terminal

Abstract

When the terminal transmits and receives the physical shared channel, in a second state different from the first state, it is assumed that the arrangement density of demodulation reference signals in at least one of the frequency direction and the time direction is increased.

Description

Technical Field

[0001] The present disclosure relates to a terminal for transmitting and receiving a physical shared channel. Background Art

[0002] The 3rd Generation Partnership Project (3GPP) has standardized the fifth-generation mobile communication system (also called 5G, New Radio (NR) or Next Generation (NG)), and has also promoted the standardization of the next generation called Beyond 5G, 5G Evolution or 6G.

[0003] For example, in 3GPP Release-17, it was agreed to conduct research on coverage enhancement (CE) in NR (Non-Patent Document 1).

[0004] Prior art literature

[0005] Non-patent literature

[0006] Non-patent document 1: "New SID on NR coverage enhancement", RP-193240, 3GPP TSGRAN Meeting #86, 3GPP, December 2019 Summary of the invention

[0007] In order to achieve coverage enhancement in NR, the maximum coupling loss (MCL) of physical channels (PDSCH (Physical Downlink Shared Channel), PUSCH (Physical Uplink Shared Channel), PDCCH (Physical Downlink Control Channel) and PUCCH (Physical Uplink Control Channel) was evaluated. The result showed that there is room for improvement at least for PDSCH and PUSCH (physical shared channel).

[0008] Specifically, it may be considered to improve the channel estimation accuracy of the wireless channel when the terminal is located at the end of the cell.

[0009] Therefore, the following disclosure is made in view of the above situation, and its purpose is to provide a terminal that can improve the channel estimation accuracy of the wireless channel at the end of the cell and support coverage enhancement.

[0010] One embodiment of the present disclosure is a terminal (UE 200) comprising: a transceiver unit (wireless signal transceiver unit 210) for transmitting and receiving a physical shared channel; and a control unit (control unit 270) for providing a demodulation reference signal having a configuration density increased in at least one of a frequency direction and a time direction in a second state different from the first state. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a diagram schematically showing the overall structure of the wireless communication system 10 .

[0012] Figure 2 1 is a diagram showing a configuration example of a radio frame, a subframe, and a time slot used in the wireless communication system 10 .

[0013] Figure 3 is a functional block diagram of UE 200.

[0014] Figure 4 It is a diagram showing the MCL evaluation results of the physical channels in FR1.

[0015] Figure 5 It is a diagram showing the MCL evaluation results of the physical channels in FR2.

[0016] Fig. 6A This is a diagram showing a mapping example (part 1) of DMRS specified in 3GPP Release-15.

[0017] Figure 6B This is a diagram showing a mapping example (part 2) of DMRS specified in 3GPP Release-15.

[0018] Figure 6C This is a diagram showing a mapping example (part 3) of DMRS specified in 3GPP Release-15.

[0019] Fig.6D This is a diagram showing a mapping example (part 4) of DMRS specified in 3GPP Release-15.

[0020] Fig. 6E This is a diagram showing a mapping example (part 5) of DMRS specified in 3GPP Release-15.

[0021] Fig. 6F This is a diagram showing a mapping example (part 6) of DMRS specified in 3GPP Release-15.

[0022] Figure 7 is a diagram showing an example of BLER characteristics of a PUSCH.

[0023] Figure 8 This is a diagram showing a structural example of a DMRS configuration Type related to action example 1.

[0024] Fig.9A It is a diagram showing a mapping example (part 1) of DMRS according to DMRS configuration Type=1.

[0025] Fig. 9B This is a diagram showing a mapping example (part 2) of DMRS according to DMRS configuration Type=1.

[0026] Fig. 10A This is a diagram showing a mapping example (part 1) of DMRS according to DMRS configuration Type=2.

[0027] Fig. 10B This is a diagram showing a mapping example (part 2) of DMRS according to DMRS configuration Type=2.

[0028] Fig.11A This is a diagram showing a mapping example (part 1) of DMRS related to Action Example 2.

[0029] Fig. 11B This is a diagram showing a mapping example (part 2) of DMRS related to action example 2.

[0030] Fig. 11C This is a diagram showing a mapping example (part 3) of DMRS related to action example 2.

[0031] Fig.11D This is a diagram showing a mapping example (part 4) of DMRS related to action example 2.

[0032] Fig. 12A This is a diagram showing a mapping example (part 1) of DMRS related to Action Example 3.

[0033] Fig. 12B This is a diagram showing a mapping example (part 2) of DMRS related to action example 3.

[0034] Fig. 12C This is a diagram showing a mapping example (part 3) of DMRS related to action example 3.

[0035] Fig.12D This is a diagram showing a mapping example (part 4) of DMRS related to action example 3.

[0036] Fig.13 This is a diagram showing a structural example of DMRS-DownlinkConfig related to Action Example 4.

[0037] Fig.14 It is a diagram showing the BLER characteristics when the number of symbols to which DMRS is mapped is changed.

[0038] Fig.15 This is a diagram showing an example of the hardware configuration of the UE 200 . DETAILED DESCRIPTION

[0039] Hereinafter, the embodiments will be described based on the drawings. In addition, the same or similar reference numerals are given to the same functions and structures, and the description thereof will be appropriately omitted.

[0040] (1) Overall schematic structure of wireless communication system

[0041] Figure 1 This is a schematic diagram of the overall structure of the wireless communication system 10 involved in this embodiment. The wireless communication system 10 is a wireless communication system that complies with the 5G New Radio (New Radio: NR), including a next-generation radio access network 20 (Next Generation-Radio Access Network 20, hereinafter referred to as NG-RAN 20), and a terminal 200 (User Equipment 200, hereinafter referred to as UE 200).

[0042] In addition, the wireless communication system 10 may be a wireless communication system that complies with a method called Beyond 5G, 5G Evolution, or 6G.

[0043] NG-RAN 20 includes a radio base station 100A (hereinafter referred to as gNB 100A) and a radio base station 100B (hereinafter referred to as gNB 100B). In addition, the specific structure of the wireless communication system 10 including the number of gNBs and UEs is not limited to Figure 1 Example shown.

[0044] The NG-RAN 20 actually includes a plurality of NG-RAN nodes, specifically, gNBs, and is connected to a 5G-compliant core network (5GC, not shown). In addition, the NG-RAN 20 and 5GC may be simply referred to as a "network".

[0045] gNB 100A and gNB 100B are 5G-compliant wireless base stations, and perform 5G-compliant wireless communications with UE 200. gNB 100A, gNB 100B, and UE 200 are capable of supporting Massive MIMO for generating beams with higher directivity by controlling wireless signals transmitted from multiple antenna elements, carrier aggregation (CA) for bundling and using multiple component carriers (CCs), and dual connectivity (DC) for simultaneously communicating between the UE and two NG-RAN nodes.

[0046] The wireless communication system 10 supports FR1 and FR2. The frequency band of each FR is as follows.

[0047] FR1: 410MHz~7.125GHz

[0048] FR2: 24.25 GHz to 52.6 GHz

[0049] In FR1, a sub-carrier spacing (SCS) of 15, 30 or 60 kHz is used, and a bandwidth (BW) of 5 to 100 MHz is used. FR2 may have a higher frequency than FR1, use an SCS of 60 or 120 kHz (including 240 kHz), and use a bandwidth (BW) of 50 to 400 MHz.

[0050] In addition, the wireless communication system 10 may support a frequency band higher than the frequency band of FR2. Specifically, the wireless communication system 10 supports a frequency band exceeding 52.6 GHz and up to 114.25 GHz.

[0051] In addition, cyclic prefix-orthogonal frequency division multiplexing (CP-OFDM) / discrete Fourier transform-spread (DFT-S-OFDM) with a larger sub-carrier spacing (SCS) can be applied. In addition, DFT-S-OFDM can be applied not only to the uplink (UL) but also to the downlink (DL).

[0052] Figure 2 A configuration example of a radio frame, a subframe, and a time slot used in the wireless communication system 10 is shown.

[0053] like Figure 2As shown, one time slot is composed of 14 symbols. The larger (wider) the SCS is, the shorter the symbol period (and the time slot period) is. In addition, the number of symbols constituting one time slot may not necessarily be 14 symbols (for example, 28 or 56 symbols). In addition, the number of time slots per subframe may vary according to the SCS.

[0054] in addition, Figure 2 The time direction (t) shown may be referred to as a time domain, a symbol period, or a symbol time, etc. In addition, the frequency direction may be referred to as a frequency domain, a resource block, a subcarrier, or a BWP (Bandwidth part).

[0055] In addition, the wireless communication system 10 can support coverage enhancement (CE) for expanding the coverage of the cell formed by the gNB 100A (and gNB 100B, the same below). In coverage enhancement, a mechanism for improving the reception success rate of various physical channels can be provided.

[0056] In this embodiment, since coverage enhancement is supported, the wireless communication system 10 can support changes in resource allocation (frequency direction and / or time direction) of a predetermined physical channel, improvements in power density (PSD: Power Spectrum Density), and improvements in channel estimation accuracy.

[0057] (2) Functional block structure of wireless communication system

[0058] Next, a functional block configuration of the wireless communication system 10 will be described. Specifically, a functional block configuration of the UE 200 will be described.

[0059] Figure 3 is a functional block diagram of UE 200. Figure 3 As shown, UE 200 includes a radio signal transceiver 210 , an amplifier 220 , a modulation and demodulation unit 230 , a control signal and reference signal processing unit 240 , an encoding and decoding unit 250 , a data transceiver 260 , and a control unit 270 .

[0060] The wireless signal transceiver 210 transmits and receives wireless signals conforming to NR. The wireless signal transceiver 210 supports Massive MIMO, CA that bundles and uses multiple CCs, and DC that simultaneously communicates between the UE and two NG-RAN Nodes.

[0061] Specifically, the wireless signal transceiver 210 transmits and receives wireless signals via various physical channels. In particular, in this embodiment, the wireless signal transceiver 210 constitutes a transceiver that transmits and receives a physical shared channel.

[0062] Furthermore, the wireless signal transceiver 210 can transmit capability information of the UE 200 related to the transmission and reception of the various physical channels to the network. Specifically, the wireless signal transceiver 210 can transmit capability information of the UE 200 related to the reception of a demodulation reference signal (DMRS) to the network.

[0063] The capability information of the UE 200 may be interpreted as UE capability information specified in 3GPP TS38.331 and the like.

[0064] The wireless signal transceiver 210 can transmit UE capability information via a predetermined uplink physical channel. In addition, the content of UE capability information related to the transmission and reception of the physical channel will be further described later.

[0065] The amplifier unit 220 is composed of a PA (Power Amplifier) / LNA (Low Noise Amplifier) ​​etc. The amplifier unit 220 amplifies the signal output from the modulation and demodulation unit 230 to a predetermined power level. In addition, the amplifier unit 220 amplifies the RF signal output from the wireless signal transmission and reception unit 210 .

[0066] The modem unit 230 performs data modulation / demodulation, transmission power setting, resource block allocation, etc. according to each predetermined communication destination (gNB 100A, etc.). In the modem unit 230, Cyclic Prefix-Orthogonal Frequency Division Multiplexing (CP-OFDM) / Discrete Fourier Transform-Spread (DFT-S-OFDM) can be applied. In addition, DFT-S-OFDM can be applied not only to the uplink (UL) but also to the downlink (DL).

[0067] The control signal / reference signal processing unit 240 performs processing related to various control signals transmitted and received by the UE 200 and processing related to various reference signals transmitted and received by the UE 200 .

[0068] Specifically, the control signal / reference signal processing unit 240 receives various control signals (e.g., control signals of the radio resource control layer (RRC)) transmitted from the gNB 100A (or gNB 100B, the same below) via a predetermined control channel. In addition, the control signal / reference signal processing unit 240 transmits various control signals toward the gNB 100A via a predetermined control channel.

[0069] The control signal / reference signal processing unit 240 performs processing using reference signals (RS) such as a demodulation reference signal (DMRS) and a phase tracking reference signal (PTRS).

[0070] DMRS is a terminal-specific reference signal (pilot signal) known between the base station and the terminal for estimating a fading channel used for data demodulation. PTRS is a terminal-specific reference signal for estimating phase noise, which is a problem in high frequency bands.

[0071] In addition, in addition to DMRS and PTRS, reference signals may also include a channel state information-reference signal (CSI-RS), a sounding reference signal (SRS), and a positioning reference signal (PRS) for position information.

[0072] In addition, the channels include control channels and data channels. The control channels include PDCCH (Physical Downlink Control Channel), PUCCH (Physical Uplink Control Channel), RACH (Random Access Channel, including Downlink Control Information (DCI) of Random Access Radio Network Temporary Identifier (RA-RNT)), and Physical Broadcast Channel (PBCH).

[0073] In addition, the data channel includes PDSCH (Physical Downlink Shared Channel), PUSCH (Physical Uplink Shared Channel), etc. Data refers to data transmitted via the data channel.

[0074] In addition, the physical channel may include at least PDCCH, PUCCH, PUSCH and PDSCH.

[0075] The encoding / decoding unit 250 performs data segmentation / concatenation and channel coding / decoding, etc. according to each predetermined communication destination (gNB 100A, etc.).

[0076] Specifically, the encoding / decoding unit 250 divides the data output from the data transceiver unit 260 into predetermined sizes and performs channel coding on the divided data. In addition, the encoding / decoding unit 250 decodes the data output from the modulation / demodulation unit 230 and concatenates the decoded data.

[0077] The data transceiver 260 performs transmission and reception of protocol data units (PDU) and service data units (SDU). Specifically, the data transceiver 260 performs assembly / disassembly of PDU / SDU in multiple layers (such as the medium access control layer (MAC), the radio link control layer (RLC), and the packet data convergence protocol layer (PDCP)). In addition, the data transceiver 260 performs error correction and retransmission control of data according to hybrid ARQ (Hybrid automatic repeat request).

[0078] The control unit 270 controls each functional block constituting the UE 200. In particular, in the present embodiment, the control unit 270 supports coverage enhancement (CE), and thus can perform various controls related to physical channels.

[0079] Specifically, the control unit 270 can assume that the configuration density of DMRS in at least one of the frequency direction and the time direction is increased in a state (which can be called a second state) supporting coverage enhancement different from the normal state (which can be called a first state).

[0080] More specifically, when supporting a coverage enhancement state, the control unit 270 may assume that the DMRS has an increased symbol duration in the time direction.

[0081] Furthermore, when supporting a state of coverage enhancement, the control unit 270 may assume that the number of subcarriers (which may be replaced with resource blocks) in the frequency direction is increased by DMRS.

[0082] In addition, a specific configuration example of the DMRS used in a state supporting coverage enhancement will be further described later.

[0083] When supporting coverage enhancement, the control unit 270 may assume that the position (subcarrier) in the frequency direction to which the DMRS is allocated is different for each position (symbol) in the time direction to which the DMRS is allocated.

[0084] Specifically, when DMRS is mapped to even-numbered subcarriers such as subcarriers 0, 2, 4, ... at a position in the time direction (for example, pos 2), it can be assumed that at the next position in the time direction where DMRS is mapped (pos11), DMRS is mapped to odd-numbered subcarriers such as 1, 3, 5, ... instead of even-numbered subcarrier 0. In addition, a specific example of such DMRS mapping will be further described later.

[0085] In addition, the control unit 270 may assume the configuration of DMRS used to support the coverage enhancement state based on the signaling of the higher layer.

[0086] Specifically, the control unit 270 can assume the configuration of the DMRS used to support the coverage enhancement state based on the information element (IE) specified in the RRC layer. The IE is transmitted from the network to the UE 200 through a predetermined downlink physical channel, for example.

[0087] (3) Operation of wireless communication system

[0088] Next, a description will be given of the operation of the wireless communication system 10. Specifically, a description will be given of the operation related to transmission and reception performed by the UE 200 supporting the physical shared channel (PDSCH and PUSCH) of coverage enhancement (CE).

[0089] (3.1) Prerequisites

[0090] In the study item (see RP-193240) set by 3GPP, it is envisaged to realize coverage enhancement in both the FR1 and FR2 frequency bands.

[0091] The target scenarios include providing services from outdoor (O) gNB to indoor (I) UE (FR1 scenario), and from indoor gNB to indoor UE (FR2 scenario). In addition, coverage enhancement in urban areas, suburbs, and rural areas (including places that constitute long-distance communications) is targeted.

[0092] In addition, the main target services are VoIP (Voice over IP) and eMBB (enhanced Mobile Broadband).

[0093] Based on such scenarios and target services, the maximum coupling loss (MCL) of physical channels (specifically, PDSCH, PUSCH, PDCCH, PUCCH) was evaluated, and as a result, it was found that there was a need for improvement as shown below.

[0094] (FR1)

[0095] PUSCH: about 10dB (VoIP), about 15dB (eMBB)

[0096] PDCCH: about 5dB (VoIP)

[0097] (FR2)

[0098] PUSCH: about 5dB (eMBB)

[0099] PDCCH: about 10dB (VoIP)

[0100] PUCCH: about 5dB (VoIP)

[0101] Figure 4 The MCL evaluation results of the physical channels in FR1 are shown. Figure 5 The MCL evaluation results of the physical channels in FR2 are shown.

[0102] The following describes operations related to improvements of PDSCH and PUSCH for supporting coverage enhancement.

[0103] In order to improve the channel estimation accuracy of the wireless channel (which can be interpreted as including PDSCH and PUSCH) in UE 200 located at the edge (cell end) of the cell formed by gNB 100A (or gNB 100B, the same below), it is possible to consider increasing the density of DMRS, that is, increasing the amount of DMRS mapped in the frequency direction and / or time direction.

[0104] Figure 6A to Figure 6F Mapping examples of DMRS specified in 3GPP Release-15 (No. 1 to No. 6) are shown.

[0105] In addition, regarding the PUSCH, only when precoding is not required and the number of symbols (number of OFDM symbols) is two or less, the DMRS and the PUSCH are frequency division multiplexed (FDM).

[0106] Figure 7 An example of the BLER characteristics of PUSCH is shown. Specifically, Figure 7 Shown as Fig.6D (4) shows the BLER characteristics of the PUSCH when the DMRS is densely mapped.

[0107] like Figure 7 As shown, when compared with the case where ideal channel estimation is performed, it can be confirmed that a difference of about 5 dB occurs.

[0108] The following describes an operation that can increase the density of DMRS resource configuration in the frequency direction and / or the time direction (which can be replaced by the mapping amount) in order to improve the channel estimation accuracy of the wireless channel.

[0109] (3.2) Operation Overview

[0110] In order to increase the density of DMRS resources in the frequency direction and / or the time direction and improve the channel estimation accuracy of the wireless channel, the following describes operation examples 1 to 5. The overview of operation examples 1 to 5 is as follows.

[0111] (Action Example 1): Increase the DMRS configuration density in the time direction

[0112] Even when the DMRS symbol duration is 2 symbols, additional DMRS (Additional DMRS symbol positions pos2, pos3) settings can be performed.

[0113] Specifically, the setting may be added to Table 6.4.1.1.3-4 of 3GPP TS38.211. Alternatively, it may be specified as a new DMRS configuration type (DMRS configuration Type) (eg, Type 3).

[0114] (Action Example 2): Increase the DMRS configuration density in the frequency direction

[0115] A new DMRS configuration Type that increases the configuration density in the frequency direction may be added.

[0116] (Action Example 3): Mapping of DMRS in the time direction and frequency direction

[0117] The mapping position in the frequency direction can be changed according to each symbol to which the DMRS is mapped. Specifically, when the DMRS is mapped to even-numbered subcarriers such as subcarriers 0, 2, 4, etc. at a position in the time direction (e.g., pos 2), the DMRS is mapped to odd-numbered subcarriers such as 1, 3, 5, etc. at the next position in the time direction to which the DMRS is mapped (pos 11), instead of the even-numbered subcarrier 0.

[0118] (Action Example 4): DMRS Setting Method

[0119] Similar to 3GPP Release-15, DMRS can be configured using IE of the RRC layer (specifically, DMRS-DownlinkConfig, DMRS-UplinkConfig).

[0120] Specifically, when UE 200 reports the UE capability indicating "DMRS symbol duration = 2, and Additional DMRS symbol positions pos2, pos3 settings are possible", maxLength = len2, and dmrs-Additional Position = pos2 (default value), pos3 settings may be possible.

[0121] In addition, a new DMRS configuration Type (e.g., Type 3) can be added to dmrs-Type.

[0122] (Action Example 5): UE Capability Report

[0123] Regarding the setting of DMRS, UE 200 reports the following capabilities of UE 200, for example:

[0124] DMRS symbol duration = 2, and whether the settings of pos2 and pos3 of Additional DMRS symbol positions are supported

[0125] Is the new DMRS configuration type supported?

[0126] (3.3) Action example

[0127] Hereinafter, operation examples 1 to 5 will be described in detail.

[0128] (3.3.1) Action Example 1

[0129] In this operation example, in order to improve the DMRS configuration density in the time direction, additional DMRS (pos2 and pos3 of Additional DMRS symbol positions) settings can be performed even when the DMRSsymbolduration is 2 symbols.

[0130] Figure 8 The structure example of DMRS configuration Type related to action example 1 is shown. Specifically, Figure 8 This includes content added to Table 6.4.1.1.3-4 of 3GPP TS38.211. More specifically, the content of parts 2 and 3 of dmrs-Additional Position may be added.

[0131] Or, as above, Figure 8 The content (table) shown may be defined as a new DMRS configurationType (eg, Type 3). In this case, part of the setting of pos 1 of Additional DMRS symbol positions may be changed (see the underlined portion in the figure).

[0132] Fig.9A , Fig. 9B , Fig. 10A as well as Fig. 10B An example of DMRS mapping for increasing the DMRS configuration density in the time direction is shown.

[0133] Specifically, Fig.9A and Fig. 9B FIG. 2 shows an example of DMRS mapping according to DMRS configuration type = 1. Fig.9A and Fig. 9B As shown, in the frequency direction, DMRS is mapped at intervals of one subcarrier. In addition, in the time direction, since DMRS symbol duration=2, DMRS is continuously mapped to two symbols (ODM symbols).

[0134] Fig. 10A and Fig. 10B FIG. 2 shows an example of DMRS mapping according to DMRS configuration type = 2. Fig. 10A and Fig. 10B As shown, in the frequency direction, the DMRS is mapped to two locations in two consecutive subcarriers.

[0135] Furthermore, in the time direction, since DMRS symbol duration=2, the DMRS is continuously mapped to two symbols (ODM symbols).

[0136] In addition, Fig. 9B and Fig. 10B In the example, since the additional DM-RS symbol position = pos 3 (Additional DMRSsymbol positions = pos 3), Fig.9A and Fig. 10A Compared to the above, the position (11) of the symbol to which the DMRS is mapped is different (offset) (see also Figure 8 (See the structural example of the DMRS configuration Type shown in the figure).

[0137] (3.3.2) Action Example 2

[0138] In this operation example, a DMRS configurationType (for example, Type 3) that increases the DMRS configuration density in the frequency direction is added.

[0139] FIG. 11A to FIG. 11D FIG. 2 shows a mapping example of DMRS related to Action Example 2. FIG. 11A to FIG. 11D As shown, in the frequency direction, DMRS can be mapped to all subcarriers (specifically, 12 subcarriers 0 to 11).

[0140] exist FIG. 11A to FIG. 11D In the DMRS, the Additional DMRS symbol positions are different, and the amount of DMRS mapped in the time direction can also be controlled.

[0141] (3.3.3) Action Example 3

[0142] In this operation example, the mapping position in the frequency direction is changed for each symbol to which the DMRS is mapped.

[0143] Specifically, a different DMRS configuration Type (for example, Type 3) may be added for mapping in the frequency direction according to each symbol (OFDM symbol) to which the DMRS is mapped.

[0144] Alternatively, for example, a mapping mode field may be added to DMRS-DownlinkConfig and / or DMRS-UplinkConfig, and a mapping position of the DMRS in the frequency direction of each OFDM symbol may be set.

[0145] For example, mapping pattern = 0 may be set to mapping in accordance with 3GPP Release-15 and 16, and mapping pattern = 1 may be set to a mapping pattern in which the mapping position in the frequency direction is changed for each OFDM symbol as in this operation example.

[0146] FIG. 12A to FIG. 12D FIG. 4 shows a mapping example of DMRS related to Action Example 3. FIG. 12A to FIG. 12D As shown, when the number (position) of the OFDM symbol is an even number, the DMRS is mapped to an even-numbered subcarrier, and when the number (position) of the OFDM symbol is an odd number, the DMRS is mapped to an odd-numbered subcarrier.

[0147] That is, when DMRS is mapped to an even-numbered subcarrier such as 0, 2, 4, ... at a position in the time direction (for example, pos 2), at the next position in the time direction where DMRS is mapped (pos 11), DMRS can be mapped to an odd-numbered subcarrier such as 1, 3, 5, ... instead of the even-numbered subcarrier 0.

[0148] exist FIG. 12A to FIG. 12D In the case of additional DM-RS symbol positions, the amount of DMRS mapped in the time direction can also be controlled. Fig. 12A In the configuration, DMRS is mapped to only one OFDM symbol in the time direction, and the mapping position in the frequency direction is not changed for each symbol to which DMRS is mapped, but constitutes DMRS configuration Type = 3.

[0149] (3.3.4) Action Example 4

[0150] This operation example is related to the configuration method of DMRS. As described above, the configuration of the mapped DMRS can be configured using DMRS-DownlinkConfig and / or DMRS-UplinkConfig, similar to 3GPP Release-15.

[0151] Fig.13 The structure example of DMRS-DownlinkConfig related to Action Example 4 is shown. Fig.13 As shown, as the dmrs-Type field of DMRS-DownlinkConfig, in addition to type2, type3 corresponding to the new DMRS configuration Type mentioned above can be added.

[0152] As described above, when UE 200 reports the UE capability "indicating that DMRS symbol duration=2 and Additional DMRS symbol positions pos2 and pos3 can be set", maxLength=len2 and dmrs-Additional Position=pos2 (default value), pos3 can be set.

[0153] (3.3.5) Action Example 5

[0154] In this action example, UE 200 may send capability information (UE capability information) of UE 200 related to transmission and reception of PDSCH and PUSCH to the network.

[0155] Specifically, regarding DMRS, for example, UE 200 can report the following capabilities (Capability) of UE 200.

[0156] DMRSsymbol duration = 2, and whether the settings of pos2 and pos3 of Additional DMRS symbol positions are supported

[0157] Is the new DMRS configuration type supported?

[0158] Specifically, for the report of UE capability (which may be replaced by the sending of UE capability information), regarding the frequency band supported by UE 200 (which may be FR or Band), any of the following may be followed.

[0159] · Report unified support for all frequencies (support as UE 200)

[0160] Report support availability for each frequency

[0161] Report support for each frequency range (e.g., FR1, FR2)

[0162] In addition, the reporting of the duplex mode supported by UE 200 may follow any of the following.

[0163] Report whether it is supported as UE 200

[0164] Report by duplex mode (TDD, FDD)

[0165] (4) Action and Effect

[0166] Next, the operation and effects obtained by the wireless communication system 10 supporting the above-mentioned operations related to coverage enhancement will be described.

[0167] Fig.14 FIG. 4 shows the BLER characteristics when the number of symbols to which DMRS is mapped is changed. Fig.14 As shown, the required signal-to-interference plus noise power ratio (SINR) required to achieve a block error rate (BLER) (eg, 1%) can be improved by about 1.0 dB.

[0168] Therefore, according to the above-mentioned embodiment, UE 200, in a state supporting coverage enhancement (which can be called a second state) different from a normal state (which can be called a first state), can envision a DMRS with increased configuration density in at least either the frequency direction or the time direction.

[0169] By considering such DMRS, the UE 200 can improve the channel estimation accuracy of the radio channel even when the UE 200 is located at the end of the cell, and the UE 200 can support coverage enhancement.

[0170] In the present embodiment, when UE 200 supports coverage enhancement, it is assumed that the position (subcarrier) in the frequency direction to which DMRS is allocated is different for each position (symbol) in the time direction to which DMRS is allocated.

[0171] Therefore, since the DMRS is mapped to a wider range in the frequency direction, the channel estimation accuracy can be further improved.

[0172] In this embodiment, UE 200 can assume the structure of DMRS used in the state supporting coverage enhancement based on the signaling of the higher layer (RRC). Therefore, UE 200 can easily and quickly assume the DMRS with an appropriate structure corresponding to the state of coverage enhancement.

[0173] In this embodiment, the capability information of the UE 200 related to the reception of the DMRS can be transmitted to the network. Therefore, the network can transmit an appropriate DMRS corresponding to the capability of the UE 200.

[0174] (5) Other Implementation Methods

[0175] Although the embodiments have been described above, it is apparent to those skilled in the art that the present invention is not limited to the description of the embodiments and that various modifications and improvements can be made.

[0176] For example, in the above embodiments, the configuration related to DMRS is changed when coverage is enhanced, but it is not necessarily limited to when coverage is enhanced. For example, the second state can be interpreted as a state in which at least one configuration related to DMRS is different from the first state.

[0177] In the above-mentioned embodiment, the demodulation reference signal (DMRS) is described, but the same changes can be made to other reference signals.

[0178] In addition, the block diagram ( Figure 3 ) shows blocks in units of functions. These functional blocks (structural parts) are implemented by any combination of at least one of hardware and software. In addition, there is no particular limitation on the implementation method of each functional block. That is, each functional block can be implemented using a device that is physically or logically combined, or two or more physically or logically separated devices can be directly or indirectly connected (for example, using wires, wirelessly, etc.) and implemented using these multiple devices. The functional block can also be implemented by combining software with the above-mentioned one device or the above-mentioned multiple devices.

[0179] Functionally, it includes judging, deciding, determining, calculating, calculating, processing, deriving, investigating, searching, confirming, receiving, sending, outputting, accessing, solving, selecting, selecting, establishing, comparing, assuming, expecting, regarding, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, assigning, etc., but is not limited to these. For example, the functional block (structural part) that enables the sending function is called a transmitting unit or a transmitter. In short, as mentioned above, there is no particular limitation on the implementation method.

[0180] Furthermore, the above-mentioned UE 200 may also function as a computer that performs the processing of the wireless communication method of the present disclosure. Fig.15 2 is a diagram showing an example of the hardware configuration of UE 200. Fig.15 As shown, UE 200 may also be configured as a computer device including a processor 1001, a memory 1002 (memory), a storage 1003 (storage), a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

[0181] In the following description, the word "device" may be replaced by "circuit", "device", "unit", etc. The hardware structure of the device may include one or more of the devices shown in the figure, or may exclude some of the devices.

[0182] Each functional block of UE 200 (see Figure 3 ) is implemented by any hardware element or combination of hardware elements of the computer device.

[0183] In addition, each function in UE 200 is implemented by the following method: predetermined software (program) is read into hardware such as processor 1001 and memory 1002, so that processor 1001 performs calculations and controls the communication of communication device 1004 or controls at least one of the reading and writing of data in memory 1002 and storage 1003.

[0184] The processor 1001 controls the entire computer by, for example, executing an operating system. The processor 1001 may be constituted by a central processing unit (CPU) including an interface with peripheral devices, a control device, a calculation device, a register, and the like.

[0185] In addition, the processor 1001 reads a program (program code), a software module or data, etc. from at least one of the memory 1003 and the communication device 1004 to the memory 1002, and performs various processes accordingly. As a program, a program that causes a computer to perform at least a part of the actions described in the above-mentioned embodiments is used. In addition, with respect to the above-mentioned various processes, although it is described that the above-mentioned various processes are performed by one processor 1001, the above-mentioned various processes can also be performed simultaneously or sequentially by more than two processors 1001. The processor 1001 can also be installed by more than one chip. In addition, the program can also be sent from the network via a telecommunication line.

[0186] The memory 1002 is a computer-readable recording medium, and may be composed of at least one of a read-only memory (ROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a random access memory (RAM), etc. The memory 1002 may also be referred to as a register, a cache, a main memory (main storage device), etc. The memory 1002 may store a program (program code), a software module, etc. that can execute a method according to an embodiment of the present disclosure.

[0187] The memory 1003 is a computer-readable recording medium, and may be composed of at least one of an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a floppy disk, a magneto-optical disk (e.g., a compressed disk, a digital versatile disk, a Blu-ray (registered trademark) disk, a smart card, a flash memory (e.g., a card, a stick, a key drive), a Floppy (registered trademark) disk, a magnetic strip, etc. The memory 1003 may also be referred to as an auxiliary storage device. The above-mentioned recording medium may be, for example, other appropriate media such as a database, a server, etc. that includes at least one of the memory 1002 and the memory 1003.

[0188] The communication device 1004 is hardware (transceiver) used to communicate between computers via at least one of a wired network and a wireless network, and may also be called a network device, a network controller, a network card, a communication module, etc.

[0189] The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc., for example, in order to realize at least one of frequency division duplex (FDD) and time division duplex (TDD).

[0190] The input device 1005 is an input device that receives input from the outside (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.). The output device 1006 is an output device that implements output to the outside (e.g., a display, a speaker, an LED light, etc.). In addition, the input device 1005 and the output device 1006 may also be integrally formed (e.g., a touch panel).

[0191] In addition, the processor 1001 and the memory 1002 and other devices are connected via a bus 1007 for communicating information. The bus 1007 may be configured using a single bus or may be configured using different buses for each device.

[0192] In addition, the device may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), a field programmable gate array (FPGA), etc., and a part or all of each functional block may be implemented by the hardware. For example, the processor 1001 may also be installed using at least one of these hardware.

[0193] In addition, the notification of information is not limited to the form / implementation method described in the present disclosure, and other methods may also be used. For example, the notification of information may be implemented through physical layer signaling (e.g., downlink control information (Downlink Control Information: DCI), uplink control information (Uplink Control Information: UCI)), high-level signaling (e.g., RRC signaling, medium access control (Medium Access Control: MAC) signaling, broadcast information (Master Information Block: MIB, System Information Block: SIB)), other signals or a combination thereof. In addition, RRC signaling may also be referred to as an RRC message, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, etc.

[0194] Each form / embodiment described in the present disclosure may also be applied to at least one of Long Term Evolution (LTE), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), Future Radio Access (FRA), New Radio (NR), W-CDMA (registered trademark), GSM (registered trademark), CDMA 2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), a system using other appropriate systems, and a next-generation system extended therefrom. In addition, a combination of a plurality of systems (for example, a combination of at least one of LTE and LTE-A with 5G, etc.) may also be applied.

[0195] The processing procedures, timings, processes, etc. of each form / implementation described in this disclosure may be changed in order without contradiction. For example, for the method described in this disclosure, the elements of various steps are presented in an illustrative order, but are not limited to the specific order presented.

[0196] In the present disclosure, specific actions performed by a base station are sometimes performed by its upper node depending on the situation. In a network consisting of one or more network nodes having a base station, various actions performed to communicate with a terminal can be performed by at least one of the base station and other network nodes other than the base station (for example, consider MME or S-GW, etc., but not limited to these). In the above, the case where there is one other network node other than the base station is illustrated, but the other network node may also be a combination of multiple other network nodes (for example, MME and S-GW).

[0197] Information, signals (information, etc.) can be output from a higher layer (or lower layer) to a lower layer (or higher layer), and can also be input or output via multiple network nodes.

[0198] The input or output information can be stored in a specific location (e.g., memory) or managed using a management table. The input or output information can be rewritten, updated, or appended. The output information can also be deleted. The input information can also be sent to other devices.

[0199] The determination may be made by a value represented by one bit (0 or 1), by a Boolean value (Boolean: true or false), or by comparison of numerical values ​​(for example, comparison with a predetermined value).

[0200] Each form / implementation described in the present disclosure may be used alone or in combination, and may be switched depending on the execution. In addition, notification of scheduled information is not limited to being performed explicitly (e.g., notification of "yes X"), but may also be performed implicitly (e.g., notification of the scheduled information is not performed).

[0201] Software, whether referred to as software, firmware, middleware, microcode, hardware description language, or by other names, shall be interpreted broadly to refer to commands, sets of commands, codes, code segments, program codes, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc.

[0202] In addition, software, commands, information, etc. may be sent and received via a transmission medium. For example, when software is sent from a web page, server, or other remote source using at least one of wired technology (coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), etc.) and wireless technology (infrared, microwave, etc.), at least one of these wired technology and wireless technology is included in the definition of transmission medium.

[0203] The information, signals, etc. described in the present disclosure may also be represented by any of a variety of different technologies. For example, data, commands, instructions, information, signals, bits, symbols, chips, etc. that may be involved in the above description as a whole may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any combination thereof.

[0204] In addition, the terms described in the present disclosure and the terms required for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may also be a signal (signaling). In addition, a signal may also be a message. In addition, a component carrier (CC) may be referred to as a carrier frequency, a cell, a frequency carrier, etc.

[0205] As used in this disclosure, the terms "system" and "network" may be used interchangeably.

[0206] In addition, the information, parameters, etc. described in the present disclosure may be represented by absolute values, relative values ​​to predetermined values, or other corresponding information. For example, wireless resources may also be indicated by indexes.

[0207] The names used for the above parameters are not limiting in any way. Furthermore, the formulas etc. using these parameters may sometimes differ from those explicitly disclosed in this disclosure. Various channels (e.g., PUCCH, PDCCH, etc.) and information elements may be identified by appropriate names, and therefore the various names assigned to these various channels and information elements are not limiting in any way.

[0208] In the present disclosure, the terms "base station (BS)", "wireless base station", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "carrier", "component carrier" and the like are used interchangeably. Sometimes, a base station is also referred to as a macro cell, a small cell, a micro cell, a pico cell, etc.

[0209] A base station can accommodate one or more (e.g., three) cells (also called sectors). When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be divided into multiple smaller areas, each of which can also provide communication services through a base station subsystem (e.g., a small base station for indoor use (Remote Radio Head: RRH).

[0210] The terms "cell" or "sector" refer to a part or the entirety of a coverage area of ​​at least one of a base station and a base station subsystem that provide communication services within the coverage area.

[0211] In the present disclosure, terms such as “mobile station (MS)”, “user terminal (user terminal)”, “user equipment (UE)”, and “terminal” may be used interchangeably.

[0212] For mobile stations, those skilled in the art sometimes also use the following terms: subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other appropriate terms.

[0213] At least one of the base station and the mobile station may also be referred to as a transmitting device, a receiving device, a communication device, etc. In addition, at least one of the base station and the mobile station may be a device mounted on a mobile body, the mobile body itself, etc. The mobile body may be a means of transportation (e.g., a car, an airplane, etc.), a mobile body that moves in an unmanned manner (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). In addition, at least one of the base station and the mobile station also includes a device that does not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an Internet of Things (IoT) device such as a sensor.

[0214] In addition, the base station in the present disclosure may also be replaced by a mobile station (user terminal, the same below). For example, various forms / implementations of the present disclosure may also be applied to a structure in which the communication between a base station and a mobile station is replaced by communication between multiple mobile stations (for example, may also be referred to as device-to-device (D2D), vehicle-to-everything (V2X), etc.). In this case, it is also possible to set a structure in which the mobile station has the functions of the base station. In addition, terms such as "uplink" and "downlink" may also be replaced by terms corresponding to communication between terminals (for example, "side"). For example, uplink channels, downlink channels, etc. may also be replaced by side channels.

[0215] Likewise, the mobile station in the present disclosure may be replaced by a base station. In this case, the base station may have the same functions as the mobile station.

[0216] A radio frame may be composed of one or more frames in the time domain. In the time domain, one or more frames may be referred to as subframes. A subframe may also be composed of one or more time slots in the time domain. A subframe may be a fixed time length (e.g., 1 ms) that is independent of a numerology.

[0217] A parameter set may be a communication parameter applied to at least one of the transmission and reception of a certain signal or channel. The parameter set may, for example, represent at least one of a subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, wireless frame structure, specific filtering processing performed by a transceiver in the frequency domain, specific windowing processing performed by a transceiver in the time domain, and the like.

[0218] A slot may be composed of one or more symbols (Orthogonal Frequency Division Multiplexing (OFDM) symbols, Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols, etc.) in the time domain. A slot may be a time unit based on a parameter set.

[0219] A time slot may contain multiple mini-slots. Each mini-slot may be composed of one or more symbols in the time domain. In addition, a mini-slot may also be referred to as a sub-slot. A mini-slot may be composed of fewer symbols than a time slot. A PDSCH (or PUSCH) transmitted in units of time greater than a mini-slot may be referred to as a PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a mini-slot may be referred to as a PDSCH (or PUSCH) mapping type B.

[0220] A radio frame, a subframe, a time slot, a mini-time slot, and a symbol all represent time units for transmitting signals. A radio frame, a subframe, a time slot, a mini-time slot, and a symbol may be referred to by other corresponding names.

[0221] For example, 1 subframe can be called a transmission time interval (TTI), multiple consecutive subframes can also be called a TTI, and 1 time slot or 1 mini time slot can also be called a TTI. That is, at least one of the subframe and the TTI can be a subframe (1ms) in the existing LTE, or a period shorter than 1ms (for example, 1-13 code elements), or a period longer than 1ms. In addition, the unit representing TTI can be a time slot, a mini time slot, etc. instead of a subframe.

[0222] Here, TTI refers to, for example, the minimum time unit for scheduling in wireless communication. For example, in the LTE system, the base station schedules the allocation of wireless resources (frequency bandwidth, transmission power, etc. that can be used in each user terminal) to each user terminal in units of TTI. In addition, the definition of TTI is not limited to this.

[0223] TTI can be a transmission time unit for data packets (transport blocks), code blocks, code words, etc. after channel coding, or a processing unit for scheduling, link adaptation, etc. In addition, when TTI is assigned, the time interval (e.g., the number of symbols) to which the transport block, code block, code word, etc. is actually mapped can be shorter than the TTI.

[0224] In addition, when 1 time slot or 1 mini time slot is called TTI, more than one TTI (ie, more than one time slot or more than one mini time slot) can constitute the minimum time unit of scheduling. In addition, the number of time slots (mini time slots) constituting the minimum time unit of scheduling can be controlled.

[0225] A TTI having a time length of 1 ms is also called a normal TTI (TTI in LTE Rel.8-12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a time slot, etc. A TTI shorter than a normal TTI may be called a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a mini-time slot, a sub-time slot, a time slot, etc.

[0226] In addition, for a long TTI (for example, a normal TTI, a subframe, etc.), it can be replaced with a TTI having a time length exceeding 1ms, and for a short TTI (for example, a shortened TTI, etc.), it can be replaced with a TTI length that is smaller than the long TTI (longTTI) and has a TTI length of more than 1ms.

[0227] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain. In the frequency domain, it may contain one or more consecutive subcarriers. The number of subcarriers contained in an RB may be the same regardless of the parameter set, for example, it may be 12. The number of subcarriers contained in an RB may also be determined according to the parameter set.

[0228] In addition, the time domain of an RB may include one or more symbols, and may be the length of 1 slot, 1 mini slot, 1 subframe, or 1 TTI. 1 TTI, 1 subframe, etc. may be composed of one or more resource blocks, respectively.

[0229] In addition, one or more RBs may be referred to as a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, and the like.

[0230] In addition, a resource block may be composed of one or more resource elements (RE). For example, 1 RE may be a radio resource region of 1 subcarrier and 1 symbol.

[0231] A Bandwidth Part (BWP) (also called a partial bandwidth, etc.) represents a subset of contiguous common RBs (common resource blocks) for a parameter set in a certain carrier. Here, a common RB can be identified by the index of the RB based on the common reference point of the carrier. PRBs are defined in a certain BWP and numbered within the BWP.

[0232] The BWP may include a BWP for UL (UL BWP) and a BWP for DL ​​(DL BWP). One or more BWPs may be configured for a UE within one carrier.

[0233] At least one of the set BWPs may be active, and it is not assumed that the UE transmits or receives a predetermined signal / channel outside the activated BWP. In addition, "cell", "carrier" and the like in the present disclosure may be replaced with "BWP".

[0234] The above structures of radio frames, subframes, time slots, mini-time slots, and symbols are only examples. For example, the number of subframes included in a radio frame, the number of time slots per subframe or radio frame, the number of mini-time slots included in a time slot, the number of symbols and RBs included in a time slot or mini-time slot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, and the like can be changed in various ways.

[0235] The terms "connected", "coupled" or all variations of these terms are intended to indicate any direct or indirect connection or combination between two or more elements, and may include the situation where there is one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The combination or connection between elements may be a physical combination or connection, a logical combination or connection, or a combination of these. For example, "access" may be used to replace "connection". In the context of the present disclosure, for two elements, it may be considered that they are "connected" or "coupled" to each other by using at least one of one or more wires, cables, and printed electrical connections, and as some non-limiting and non-inclusive examples, by using electromagnetic energy having wavelengths in the wireless frequency domain, microwave region, and light (including both visible and invisible) region, etc.

[0236] The reference signal may be referred to as Reference Signal (RS) for short, or may be referred to as a pilot signal depending on the applied standard.

[0237] The phrase "according to" used in the present disclosure does not mean "only according to" unless otherwise expressly stated. In other words, the phrase "according to" means both "only according to" and "at least according to".

[0238] The "unit" in the configuration of each of the above-mentioned devices may be replaced with a "section", "circuit", "device" or the like.

[0239] Any reference to an element using the terms "first", "second", etc. used in this disclosure does not necessarily limit the number and order of these elements. These terms are used in this disclosure as a simple method to distinguish between two or more elements. Therefore, a reference to a first and a second element does not mean that only two elements can be used here or that the first element must precede the second element in any form.

[0240] When the terms "include," "including," and variations thereof are used in the present disclosure, these terms are intended to be inclusive, as is the term "comprising." Furthermore, the term "or" used in the present disclosure does not mean an exclusive or.

[0241] In the present disclosure, when an article is added by translation, such as a, an, and the in English, for example, the present disclosure also includes the case where the noun following the article is in plural form.

[0242] The terms "determining" and "determining" used in the present disclosure sometimes also include situations of various actions. "Determining" and "determining" may include, for example, considering matters that have been judged, calculated, calculated, processed, derived, investigated, searched (for example, searched in a table, database or other data structure), confirmed (ascertaining) as matters that have been "judged" or "determined", etc. In addition, "determining" and "determining" may include considering matters that have been received (for example, receiving information), transmitted (for example, transmitting information), input, output, accessed (for example, accessed data in memory) as matters that have been "judged" or "determined", etc. In addition, "determining" and "determining" may include considering matters that have been resolved (resolving), selected (selecting), chosen (choosing), established (establishing), compared (comparing), etc. as matters that have been "judged" or "determined". That is, "determining" and "determining" may include matters that have been "judged" or "determined" by any action. In addition, the word “determine” can also be replaced by “assuming”, “expecting”, “considering”, etc.

[0243] In the present disclosure, the term "A and B are different" may also mean "A and B are different from each other". In addition, the term may also mean "A and B are different from C, respectively". The terms "separate" and "combined" may also be interpreted in the same way as "different".

[0244] The present disclosure is described in detail above, but it should be clear to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure can be implemented as a modification and variation without departing from the subject matter and scope of the present disclosure as determined by the claims. Therefore, the purpose of the description of the present disclosure is to illustrate and not to have any limiting meaning on the present disclosure.

[0245] Description of labels:

[0246] 10 Wireless Communication Systems

[0247] 20 NG-RAN

[0248] 100A,100B gNB

[0249] UE 200

[0250] 210 Wireless signal transceiver

[0251] 220 Amplifier

[0252] 230 Modem Unit

[0253] 240 Control signal and reference signal processing unit

[0254] 250 Encoding / Decoding Unit

[0255] 260 Data Transceiver

[0256] 270 Control Department

[0257] 1001 Processor

[0258] 1002 Memory

[0259] 1003 Memory

[0260] 1004 Communication device

[0261] 1005 Input Device

[0262] 1006 Output Device

[0263] 1007 Bus

Claims

1. A terminal, wherein: The terminal has: a transceiver unit for transmitting and receiving a physical shared channel; and a control unit that assumes that, in a second state different from the first state, the demodulation reference signal has an increased arrangement density in at least one of the frequency direction and the time direction, In the second state, the control unit assumes that the position in the frequency direction to which the demodulation reference signal is assigned differs for each position in the time direction to which the demodulation reference signal is assigned.

2. The terminal according to claim 1, wherein: The control unit assumes the arrangement of the demodulation reference signal to be used in the second state based on signaling from a higher layer.

3. The terminal according to claim 1, wherein: The transceiver transmits capability information of the terminal related to reception of the demodulation reference signal to a network.

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