Method and device for transmitting and receiving uplink signal

Abstract

A method according to an embodiment of the present specification comprises the steps of: receiving DCI for scheduling of a PUSCH; transmitting a DMRS related to the PUSCH; and transmitting a PTRS related to the PUSCH. The DCI comprises i) an antenna port field and ii) a PTRS-DMRS association field. One or more DMRS ports are indicated on the basis of the antenna port field. On the basis of the PTRS-DMRS association field, for each of groups on the basis of scheduled RBs, an association between the one or more DMRS ports and at least one PTRS port is indicated.

Description

Method and device for transmitting and receiving uplink signals

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

[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 operations, the same precoding (wideband precoding) is applied to scheduled RBs for PUSCH, and PTRS-DMRS association is indicated based on this. In the future, precoding for each subband (subband precoding) may be supported in a frequency-selective channel environment.

[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. In other words, the order of DMRS ports with good channel quality is different for each subband, and the PTRS port combination for each subband may be different. Accordingly, since PTRS-DMRS association must be indicated for each subband, the payload size required for PTRS-DMRS association may increase by a factor of the number of subbands to which different precodings are applied. For example, if PTRS-DMRS association is indicated for two subbands, the payload size required to indicate PTRS-DMRS association may double compared to the payload size according to the existing method.

[0006] The purpose of this specification is to minimize the overhead required for PTRS-DMRS association instructions while supporting fine-grained precoding in terms of frequency.

[0007] 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.

[0008] 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), transmitting a demodulation reference signal (DMRS) related to the PUSCH, and transmitting a phase tracking reference signal (PTRS) related to the PUSCH.

[0009] The above DCI includes i) an antenna port field and ii) a PTRS-DMRS association field. One or more DMRS ports are indicated based on the antenna port field.

[0010] Based on the PTRS-DMRS association field, for each of the groups based on scheduled resource blocks (RBs), an association between the one or more DMRS ports and at least one PTRS port is indicated.

[0011] The above PTRS-DMRS association field may be based on a plurality of fields. The association for each of the groups may be indicated based on the plurality of fields.

[0012] The number of the above multiple fields may be based on the number of groups set based on upper layer signaling.

[0013] The above groups can be determined based on i) the scheduled RBs and ii) the number of groups.

[0014] Each group may contain RB groups. Each RB group may contain one or more RBs.

[0015] The above RB groups can be continuous in the frequency domain.

[0016] The above RB groups may be associated with the same precoder.

[0017] The above groups may be associated with different precoders.

[0018] Information representing the association for each of the groups may be jointly encoded in the PTRS-DMRS association field.

[0019] The above association may be i) indicated based on the PTRS-DMRS association field, or ii) defined.

[0020] i) the PUSCH is associated with two codewords, and ii) the maximum number of the at least one PTRS port is set to 1: the association may be defined based on i) one PTRS port and ii) a DMRS port associated with a codeword having a higher Modulation and Coding Scheme (MCS) among the two codewords.

[0021] The above one PTRS port may be associated with a first DMRS port among the DMRS ports associated with the codeword having the high MCS.

[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 above instructions are characterized in that they cause the terminal to perform all steps of any one of the above methods based on being executed by the one or more processors.

[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 device to perform all steps of any one of said methods based on being executed by said one or more processors.

[0026] A non-transitory computer-readable medium according to another embodiment of the present disclosure stores instructions.

[0027] The above instructions are characterized in that they cause the terminal to perform all steps of any one of the above methods based on being executed by one or more processors.

[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), receiving a demodulation reference signal (DMRS) related to the PUSCH, and receiving a phase tracking reference signal (PTRS) related to the PUSCH.

[0029] The above DCI includes i) an antenna port field and ii) a PTRS-DMRS association field. One or more DMRS ports are indicated based on the antenna port field.

[0030] Based on the PTRS-DMRS association field, for each of the groups based on scheduled resource blocks (RBs), an association between the one or more DMRS ports and at least one PTRS port is indicated.

[0031] A base station includes one or more transceivers, one or more processors, and one or more memories connected to the one or more processors and storing instructions.

[0032] The above instructions are characterized in that they cause the base station to perform all steps of the method based on being executed by the one or more processors.

[0033] According to the embodiment of the present specification, PTRS-DMRS association is indicated for each group, which can reduce DCI overhead compared to indicating PTRS-DMRS association for each subband to which precoding is applied.

[0034] 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.

[0035] Figure 1 is a diagram showing an example of uplink transmission and reception operation.

[0036] FIG. 2 illustrates an example of an SB group according to one embodiment of the present specification.

[0037] FIG. 3 illustrates another example of an SB group according to one embodiment of the present specification.

[0038] FIG. 4 illustrates another example of an SB group according to one embodiment of the present specification.

[0039] FIG. 5 is a flowchart illustrating a method according to one embodiment of the present specification.

[0040] FIG. 6 is a flowchart illustrating a method according to another embodiment of the present specification.

[0041] FIG. 7 is a drawing showing the configuration of a first device and a second device according to an embodiment of the present specification.

[0042] 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, one of ordinary skill in the art will appreciate that the present invention may be practiced without these specific details.

[0043] 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.

[0044] 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.

[0045] DMRS (demodulation reference signal)

[0046] DMRS reception procedure

[0047] Let's look at DMRS-related operations for PDSCH reception.

[0048] 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.

[0049] 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.

[0050] 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,

[0051] - The terminal can be set to the upper layer parameter dmrs-Type, and the set DM-RS configuration type is used to receive PDSCH.

[0052] - 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.

[0053] The number of DM-RS ports can be scheduled by the antenna port index of DCI format 1_1.

[0054] 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.

[0055] Table 1 below shows an example of a DMRS-DownlinkConfig IE used to configure downlink DMRS for PDSCH.

[0056]

[0057] 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.

[0058] For DM-RS setup type 1,

[0059] - 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,

[0060] The terminal can assume that none of the remaining orthogonal antenna ports are associated with transmission of PDSCH to other terminals.

[0061] For DM-RS setup type 2,

[0062] - 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,

[0063] The terminal can assume that none of the remaining orthogonal antenna ports are associated with transmission of PDSCH to other terminals.

[0064] An example of the DL DMRS procedure is described below.

[0065] The base station transmits DMRS configuration information to the terminal.

[0066] 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.

[0067] 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.

[0068] 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).

[0069] 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.

[0070] The above base station generates a sequence used for DMRS.

[0071] The sequence for the above DMRS is generated according to the mathematical expression 1 below.

[0072]

[0073] 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.

[0074]

[0075] Here, is the number of OFDM symbols in the slot, is the slot number within the frame.

[0076] 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.

[0077] - 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.

[0078] - , 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.

[0079] 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.

[0080] The base station transmits the DMRS to the terminal on the resource element. The terminal receives the PDSCH using the received DMRS.

[0081] UE DMRS transmission procedure

[0082] 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.

[0083] 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.

[0084] 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).

[0085] Table 2 below shows an example of a DMRS-UplinkConfig IE used to configure uplink DMRS for PUSCH.

[0086]

[0087] 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.

[0088] 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).

[0089] Below, we will look at the UE DM-RS transmission procedure in more detail.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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,

[0095] - 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.

[0096] - The terminal can set the maximum number of front-loaded DM-RS symbols for PUSCH by the upper layer parameter maxLength in DMRS-UplinkConfig.

[0097] 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.

[0098] - 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.

[0099] 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.

[0100] PTRS (Phase Tracking Reference Signal)

[0101] 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.

[0102] Below, the operations related to DL PTRS and UL PTRS are described in detail.

[0103] DL PTRS related actions

[0104] Below, an example of the DL PTRS procedure is described in detail.

[0105] 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.

[0106] 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.

[0107] 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.

[0108]

[0109] Here, is located and subcarriers is the DMRS given in .

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] The base station transmits the PTRS to the terminal on the above resource element.

[0116] UL PTRS related actions

[0117] 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.

[0118] Downlink transmission and reception operations

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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'.

[0124] 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.

[0125] Uplink transmission and reception operation

[0126] Figure 1 is a diagram showing an example of uplink transmission and reception operation.

[0127] 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.

[0128] 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}.

[0129] 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.

[0130] 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).

[0131] 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).

[0132] Multi-TRP (Transmission / Reception Point) related operations

[0133] 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.

[0134] 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 resource 1 and resource 2, high reliability can be achieved. This DL MTRP URLLC can be applied to PDSCH / PDCCH.

[0135] 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 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.

[0136] SDCI or MDCI based MTRP transmission

[0137] 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.

[0138] R16 NR MTRP Transmission

[0139] The R16 NR standard supports S-DCI based MTRP PDSCH and M-DCI based MTRP PDSCH transmission methods.

[0140] R16 M-DCI based MTRP PDSCH

[0141] 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.

[0142] 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.

[0143] R17 NR MTRP Transmission

[0144] 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.

[0145] R17 MTRP SFN PDCCH

[0146] 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.

[0147] R17 MTRP SFN PDSCH

[0148] 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.

[0149] 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.

[0150] 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.

[0151] R17 SDCI based multi-TB PUSCH / PDSCH scheduling

[0152] 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.

[0153] Description of STxMP (Simultaneous Transmission across Multi-panels)

[0154] 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 future, advanced UEs may relax this restriction and transmit multiple channels or RSs 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.

[0155] 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.

[0156] Two methods are being considered for the R18 STxMP transmission technique: SFN and SDM.

[0157] 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).

[0158] 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.

[0159] 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.

[0160] Description of the Unified TCI framework

[0161] 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.

[0162] AIML related explanation

[0163] 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.).

[0164] 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.

[0165] 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.

[0166] In this specification, 'DMRS (or PTRS)' may mean 'DM-RS (or PT-RS)' and vice versa.

[0167] 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).

[0168] 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).

[0169] 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.

[0170] 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.

[0171] Proposal 1

[0172] The task to be solved

[0173] If PTRS-DMRS association is indicated for each SB, a problem occurs in which DCI overhead increases excessively.

[0174] For example, to indicate a PTRS-DMRS association for each SB, the DCI may need to include as many PTRS-DMRS association fields as the number of SBs. For example, to indicate a PTRS-DMRS association for each SB, the DCI may need to include a field whose size indicates the PTRS-DMRS association for all SBs.

[0175] That is, when PTRS-DMRS association is indicated for each subband as precoding is supported for each subband, the number of PTRS-DMRS association fields or the field size of DCI may increase excessively. Methods for resolving the above-described problems will be examined in detail below.

[0176] Method 1-1

[0177] To reduce DCI overhead, a method of grouping SBs and indicating PTRS-DMRS association for each group may be considered.

[0178] Figures 2 through 5 below illustrate SB groups configured based on 20 RBs. The following description assumes 20 scheduled RBs. This assumption is for convenience of explanation and does not limit the number of RBs to which the embodiments of this specification are applied to to 20. The embodiments of this specification can also be applied to RBs scheduled with various numbers.

[0179] FIG. 2 illustrates an example of an SB group according to one embodiment of the present specification.

[0180] Referring to FIG. 2, all scheduled RBs can be configured into SB groups. Specifically, five SB groups (SB group 1 to SB group 5) can be configured / determined based on the 20 scheduled RBs. PTRS-DMRS association can be directed based on the five SB groups. The SB group configuration / determination method is described in more detail below.

[0181] Referring to Figure 2, there are a total of 10 SBs, each consisting of two adjacent RBs. SB grouping based on a specific unit can be performed for the 10 SBs (SB#0 to SB#9). For example, the specific unit can be defined as two SBs.

[0182] In one embodiment, a PTRS-DMRS association field may be introduced for each SB group (e.g., SB group 1, 2). That is, the DCI may include a total of five PTRS-DMRS association fields.

[0183] According to one embodiment, a field related to all SB groups may be introduced. That is, the DCI may include the field. Based on the field, PTRS-DMRS association information may be indicated for each SB group.

[0184] For example, it can be assumed that RB #0, RB #1, RB #10, and RB #11 are scheduled. The scheduled SBs are SB #0 and SB #5. In this case, the PTRS-DMRS association can be indicated as follows.

[0185] PTRS-DMRS association information may be indicated based on the first and third fields related to SB group 1 and SB group 3 among the five PTRS-DMRS association fields. Zero padding may be applied to the remaining fields (the second field, the third field, and the fifth field). In other words, when interpreting the remaining fields, the UE assumes that zeros are padded. In other words, the UE ignores the remaining fields.

[0186] Meanwhile, as the number of SB groups increases, the number and size of PTRS-DMRS association fields also increase. In this case, the overall DCI payload size dynamically changes, potentially complicating DCI decoding at the terminal. To address this issue, the following embodiments may be considered.

[0187] In one embodiment, the number of SB groups may be fixed to N. Specifically, the base station may set the number of SB groups of the scheduled PUSCH, N, to the terminal based on RRC signaling.

[0188] When the number N of the above SB groups is set, the following operations can be performed in relation to SB grouping. For example, the number of RBs configured / included in the SB can be dynamically changed (e.g., indicating the number of RBs configuring the SB based on DCI). For example, the number of SBs within an SB group can be dynamically changed (e.g., indicating the number of SBs within an SB group based on DCI).

[0189] Based on the above-described embodiment, it can be assumed that the number of SB groups N is set to 2. This will be described in detail below with reference to FIGS. 3 and 4.

[0190] FIG. 3 illustrates another example of an SB group according to one embodiment of the present specification.

[0191] Referring to FIG. 3, two SB groups (SB group 1 to SB group 2) can be configured / determined based on the 20 scheduled RBs. Specifically, four SBs (e.g., SB #0 to SB #3) can be configured / determined based on the 20 RBs. For example, each SB (e.g., SB #0) can be composed of five adjacent RBs (e.g., RB #0 to RB #4).

[0192] SB grouping can be performed in specific units for the above four SBs. For example, the specific unit can be determined based on the number N of SB groups. As a specific example, the specific unit can be determined as a value (2) obtained by dividing the total number of SBs (e.g., 4) by N (e.g., 2).

[0193] Based on the above SB grouping, two SB groups (SB group #1, SB group #2) can be configured / determined.

[0194] FIG. 4 illustrates another example of an SB group according to one embodiment of the present specification.

[0195] Referring to FIG. 4, two SB groups (SB group 1 to SB group 2) can be configured / determined based on the 20 scheduled RBs. Specifically, 10 SBs (e.g., SB #0 to SB #9) can be configured / determined based on the 20 RBs. For example, each SB (e.g., SB #0) can be composed of two adjacent RBs (e.g., RB #0 to RB #1).

[0196] SB grouping can be performed in specific units for the above 10 SBs. For example, the specific unit can be determined based on the number N of SB groups. As a specific example, the specific unit can be determined as a value (5) obtained by dividing the total number of SBs (e.g., 10) by N (e.g., 2).

[0197] Based on the above SB grouping, two SB groups (SB group #1, SB group #2) can be configured / determined.

[0198] The fields of DCI for indicating PTRS-DMRS association for N (e.g. 2) SB groups configured as above may be as follows.

[0199] For example, the DCI may include a total of N (e.g., 2) PTRS-DMRS association fields. For example, the DCI may include fields related to N SB groups. Based on the fields, the PTRS-DMRS association for each SB group may be indicated.

[0200] The total number of SB groups needs to be fixed. The reasons for fixing the total number of SB groups are explained in detail below.

[0201] The bandwidth over which PUSCH is scheduled varies greatly, from narrowband to wideband, and may also vary depending on the amount of UL data the UE wishes to transmit, the UL traffic status of the base station, and the UL channel status. In other words, if the number of SB groups is not fixed, the number of SB groups may also continuously change according to the fluctuations in the bandwidth over which PUSCH is scheduled. If the field for indicating PTRS-DMRS association of each SB group is configured by considering all cases related to the number of SB groups, the implementation complexity of DCI transmission / reception / decoding operations may increase excessively.

[0202] Therefore, the total number of SB groups indicating the number of PTRS-DMRS association fields needs to be fixed. For this purpose, the following embodiments may be considered.

[0203] For example, the number of PTRS-DMRS association fields (i.e., the number of SB groups) may be set by the base station to the terminal or may be specified / defined in advance.

[0204] In one embodiment, a method of jointly encoding PTRS-DMRS association information for each SB group by increasing a single PTRS-DMRS association field to X bits may be considered. An SB PUSCH scheduling mode in which scheduling based on the above-described SBs is enabled may be set. The single PTRS-DMRS association field may be defined / set / configured as follows. The total size of the PTRS-DMRS association field for all SB groups (e.g., X bits) may be defined in advance or set based on RRC signaling.

[0205] Method 1-2

[0206] For SB PUSCH scheduling, the PTRS-DMRS association instruction can be omitted. That is, the first DMRS port of the scheduled PUSCH can be connected to PTRS port 0 regardless of the SB. Since the PTRS DMRS association field is not required for each SB / SB group, DCI overhead can be reduced.

[0207] In a frequency selective channel, even if the first DMRS port is not the best DMRS port (i.e., the DMRS port with the best SINR) in a specific SB, the first DMRS port may be the best DMRS port in other SBs. Considering this characteristic, PTRS port 0 may be associated with the best DMRS port in some SBs (e.g., SB #0), with the second-best DMRS port in another SB (e.g., SB #1), and with the worst DMRS port in yet another SB (e.g., SB #2). As a result, PTRS port 0 may not always be associated with the best DMRS port, but it may be associated with the best DMRS port in some SBs and achieve good performance. Taking this into account, the PTRS-DMRS association can be defined based on the following embodiments.

[0208] In one embodiment, when there are multiple PTRS ports (e.g., PTRS ports 0 to 3), the PTRS ports may be connected to the DMRS ports of the scheduled PUSCH (e.g., 1st DMRS port to 4th DMRS port).

[0209] In one embodiment, a DMRS port connected to a PTRS port may be defined / configured to rotate based on the SB. This may achieve diversity gain.

[0210] As a concrete example, the association between a PTRS port and a DMRS port can be defined as follows. In SB 1, a PTRS port can be associated with the first PUSCH DMRS port. In SB 2, a PTRS port can be associated with the second DMRS port. As described above, the PTRS ports can be defined to be sequentially connected from the first DMRS port to the last DMRS port for each SB. After a PTRS port is connected to the last DMRS port, the PTRS ports can be sequentially connected from the first DMRS port to the last DMRS port for the remaining SBs in the same manner.

[0211] Through the above method, PTRS port 0 can be connected to the best DMRS port in some SBs, the second-best DMRS port in other SBs, and the worst DMRS port in still other SBs. As a result, PTRS port 0 may not always be connected to the best DMRS port, but it can still achieve good performance in some SBs by connecting to the best DMRS port.

[0212] Additionally, it can be assumed that two codewords are scheduled for the terminal and the number of PTRS ports is set to 1. According to the conventional method, a PTRS port can be associated with one of the DMRS ports indicated by the PTRS-DMRS association field for the codeword of the Higher MCS (Modulation and Coding Scheme). Considering the above rules, the PTRS ports for each SB described above can be mapped / connected to the DMRS ports as follows.

[0213] For example, one PTRS port can be mapped / connected only to a DMRS port (e.g., the first DMRS port) of the codeword of the Higher MCS.

[0214] For example, one PTRS port can be mapped / connected to the DMRS port of the corresponding codeword while rotating the codeword.

[0215] As a more specific example, the PTRS port can be mapped by rotating the first DMRS port of each codeword. Specifically, the PTRS port in SB 1 (or SB 3) can be mapped to the first DMRS port of codeword 1, and the PTRS port in SB 2 (or SB 4) can be mapped to the first DMRS port of codeword 2.

[0216] 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. 7 described below.

[0217] 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. 7) in the form of commands / programs (e.g., instructions, executable codes) for driving at least one processor (e.g., 110, 210 of FIG. 7).

[0218] The embodiments described below are specifically described with reference to FIGS. 5 and 6 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.

[0219] FIG. 5 is a flowchart illustrating a method according to one embodiment of the present specification.

[0220] Referring to FIG. 5, a method according to one embodiment of the present specification includes a DCI receiving step (S510), a DMRS transmitting step (S520), and a PTRS transmitting step (S530).

[0221] In S510, the terminal receives downlink control information (DCI) for scheduling a physical uplink shared channel (PUSCH) from the base station.

[0222] In S520, the terminal transmits a demodulation reference signal (DMRS) related to the PUSCH to the base station.

[0223] In S530, the terminal transmits a phase tracking reference signal (PTRS) related to the PUSCH to the base station.

[0224] For example, the DCI may include i) an antenna port field and ii) a PTRS-DMRS association field. One or more DMRS ports may be indicated based on the antenna port field.

[0225] A PTRS-DMRS association may be indicated for a portion of scheduled resource blocks (e.g., a subband composed of one or more RBs) based on at least one of the above-described methods 1-1 and / or 1-2. Specifically, for each of the groups based on scheduled resource blocks (RBs), an association between the one or more DMRS ports and at least one PTRS port may be i) indicated (e.g., method 1-2) or ii) defined (e.g., method 1-2) based on the PTRS-DMRS association field. This will be described in detail below.

[0226] In one embodiment, based on the PTRS-DMRS association field, an association between one or more DMRS ports and at least one PTRS port may be indicated for each of groups based on scheduled resource blocks (RBs). This embodiment may be based on method 1-1.

[0227] In one embodiment, the PTRS-DMRS association field may be based on a plurality of fields. The association for each of the groups may be indicated based on the plurality of fields. The present embodiment may be based on method 1-1. That is, the plurality of fields may mean PTRS-DMRS association fields based on the number of SB groups described above. The groups may mean the SB groups described above.

[0228] For example, the number of the plurality of fields may be based on the number of groups (e.g., N) set based on upper layer signaling.

[0229] For example, the groups may be determined based on i) the scheduled RBs and ii) the number of groups.

[0230] In one embodiment, each group may include RB groups. Each RB group may include one or more RBs. This embodiment may be based on Method 1-1.

[0231] In this specification, 'group' may mean the 'SB group' described above, and 'RB group' may mean the 'SB' described above.

[0232] For example, the RB groups may be contiguous in the frequency domain. This embodiment takes into account that adjacent RBs have similar channel conditions. That is, by indicating PTRS-DMRS associations for contiguous RBs in the frequency domain based on a single field or a limited number of bits, DCI overhead can be reduced.

[0233] For example, the RB groups may be associated with the same precoder. RB groups based on the same precoder may have a common PTRS-DMRS association. Therefore, the DCI overhead can be reduced by indicating the PTRS-DMRS association for RBs based on the same precoder based on a single field (e.g., one of the multiple fields described above) or a limited number of bits (e.g., X bits, a field in which PTRS-DMRS association information for each group is jointly encoded).

[0234] For example, the above groups may be associated with different precoders. As a specific example, referring to Figure 2, assume that two precoders are associated with five groups (e.g., SB group 1 to SB group 5). The first, third, and fifth groups may be associated with the first precoder, and the second and fourth groups may be associated with the second precoder.

[0235] In one embodiment, information indicating the association for each of the groups may be jointly encoded in the PTRS-DMRS association field. This embodiment may be based on method 1-1. The payload size (e.g., X bits) of the PTRS-DMRS association field may be predefined or set based on RRC signaling.

[0236] In one embodiment, based on: i) the PUSCH is associated with two codewords, and ii) the maximum number of the at least one PTRS port is set to 1 (e.g., the higher layer parameter maxNrofPorts is set to n1): the association may be defined based on i) one PTRS port and ii) a DMRS port associated with a codeword having a higher Modulation and Coding Scheme (MCS) among the two codewords. The present embodiment may be based on Method 1-2. The one PTRS port may be associated with a first DMRS port among the DMRS ports associated with the codeword having the higher MCS.

[0237] The operations based on S510 to S530 described above can be implemented by the device of FIG. 7. 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 S510 to S530.

[0238] The embodiments described below are specifically described in terms of base station operation.

[0239] S610 to S630 described below correspond to S510 to S530 described in FIG. 5. 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. 5 corresponding to the operation. For example, the description / embodiment of S510 to S530 of FIG. 5 may be additionally applied to the base station operation of S610 to S630 described below.

[0240] FIG. 6 is a flowchart illustrating a method according to another embodiment of the present specification.

[0241] Referring to FIG. 6, a method according to another embodiment of the present specification includes a DCI transmission step (S610), a DMRS reception step (S620), and a PTRS reception step (S630).

[0242] In S610, the base station transmits downlink control information (DCI) for scheduling a physical uplink shared channel (PUSCH) to the terminal.

[0243] In S620, the base station receives a demodulation reference signal (DMRS) related to the PUSCH from the terminal.

[0244] In S630, the base station receives a phase tracking reference signal (PTRS) related to the PUSCH from the terminal.

[0245] The operations based on S610 to S630 described above can be implemented by the device of FIG. 7. 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 S610 to S630.

[0246] 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).

[0247] 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. 7.

[0248] FIG. 7 is a drawing showing the configuration of a first device and a second device according to an embodiment of the present specification.

[0249] The first device (100) may include a processor (110), an antenna unit (120), a transceiver (130), and a memory (140).

[0250] 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).

[0251] 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.

[0252] 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.

[0253] The second device (200) may include a processor (210), an antenna unit (220), a transceiver (230), and a memory (240).

[0254] 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).

[0255] 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.

[0256] 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.

[0257] 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.

[0258] 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.

[0259] 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.

[0260] 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); A step of transmitting a demodulation reference signal (DMRS) related to the PUSCH; and A step of transmitting a phase tracking reference signal (PTRS) related to the PUSCH; including: The above DCI includes i) an antenna port field and ii) a PTRS-DMRS association field, One or more DMRS ports are indicated based on the above antenna port field, A method characterized in that, based on the PTRS-DMRS association field, an association between one or more DMRS ports and at least one PTRS port is indicated for each of the groups based on scheduled resource blocks (RBs).

2. In paragraph 1, The above PTRS-DMRS association field is based on multiple fields, A method characterized in that the association for each of the groups is indicated based on the plurality of fields.

3. In paragraph 2, A method characterized in that the number of the plurality of fields is based on the number of groups set based on upper layer signaling.

4. In paragraph 3, A method characterized in that the above groups are determined based on i) the scheduled RBs and ii) the number of groups.

5. In paragraph 1, A method characterized in that each group includes RB groups, and each RB group includes one or more RBs.

6. In paragraph 5, A method characterized in that the above RB groups are continuous in the frequency domain.

7. In paragraph 5, A method characterized in that the above RB groups are associated with the same precoder.

8. In paragraph 7, A method characterized in that the above groups are associated with different precoders.

9. In paragraph 1, A method characterized in that information indicating the association for each of the groups is jointly encoded in the PTRS-DMRS association field.

10. In paragraph 1, A method characterized in that the above association is i) indicated based on the PTRS-DMRS association field, or ii) defined.

11. In paragraph 10, i) the PUSCH is associated with two codewords, and ii) the maximum number of at least one PTRS port is set to 1: A method characterized in that the above association is defined based on i) one PTRS port and ii) a DMRS port associated with a codeword having a higher Modulation and Coding Scheme (MCS) among the two codewords.

12. In paragraph 11, A method characterized in that said one PTRS port is associated with a first DMRS port among the DMRS ports associated with said codeword having said high MCS.

13. At 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, based on being executed by the one or more processors, cause the terminal to perform all steps of the method according to any one of claims 1 to 12.

14. 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 device to perform all steps of a method according to any one of claims 1 to 12, based on being executed by said one or more processors.

15. In a non-transitory computer-readable medium storing instructions, A non-transitory computer-readable medium characterized in that the instructions, based on being executed by one or more processors, cause a terminal to perform all steps of a method according to any one of claims 1 to 12.

16. In the method, A step of transmitting downlink control information (DCI) for scheduling a physical uplink shared channel (PUSCH); A step of receiving a demodulation reference signal (DMRS) related to the PUSCH; and A step of receiving a phase tracking reference signal (PTRS) related to the PUSCH; including: The above DCI includes i) an antenna port field and ii) a PTRS-DMRS association field, One or more DMRS ports are indicated based on the above antenna port field, A method characterized in that, based on the PTRS-DMRS association field, an association between one or more DMRS ports and at least one PTRS port is indicated for each of the groups based on scheduled resource blocks (RBs).

17. 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, based on being executed by the one or more processors, cause the base station to perform all steps of the method according to claim 16.

Images