (5G network), AI system, RSU (road side unit), vehicle, robot, drone (Unmanned Aerial Vehicle, UAV), AR (Augmented Reality) device, VR (Virtual Reality) device, etc. In addition, the terminal may be fixed or mobile, and may be replaced with terms such as UE (User Equipment), MS (Mobile Station), UT (user terminal), MSS (Mobile Subscriber Station), SS (Subscriber Station), AMS (Advanced Mobile Station), WT (Wireless terminal), MTC (Machine-Type Communication) device, M2M (Machine-to-Machine) device, D2D (Device-to-Device) device, vehicle, robot, AI module, drone (Unmanned Aerial Vehicle, UAV), AR (Augmented Reality) device, VR (Virtual Reality) device, etc.

[0044] DMRS (demodulation reference signal)

[0045] DMRS reception procedure

[0046] Let's look at DMRS-related operations for PDSCH reception.

[0047] When receiving a PDSCH scheduled by DCI format 1_0 or before any dedicated higher layer configuration of the dmrs-AdditionalPosition, maxLength and dmrs-Type parameters, the UE assumes that no PDSCH is present in any symbol carrying a DM-RS except for a PDSCH with an allocated duration of 2 symbols with PDSCH mapping type B, a single symbol front-loaded DM-RS with configuration type 1 is transmitted on DM-RS port 1000, and that none of the remaining orthogonal antenna ports are associated with a PDSCH transmission to another UE.

[0048] Additionally, for a PDSCH with mapping type A, the UE assumes that there are dmrs-AdditionalPosition='pos2' and up to two additional single-symbol DM-RSs in the slot according to the PDSCH duration indicated in the DCI. For a PDSCH with an allocated duration of 7 symbols for a normal CP or 6 symbols for an extended CP with mapping type B, when a front-loaded DM-RS symbol is in the 1st or 2nd symbol of the PDSCH allocated duration, respectively, the UE assumes that there is one additional single-symbol DM-RS in the 5th or 6th symbol. Otherwise, the UE assumes that no additional DM-RS symbol is present. And, for a PDSCH having an allocation duration of 4 symbols with mapping type B, the terminal assumes that no additional DM-RS exists, and for a PDSCH having an allocation duration of 2 symbols with mapping type B, the terminal assumes that no additional DM-RS exists, and the terminal assumes that the PDSCH exists within a symbol carrying a DM-RS.

[0049] When receiving a PDSCH scheduled by DCI format 1_1 by a PDCCH with a CRC scrambled by C-RNTI, MCS-C-RNTI or CS (configured scheduling)-RNTI,

[0050] - The terminal can be set to the upper layer parameter dmrs-Type, and the set DM-RS configuration type is used to receive PDSCH.

[0051] - The terminal can be configured with the maximum number of front-loaded DM-RS symbols for the PDSCH by the upper layer parameter maxLength given by DMRS-DownlinkConfig.

[0052] The number of DM-RS ports can be scheduled by the antenna port index of DCI format 1_1.

[0053] The DMRS configuration type is configured by the dmrs-Type parameter in the DMRS-DownlinkConfig IE in Table 1. DMRS configuration type 1 has higher RS ​​density in the frequency domain and supports up to 4 (8) ports for single (double)-symbol DMRS. In addition, DMRS configuration type 1 supports length 2 F-CDM and FDM for single-symbol DMRS, and length 2 F / T-CDM and FDM for double-symbol DMRS. DMRS configuration type 2 supports more DMRS antenna ports and supports up to 6 (12) ports for single (double)-symbol DMRS.

[0054] Table 1 below shows an example of a DMRS-DownlinkConfig IE used to configure downlink DMRS for PDSCH.

[0055]

[0056] In Table 1, the dmrs-AdditionalPosition parameter indicates the position of additional DM-RS in DL, and if the parameter is not present, the UE applies the value pos2. The dmrs-Type parameter indicates the selection of DMRS type to be used for DL, and if the parameter is not present, the UE uses DMRS type 1. The maxLength parameter indicates the maximum number of OFDM symbols for DL ​​front-loaded DMRS, and len1 corresponds to the value 1. The PhaseTrackingRS parameter configures DL PTRS, and if the parameter is not present or is canceled, the UE assumes that there is no DL PTRS.

[0057] For DM-RS setup type 1,

[0058] - If the terminal is scheduled with one code word and the antenna port mapping is assigned with indices of {2, 9, 10, 11, or 30}, or if the terminal is scheduled with two code words,

[0059] The terminal can assume that none of the remaining orthogonal antenna ports are associated with transmission of PDSCH to other terminals.

[0060] For DM-RS setup type 2,

[0061] - If the terminal is scheduled with one codeword and the antenna port mapping is assigned with indices of {2,10,23}, or if the terminal is scheduled with two codewords,

[0062] The terminal can assume that none of the remaining orthogonal antenna ports are associated with transmission of PDSCH to other terminals.

[0063] An example of the DL DMRS procedure is described below.

[0064] The base station transmits DMRS configuration information to the terminal.

[0065] The above DMRS configuration information may refer to DMRS-DownlinkConfig IE. The DMRS-DownlinkConfig IE may include a dmrs-Type parameter, a dmrs-AdditionalPosition parameter, a maxLength parameter, a phaseTrackingRS parameter, etc.

[0066] The above dmrs-Type parameter is a parameter for selecting the DMRS configuration type to be used for DL. In NR, DMRS can be divided into two configuration types: (1) DMRS configuration type 1 and (2) DMRS configuration type 2. DMRS configuration type 1 is a type with a higher RS ​​density in the frequency domain, and DMRS configuration type 2 is a type with more DMRS antenna ports.

[0067] The above dmrs-AdditionalPosition parameter is a parameter indicating the position of an additional DMRS in the DL. If the parameter does not exist, the terminal applies the value pos2. The first position of the front-loaded DMRS is determined according to the PDSCH mapping type (type A or type B), and an additional DMRS may be configured to support a high-speed terminal. The front-loaded DMRS occupies one or two consecutive OFDM symbols and is indicated by RRC signaling and DCI (downlink control information).

[0068] The above maxLength parameter is a parameter indicating the maximum number of OFDM symbols for DL ​​front-loaded DMRS. The above phaseTrackingRS parameter is a parameter that configures DL PTRS. If the parameter does not exist or is canceled, the terminal assumes that there is no DL PTRS.

[0069] The above base station generates a sequence used for DMRS.

[0070] The sequence for the above DMRS is generated according to the mathematical expression 1 below.

[0071]

[0072] The above pseudo-random sequence is defined in 3gpp TS 38.211 5.2.1, i.e. can be a length-31 Gold sequence using two m-sequences. The pseudo-random sequence generator is initialized by the following mathematical expression 2.

[0073]

[0074] Here, is the number of OFDM symbols in the slot, is the slot number within the frame.

[0075] and, is provided, and if the PDSCH is scheduled by a PDCCH using DCI format 1_1 with a CRC scrambled by C-RNTI, MCS-C-RNTI or CS-RNTI, it is given by the higher-layer parameters scramblingID0 and scramblingID1 in the DMRS-DownlinkConfig IE, respectively.

[0076] - is provided, if the PDSCH is scheduled by a PDCCH using DCI format 1_0 with a CRC scrambled by the C-RNTI, MCS-C-RNTI, or CS-RNTI, given by the higher-layer parameter scramblingID0 in the DMRS-DownlinkConfig IE.

[0077] - , otherwise, quantity When DCI format 1_1 is used, it is given by the DMRS sequence initialization field in the DCI associated with the PDSCH transmission.

[0078] The base station maps the generated sequence to a resource element. Here, the resource element may mean at least one of time, frequency, antenna port, or code.

[0079] The base station transmits the DMRS to the terminal on the resource element. The terminal receives the PDSCH using the received DMRS.

[0080] UE DMRS transmission procedure

[0081] Let's examine DMRS-related operations for PUSCH reception. As discussed, UL refers to signal transmission (or communication) from the terminal to the base station. UL DMRS-related operations are similar to the DL DMRS-related operations discussed above, and the names of the DL-related parameters can be replaced with those for UL.

[0082] That is, DMRS-DownlinkConfig IE can be replaced with DMRS-UplinkConfig IE, PDSCH mapping type can be replaced with PUSCH mapping type, and PDSCH can be replaced with PUSCH. In addition, in DL DMRS related operations, the base station can be replaced with the terminal, and the terminal can be replaced with the base station. Sequence generation for UL DMRS can be defined differently depending on whether transform precoding is enabled.

[0083] More specifically, DMRS uses a PN sequence when CP-OFDM (cyclic prefix orthogonal frequency division multiplexing) is used (or when transform precoding is not enabled), and uses a ZC sequence with a length of 30 or more when DFT-s-OFDM (Discrete Fourier Transform-spread-OFDM) is used (when transform precoding is enabled).

[0084] Table 2 below shows an example of a DMRS-UplinkConfig IE used to configure uplink DMRS for PUSCH.

[0085]

[0086] In Table 2, the dmrs-AdditionalPosition parameter indicates the position of additional DM-RS in UL. If this parameter is not present, the UE applies the value pos2. The dmrs-Type parameter indicates the selection of DMRS type to be used for UL. If this parameter is not present, the UE uses DMRS type 1.

[0087] The maxLength parameter indicates the maximum number of OFDM symbols for UL front-loaded DMRS, and len1 corresponds to a value of 1. The PhaseTrackingRS parameter configures UL PTRS. The transformPrecodingDisabled parameter indicates DMRS-related parameters for Cyclic Prefix OFDM. The transformPrecodingEnabled parameter indicates DMRS-related parameters for DFT-s-OFDM (Transform Precoding).

[0088] Below, we will look at the UE DM-RS transmission procedure in more detail.

[0089] If the transmitted PUSCH is neither scheduled by DCI format 0_1 ​​with CRC scrambled by C-RNTI, CS-RNTI or MCS-C-RNTI nor corresponds to a configured grant, the UE uses a single symbol front-loaded DM-RS of configuration type 1 on DM-RS port 0, and the remaining REs not used for DM-RS in the symbols are not used for any PUSCH transmission except for a PUSCH with an allocated duration of 2 or fewer OFDM symbols with disabled transform precoding. Additional DM-RS may be transmitted depending on the scheduling type and PUSCH duration, taking into account whether frequency hopping is enabled.

[0090] When frequency hopping is disabled: The UE assumes that dmrs-AdditionalPosition is equal to 'pos2' and up to two additional DM-RS can be transmitted per PUSCH duration.

[0091] When frequency hopping is enabled: The UE assumes that dmrs-AdditionalPosition is equal to 'pos1' and at most one additional DM-RS can be transmitted per PUSCH duration.

[0092] When the transmitted PUSCH is scheduled by activation DCI format 0_0 with CRC scrambled by CS-RNTI, the UE uses a single symbol front-loaded DM-RS of a configuration type provided by a higher layer parameter dmrs-Type of configuredGrantConfig on DM-RS port 0, and the remaining REs that are not used for DM-RS in the symbols are not used for any PUSCH transmission except for a PUSCH with an allocated duration of two or fewer OFDM symbols with disabled transform precoding, and an additional DM-RS with dmrs-AdditionalPosition from configuredGrantConfig can be transmitted based on the scheduling type and the PUSCH duration, taking into account whether frequency hopping is enabled.

[0093] When the transmitted PUSCH corresponds to a scheduled or configured grant by DCI format 0_1 ​​with a CRC scrambled by C-RNTI, CS-RNTI or MCS-RNTI,

[0094] - The terminal can be configured with the upper layer parameter dmrs-Type in DMRS-UplinkConfig, and the configured DM-RS configuration type is used for PUSCH transmission.

[0095] - The terminal can set the maximum number of front-loaded DM-RS symbols for PUSCH by the upper layer parameter maxLength in DMRS-UplinkConfig.

[0096] When a terminal transmitting a PUSCH sets the upper layer parameter phaseTrackingRS in DMRS-UplinkConfig, the terminal can assume that the following settings do not occur simultaneously for the transmitted PUSCH.

[0097] - For DM-RS configuration type 1 and type 2, any DM-RS port among 4-7 or 6-11 is scheduled for each UE, and PT-RS is transmitted from the terminal.

[0098] For PUSCH scheduled by DCI format 0_1, by activated DCI format 0_1 ​​with CRC scrambled by CS-RNTI or by configured grant type 1 configuration, the UE assumes that the DM-RS CDM group is not used for data transmission.

[0099] PTRS (Phase Tracking Reference Signal)

[0100] In the 5G NR standard, a phase-tracking reference signal (PTRS) was introduced to compensate for impairments caused by phase noise in high-frequency bands. This is because phase noise causes common phase error (CPE) and inter-carrier interference (ICI) in the frequency domain.

[0101] Below, the operations related to DL PTRS and UL PTRS are described in detail.

[0102] DL PTRS related actions

[0103] Below, an example of the DL PTRS procedure is described in detail.

[0104] The base station transmits PTRS configuration information to the terminal. The PTRS configuration information may refer to the PTRS-DownlinkConfig IE. The PTRS-DownlinkConfig IE may include the frequencyDensity parameter, the timeDensity parameter, the epre-Ratio parameter, the resourceElementOffset parameter, and the like.

[0105] The above frequencyDensity parameter is a parameter indicating the presence and frequency density of DL PTRS as a function of the scheduled BW. The above timeDensity parameter is a parameter indicating the presence and time density of DL PTRS as a function of the modulation and coding scheme (MCS). The above epre-Ratio parameter is a parameter indicating the EPRE (Energy Per Resource Element) between PTRS and PDSCH.

[0106] The base station generates a sequence used for PTRS. The sequence for PTRS is generated using the DMRS sequence of the same subcarrier, as shown in Equation 3 below. Sequence generation for PTRS can be defined differently depending on whether transform precoding is enabled, and Equation 3 below shows an example when transform precoding is disabled.

[0107]

[0108] Here, is located and subcarriers is the DMRS given in .

[0109] That is, the sequence of PTRS uses the sequence of DMRS, but more specifically, the sequence of PTRS in subcarrier k is identical to the sequence of DMRS in subcarrier k.

[0110] The base station maps the generated sequence to a resource element. Here, the resource element may mean at least one of time, frequency, antenna port, or code.

[0111] The position of the PTRS in the time domain is mapped to a specific symbol interval starting from the start symbol of the PDSCH allocation. If a DMRS symbol exists, the mapping is performed from the symbol following the DMRS symbol. The specific symbol interval may be 1, 2, or 4 symbols.

[0112] And, with respect to resource element mapping of PTRS, the frequency location of PTRS is determined by the frequency location of the associated DMRS port and the upper layer parameter UL-PTRS-RE-offset. Here, UL-PTRS-RE-offset is included in the PTRS configuration and indicates the subcarrier offset for UL PTRS for CP-OFDM.

[0113] For DL, a PTRS port is associated with the DMRS port with the lowest index among the scheduled DMRS ports. For UL, the base station configures which DMRS port is associated with a PTRS port via UL DCI.

[0114] The base station transmits the PTRS to the terminal on the above resource element.

[0115] UL PTRS related actions

[0116] UL PTRS-related operations are similar to DL PTRS-related operations discussed above, and the names of the parameters related to DL PTRS can be replaced with the names of the parameters related to UL PTRS. That is, PTRS-DownlinkConfig IE can be replaced with PTRS-UplinkConfig IE, and in DL PTRS-related operations, the base station can be replaced with the terminal, and the terminal can be replaced with the base station. Similarly, sequence generation for PTRS can be defined differently depending on whether transform precoding is enabled.

[0117] Downlink transmission and reception operations

[0118] The base station schedules downlink transmissions, including frequency / time resources, transport layers, downlink precoders, and MCS. In particular, the base station can determine a beam for PDSCH transmission to a terminal through beam management operations.

[0119] And, the terminal receives downlink control information (DCI: Downlink Control Information) for downlink scheduling (i.e., including scheduling information of PDSCH) from the base station on the PDCCH. DCI format 1_0 or 1_1 can be used for downlink scheduling, and in particular, DCI format 1_1 includes the following information: DCI format identifier (Identifier for DCI formats), bandwidth part indicator, frequency domain resource assignment, time domain resource assignment, PRB bundling size indicator, rate matching indicator, ZP CSI-RS trigger, antenna port(s), transmission configuration indication (TCI: Transmission configuration indication), SRS request, DMRS (Demodulation Reference Signal) sequence initialization.

[0120] In particular, the number of DMRS ports can be scheduled according to each state / index indicated in the Antenna port(s) field, and also single-user (SU) / multi-user (MU) transmission scheduling is possible. Specifically, the order of DMRS ports corresponding to the number of CWs can be predefined according to dmrs-type and maxLength, and the number and / or order of DMRS ports can be indicated through the antenna port field of DCI.

[0121] Additionally, the TCI field consists of 3 bits, and dynamically indicates QCL for DMRS by indicating up to 8 TCI states depending on the TCI field value. Then, the terminal receives downlink data from the base station on the PDSCH. When the terminal detects a PDCCH including DCI format 1_0 or 1_1, it decodes the PDSCH according to the instructions of the corresponding DCI.

[0122] Here, when the terminal receives a PDSCH scheduled by DCI format 1_1, the terminal can set the DMRS configuration type by the upper layer parameter 'dmrs-Type', and the DMRS configuration type is used to receive the PDSCH. In addition, the terminal can set the maximum number of front-loaded DMRS symbols for the PDSCH by the upper layer parameter 'maxLength'.

[0123] For DMRS configuration type 1, if the terminal is scheduled with a single codeword and is assigned an antenna port mapped to an index of {2, 9, 10, 11, or 30}, or if the terminal is scheduled with two codewords, the terminal assumes that all remaining orthogonal antenna ports are not associated with PDSCH transmissions to another terminal. Alternatively, for DMRS configuration type 2, if the terminal is scheduled with a single codeword and is assigned an antenna port mapped to an index of {2, 10, or 23}, or if the terminal is scheduled with two codewords, the terminal assumes that all remaining orthogonal antenna ports are not associated with PDSCH transmissions to another terminal.

[0124] Uplink transmission and reception operation

[0125] Figure 1 is a diagram showing an example of uplink transmission and reception operation.

[0126] Referring to Figure 1, the base station schedules uplink transmissions, such as frequency / time resources, transmission layers, uplink precoder, and MCS (S110). In particular, the base station can determine a beam for PUSCH transmission by the terminal through beam management operations. Then, the terminal receives DCI for uplink scheduling (i.e., including PUSCH scheduling information) from the base station on the PDCCH (S120). DCI format 0_0 or 0_1 can be used for uplink scheduling, and in particular, DCI format 0_1 ​​includes the following information: DCI format identifier, UL / SUL (Supplementary uplink) indicator, UL / SUL indicator, bandwidth part indicator, frequency domain resource assignment, time domain resource assignment, frequency hopping flag, modulation and coding scheme (MCS), SRS resource indicator (SRI), precoding information and number of layers, antenna port(s), SRS request, DMRS sequence initialization, UL-SCH (Uplink Shared Channel) indicator.

[0127] In particular, SRS resources set within the SRS resource set associated with the upper layer parameter 'usage' can be indicated by the SRS resource indicator field. In addition, 'spatialRelationInfo' can be set for each SRS resource, and its value can be one of {CRI, SSB, SRI}.

[0128] Then, the terminal transmits uplink data to the base station on the PUSCH (S130). If the terminal detects a PDCCH containing DCI format 0_0 or 0_1, it transmits the corresponding PUSCH according to the instructions of the corresponding DCI. Two transmission methods are supported for PUSCH transmission: codebook-based transmission and non-codebook-based transmission.

[0129] For codebook-based transmission, when the upper layer parameter 'txConfig' is set to 'codebook', the terminal is configured for codebook-based transmission. On the other hand, when the upper layer parameter 'txConfig' is set to 'nonCodebook', the terminal is configured for non-codebook-based transmission. If the upper layer parameter 'txConfig' is not set, the terminal does not expect to be scheduled by DCI format 0_1. When PUSCH is scheduled by DCI format 0_0, PUSCH transmission is based on a single antenna port. For codebook-based transmission, PUSCH can be scheduled by DCI format 0_0, DCI format 0_1, or semi-statically. When this PUSCH is scheduled by DCI format 0_1, the UE determines a PUSCH transmission precoder based on the SRI, the Transmit Precoding Matrix Indicator (TPMI), and the transmission rank from the DCI, as given by the SRS resource indicator field and the Precoding information and number of layers field. The TPMI is used to indicate a precoder to be applied across antenna ports, and corresponds to the SRS resource selected by the SRI when multiple SRS resources are configured. Alternatively, when a single SRS resource is configured, the TPMI is used to indicate a precoder to be applied across antenna ports, and corresponds to the single SRS resource. The transmission precoder is selected from an uplink codebook having the same number of antenna ports as the upper layer parameter 'nrofSRS-Ports'. When the upper layer in which the UE is set to 'codebook' is configured with the parameter 'txConfig', the UE is configured with at least one SRS resource.The SRI indicated in slot n is associated with the most recent transmission of the SRS resource identified by the SRI, where the SRS resource precedes the PDCCH carrying the SRI (i.e., slot n).

[0130] For non-codebook based transmission, PUSCH can be scheduled in DCI format 0_0, DCI format 0_1, or semi-statically. When multiple SRS resources are configured, the UE can determine the PUSCH precoder and transmission rank based on the wideband SRI, which is given by the SRS resource indicator in the DCI or the higher layer parameter 'srs-ResourceIndicator'. The UE uses one or multiple SRS resources for SRS transmission, and the number of SRS resources can be configured for simultaneous transmission within the same RB based on the UE capability. Only one SRS port is configured for each SRS resource. Only one SRS resource can be configured with the higher layer parameter 'usage' set to 'nonCodebook'. The maximum number of SRS resources that can be configured for non-codebook based uplink transmission is 4. The SRI indicated in slot n is associated with the most recent transmission of the SRS resource identified by the SRI, where the SRS transmission precedes the PDCCH carrying the SRI (i.e., slot n).

[0131] Multi-TRP (Transmission / Reception Point) related operations

[0132] The M-TRP transmission method, in which M TRPs transmit data to one terminal (User equipment, UE), can be broadly divided into two types: eMBB M-TRP transmission, which is a method for increasing the transmission rate, and URLLC M-TRP transmission, which is a method for increasing the reception success rate and reducing latency.

[0133] In the methods proposed in this specification, DL MTRP-URLLC means that multiple TRPs transmit the same data / DCI using different layer / time / frequency resources. For example, TRP 1 transmits the same data / DCI on resource 1, and TRP 2 transmits the same data / DCI on resource 2. A UE configured with the DL MTRP-URLLC transmission method receives the same data / DCI using different layer / time / frequency resources. At this time, the UE is instructed by the base station which QCL RS / type (i.e., DL TCI state) to use in the layer / time / frequency resource where the same data / DCI is received. For example, if the same data / DCI is received on resource 1 and resource 2, the UE is instructed which DL TCI state is used on resource 1 and which DL TCI state is used on resource 2. Since the UE receives the same data / DCI through both resource 1 and resource 2, high reliability can be achieved. This DL MTRP URLLC can be applied to PDSCH / PDCCH.

[0134] Conversely, UL MTRP-URLLC means that multiple TRPs receive the same data / UCI from a UE using different layer / time / frequency resources. For example, TRP 1 receives the same data / UCI from the UE on resource 1, and TRP 2 receives the same data / UCI from the UE on resource 2, and then shares the received data / UCI through the connected backhaul link between the TRPs. A UE configured with the UL MTRP-URLLC transmission method transmits the same data / UCI using different layer / time / frequency resources. At this time, the UE is instructed by the base station which Tx beam and which Tx power (i.e., UL TCI state) to use in the layer / time / frequency resource transmitting the same data / UCI. For example, if the same data / UCI is transmitted on resource 1 and resource 2, the UE is instructed on which UL TCI state is used on resource 1 and which UL TCI state is used on resource 2. This UL MTRP URLLC can be applied to PUSCH / PUCCH.

[0135] SDCI or MDCI based MTRP transmission

[0136] Also, from the perspective of DCI (downlink control information) transmission, the M-TRP (multiple TRP) transmission method can be divided into i) M-DCI (multiple DCI) based M-TRP transmission in which each TRP transmits a different DCI, and ii) S-DCI (single DCI) based M-TRP transmission in which one TRP transmits a DCI. For example, in the case of S-DCI, since all scheduling information for data transmitted by M TRP must be transmitted through a single DCI, it can be used in an ideal BH (ideal BackHaul) environment in which dynamic cooperation between two TRPs is possible.

[0137] R16 NR MTRP Transmission

[0138] The R16 NR standard supports S-DCI based MTRP PDSCH and M-DCI based MTRP PDSCH transmission methods.

[0139] R16 M-DCI based MTRP PDSCH

[0140] M-DCI based MTRP PDSCH transmission Each TRP schedules and transmits PDSCH through DCI. That is, TRP 1 transmits PDSCH 1 through DCI 1, and TRP 2 transmits PDSCH 2 through DCI 2. When PDSCH 1 and PDSCH 2 overlap in the same frequency time resource, two PDSCHs are received for the same RE, which increases resource efficiency and increases transmission capacity. To this end, the R16 standard introduces a CORESET pool, which is a group of multiple CORESETs. TRP 1 transmits a PDCCH through a CORESET belonging to CORESET pool 0, and the PDSCH scheduled by the PDCCH is also transmitted by TRP 1. TRP 2 transmits a PDCCH through a CORESET belonging to CORESET pool 1, and the PDSCH scheduled by the PDCCH is also transmitted by TRP 2. PUSCH can also schedule PUSCH transmission to a specific TRP for the UE through a CORESET belonging to each COERSET pool. For PUCCH, some PUCCH resources are scheduled by TRP 1 to receive UCI, and the remaining PUCCH resources are scheduled by TRP 2 to receive UCI. In the case of PUSCH or PUCCH, the channels scheduled / used by each TRP are TDMed with each other, so there is no overlap, and thus no increase in transmission capacity is expected. However, the UE can transmit independent PUSCH / PUCCH for each TRP 1 and 2.

[0141] Additionally, the UE may recognize the PUSCH (or PUCCH) scheduled by the DCI received in different CORESETs (or CORESETs belonging to different CORESET groups) as a PUSCH (or PUCCH) transmitted in different TRPs or as a PUSCH (or PUCCH) of different TRPs. Furthermore, the method for UL transmissions (e.g. PUSCH / PUCCH) transmitted in different TRPs can be equally applied to UL transmissions (e.g. PUSCH / PUCCH) transmitted in different panels belonging to the same TRP.

[0142] R17 NR MTRP Transmission

[0143] The R17 NR standard supports MTRP PDCCH repeated transmission, MTRP PDCCH / PDSCH SFN transmission, S-DCI based MTRP PUSCH repeated transmission, and single PUCCH resource based MTRP PUCCH repeated transmission. All of these transmission techniques are URLLC target enhancements to increase reliability, in which the same contents (i.e., DCI or UL TB or UCI) are repeatedly transmitted. In the case of MTRP PDCCH repeated transmission, it is repeatedly transmitted in TDM or FDM, MTRP PDCCH / PDSCH SFN is repeatedly transmitted in the same time / frequency / layer, S-DCI based MTRP PUSCH repeated transmission is TDM, and single PUCCH resource based MTRP PUCCH repeated transmission is repeatedly transmitted in TDM.

[0144] R17 MTRP SFN PDCCH

[0145] As a special case of MTRP PDCCH repetition, multiple TRPs can repeatedly transmit the same DCI through the same time / frequency / DMRS port, which can be called SFN PDCCH transmission. However, for SFN PDCCH transmission, instead of configuring multiple CORESETs with different TCI states, the base station configures multiple TCI states in a single CORESET. When the UE receives a PDCCH candidate through the SS set associated with that single CORESET, it performs channel estimation of the PDCCH DMRS using all of the multiple TCI states and attempts to decode.

[0146] R17 MTRP SFN PDSCH

[0147] When the above MTRP PDSCH is repeatedly transmitted, the two TRPs repeatedly transmit the corresponding channel on different resources. However, as a special case, if the two TRPs use the same resources, that is, if the same channel is repeatedly transmitted through the same frequency, time, and layer (=DMRS port), the reliability of the corresponding channel can be improved. In this case, the repeatedly transmitted identical channels are received combined over the air because the resources are not distinguished, so the receiver recognizes them as a single channel. In the R17 NR standard, two DL TCI states for PDSCH DMRS reception can be set for PDSCH SFN transmission.

[0148] For convenience of explanation, this specification applies the proposed method assuming cooperative transmission / reception between 2 TRPs. However, it can be expanded to a multi-TRP environment of 3 or more, and can also be expanded to a multi-panel environment. Different TRPs can be recognized by the UE as different TCI states, and when the UE receives / transmits data / DCI / UCI using TCI state 1, it means that the data / DCI / UCI has been received / transmitted from / to TRP 1.

[0149] In this specification, TO (Transmission Occasion) means each channel transmitted at a different time when multiple channels are TDMed, each channel transmitted on a different frequency / RB when FDMed, and each channel transmitted on a different layer / beam / DMRS port when SDMed. One TCI state is mapped to each TO. When the same channel is repeatedly transmitted, a complete DCI / data / UCI is transmitted to one TO, and the receiving end receives multiple TOs to increase the reception success rate.

[0150] R17 SDCI based multi-TB PUSCH / PDSCH scheduling

[0151] In R17 NR, a method for scheduling multiple PUSCH / PDSCH simultaneously with a single DCI is supported in the ultra-high frequency band (beyond 5.26 GHz). For example, multiple TDRAs (=TOs) can be indicated at once through the TDRA field of the PUSCH scheduling DCI, and a different TB is transmitted via the PUSCH for each TO. The FDRA, MCS, TPMI, and SRI values ​​of the DCI are commonly applied to multiple scheduled TBs. In addition, the NDI and RV for each TB are individually indicated through the DCI, and a single HARQ number is indicated, but they sequentially increase in the order of the TOs based on the initial TO.

[0152] Description of STxMP (Simultaneous Transmission across Multi-panels)

[0153] In R18, a method for a UE to simultaneously transmit multiple channels / RSs of the same type or multiple channels / RSs of different types is being discussed. In the case of existing UEs, the operation of transmitting multiple channels / RSs at a time is restricted (e.g., simultaneous transmission of multiple SRS resources of different SRS sets is possible for UL beam measurement, but simultaneous transmission of multiple PUSCHs is not possible). However, in the case of advanced UEs in the future, this restriction will be relaxed and multiple channels or RSs will be transmitted simultaneously using multiple transmission panels. Such UEs are called STxMP UEs. For example, two PUSCHs corresponding to two UL TBs are scheduled on the same RE, and Spatial relation RS 1 and PC parameter Set 1 (i.e., UL TCI state 1) and Spatial relation RS 2 and PC parameter Set 2 (i.e., UL TCI state 2) are set for PUSCH 1 and 2 transmission, respectively. The UE transmits PUSCH 1 using panel 1 corresponding to UL TCI state 1 and simultaneously transmits PUSCH 2 using panel 2 corresponding to UL TCI state 2.

[0154] When a base station schedules a PUSCH through DCI, it can indicate whether the PUSCH will be transmitted as STxMP, as a single panel, or as MTRP PUSCH repetitions. Of course, the UE must have STxMP capability, and the STxMP mode must be enabled in advance, such as through RRC signaling. To achieve this, the existing SRS resource set indication field can be redefined and used, or a new DCI field can be introduced.

[0155] Two methods are being considered for the R18 STxMP transmission technique: SFN and SDM.

[0156] The SFN method transmits the same channel from one panel to another. However, since the UL channels of each panel are different, each panel is transmitted using a different precoder, different transmission power, and different transmission beam (i.e., spatial relation RS indicated by the UL TCI).

[0157] The SDM method is a method that can be transmitted from rank 2 and above, and it is a method in which panel 1 transmits some of the multi-layers and panel 2 transmits the remaining layers. For example, in 2-layer transmission, panel 1 transmits the 1st layer and panel 2 transmits the 2nd layer. Even in this case, since the UL channels of each panel are different, different precoders, different transmission powers, and different transmission beams (i.e., spatial relation RS indicated by UL TCI) are transmitted for each panel.

[0158] Panel is not a term used in the standard, and other resources / terms corresponding to panel are used. For example, different panels may be mapped to different SRS resource sets or SRS resources. For example, the first panel may be mapped to SRS resource set 0, the second panel may be mapped to SRS resource set 1, and the SRS resources in SRS resource set 0 may refer to the transmit antenna ports of the first panel, and the SRS resources in SRS resource set 1 may refer to the transmit antenna ports of the second panel.

[0159] Description of the Unified TCI framework

[0160] In R17, both the UL TCI state and the DL TCI state can be indicated through DL DCI (e.g. DCI format 1-1 or 1-2), or only the UL TCI state can be indicated without indicating the DL TCI state. Accordingly, the methods used for configuring UL beam and power control (PC) in the existing R15 / R16 are replaced in R17 with the above UL TCI state indication method. More specifically, in R17, one UL TCI state can be indicated through the TCI field of the DL DCI, and the UL TCI state is applied to all PUSCHs and all PUCCHs after a certain time called the beam application time, and can be applied to some or all of the indicated SRS resource sets. In R18, a method in which multiple UL TCI states (and / or DL ​​TCI states) are indicated through the TCI field of the DL DCI is under discussion.

[0161] AIML related explanation

[0162] With the advancement of AI / ML (Artificial intelligence / machine learning) technology, the node(s) and terminal(s) that make up the wireless communication network are becoming more intelligent / advanced. In particular, due to the intelligence of the network / base station, it is expected that various network / base station decision parameter values ​​(e.g., transmission / reception power of each base station, transmission power of each terminal, precoder / beam of the base station / terminal, time / frequency resource allocation for each terminal, duplex method of each base station, etc.) can be quickly optimized and derived / applied according to various environmental parameters (e.g., distribution / location of base stations, distribution / location / material of buildings / furniture, etc., location / movement direction / speed of terminals, climate information, etc.).

[0163] The previously discussed contents (DMRS, PTRS, UL transmission / reception operations, MTRP-related operations, AI / ML, etc.) can be applied in combination with the methods proposed in this specification, which will be described later, or can be supplemented to clarify the technical characteristics of the methods proposed in this specification. The methods described below are distinguished only for convenience of explanation, and it goes without saying that some components of one method can be substituted for some components of another method, or they can be applied in combination with each other.

[0164] In this specification, 'port' and 'antenna port' may be interpreted as having the same meaning. For example, PTRS (DMRS) port means PTRS (DMRS) antenna port, and vice versa.

[0165] In this specification, 'DMRS (or PTRS)' may mean 'DM-RS (or PT-RS)' and vice versa.

[0166] Subband precoding for UL PUSCH transmission may be supported in NR MIMO Rel19 or later releases. Different precodings may be supported for each subband (SB) in the future. In this specification, a 'subband' may refer to a frequency resource smaller than a frequency band to which existing precoding is applied. For example, a 'subband' may be interpreted / replaced as a part of a scheduled band / scheduled resource block(s). For example, a 'subband' may be interpreted / replaced as one or more resource blocks (RBs).

[0167] The precoding operations supported according to the existing method are as follows: For PUSCH, wideband precoding is supported in which the same precoder is applied to the scheduled band / scheduled resource block(s).

[0168] Since different precodings are supported for each subband, a method in which the base station instructs the terminal to select a subband-specific precoder for codebook-based PUSCH transmission may be considered. This operation can achieve optimized digital beamforming for each subband and higher UL throughput in a frequency-selective channel.

[0169] As described above, when the precoder varies by SB, the precoder applied to each DMRS port of each SB also varies. Since the order of DMRS ports with high channel quality may vary for each SB, a method and device for establishing / defining / directing PTRS-DMRS associations for each subband is required. This will be discussed in detail below.

[0170] Proposal 1

[0171] The task to be solved

[0172] When performing PTRS-DMRS association for each subband (SB) or subband group (SB group), a different number of PTRS ports can be set for each SB or SB group.

[0173] For example, the PTRS ports indicated by SB may be as follows:

[0174] [1] SB#0 - PTRS port#0

[0175] [2] SB#1 - PTRS port#0

[0176] [3] SB#2 - PTRS port#0 & PTRS port#1

[0177] [4] SB#3 - PTRS port#0

[0178] The number of PTRS ports can be determined based on the number of oscillators in the UE. For example, M different transmission panels are implemented with M different oscillators. That is, one oscillator is used per panel, and different panels can have different oscillators. In the above example, PUSCH transmission can be performed as follows.

[0179] 1) PUSCH is transmitted based on one panel in SB#0, SB#1, and SB#3. 2) PUSCH is transmitted based on two panels in SB#2.

[0180] An uplink transmission panel (UL Tx Panel) can be expressed as a spatial domain filter or an uplink beam indicated based on a UL TCI state. Referring to the PUSCH transmission operation according to the above example, different spatial domain filters or uplink beams based on two UL TCI states are used in SB#2. In this way, when the terminal panel / panel combination transmitted for each SB is different, uplink power control (UL power control) and beam management (BM) may also be affected. In other words, uplink power control and beam management operations may need to be defined / configured as many times as the number of different panel / panel combinations. In this case, it may be inefficient in terms of the implementation complexity required to support subband precoding.

[0181] To solve the above-mentioned problems, the following methods may be considered.

[0182] Method 1-1

[0183] A method may be considered in which a PUSCH is transmitted on a single panel / beam, but only the (digital) precoder applied to the PUSCH is changed on an SB basis. To this end, the SB precoder may be indicated only for the Transmit Precoding Matrix Indicator (TPMI), Transmission Rank Indicator (TRI) (for Codebook Based UL transmission, CB), and / or SRS resource (for Non-Codebook Based UL transmission, NCB) corresponding to the same PTRS port (or the same combination of PTRS ports). A specific example will be described below.

[0184] It can be assumed that 4 ports are scheduled for PUSCH (Rank 4). In this case, indicating the SB precoder only for the TPMI / TRI (for CB) corresponding to the same PTRS port (combination) can be interpreted as the following operation.

[0185] TPMI-based SB precoder instructions for scheduled subbands

[0186] For example, the SB precoder may be a precoder that i) uses PUSCH antenna ports 1000 and 1002, and ii) does not use PUSCH antenna ports 1001 and 1003. The same PTRS port may be PTRS port 0. The PUSCH antenna ports 1000 and 1002 may share the PTRS port 0. In other words, the PTRS 0 may be associated with UL layer 'x' among the layers transmitted based on the PUSCH antenna ports 1000 and 1002.

[0187] As another example, the SB precoder may be a precoder that i) uses PUSCH antenna ports 1001 and 1003, and ii) does not use PUSCH antenna ports 1000 and 1002. The same PTRS port may be PTRS port 1. The PUSCH antenna ports 1001 and 1003 may share the PTRS port 1. In other words, the PTRS 1 may be associated with UL layer 'y' among the layers transmitted based on the PUSCH antenna ports 1001 and 1003.

[0188] Here, 'x' and / or 'y' can be given based on the PTRS-DMRS association field of DCI (e.g., DCI format 0_1, DCI format 0_2, DCI format 0_3).

[0189] Indicating the SB precoder only for SRS resources (for NCBs) corresponding to the same PTRS port (combination) may mean that for scheduled subbands (scheduled SBs), only SRS resources with the same PTRS port index value are indicated through the SRI field.

[0190] The following is a detailed explanation of the TPMI-related examples described above.

[0191] For example, in the case of CB, it can be assumed that there are two SBs each consisting of 4 RBs. In the 4-port partial coherent codebook, the PMI corresponding to PTRS port 0 for SB 0 and SB 1 is limited to TPMI indices 0, 2, 4, 5, 6, and 7 as shown in Table 3 below. The PMI based on the TPMI indices may be related to the layer(s) using PUSCH antenna ports 1000 and 1002.

[0192] Table 3 below illustrates the precoding matrix W for single layer transmission using four antenna ports.

[0193]

[0194] The base station can indicate SB PMI within its limited PMIs (e.g., PMI indication based on six TPMI indices 0, 2, 4-7). Compared to indicating PMI based on all PMIs (27 TPMI indices) (5 bits), the payload for PMI indication can be reduced to 3 bits.

[0195] For example, to indicate the PMI corresponding to PTRS port 0 to SB 0 and SB 1 using a 2-port codebook, 3 bits are required. However, as shown in Table 4 below, the TPMI index for indicating the PMI corresponding to PTRS port 0 can be limited to TPMI index 2, 3, 4, and 5. If the base station indicates the SB PMI within the limited PMIs, the number of bits required for the PMI indication is reduced from 3 bits to 2 bits.

[0196] Table 4 below illustrates the precoding matrix W for single layer transmission using two antenna ports.

[0197]

[0198] The above-described TPMI indices can be indicated based on the DCI field (Precoding information and number of layers or Second Precoding information). The DCI field based on Tables 3 and 4 can be defined as shown in Tables 5 and 6 below.

[0199] Table 5 illustrates the Precoding information and number of layers (or Second Precoding information) for four antenna ports.

[0200]

[0201] Table 6 illustrates the Precoding information and number of layers (or Second Precoding information) for two antenna ports.

[0202]

[0203] For example, in the case of NCB, it can be assumed that there are two SBs consisting of 4RBs. There are four SRS resources in the SRS resource set (e.g., ), it is assumed that the PTRS port index set by RRC for each SRS resource is PTRS index 0, 0, 1, 1 in the order of the index of the SRS resource (0, 1, 2, 3).

[0204] The SRI corresponding to PTRS port 0 in SB 0 and SB 1 is SRI(s) as shown in Table 7 below. Among the indices 0 to 15, it can be limited to indices 0, 1, and 4. The base station can indicate SB SRI within the limited SRIs. Compared to indicating SRI based on all indices (e.g., 0 to 15) (4 bits), the number of bits required for SRI indication is reduced to 2 bits.

[0205] Table 7 below (Maximum number of layers is 4) Example of SRI indication for non-codebook based PUSCH transmission.

[0206]

[0207] Method 1-2

[0208] Scheduling restrictions may be introduced to limit the PTRS port combinations to be indicated in the SB TPMI / SRI(s) mapped to the same PTRS (combination). For PUSCH scheduling, it can be assumed that the same PTRS port combination is configured / indicated for each SB (group). That is, the UE does not expect different PTRS port combinations to be indicated for each SB (group).

[0209] When a base station schedules a CB PUSCH (codebook based PUSCH) based on 4 ports to a terminal according to the above scheduling restrictions, the base station can operate as follows.

[0210] For example, the base station may direct only the SB precoder that uses PUSCH antenna ports 1000 and 1002 for SBs scheduled for the terminal and does not use PUSCH antenna ports 1001 and 1003 to the TPMI. Alternatively, the base station may direct only the SB precoder that uses PUSCH antenna ports 1001 and 1003 for SBs scheduled for the terminal and does not use PUSCH antenna ports 1000 and 1002 to the TPMI.

[0211] For example, a base station can use a 2-port codebook to limit the PMI corresponding to PTRS port 0 to SB 0 and SB 1. When NCB PUSCH is scheduled according to the above restriction, the base station can operate as follows. The base station can only indicate to the UE the SRS resource (SRI)(s) with the same PTRS port index value through the SRI field for the scheduled SBs.

[0212] The above suggestions can be finally applied through a combination / combination.

[0213] In terms of implementation, the operations of the base station / terminal according to the embodiments described above (e.g., operations based on at least one of Method 1-1 and Method 1-2) can be processed by the device (e.g., 100, 200) of FIG. 4 described below.

[0214] In addition, the operations of the base station / terminal according to the above-described embodiment (e.g., operations based on at least one of methods 1-1 to 1-2) may be stored in a memory (e.g., 140, 240 of FIG. 4) in the form of commands / programs (e.g., instructions, executable codes) for driving at least one processor (e.g., 110, 210 of FIG. 4).

[0215] The embodiments described below are specifically described with reference to FIGS. 2 and 3 in terms of the operation of the terminal and base station. The methods described below are distinguished for convenience of explanation, and it is understood that some components of one method may be substituted for or combined with some components of another method.

[0216] FIG. 2 is a flowchart illustrating a method according to one embodiment of the present specification.

[0217] Referring to FIG. 2, a method according to one embodiment of the present specification includes a DCI reception step (S210) and a PUSCH transmission step (S220).

[0218] In S210, the terminal receives downlink control information (DCI) for scheduling a physical uplink shared channel (PUSCH) from the base station.

[0219] For example, a precoder may be determined based on the DCI. The precoder may be associated with codebook-based UL transmission or non-codebook-based UL transmission. Specifically, the transmission scheme associated with the PUSCH may be configured as codebook-based or non-codebook-based. The precoder may be interpreted / replaced as a PUSCH transmission precoder or a PUSCH precoder.

[0220] In S220, the terminal transmits the PUSCH to the base station based on the precoder.

[0221] In one embodiment, i) a Transmit Precoding Matrix Index (TPMI) and / or ii) a Sounding Reference Signal Resource Indicator (SRI) for determining the precoder may be indicated based on the DCI.

[0222] For example, for determining the precoder associated with the codebook-based uplink transmission, the TPMI and the SRI may be indicated based on the DCI. For example, for determining the precoder associated with the non-codebook-based uplink transmission, the SRI may be indicated based on the DCI.

[0223] Embodiments based on at least one of the above-described methods 1-1 and / or 1-2 may be considered for applying / supporting frequency-specific precoding (e.g., subband precoding). These are described in detail below.

[0224] In one embodiment, the TPMI may be indicated based on a first field indicating one of the first indices. The precoder may be associated with one or more scheduled resource blocks (RBs). The first indices may be associated with TPMIs based on the same Phase Tracking Reference Signal (PTRS) port.

[0225] In one embodiment, the PUSCH may be associated with four antenna ports 1000 to 1003. The same PTRS port may be PTRS port 0 or PTRS port 1 associated with two of the four antenna ports. TPMIs based on PTRS port 0 or PTRS port 1 will be described in detail below.

[0226] For example, the TPMIs based on the same PTRS port may be associated with precoding matrices whose elements associated with the remaining two of the four antenna ports are 0.

[0227] For example, based on the same PTRS port being PTRS port 0 associated with antenna ports 1000 and 1002, the TPMIs based on the same PTRS port may be associated with the precoding matrices whose second and fourth elements are 0 associated with antenna ports 1001 and 1003 (e.g., precoding matrices based on TPMI indices 0, 2, 4, 5, 6, 7 of Table 3). In the present specification, 'precoding matrix' may be interpreted / replaced with 'precoder matrix'.

[0228] Referring to Tables 3 and 4, each element associated with each antenna port of the precoding matrix may mean an element of each row of the precoding matrix. A precoding matrix for four antenna ports is a matrix consisting of four rows. The number of columns of the precoding matrix corresponds to the number of layers. For example, in the case of a single layer transmission based on four antenna ports, the precoding matrix is ​​a 4X1 matrix (see Table 3). For example, in the case of a single layer transmission based on two antenna ports, the precoding matrix is ​​a 2X1 matrix (see Table 4).

[0229] Referring to Table 3, the element in the first row of the precoding matrix is ​​associated with the first antenna port (e.g., antenna port 1000), the element in the second row of the precoding matrix is ​​associated with the second antenna port (e.g., antenna port 1001), the element in the third row of the precoding matrix is ​​associated with the third antenna port (e.g., antenna port 1002), and the element in the fourth row of the precoding matrix is ​​associated with the fourth antenna port (e.g., antenna port 1003).

[0230] For example, based on the same PTRS port being PTRS port 1 associated with antenna ports 1001 and 1003, the TPMIs based on the same PTRS port may be associated with the precoding matrices whose first and third elements are 0 associated with antenna ports 1000 and 1002 (e.g., precoding matrices based on TPMI indices 1, 3, 8, 9, 10, 11 of Table 3).

[0231] In one embodiment, the first field may be a precoding information and number of layers field. That is, the DCI may include precoding information and number of layers fields. The first indices may be indices of a table defined based on the TPMIs based on the same PTRS port. For example, referring to Table 5, the first indices may be indices 0-5 of a table defined based on TPMIs (TPMI index 0, 2, 4, 5, 6, 7) based on the same PTRS port (PTRS port 0).

[0232] In one embodiment, the SRI may be indicated based on an SRI field indicating one of the second indices. That is, the DCI may include the SRI field. The second indices may be associated with SRIs based on the same PTRS port.

[0233] For example, the SRIs based on the same PTRS port may be associated with SRS resources within the SRS resource set for which the same PTRS port is set. A specific example is described below.

[0234] i) The number of SRS resources in the SRS resource set is 4 (e.g. ), ii) based on the same PTRS port being set in two SRS resources among the four SRS resources: the SRIs based on the same PTRS port may be two SRIs associated with the two SRS resources among the four SRIs. Referring to Table 7, four SRS resources 0 to 3 are associated with four SRIs 0 to 3. If the same PTRS port (e.g., PTRS port 0) is set in two SRS resources 0, 1, the SRIs based on the same PTRS port may be SRIs 0, 1. That is, the second indices may mean indices 0, 1, 4 of Table 7 indicating at least one of the SRIs 0, 1.

[0235] The operations based on S210 to S220 described above can be implemented by the device of FIG. 4. For example, the terminal (200) can control one or more transceivers (230) and / or one or more memories (240) to perform the operations based on S210 to S220.

[0236] The embodiments described below are specifically described in terms of base station operation.

[0237] S310 to S320 described below correspond to S210 to S220 described in FIG. 2. Considering the above correspondence, redundant descriptions are omitted. That is, the specific description of the base station operation described below may be replaced with the description / embodiment of FIG. 2 corresponding to the operation. For example, the description / embodiment of S210 to S220 of FIG. 2 may be additionally applied to the base station operation of S310 to S320 described below.

[0238] FIG. 3 is a flowchart illustrating a method according to another embodiment of the present specification.

[0239] Referring to FIG. 3, a method according to another embodiment of the present specification includes a DCI transmission step (S310) and a PUSCH reception step (S320).

[0240] In S310, the base station transmits downlink control information (DCI) for scheduling a physical uplink shared channel (PUSCH) to the terminal.

[0241] In S320, the base station receives the PUSCH from the terminal based on the precoder.

[0242] The operations based on S310 to S320 described above can be implemented by the device of FIG. 4. For example, the base station (100) can control one or more transceivers (130) and / or one or more memories (140) to perform the operations based on S310 to S320.

[0243] The operations / terms based on the embodiments described above have been described assuming a 5G system. However, this is for convenience of explanation and is not intended to limit the scope of application of the technical problems and problem-solving means to be solved by this specification to a specific system. That is, the technical problems / technical issues / problems mentioned in this specification may equally exist in other systems (e.g., 6G systems). It is self-evident that the embodiments of this specification can be expanded and applied to solve problems equally existing in the other systems. Therefore, for the expanded application of the embodiments of this specification to other systems, the terms defined / described based on the 5G system may be replaced / changed with terms defined in the other systems (or generalized terms not specific to a system). For example, PRACH, PUSCH, PUCCH, or SRS may be replaced / changed with uplink signals (or uplink channels). For example, SSB, CSI-RS, PDSCH, and PDCCH may be replaced / changed with downlink signals (or downlink channels).

[0244] Hereinafter, a device to which an embodiment of the present specification can be applied (a device that implements a method / operation according to an embodiment of the present specification) is described with reference to FIG. 4.

[0245] FIG. 4 is a drawing showing the configuration of a first device and a second device according to an embodiment of the present specification.

[0246] The first device (100) may include a processor (110), an antenna unit (120), a transceiver (130), and a memory (140).

[0247] The processor (110) performs baseband-related signal processing and may include a higher layer processing unit (111) and a physical layer processing unit (115). The higher layer processing unit (111) may process operations of a MAC layer, an RRC layer, or higher layers. The physical layer processing unit (115) may process operations of a PHY layer. For example, when the first device (100) is a base station device in base station-terminal communication, the physical layer processing unit (115) may perform uplink reception signal processing, downlink transmission signal processing, etc. For example, when the first device (100) is a first terminal device in terminal-to-terminal communication, the physical layer processing unit (115) may perform downlink reception signal processing, uplink transmission signal processing, sidelink transmission signal processing, etc. In addition to performing baseband-related signal processing, the processor (110) may also control the overall operation of the first device (100).

[0248] The antenna unit (120) may include one or more physical antennas, and when it includes multiple antennas, it may support MIMO transmission and reception. The transceiver (130) may include an RF (Radio Frequency) transmitter and an RF receiver. The memory (140) may store information processed by the processor (110), and software, an operating system, applications, etc. related to the operation of the first device (100), and may also include components such as a buffer.

[0249] The processor (110) of the first device (100) may be configured to implement the operation of the base station in the base station-to-terminal communication (or the operation of the first terminal device in the terminal-to-terminal communication) in the embodiments described in the present disclosure.

[0250] The second device (200) may include a processor (210), an antenna unit (220), a transceiver (230), and a memory (240).

[0251] The processor (210) performs baseband-related signal processing and may include a higher layer processing unit (211) and a physical layer processing unit (215). The higher layer processing unit (211) may process operations of a MAC layer, an RRC layer, or higher layers. The physical layer processing unit (215) may process operations of a PHY layer. For example, when the second device (200) is a terminal device in base station-terminal communication, the physical layer processing unit (215) may perform downlink reception signal processing, uplink transmission signal processing, etc. For example, when the second device (200) is a second terminal device in terminal-to-terminal communication, the physical layer processing unit (215) may perform downlink reception signal processing, uplink transmission signal processing, sidelink reception signal processing, etc. In addition to performing baseband-related signal processing, the processor (210) may also control the overall operation of the second device (210).

[0252] The antenna unit (220) may include one or more physical antennas, and when it includes multiple antennas, it may support MIMO transmission and reception. The transceiver (230) may include an RF transmitter and an RF receiver. The memory (240) may store information processed by the processor (210), software, an operating system, applications, etc. related to the operation of the second device (200), and may also include components such as a buffer.

[0253] The processor (210) of the second device (200) may be configured to implement operations of the terminal in base station-to-terminal communication (or operations of the second terminal device in terminal-to-terminal communication) in the embodiments described in the present disclosure.

[0254] In the operation of the first device (100) and the second device (200), the same explanations given for the base station and the terminal (or the first terminal and the second terminal in the terminal-to-terminal communication) in the examples of the present disclosure may be applied, and redundant explanations are omitted.

[0255] Here, the wireless communication technology implemented in the device (100, 200) of the present disclosure may include not only LTE, NR, and 6G, but also Narrowband Internet of Things (NB-IoT) for low-power communication. For example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology, and may be implemented in standards such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the above-described names.

[0256] Additionally or alternatively, the wireless communication technology implemented in the device (100, 200) of the present disclosure may perform communication based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and may be called by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology may be implemented by at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and is not limited to the above-described names.

[0257] Additionally or alternatively, the wireless communication technology implemented in the device (100, 200) of the present disclosure may include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) that take low-power communication into account, and is not limited to the above-described names. For example, ZigBee technology can create personal area networks (PANs) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and may be called by various names.

Claims

1. In the method, A step of receiving downlink control information (DCI) for scheduling a physical uplink shared channel (PUSCH), wherein a precoder is determined based on the DCI; and A step of transmitting the PUSCH based on the precoder; including: A Transmit Precoding Matrix Index (TPMI) and / or a Sounding Reference Signal Resource Indicator (SRI) for determining the above precoder are indicated based on the DCI, The above TPMI is indicated based on a first field indicating one of the first indices, The above precoder is associated with one or more scheduled resource blocks (RBs), A method characterized in that the above first indices are related to TPMIs based on the same Phase Tracking Reference Signal (PTRS) port.

2. In paragraph 1, The above PUSCH is associated with four antenna ports 1000 to 1003, A method characterized in that the above identical PTRS port is PTRS port 0 or PTRS port 1 associated with two of the four antenna ports.

3. In paragraph 2, A method characterized in that the TPMIs based on the same PTRS port are associated with precoding matrices in which elements associated with the remaining two antenna ports among the four antenna ports are 0.

4. In paragraph 3, Based on the above identical PTRS port being PTRS port 0 associated with antenna ports 1000 and 1002, A method characterized in that the TPMIs based on the same PTRS port are associated with the precoding matrices whose second and fourth elements are 0, which are associated with antenna ports 1001 and 1003.

5. In paragraph 3, Based on the above identical PTRS port being PTRS port 1 associated with antenna ports 1001 and 1003, A method characterized in that the TPMIs based on the same PTRS port are associated with the precoding matrices whose first and third elements are 0, which are associated with antenna ports 1000 and 1002.

6. In paragraph 1, A method characterized in that the first field is a precoding information and number of layers field.

7. In paragraph 6, A method characterized in that the above first indices are indices of a table defined based on the TPMIs based on the same PTRS port.

8. In paragraph 1, The above SRI is indicated based on an SRI field indicating one of the second indices, A method characterized in that the second indices are related to SRIs based on the same PTRS port.

9. In paragraph 8, The above SRIs based on the same PTRS port are: A method characterized in that the SRS resources in the SRS resource set are related to the SRS resources in which the same PTRS port is set.

10. In paragraph 8, i) the number of SRS resources in the SRS resource set is 4, and ii) the same PTRS port is set to 2 of the 4 SRS resources: A method characterized in that the SRIs based on the same PTRS port are two SRIs among four SRIs related to the two SRS resources.

11. In the terminal, One or more transmitters and receivers; one or more processors; and One or more memories connected to said one or more processors and storing instructions, A terminal characterized in that the instructions are set to cause the one or more processors to perform all steps of the method according to any one of claims 1 to 10, based on being executed by the one or more processors.

12. In a device comprising one or more memories and one or more processors functionally connected to the one or more memories, A device characterized in that said one or more memories store instructions that cause said one or more processors to perform all steps of a method according to any one of claims 1 to 10, based on execution by said one or more processors.

13. In one or more non-transitory computer-readable media storing instructions, One or more non-transitory computer-readable media characterized in that the instructions executable by one or more processors cause the one or more processors to perform all steps of the method according to any one of claims 1 to 10.

14. In the method, A step of transmitting downlink control information (DCI) for scheduling a physical uplink shared channel (PUSCH), wherein a precoder is determined based on the DCI; and A step of receiving the PUSCH based on the precoder; including: A Transmit Precoding Matrix Index (TPMI) and / or a Sounding Reference Signal Resource Indicator (SRI) for determining the above precoder are indicated based on the DCI, The above TPMI is indicated based on a first field mapped to one of the defined indices, The above precoder is associated with one or more scheduled resource blocks (RBs), A method characterized in that the above defined indices are related to TPMIs based on the same Phase Tracking Reference Signal (PTRS) port.

15. At the base station, One or more transmitters and receivers; one or more processors; and One or more memories connected to said one or more processors and storing instructions, A base station characterized in that the instructions are set to cause the one or more processors to perform all steps of the method according to claim 14, based on the instructions being executed by the one or more processors.

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