Method and apparatus for transmitting and receiving ptrs

Abstract

A method according to one embodiment of the present specification comprises the steps of: transmitting performance information; receiving configuration information related to a DMRS; receiving DCI for scheduling of a PDSCH; receiving the DMRS for the PDSCH; and receiving a PTRS on the basis of PRBs for the PDSCH. The performance information further includes information indicating whether reception of the PTRS is supported in at least one RE in the PRBs related to the PDSCH, without scheduling restriction.

Description

Method and device for transmitting and receiving PTRS

[0001] The present specification relates to a method and device for transmitting and receiving PTRS in a wireless communication system.

[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] Meanwhile, with the Rel-18 enhancement, the FDD OCC length has doubled compared to the previous one. Specifically, the FD OCC length for enhanced DMRS type 1 is 4.

[0005] In order to apply the FD OCC of the enhanced DMRS type 1 described above, scheduling must be performed in units of four REs. However, if the number of consecutively scheduled Physical Resource Blocks (PRBs) for the PDSCH is odd or the PRB offset from CRB 0 (common resource block 0) is odd, there may be cases where only two REs remain in the first PRB and / or the last PRB. Such REs to which the FD OCC of the enhanced DMRS type 1 cannot be applied are called orphan REs.

[0006] Scheduling restrictions (the number of PRBs and the PRB offset are even) are defined to prevent the above-described orphan RE from occurring. A terminal supporting orphan RE can report as a capability that PDSCH reception without the above-described scheduling restriction is supported.

[0007] For a terminal that reports support for PDSCH reception without the aforementioned scheduling restrictions, the base station schedules the PDSCH without the scheduling restrictions. At this time, a Phase Tracking Reference Signal (PTRS) is mapped and transmitted within the PRBs scheduled for the PDSCH. Since the base station cannot determine whether the terminal can process PTRS in an orphan RE, the following problems may arise.

[0008] While PTRS is transmitted on orphan REs, DMRS can be transmitted on the remaining REs excluding the orphan REs. In this case, the subcarrier locations where phase noise is measured via PTRS differ from those where phase noise is measured via DMRS, which may degrade phase noise estimation performance.

[0009] The purpose of this specification is to propose a method to solve the above-mentioned problems.

[0010] 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 this specification pertains from the description below.

[0011] A method performed by a terminal according to one embodiment of the present disclosure includes the steps of transmitting capability information to a base station, receiving configuration information related to a demodulation reference signal (DMRS) from the base station, receiving downlink control information (DCI) for scheduling a physical downlink shared channel (PDSCH) from the base station, receiving the DMRS for the PDSCH from the base station, and receiving a phase tracking reference signal (PTRS) based on physical resource blocks (PRBs) for the PDSCH from the base station.

[0012] DMRS configuration based on the above configuration information is based on enhanced DMRS type 1.

[0013] The above performance information includes information indicating whether reception of the PDSCH without scheduling restriction for the enhanced DMRS type 1 is supported.

[0014] Based on the support of the reception of the PDSCH without the scheduling restriction, the performance information is characterized in that it further includes information indicating whether reception of the PTRS is supported in at least one resource element (RE) within the PRBs related to the PDSCH without the scheduling restriction.

[0015] The above PRBs may be consecutively scheduled PRBs.

[0016] Based on the fact that the reception of the PDSCH without the above scheduling restriction is not supported: the number of the PRBs may be even,

[0017] The PRB offset associated with the PDSCH from common resource block 0 may be an even number.

[0018] The at least one RE may include i) the first two REs of a first PRB among the PRBs and / or ii) the last two REs of a last PRB among the PRBs.

[0019] The length of the Frequency Domain-Orthogonal Cover Code (FD-OCC) associated with the above enhanced DMRS type 1 may be 4.

[0020] The FD-OCC applied to one of the ports associated with the enhanced DMRS Type 1 may be i) [+1 +1 +1 +1], ii) [+1 -1 +1 -1], iii) [+1 +1 -1 -1] or iv) [+1 -1 -1 +1].

[0021] For the above enhanced DMRS Type 1, there can be six subcarrier indices associated with ports belonging to the same CDM (Code Division Multiplexing) group within one PRB.

[0022] Based on the above ports being ports 0, 1, 8 and 9 belonging to CDM group 0, the subcarrier indices can be 0, 2, 4, 6, 8 and 10.

[0023] The at least one RE may include i) REs based on subcarrier indices 0 and 2 and / or ii) REs based on subcarrier indices 8 and 10.

[0024] A PRB can be defined as 12 consecutive subcarriers.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] In another embodiment of the present disclosure, one or more non-transitory computer-readable media store instructions, the instructions being executable by one or more processors, characterized in that they cause the one or more processors to perform all steps of any one of the methods.

[0030] A method performed by a base station according to another embodiment of the present specification includes the steps of receiving capability information from a terminal, transmitting configuration information related to a demodulation reference signal (DMRS) to the terminal, transmitting downlink control information (DCI) for scheduling a physical downlink shared channel (PDSCH) to the terminal, transmitting the DMRS for the PDSCH to the terminal, and transmitting a phase tracking reference signal (PTRS) based on physical resource blocks (PRBs) for the PDSCH to the terminal.

[0031] DMRS configuration based on the above configuration information is based on enhanced DMRS type 1.

[0032] The above performance information includes information indicating whether reception of the PDSCH without scheduling restriction for the enhanced DMRS type 1 is supported.

[0033] Based on the reception of the PDSCH without scheduling restrictions being supported by the terminal, the performance information is characterized in that it further includes information indicating whether reception of the PTRS is supported in at least one resource element (RE) within the PRBs associated with the PDSCH without scheduling restrictions.

[0034] According to another embodiment of the present disclosure, a base station includes one or more transceivers, one or more processors, and one or more memories coupled to the one or more processors and storing instructions.

[0035] 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.

[0036] According to an embodiment of the present specification, PTRS is transmitted in REs that take into account the performance of a terminal supporting an orphan RE. This can prevent degradation of phase noise estimation performance related to enhanced DMRS type 1 and maximize frequency resource utilization. For example, if a terminal does not support channel / phase noise estimation in an orphan RE, PTRS is transmitted in REs other than the orphan RE, thereby preventing degradation of phase noise estimation performance. For example, if a terminal supports channel / phase noise estimation in an orphan RE, the orphan RE can be utilized for PTRS transmission, thereby improving frequency resource utilization.

[0037] 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 a person having ordinary skill in the technical field to which this specification belongs from the description below.

[0038] Figure 1 is a flowchart showing an example of a DL DMRS procedure.

[0039] Figure 2 shows an example of downlink transmission and reception operations.

[0040] Figure 3 is a diagram showing an example of a location where an orphan RE occurs.

[0041] Figure 4 is a diagram showing an example of a location where an orphan RE occurs in terminal-specific scheduling.

[0042] Figure 5 is a drawing showing an example of a location where an orphan RE occurs in MTRP FDM operation.

[0043] Figure 6 is a drawing showing another example of a location where an orphan RE occurs in MTRP FDM operation.

[0044] FIG. 7 is a flowchart illustrating a method performed by a terminal according to one embodiment of the present specification.

[0045] FIG. 8 is a flowchart illustrating a method performed by a base station according to another embodiment of the present specification.

[0046] FIG. 9 is a drawing showing the configuration of a first device and a second device according to an embodiment of the present specification.

[0047] Hereinafter, preferred embodiments according to the present disclosure 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 explain exemplary embodiments of the present disclosure and is not intended to represent the only embodiments in which the present disclosure may be practiced. The following detailed description includes specific details to provide a thorough understanding of the present disclosure. However, one of ordinary skill in the art will appreciate that the present disclosure may be practiced without these specific details.

[0048] In some cases, to avoid ambiguity in the concepts of this specification, well-known structures and devices may be omitted or illustrated in block diagram form focusing on the core functions of each structure and device.

[0049] 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.

[0050] DMRS (demodulation reference signal)

[0051] DMRS reception procedure

[0052] Let's look at DMRS-related operations for PDSCH reception.

[0053] 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.

[0054] 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.

[0055] 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,

[0056] - The terminal can be set to the upper layer parameter dmrs-Type, and the set DM-RS configuration type is used to receive PDSCH.

[0057] - 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.

[0058] The number of DM-RS ports can be scheduled by the antenna port index of DCI format 1_1.

[0059] 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.

[0060] Table 1 below shows an example of a DMRS-DownlinkConfig IE used to configure downlink DMRS for PDSCH.

[0061]

[0062] 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.

[0063] The dmrs-TypeEnh parameter enables the use of enhanced DMRS type 1 or enhanced DMRS type 2. If the dmrs-TypeEnh parameter is set and dmrs-Type is not set, the UE uses enhanced DMRS type 1 (DMRS eType 1). If the dmrs-TypeEnh parameter and dmrs-Type are set, the UE uses enhanced DMRS type 2 (DMRS eType 2).

[0064] For DM-RS setup type 1,

[0065] - 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,

[0066] The terminal can assume that none of the remaining orthogonal antenna ports are associated with transmission of PDSCH to other terminals.

[0067] For DM-RS setup type 2,

[0068] - 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,

[0069] The terminal can assume that none of the remaining orthogonal antenna ports are associated with transmission of PDSCH to other terminals.

[0070] Figure 1 is a flowchart showing an example of a DL DMRS procedure.

[0071] The base station transmits DMRS configuration information to the terminal (S110).

[0072] 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.

[0073] 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.

[0074] 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).

[0075] 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.

[0076] The above base station generates a sequence used for DMRS (S120).

[0077] The sequence for the above DMRS is generated according to the mathematical expression 1 below.

[0078]

[0079] 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.

[0080]

[0081] Here, is the number of OFDM symbols in the slot, is the slot number within the frame.

[0082] 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.

[0083] - 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.

[0084] - , 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.

[0085] The base station maps the generated sequence to a resource element (S130). Here, the resource element may mean at least one of time, frequency, antenna port, or code.

[0086] The base station transmits the DMRS to the terminal on the resource element (S140). The terminal receives the PDSCH using the received DMRS.

[0087] UE DMRS transmission procedure

[0088] 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.

[0089] 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.

[0090] 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).

[0091] Table 2 below shows an example of a DMRS-UplinkConfig IE used to configure uplink DMRS for PUSCH.

[0092]

[0093] 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.

[0094] 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).

[0095] Below, we will look at the UE DM-RS transmission procedure in more detail.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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 the configuration type provided by the upper 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 considering whether frequency hopping is enabled.

[0100] 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,

[0101] - 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.

[0102] - The terminal can set the maximum number of front-loaded DM-RS symbols for PUSCH by the upper layer parameter maxLength in DMRS-UplinkConfig.

[0103] 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.

[0104] - 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.

[0105] 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.

[0106] PTRS (Phase Tracking Reference Signal)

[0107] 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.

[0108] Below, the DL PTRS related operations are described in detail.

[0109] DL PTRS related actions

[0110] 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.

[0111] 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.

[0112] 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.

[0113]

[0114] Here, is located and subcarriers is the DMRS given in .

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] The base station transmits the PTRS to the terminal on the above resource element.

[0121] Below, we will examine the downlink transmission and reception operations and the uplink transmission and reception operations in turn.

[0122] Downlink transmission and reception operations

[0123] Figure 2 shows an example of downlink transmission and reception operations.

[0124] The base station can schedule downlink transmissions, such as frequency / time resources, transport layers, downlink precoders, and MCS (S210). For example, the base station can determine a beam for transmitting PDSCH to a terminal.

[0125] The terminal can receive downlink control information (DCI: Downlink Control Information) for downlink scheduling (i.e., including scheduling information of PDSCH) from the base station on the PDCCH (S220).

[0126] For downlink scheduling, DCI format 1_0 or DCI format 1_1 may be used, and DCI format 1_1 may include information such as the following example. For example, DCI format 1_1 may include at least one of an identifier for DCI formats, a bandwidth part indicator, a frequency domain resource assignment, a time domain resource assignment, a PRB bundling size indicator, a rate matching indicator, a ZP CSI-RS trigger, an antenna port(s), a transmission configuration indication (TCI), an SRS request, and a demodulation reference signal (DMRS) sequence initialization.

[0127] In particular, depending on each state indicated in the Antenna port(s) field, a number of DMRS ports can be scheduled, and also single-user (SU) / multi-user (MU) transmission scheduling is possible.

[0128] Additionally, the TCI field consists of 3 bits, and QCL for DMRS can be dynamically indicated by indicating up to 8 TCI states depending on the TCI field value.

[0129] The terminal can receive downlink data from the base station on the PDSCH (S230).

[0130] When a terminal detects a PDCCH including DCI format 1_0 or 1_1, the terminal can decode the PDSCH according to an instruction by the corresponding DCI. Here, when the terminal receives a PDSCH scheduled by DCI format 1, the terminal can set a DMRS configuration type by a higher layer parameter 'dmrs-Type', and the DMRS type is used to receive the PDSCH. In addition, the terminal can set a maximum number of DMRS symbols to be front-loaded for the PDSCH by a higher layer parameter 'maxLength'.

[0131] 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.

[0132] When a UE receives a PDSCH, a precoding granularity P' can be assumed to be a consecutive resource block in the frequency domain. Here, P' can correspond to one of the values ​​{2, 4, wideband}. If P' is determined to be wideband, the UE does not expect to be scheduled with non-contiguous PRBs and can assume that the same precoding is applied to the allocated resources. On the other hand, if P' is determined to be any one of {2, 4}, the precoding resource block group (PRG) is divided into P' consecutive PRBs. The actual number of consecutive PRBs in each PRG can be one or more. The UE can assume that the same precoding is applied to the consecutive downlink PRBs in the PRG.

[0133] In order for the terminal to determine the modulation order, target code rate, and transport block size within the PDSCH, the terminal can first read the 5-bit MCD field within the DCI and determine the modulation order and target code rate. Then, the terminal can read the redundancy version field within the DCI and determine the redundancy version. Then, the terminal can determine the transport block size using the number of layers and the total number of allocated PRBs before rate matching.

[0134] Uplink transmission and reception operation

[0135] The base station schedules uplink transmissions, including frequency / time resources, transport layers, uplink precoders, and MCS. In particular, the base station can determine the beam for PUSCH transmission by the terminal through beam management operations. Furthermore, the terminal receives DCI for uplink scheduling (i.e., including PUSCH scheduling information) from the base station on the PDCCH. 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.

[0136] 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}.

[0137] The terminal then transmits uplink data to the base station on the PUSCH. When the terminal detects a PDCCH containing DCI format 0_0 or 0_1, it transmits the PUSCH according to the instructions of the DCI. Two transmission methods are supported for PUSCH transmission: codebook-based transmission and non-codebook-based transmission.

[0138] 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).

[0139] 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).

[0140] <R16 NR MTRP 전송 관련 설명>

[0141] - R16 S-DCI based MTRP PDSCH

[0142] One of SDM / FDM / TDM methods can be used for S-DCI based MTRP PDSCH transmission.

[0143] In SDM, a single TB is transmitted in multiple layers, with layers belonging to different DMRS CDM groups transmitted via different Tx beams (i.e., QCL RS or TCI states). This increases the number of layers compared to the existing STRP transmission method, thereby improving transmission capacity. Furthermore, when a single TB is transmitted in multiple layers, some layers are transmitted via TRP 1, and the remaining layers via TRP 2. Therefore, channel reliability can be improved due to diversity gain.

[0144] For FDM, two schemes are supported: scheme 2a and 2b. According to scheme 2a, a single TB is transmitted based on multi-RBs. Different Tx beams (i.e., QCL RS or TCI states) are applied to RBs belonging to different RB groups. According to scheme 2b, the same TB is transmitted based on different RB groups. Different Tx beams (i.e., QCL RS or TCI states) are applied to RBs belonging to different RB groups.

[0145] The previously discussed concepts (DMRS, DL transmission / reception operations, MTRP operations, 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 for convenience of explanation, and it is obvious 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.

[0146] In this specification, 'port' and 'antenna port' may be interpreted interchangeably. For example, DMRS port refers to DMRS antenna port, and vice versa.

[0147] In this specification, 'DMRS' can mean 'DM-RS', and the opposite case can be interpreted equally. In this specification, the DMRS port indicated by the antenna port field of the DCI for scheduling the PDSCH can be interpreted / replaced as port, antenna port, or DMRS antenna port. For example, 'port' can be interpreted / replaced as DMRS port, antenna port, or DMRS antenna port.

[0148] In this specification, 'RB' can be interpreted / replaced with 'PRB' and vice versa. For example, two RBs can be interpreted / replaced with two PRBs. For example, one RB (one PRB) can be defined as 12 consecutive subcarriers.

[0149] <Proposal>

[0150] Below we will look specifically at how to set up PTRS when an orphan RE occurs in Release 18.

[0151] The proposed method described below is based on the UE PTRS transmission procedure (UL PTRS). However, this is for convenience of explanation, and it is self-evident that the embodiments described below can be applied in the same manner to the PTRS reception procedure (DL PTRS).

[0152] In Release 18, FD-OCC (Frequency Domain-Orthogonal Cover Code) with a length twice that of the existing one is supported to double the number of DMRS ports. As described above, since the FD-OCC length is increased from 2 to 4, Orphan REs may occur. For example, in Legacy, FD-OCC length=2, and transmission is performed in units of 2 samples (i.e., 2 Resource Elements, RE, units). In R18, FD-OCC length=4, and transmission is performed in units of 4 samples (i.e., 4 RE units). In this case, in order to apply the FD-OCC, the number of scheduled RBs must be even. If the number of scheduled RBs is odd (e.g., 1), transmission in units of 4 REs may not occur at the edge of the scheduling bandwidth. This will be described in detail with reference to FIG. 3 below.

[0153] Figure 3 is a diagram showing an example of a location where an orphan RE occurs.

[0154] Referring to FIG. 3, one RB can be allocated / scheduled for ports 0, 1, 8, and 9 belonging to the same CDM (Code Division Multiplexing) group 0. In the case of enhanced DMRS type 1, there are a total of six subcarrier indices (e.g., subcarrier index 0, 2, 4, 6, 8, 10) to which DMRS based on four ports (e.g., ports 0, 1, 8, 9) belonging to the same CDM group (e.g., CDM group 0) within one RB (subcarrier index 0~11) can be mapped. Accordingly, REs based on the remaining two subcarrier indices excluding the four subcarrier indices become orphan REs. This will be described in detail below.

[0155] The number of REs scheduled in a Channel Estimation (CE) Window is a multiple of 4 (4). Referring to (a) of Fig. 3, the FD-OCC may be applied to four REs based on subcarrier indices 4, 6, 8, and 10. Referring to (b) of Fig. 3, the FD-OCC may be applied to four REs based on subcarrier indices 0, 2, 4, and 6. As a specific example, the FD-OCC applied to each port in the four REs is as follows. FD-OCC [+1 +1 +1 +1] may be applied to port 0 (e.g., port 1000). FD-OCC [+1 -1 +1 -1] may be applied to port 1 (e.g., port 1001). For port 8 (e.g. port 1008), FD-OCC [+1 +1 -1 -1] can be applied. For port 9 (e.g. port 1009), FD-OCC [+1 -1 -1 +1] can be applied.

[0156] The number of REs scheduled in the remaining area excluding the channel estimation window in 1 RB (2) is not a multiple of 4. Referring to (a) of Fig. 3, two REs based on subcarrier indices 0 and 2 correspond to orphan REs to which the FD-OCC cannot be applied. Referring to (b) of Fig. 3, two REs based on subcarrier indices 8 and 10 correspond to orphan REs to which the FD-OCC cannot be applied.

[0157] As in the agreement in Table 3 below, among Rel-18 UEs, there may be terminals that support orphan REs and terminals that do not support orphan REs.

[0158] For terminals that do not support orphan REs, the base station can perform scheduling for the terminal to prevent orphan REs from occurring. For example, the base station can schedule PDSCHs for the terminal based on scheduling restrictions.

[0159] For terminals that support orphan REs, the base station can perform scheduling for the terminal without considering the occurrence of orphan REs. For example, the base station can schedule PDSCHs for the terminal without scheduling restrictions.

[0160] For terminals that support legacy operations or R18 UEs that do not support orphan REs, PTRS is not configured in the orphan RE. For terminals that support orphan REs among R18 UEs, PTRS may be configured in the orphan RE.

[0161] The specific method by which a terminal supporting orphan RE among R18 UEs handles orphan RE may vary depending on the implementation method (conclusion in Table 3 below).

[0162]

[0163] The technical problems to be solved in this specification are described in detail below.

[0164] When an orphan RE occurs, the UE's handling of the orphan RE can be implemented in various ways. For example, the UE may be configured not to use the orphan RE for channel estimation. The base station may transmit the associated PTRS to the UE in the subcarrier location of the orphan RE. In this case, the following issues may arise:

[0165] The subcarrier locations for measuring phase noise through the PTRS (e.g., the subcarrier index of the orphan RE) and the subcarrier locations for measuring channel and phase noise through the DMRS (e.g., the subcarrier index of the RE excluding the orphan RE) are different. This causes a problem of deterioration in phase noise estimation performance.

[0166] According to the existing operation (legacy operation), phase noise estimation (e.g., common phase error (CPE) estimation) is performed as follows. At the DMRS symbol location, phase noise estimation is performed via the DMRS. In symbols where the DMRS is not transmitted, phase noise estimation is performed via the PTRS. For the technical reasons mentioned above, the subcarrier location of the PTRS is defined to be the same as the subcarrier location where the associated DMRS port is transmitted.

[0167] The above technical issue can be resolved by having the base station set the PTRS location while avoiding orphaned REs. The following methods can be considered to support this.

[0168] The terminal may not expect PTRS to be transmitted at an orphan RE location. In other words, when the base station configures PTRS RB and RE locations, it does not configure them at an orphan RE location. Here, the orphan RE may be based on at least one of the following: i) to iii).

[0169] i) When the number of consecutively scheduled PRBs is odd, the first two REs of the first PRB (e.g., the first two REs of the first PRB among three PRBs)

[0170] ii) When the number of consecutively scheduled PRBs is odd, the last two 2 REs of the last PRB (e.g., the last two REs of the third PRB out of three PRBs)

[0171] iii) REs to which length 4 FD-OCC is not applied (e.g., REs other than those grouped into 4 RE units in scheduled PRBs)

[0172] The location where the orphan RE occurs is as described above in Fig. 3. The operation according to the present embodiment will be described in detail below with reference to Fig. 3.

[0173] Terminals perform channel estimation on a per-RB basis and may report REs corresponding to orphan REs as unused. Terminals that support orphan REs may not expect PTRS mapping to the orphan RE location.

[0174] Referring to (a) of FIG. 3, the terminal may report two REs based on subcarrier indices 0 and 2 as unused to the base station. The two REs may be orphan REs based on i) described above. In other words, when the number of consecutively scheduled PRBs is odd (1), the first two REs of the first PRB (RB1) may be two REs based on subcarrier indices 0 and 2.

[0175] Referring to (b) of FIG. 3, the terminal may report two REs based on subcarrier indices 8 and 10 as unused to the base station. The two REs may be orphan REs based on ii) described above. In other words, when the number of consecutively scheduled PRBs is odd (1), the last two REs of the last PRB (RB1) may be two REs based on subcarrier indices 8 and 10.

[0176] For a terminal that estimates a channel / phase noise / CPE in an orphan RE, PTRS may be transmitted to the RE location. However, for a terminal that does not estimate a channel / phase noise / CPE in the orphan RE, the base station must prevent PTRS from being transmitted to the location. As described above, whether a terminal can process PTRS transmitted in an orphan RE may vary depending on the implementation of the terminal that handles the orphan RE. Since the terminal implementation related to the orphan RE handling method is not defined / reported as a capability, it may be ambiguous from the base station's perspective whether PTRS should be mapped / transmitted to the orphan RE. In this regard, the following embodiments may be considered. For example, a terminal may report to the base station through a terminal capability whether PTRS reception is supported at an orphan RE location. For example, a terminal may report to the base station an RE location where PTRS mapping is possible and / or an RE location where PTRS mapping is not possible.

[0177] Based on this information, the base station can determine / set the PTRS transmission location (i.e., the RE location to which the PTRS is mapped) for the corresponding terminal.

[0178] From an MU MIMO perspective, not only must the number of consecutive PRBs be even, but the PRB offset must also be even to avoid orphan REs. For example, referring to Table 3, the following two conditions related to scheduling restrictions must be met to avoid orphan REs.

[0179] 1) The number of PRBs scheduled consecutively for PDSCH is even.

[0180] 2) The offset (PRBs) from common resource block 0 (or point A) is even.

[0181] The above offset may mean the number of PRBs from point A (CRB 0) to the scheduled PDSCH.

[0182] For example, if the number of consecutively scheduled PRBs for UE 1 for MU-MIMO is even, the number of consecutively scheduled PRBs for UE 2 is even, and the offset for each UE is even, orphan REs do not occur. However, if the offset is odd, orphan REs do occur. This will be described in detail with reference to FIG. 4 below.

[0183] Figure 4 is a diagram showing an example of a location where an orphan RE occurs in terminal-specific scheduling.

[0184] Referring to FIG. 4, the number of PRBs (RB1 to RB4) consecutively scheduled for terminal 1 is 4, and the number of PRBs (RB2, RB3) consecutively scheduled for terminal 2 is 2. The offset for terminal 1 is 0, and the offset for terminal 2 is 1. Accordingly, orphan REs are generated. Specifically, REs within the box indicated by the dotted line correspond to orphan REs to which MU-MIMO operation cannot be applied.

[0185] i) FD-OCC of length 4 cannot be applied to REs based on subcarrier index 0 and 2 of RB2.

[0186] ii) FD-OCC of length 4 cannot be applied to REs based on subcarrier index 8 and 10 of RB3.

[0187] For example, a terminal may not expect PTRS mapping to an orphan RE.

[0188] For example, a terminal can report to a base station as a terminal capability whether reception of PTRS is supported at an orphan RE location.

[0189] For example, a terminal can report the location of an unused RE (orphan RE location) to a base station.

[0190] For FDM 2a and FDM 2b in MTRP, the following actions can be performed on allocated RBs.

[0191] For example, the granularity associated with PRB bundling (i.e., precoding granularity) may be determined as 2 or 4. In this case, even PRGs (even Precoding Resource Block Groups) may be assigned to TRP 1 (e.g., first TCI state), and odd PRGs (odd PRGs) may be assigned to TRP 2 (e.g., second TCI state).

[0192] For example, the precoding granularity may be determined as wideband. In this case, the first half of the allocated resource blocks (RBs) may be allocated to TRP 1 (e.g., the first TCI state), and the remaining half may be allocated to TRP 2 (e.g., the second TCI state).

[0193] Orphan REs may occur in MTRP FDM for the following reasons:

[0194] For example, the precoding granularity may be set to wideband based on RRC signaling. Furthermore, the total number of allocated RBs for the UE may be 2. In this case, the first RB is allocated to TRP 1 (the first TCI state) and the second RB is allocated to TRP 2 (the second TCI state). Since only one RB is transmitted from each TRP perspective, an orphan RE is generated. This will be described in detail below with reference to FIG. 5.

[0195] Fig. 5 is a diagram illustrating an example of a location where an orphan RE occurs in MTRP FDM operation. Referring to Fig. 5, the last two REs (subcarrier index 8, 10) of the first RB (TRP1) and the first two RBs (subcarrier index 0, 2) of the second RB (TRP2) correspond to orphan REs.

[0196] As another example, the precoding granularity may be set to wideband based on RRC signaling. Furthermore, the total number of allocated RBs for the UE may be 6. In this case, the first three RBs are allocated to TRP 1 (the first TCI state) and the remaining three RBs are allocated to TRP 2 (the second TCI state). An orphan RE occurs at the PRG edge. This will be described below with reference to FIG. 6.

[0197] Figure 6 is a diagram illustrating another example of where orphan REs occur in MTRP FDM operation. Referring to Figure 6, the last two REs (subcarrier indices 8 and 10) of the third RB (TRP 1) and the first two RBs (subcarrier indices 0 and 2) of the fourth RB (TRP2) correspond to orphan REs.

[0198] Even if the precoding granularity is wideband and the number of allocated RBs is even, orphan REs occur if an odd number of RBs are allocated to each TRP (first / second TCI state). The following actions can be considered in this regard.

[0199] For example, a terminal may not expect PTRS mapping to an orphan RE.

[0200] For example, a terminal can report to a base station as a terminal capability whether reception of PTRS is supported at an orphan RE location.

[0201] For example, a terminal can report the location of an unused RE (orphan RE location) to a base station.

[0202] In terms of implementation, the operations of the base station / terminal according to the embodiments described above (e.g., operations related to PTRS) can be processed by the device (e.g., 100, 200) of FIG. 9 described below.

[0203] In addition, the operations of the base station / terminal according to the above-described embodiment (e.g., operations related to PTRS) may be stored in a memory (e.g., 140, 240 of FIG. 9) in the form of a command / program (e.g., instruction, executable code) for driving at least one processor (e.g., 110, 210 of FIG. 9).

[0204] The embodiments described below are specifically described with reference to FIGS. 7 and 8 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.

[0205] FIG. 7 is a flowchart illustrating a method performed by a terminal according to one embodiment of the present specification.

[0206] Referring to FIG. 7, a method performed by a terminal according to one embodiment of the present specification includes a capability information transmission step (S710), a DMRS-related configuration information reception step (S720), a DCI reception step (S730), a DMRS reception step (S740), and a PTRS reception step (S750).

[0207] In S710, the terminal transmits capability information to the base station. The capability information may include information related to a capability based on one of the embodiments described above.

[0208] In S720, the terminal receives configuration information related to a demodulation reference signal (DMRS) from the base station. The configuration information related to the DMRS may be based on DMRS-DownlinkConfig in Table 1.

[0209] The DMRS configuration based on the above configuration information may be based on enhanced DMRS type 1. For the enhanced DMRS Type 1, i) ports 1000 to 1003 and 1008 to 1011 (e.g., single symbol DMRS) or ii) ports 1000 to 1015 (e.g., double symbols DMRS) may be supported. For example, if dmrs-Type(type2) is set by the configuration information and dmrs-TypeEnh(enabled) is set, the DMRS configuration may be based on enhanced DMRS type 2. For example, if dmrs-Type(type2) is not set by the configuration information and dmrs-TypeEnh(enabled) is set, the DMRS configuration may be based on the enhanced DMRS type 1.

[0210] In S730, the terminal receives downlink control information (DCI) for scheduling a physical downlink shared channel (PDSCH) from a base station. The DCI may include an antenna port field.

[0211] The above antenna port field may indicate one of the values ​​defined by the table. Each of the values ​​defined by the table may be associated with at least one port.

[0212] In S740, the terminal receives the DMRS for the PDSCH from the base station.

[0213] In S750, the terminal receives a phase tracking reference signal (PTRS) based on physical resource blocks (PRBs) for the PDSCH from the base station.

[0214] For example, the performance information may include information indicating whether reception of the PDSCH without scheduling restriction for the enhanced DMRS type 1 is supported.

[0215] In one embodiment, when the terminal supports the reception of the PDSCH without the scheduling restriction, the performance information may further include information according to the above-described embodiment.

[0216] Specifically, based on the support of the reception of the PDSCH without the scheduling restriction, the performance information may further include information indicating whether reception of the PTRS is supported in at least one Resource Element (RE) within the PRBs associated with the PDSCH without the scheduling restriction. Based on the information, REs to which the PTRS is mapped may be determined. For example, based on the support of the reception of the PTRS in the at least one RE, the REs to which the PTRS is mapped may include the at least one RE. For example, based on the not support of the reception of the PTRS in the at least one RE, the at least one RE may be excluded from the REs to which the PTRS is mapped.

[0217] For example, the PRBs may be consecutively scheduled PRBs.

[0218] For example, the PRBs associated with the PDSCH without the scheduling restriction may refer to PRBs where at least one of the two conditions based on the scheduling restriction (e.g., see Table 3) is not satisfied. The case where at least one of the two conditions based on the scheduling restriction is not satisfied may be one of the following examples 1) to 3).

[0219] 1) The number of the above PRBs may be odd.

[0220] 2) The PRB offset related to the PDSCH from the common resource block 0 related to the PRBs may be odd.

[0221] 3) The number of the above PRBs may be odd, and the PRB offset may be odd.

[0222] For example, the at least one RE may include i) the first two REs of a first PRB among the PRBs (e.g., REs based on subcarrier index 0, 2 in FIG. 3) and / or ii) the last two REs of a last PRB among the PRBs (e.g., REs based on subcarrier index 8, 10 in FIG. 3).

[0223] For example, based on the fact that the reception of the PDSCH without the scheduling restriction is not supported: the number of PRBs may be even, and the PRB offset associated with the PDSCH from common resource block 0 may be even.

[0224] The length of the Frequency Domain-Orthogonal Cover Code (FD-OCC) associated with the enhanced DMRS Type 1 may be 4. For example, the FD-OCC applied to one of the ports associated with the enhanced DMRS Type 1 may be i) [+1 +1 +1 +1], ii) [+1 -1 +1 -1], iii) [+1 +1 -1 -1], or iv) [+1 -1 -1 +1].

[0225] For example, for the enhanced DMRS Type 1, there can be 6 subcarrier indices associated with ports belonging to the same CDM (Code Division Multiplexing) group within one PRB. Accordingly, when an odd number of PRBs (and / or an odd number of PRB offsets) are scheduled / configured, REs to which FD-OCC of length 4 cannot be applied (orphan REs) are generated.

[0226] For example, based on the ports being ports 0, 1, 8 and 9 belonging to CDM group 0, the subcarrier indices may be 0, 2, 4, 6, 8 and 10. The at least one RE may include i) REs based on subcarrier indices 0 and 2 and / or ii) REs based on subcarrier indices 8 and 10 (see FIG. 3).

[0227] For example, based on the fact that the ports are ports 2, 3, 10, and 11 belonging to CDM group 1, the subcarrier indices may be 1, 3, 5, 7, 9, and 11. The at least one RE may include i) REs based on subcarrier indices 1 and 3 and / or ii) REs based on subcarrier indices 9 and 11.

[0228] For example, one PRB can be defined as 12 consecutive subcarriers.

[0229] The operations based on S710 to S750 described above can be implemented by the device of FIG. 9. 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 S710 to S750.

[0230] Some steps in the above method may be omitted or added. For example, the method may further include a PDSCH reception step. The terminal may receive the PDSCH from the base station.

[0231] The embodiments described below are specifically described in terms of base station operation.

[0232] S810 to S850 described below correspond to S710 to S750 described in FIG. 7. 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. 7 corresponding to the operation. For example, the description / embodiment of S710 to S750 of FIG. 7 may be additionally applied to the base station operation of S810 to S850 described below.

[0233] FIG. 8 is a flowchart illustrating a method performed by a base station according to another embodiment of the present specification.

[0234] Referring to FIG. 8, a method performed by a base station according to another embodiment of the present specification includes a capability information receiving step (S810), a DMRS-related configuration information transmitting step (S820), a DCI transmitting step (S830), a DMRS transmitting step (S840), and a PTRS transmitting step (S850).

[0235] In step S810, the base station receives capability information from the terminal. The capability information may include information related to a capability based on one of the embodiments described above.

[0236] In S820, the base station transmits configuration information related to the demodulation reference signal (DMRS) to the terminal.

[0237] In S830, the base station transmits downlink control information (DCI) for scheduling a physical downlink shared channel (PDSCH) to the terminal.

[0238] In S840, the base station transmits the DMRS for the PDSCH to the terminal.

[0239] In S850, the base station transmits a phase tracking reference signal (PTRS) to the terminal based on physical resource blocks (PRBs) for the PDSCH.

[0240] For example, the performance information may include information indicating whether reception of the PDSCH without scheduling restriction for the enhanced DMRS type 1 is supported.

[0241] In one embodiment, when the terminal supports the reception of the PDSCH without the scheduling restriction, the performance information may further include information according to the above-described embodiment.

[0242] Specifically, based on the reception of the PDSCH without scheduling restrictions being supported by the terminal, the performance information may further include information indicating whether reception of the PTRS is supported in at least one resource element (RE) within the PRBs associated with the PDSCH without scheduling restrictions.

[0243] The operations based on S810 to S850 described above can be implemented by the device of FIG. 9. 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 S810 to S850.

[0244] Some steps may be omitted or added in the above method. The method may further include a PDSCH transmission step. The base station may transmit the PDSCH to the terminal.

[0245] 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. 9.

[0246] FIG. 9 is a drawing showing the configuration of a first device and a second device according to an embodiment of the present specification.

[0247] The first device (100) may include a processor (110), an antenna unit (120), a transceiver (130), and a memory (140).

[0248] 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).

[0249] 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.

[0250] 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.

[0251] The second device (200) may include a processor (210), an antenna unit (220), a transceiver (230), and a memory (240).

[0252] 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).

[0253] 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.

[0254] 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.

[0255] 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.

[0256] 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.

[0257] 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.

[0258] 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 a method performed by a terminal, A step of transmitting capability information to a base station; A step of receiving configuration information related to a demodulation reference signal (DMRS) from the base station, wherein the DMRS configuration based on the configuration information is based on enhanced DMRS type 1; A step of receiving downlink control information (DCI) for scheduling a physical downlink shared channel (PDSCH) from the base station; A step of receiving the DMRS for the PDSCH from the base station; and A step of receiving a phase tracking reference signal (PTRS) based on physical resource blocks (PRBs) for the PDSCH from the base station; including, The above performance information includes information indicating whether reception of the PDSCH without scheduling restriction for the enhanced DMRS type 1 is supported, A method characterized in that, based on the support of the reception of the PDSCH without the scheduling restriction, the performance information further includes information indicating whether reception of the PTRS is supported in at least one resource element (RE) within the PRBs associated with the PDSCH without the scheduling restriction.

2. In paragraph 1, A method characterized in that the above PRBs are consecutively scheduled PRBs.

3. In paragraph 2, Based on the above reception of the PDSCH without the above scheduling restrictions not being supported: The number of the above PRBs is even, A method characterized in that the PRB offset associated with the PDSCH from common resource block 0 is an even number.

4. In paragraph 2, A method characterized in that said at least one RE comprises i) the first two REs of a first PRB among said PRBs and / or ii) the last two REs of a last PRB among said PRBs.

5. In paragraph 1, A method characterized in that the length of the frequency domain-orthogonal cover code (FD-OCC) related to the enhanced DMRS type 1 is 4.

6. In paragraph 5, A method characterized in that the FD-OCC applied to one of the ports associated with the enhanced DMRS Type 1 is i) [+1 +1 +1 +1], ii) [+1 -1 +1 -1], iii) [+1 +1 -1 -1] or iv) [+1 -1 -1 +1].

7. In paragraph 1, A method characterized in that, for the above enhanced DMRS Type 1, there are six subcarrier indices associated with ports belonging to the same CDM (Code Division Multiplexing) group within one PRB.

8. In paragraph 7, A method characterized in that the subcarrier indices are 0, 2, 4, 6, 8 and 10, based on the fact that the above ports are ports 0, 1, 8 and 9 belonging to CDM group 0.

9. In paragraph 8, A method characterized in that said at least one RE comprises i) REs based on subcarrier indices 0 and 2 and / or ii) REs based on subcarrier indices 8 and 10.

10. In paragraph 1, A method characterized in that one PRB is defined by 12 consecutive subcarriers.

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 being executed 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 a method performed by a base station, A step of receiving capability information from a terminal; A step of transmitting configuration information related to a demodulation reference signal (DMRS) to the terminal, wherein the DMRS configuration based on the configuration information is based on enhanced DMRS type 1; A step of transmitting downlink control information (DCI) for scheduling a physical downlink shared channel (PDSCH) to the terminal; a step of transmitting the DMRS for the PDSCH to the terminal; and A step of transmitting a phase tracking reference signal (PTRS) based on physical resource blocks (PRBs) for the PDSCH to the terminal; including, The above performance information includes information indicating whether reception of the PDSCH without scheduling restriction for the enhanced DMRS type 1 is supported, A method characterized in that, based on the reception of the PDSCH without scheduling restrictions being supported by the terminal, the performance information further includes information indicating whether reception of the PTRS is supported in at least one resource element (RE) within the PRBs associated with the PDSCH without scheduling restrictions.

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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