Terminal device and base station device

Abstract

Provided is a terminal device which performs transmission to a base station device, the terminal device comprising: an upper layer processing unit which receives, from the base station device, an upper layer signaling including two parameters of a repeating unit and the number of repetitions; a control unit which, by using the upper layer signaling and a prescribed field included in downlink control information, switches between first transmission that performs repetitive transmission using the two parameters and second transmission that transmits one transport block by using a wireless resource allocated by the two parameters; and a multiplexing unit which switches between DMRS arrangement related to the first transmission and DMRS arrangement related to the second transmission by means of the prescribed field included in the downlink control information.

Description

[Technical Field]

[0001] The present invention relates to a terminal device and a base station device. This application claims priority to Japanese Patent Application No. 2021-34379, filed on March 4, 2021, the contents of which are incorporated herein by reference. [Background technology]

[0002] In the New Radio (NR) communication system specified by the 3GPP (Third Generation Partnership Project), one or more Orthogonal Frequency Division Multiplexing (OFDM) symbols containing demodulation reference signals (DMRS) are inserted into a slot consisting of multiple OFDM symbols. The receiver that receives the transmitted slot performs channel estimation using the DMRS in the slot and demodulates the data signal in the slot.

[0003] In addition, NR Release 15 specifies inter-slot repeat transmission to improve communication reliability and expand coverage. Inter-slot repeat allows the same data to be transmitted repeatedly in multiple slots. However, since multiple slots are required for repeated transmission, there was a problem in terms of latency. Therefore, in NR Release 16, intra-slot repeat transmission was specified. With intra-slot repeat transmission, multiple repetition units can be set within a slot and transmission can be performed.

[0004] In specifications up to Rel-16, the DMRS that could be used for channel estimation was limited to within a repetition unit or within a slot, but channel estimation accuracy can be significantly improved by using DMRS included in different repetition units or different slots. Therefore, in NR Release 17, joint channel estimation (also known as DMRS bundling or DMRS sharing), which makes it possible to use DMRS included in different repetition units or different slots, is being studied (Non-Patent Document 1).

[0005] Up until Release 16, it was necessary to allocate a DMRS for each slot or repetition, but when channel estimation is performed using DMRSs in different slots or with different repetitions, there is a problem that the allocation of time resources for DMRS symbols becomes uneven when multiple slots or repetitions are taken into consideration. Therefore, Non-Patent Document 2 proposes that when joint channel estimation is applied, DMRSs should be rearranged so that they are evenly spaced in the time resources of multiple slots or multiple repetitions to be allocated.

[0006] Repetitive transmission is an important technology for achieving low latency because it allows data decoding for each repetitive transmission, enabling error detection during the repetitive transmission. However, when considering the entire repetitive transmission, lowering the coding rate rather than performing repetitive transmission can improve transmission characteristics. Therefore, transmitting one TB (transport block) using multiple slots is considered. Non-Patent Document 3 proposes switching between repetitive transmission and single-TB transmission using dynamic signaling. This allows repetitive transmission to be applied when low latency is required, and batch coding and transmission using 1 TB to improve transmission characteristics, enabling control according to QoS. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] Qualcomm, “Potential techniques for coverage enhancements,” 3GPP TSG-RAN WG1 Meeting #101, R1-2004499, May 2020. [Non-patent document 2] NTT DOCOMO, INC., “Joint channel estimation for PUSCH,” 3GPP TSG-RAN WG1 Meeting #104-e, R1-2101643, January 2021. [Non-patent document 3] NEC, “Discussion on TB processing over multi-slot PUSCH,” 3GPP TSG-RAN WG1 Meeting #104-e, R1- 2100943, January 2021. Summary of the Invention [Problem to be solved by the invention]

[0008] In Non-Patent Document 2, when performing joint channel estimation, a terminal device that has performed the rearrangement can obtain good transmission characteristics by rearranging DMRSs (arranging them at equal intervals in time resources). However, since the DMRS arrangement pattern differs from that of a user that does not perform the rearrangement, it becomes difficult to apply multi-user MIMO (Multiple Input Multiple Output).

[0009] One aspect of the present invention has been made in view of the above circumstances, and its object is to efficiently extend coverage by making it possible to effectively apply joint channel estimation. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems, a base station apparatus, a terminal apparatus, and a communication method according to one aspect of the present invention are configured as follows.

[0011] (1) One aspect of the present invention is a terminal device that transmits data to a base station device, and includes: an upper layer processing unit that receives upper layer signaling from the base station device, the upper layer signaling including two parameters, a repetition unit and a repetition count; a control unit that uses the upper layer signaling and a predetermined field included in downlink control information to switch between a first transmission that performs repeated transmission using the two parameters and a second transmission that transmits one transport block using radio resources allocated by the two parameters; and a multiplexing unit that switches between a DMRS allocation associated with the first transmission and a DMRS allocation associated with the second transmission using the predetermined field included in the downlink control information. (2) In one aspect of the present invention, the multiplexing unit allocates at least one reference signal for each repetition when allocating DMRS related to the first transmission, and allocates at least one reference signal in the radio resources allocated by the two parameters when allocating DMRS related to the second transmission. (3) In one aspect of the present invention, when the multiplexing unit performs DMRS allocation related to the second transmission, it divides the radio resources allocated by the two parameters into 14 symbols and allocates DMRS at predetermined positions of the divided symbols. (4) One aspect of the present invention is a base station device that receives a signal transmitted by a terminal device, the base station device comprising: an upper layer processing unit that generates upper layer signaling for the terminal device, the upper layer signaling including two parameters, a repetition unit and a repetition number; and a downlink control signal unit that uses a predetermined field included in downlink control information to switch between a first transmission that performs repeated transmission using the two parameters and a second transmission that transmits one transport block using radio resources allocated by the two parameters; and notifies the switching between a DMRS allocation associated with the first transmission and a DMRS allocation associated with the second transmission. (5) In one aspect of the present invention, the downlink control signal unit notifies that, in the case of DMRS allocation related to the first transmission, at least one reference signal is allocated for each repetition, and, in the case of DMRS allocation related to the second transmission, at least one reference signal is allocated in the radio resources allocated by the two parameters. (6) In one aspect of the present invention, when performing DMRS allocation related to the second transmission, the downlink control signal unit divides the radio resources allocated by the two parameters into 14 symbols and allocates DMRS at predetermined positions of the divided symbols. [Effects of the Invention]

[0012] According to one or more aspects of the present invention, it is possible to improve system throughput and expand communication coverage. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram illustrating an example of the configuration of a communication system 1 according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of a base station device according to the present embodiment. [Figure 3] FIG. 2 is a diagram illustrating an example of the configuration of a terminal device according to the present embodiment. [Figure 4] FIG. 2 is a diagram illustrating an example of smart DMRS deployment according to the first embodiment. [Figure 5] FIG. 2 is a diagram illustrating an example of DMRS allocation in repeated transmission and one transport block transmission according to the first embodiment. [Figure 6] FIG. 2 is a diagram illustrating an example of the relationship between the number of symbols and DMRS positions according to the first embodiment. [Figure 7] FIG. 10 is a diagram illustrating another example of DMRS allocation in repeated transmission and one transport block transmission according to the first embodiment. [Figure 8] FIG. 10 is a diagram illustrating a conventional example of use of radio resources in repeated transmission according to a second embodiment. [Figure 9]FIG. 11 is a diagram illustrating an example of use of radio resources in repeated transmission (DMRS transmission) according to a second embodiment. [Figure 10] FIG. 11 is a diagram showing an example of use of radio resources in repeated transmission (data transmission) according to the second embodiment. [Figure 11] FIG. 10 is a diagram showing a table used to determine a transport block size of 3824 or less. DETAILED DESCRIPTION OF THE INVENTION

[0014] A communication system according to this embodiment includes a base station device (cell, small cell, serving cell, component carrier, eNodeB, Home eNodeB, gNodeB) and a terminal device (terminal, mobile terminal, UE: User Equipment). In the communication system, in the case of downlink, the base station device is a transmitting device (transmitting point, transmitting antenna group, transmitting antenna port group, TRP (Tx / Rx Point)), and the terminal device is a receiving device (receiving point, receiving terminal, receiving antenna group, receiving antenna port group). In the case of uplink, the base station device is a receiving device, and the terminal device is a transmitting device. The communication system is also applicable to D2D (Device-to-Device, sidelink) communication. In that case, both the transmitting device and the receiving device are terminal devices.

[0015] The communication system is not limited to data communication between a terminal device and a base station device that requires human intervention. That is, the system can also be applied to data communication formats that do not require human intervention, such as MTC (Machine Type Communication), M2M (Machine-to-Machine Communication), IoT (Internet of Things) communication, and NB-IoT (Narrow Band IoT) (hereinafter referred to as MTC). In this case, the terminal device is an MTC terminal. The communication system can use a multicarrier transmission scheme such as CP-OFDM (Cyclic Prefix - Orthogonal Frequency Division Multiplexing) in the uplink and downlink. When higher layer parameters related to a transform precoder are configured in the uplink, the communication system uses a transmission scheme such as DFTS-OFDM (Discrete Fourier Transform Spread - Orthogonal Frequency Division Multiplexing, also referred to as SC-FDMA) that applies transform precoding, i.e., DFT. Note that the following description will be given assuming that an OFDM transmission scheme is used in the uplink and downlink, but other transmission schemes can also be applied.

[0016] The base station device and terminal device in this embodiment can communicate in frequency bands called licensed bands, which have been granted permission (license) to use by the country or region in which the wireless carrier provides services, and / or in frequency bands called unlicensed bands, which do not require permission (license) to use by the country or region.

[0017] In this embodiment, "X / Y" includes the meaning of "X or Y". In this embodiment, "X / Y" includes the meaning of "X and Y". In this embodiment, "X / Y" includes the meaning of "X and / or Y".

[0018] (First embodiment) 1 is a diagram showing an example of the configuration of a communication system 1 according to this embodiment. The communication system 1 according to this embodiment includes a base station device 10 and a terminal device 20. A coverage 10a is a range (communication area) in which the base station device 10 can connect (communicate) with the terminal device 20 (also called a cell). The base station device 10 can accommodate multiple terminal devices 20 within its coverage 10a.

[0019] 1, the uplink wireless communication r30 includes at least the following uplink physical channels: The uplink physical channels are used to transmit information output from higher layers. Physical Uplink Control Channel (PUCCH) Physical Uplink Shared Channel (PUSCH) Physical Random Access Channel (PRACH)

[0020] The PUCCH is a physical channel used to transmit uplink control information (UCI). The uplink control information includes a positive acknowledgement (ACK) / negative acknowledgement (NACK) for downlink data. Here, downlink data refers to a Downlink transport block, a Medium Access Control Protocol Data Unit (MAC PDU), a Downlink-Shared Channel (DL-SCH), a Physical Downlink Shared Channel (PDSCH), etc. The ACK / NACK is also referred to as a Hybrid Automatic Repeat request ACKnowledgement (HARQ-ACK), HARQ feedback, a HARQ response, or a signal indicating HARQ control information or delivery confirmation.

[0021] NR supports at least five formats: PUCCH format 0, PUCCH format 1, PUCCH format 2, PUCCH format 3, and PUCCH format 4. PUCCH format 0 and PUCCH format 2 consist of one or two OFDM symbols, while other PUCCHs consist of four to fourteen OFDM symbols. PUCCH format 0 and PUCCH format 1 have a bandwidth of 12 subcarriers. In PUCCH format 0, one bit (or two bits) of ACK / NACK is transmitted using a resource element of 12 subcarriers and one OFDM symbol (or two OFDM symbols).

[0022] The uplink control information includes a scheduling request (SR) used to request an uplink-shared channel (PUSCH) resource for the initial transmission. The scheduling request indicates a request for an UL-SCH resource for the initial transmission.

[0023] The uplink control information includes downlink channel state information (CSI). The downlink channel state information includes a rank indicator (RI) indicating a suitable spatial multiplexing number (number of layers), a precoding matrix indicator (PMI) indicating a suitable precoder, a channel quality indicator (CQI) specifying a suitable transmission rate, etc. The PMI indicates a codebook determined by the terminal device. The codebook is related to precoding of the physical downlink shared channel.

[0024] In NR, the upper layer parameter RI limit can be configured. There are multiple configuration parameters for RI limit, one of which is Type 1 Single Panel RI Limit, which consists of 8 bits. Type 1 Single Panel RI Limit, which is a bitmap parameter, forms a bit sequence r7, ... r2, r1. Here, r7 is the MSB (Most Significant Bit) and r0 is the LSB (Least Significant Bit). r i When is zero (i is 0, 1, ... 7), PMI and RI reporting corresponding to the precoder associated with layer i+1 are not allowed. In addition to Type 1 single-panel RI restrictions, there is also Type 1 multi-panel RI restrictions, which consist of 4 bits. The Type 1 multi-panel RI restrictions, which are bitmap parameters, form the bit sequence r4, r3, r2, r1, where r4 is the MSB and r0 is the LSB. r i When is zero (i is 0, 1, 2, 3), PMI and RI reporting corresponding to the precoder associated with layer i+1 is not allowed.

[0025] The CQI can use an index (CQI index) indicating a suitable modulation scheme (e.g., QPSK, 16QAM, 64QAM, 256QAM, etc.), coding rate, and frequency utilization efficiency in a predetermined band. The terminal device selects a CQI index from a CQI table that will enable reception of a PDSCH transport block without exceeding a block error rate (BLER) of 0.1. However, if a predetermined CQI table is set by higher layer signaling, the terminal device selects a CQI index from the CQI table that will enable reception without exceeding a BLER of 0.00001.

[0026] The PUSCH is a physical channel used to transmit uplink data (Uplink Transport Block, Uplink-Shared Channel: UL-SCH), and CP-OFDM or DFT-S-OFDM is used as the transmission scheme. The PUSCH may be used to transmit control information such as HARQ-ACK and / or channel state information for downlink data together with the uplink data. The PUSCH may be used to transmit only channel state information. The PUSCH may be used to transmit only HARQ-ACK and channel state information.

[0027] The PUSCH is used to transmit Radio Resource Control (RRC) signaling. RRC signaling is also referred to as an RRC message, RRC layer information, RRC layer signal, RRC layer parameter, or RRC information element. RRC signaling is information / signal processed in the radio resource control layer. The RRC signaling transmitted from a base station apparatus may be common signaling for multiple terminal apparatuses in a cell. The RRC signaling transmitted from a base station apparatus may be dedicated signaling for a certain terminal apparatus (also referred to as dedicated signaling). In other words, user equipment-specific information is transmitted using dedicated signaling for a certain terminal apparatus. The RRC message can include the UE capability of the terminal apparatus. The UE capability is information indicating the functions supported by the terminal apparatus.

[0028] The PUSCH is used to transmit MAC CE (Medium Access Control Element). MAC CE is information / signal processed (transmitted) in the Medium Access Control layer. For example, power headroom may be included in MAC CE and reported via PUSCH. That is, a field of MAC CE is used to indicate the level of power headroom. RRC signaling and / or MAC CE are also referred to as higher layer signaling. RRC signaling and / or MAC CE are included in a transport block.

[0029] The PRACH is used to transmit a preamble for random access. The PRACH is used to transmit a random access preamble. The PRACH is used for initial connection establishment procedures, handover procedures, connection re-establishment procedures, synchronization (timing adjustment) for uplink transmissions, and to indicate a request for PUSCH (UL-SCH) resources.

[0030] In uplink wireless communication, uplink reference signals (UL RS) are used as uplink physical signals. The uplink reference signals include demodulation reference signals (DMRS), sounding reference signals (SRS), and phase tracking reference signals (PTRS). The DMRS is related to the transmission of the physical uplink shared channel / physical uplink control channel. For example, the base station device 10 uses the demodulation reference signals to perform channel estimation / channel compensation when demodulating the physical uplink shared channel / physical uplink control channel.

[0031] The SRS is not related to transmission of the physical uplink shared channel / physical uplink control channel. The base station device 10 uses the SRS to measure the uplink channel condition (CSI measurement).

[0032] The PTRS is related to the transmission of the physical uplink shared channel / physical uplink control channel. The base station device 10 uses the PTRS for phase tracking.

[0033] 1, at least the following downlink physical channels are used in the radio communication of the downlink r31: The downlink physical channels are used to transmit information output from higher layers. Physical Broadcast Channel (PBCH) Physical Downlink Control Channel (PDCCH) Physical Downlink Shared Channel (PDSCH)

[0034] The PBCH is used to broadcast a Master Information Block (MIB, Broadcast Channel: BCH) commonly used by terminal devices. The MIB is one type of system information. For example, the MIB includes a downlink transmission bandwidth setting and a system frame number (SFN). The MIB may include information indicating at least a portion of the slot number, subframe number, and radio frame number in which the PBCH is transmitted.

[0035] The PDCCH is used to transmit downlink control information (DCI). Multiple formats (also referred to as DCI formats) are defined for the downlink control information based on the application. DCI formats may be defined based on the type and number of bits of DCI that make up one DCI format. Each format is used depending on the application. The downlink control information includes control information for downlink data transmission and control information for uplink data transmission. The DCI format for downlink data transmission is also referred to as downlink assignment (or downlink grant). The DCI format for uplink data transmission is also referred to as uplink grant (or uplink assignment).

[0036] One downlink assignment is used for scheduling one PDSCH in one serving cell. A downlink grant may be used at least for scheduling the PDSCH in the same slot as the slot in which the downlink grant is transmitted. The downlink assignment includes downlink control information such as a frequency domain resource assignment for the PDSCH, a time domain resource assignment, an MCS (Modulation and Coding Scheme) for the PDSCH, an NDI (New Data Indicator) indicating initial transmission or retransmission, information indicating a HARQ process number in the downlink, and a redundancy version indicating the amount of redundancy added to a codeword during error correction coding. The codeword is data after error correction coding. The downlink assignment may include a transmission power control (TPC) command for the PUCCH and a TPC command for the PUSCH. The uplink grant may include an aggregation level (number of transmission repetitions) indicating the number of times the PUSCH is repeatedly transmitted. The DCI format for each downlink data transmission includes information (fields) necessary for that purpose among the above information.

[0037] One uplink grant is used to notify a terminal device of the scheduling of one PUSCH in one serving cell. The uplink grant includes uplink control information such as information on resource block allocation for transmitting the PUSCH (resource block allocation and hopping resource allocation), time domain resource allocation, information on the MCS of the PUSCH (MCS / Redundancy version), information on the DMRS port, information on PUSCH retransmission, a TPC command for the PUSCH, and a downlink Channel State Information (CSI) request. The uplink grant may include information indicating an uplink HARQ process number, information indicating a redundancy version, a transmission power control (TPC) command for the PUCCH, and a TPC command for the PUSCH. Note that the DCI format for each uplink data transmission includes information (fields) necessary for that purpose from the above information.

[0038] The OFDM symbol number (position) at which a DMRS symbol is transmitted is given by the signaled duration between the first OFDM symbol of a slot and the last OFDM symbol of the PUSCH resource scheduled in that slot, in the case of PUSCH mapping type A when intra-frequency hopping is not applied. When intra-frequency hopping is not applied and PUSCH mapping type B, the OFDM symbol number (position) at which a DMRS symbol is transmitted is given by the scheduled PUSCH resource duration. When intra-frequency hopping is applied, it is given by the duration per hop. For PUSCH mapping type A, the case where the higher layer parameter indicating the number of additional DMRSs is set to 3 is supported only when the higher layer parameter indicating the position of the first DMRS is set to 2. Also, for PUSCH mapping type A, a 4-symbol duration is applicable only when the higher layer parameter indicating the position of the first DMRS is set to 2.

[0039] The PDCCH is generated by adding a Cyclic Redundancy Check (CRC) to downlink control information. In the PDCCH, the CRC parity bits are scrambled (also called an exclusive OR operation or mask) using a predetermined identifier. The parity bits are scrambled with a Cell-Radio Network Temporary Identifier (C-RNTI), a Configured Scheduling (CS)-RNTI, a Temporary C-RNTI, a Paging (P)-RNTI, a System Information (SI)-RNTI, or a Random Access (RA)-RNTI, a Semi-Persistent Channel State-Information (SP-CSI)-RNTI, or an MCS-C-RNTI. The C-RNTI and CS-RNTI are identifiers for identifying a terminal device within a cell. The Temporary C-RNTI is an identifier for identifying a terminal device that has transmitted a random access preamble during a contention-based random access procedure. The C-RNTI and Temporary C-RNTI are used to control PDSCH transmission or PUSCH transmission in a single subframe. The CS-RNTI is used to periodically allocate resources for the PDSCH or PUSCH. Here, the PDCCH (DCI format) scrambled with the CS-RNTI is used to activate or deactivate CS type 2. On the other hand, in CS type 1, the control information (MCS, radio resource allocation, etc.) included in the PDCCH scrambled with the CS-RNTI is included in higher layer parameters related to CS, and the CS is activated (configured) based on these higher layer parameters. The P-RNTI is used to transmit a paging message (Paging Channel: PCH). The SI-RNTI is used to transmit an SIB. The RA-RNTI is used to transmit a random access response (message 2 in the random access procedure).The SP-CSI-RNTI is used for semi-static CSI reporting, and the MCS-C-RNTI is used to select a lower spectral efficiency MCS table.

[0040] The PDSCH is used to transmit downlink data (downlink transport block, DL-SCH). The PDSCH is used to transmit system information messages (also referred to as System Information Blocks (SIBs)). Some or all of the SIBs can be included in RRC messages.

[0041] The PDSCH is used to transmit RRC signaling. The RRC signaling transmitted from a base station apparatus may be common to multiple terminal apparatuses in a cell (cell-specific). That is, information common to user apparatuses in the cell is transmitted using cell-specific RRC signaling. The RRC signaling transmitted from a base station apparatus may be a message dedicated to a certain terminal apparatus (also referred to as dedicated signaling). That is, user apparatus-specific information is transmitted using a message dedicated to a certain terminal apparatus.

[0042] The PDSCH is used to transmit MAC CE. RRC signaling and / or MAC CE are also referred to as higher layer signaling. The PMCH is used to transmit multicast data (Multicast Channel: MCH).

[0043] In the downlink wireless communication shown in Fig. 1, a synchronization signal (SS) and a downlink reference signal (DL RS) are used as downlink physical signals. The downlink physical signals are not used to transmit information output from higher layers, but are used by the physical layer.

[0044] The synchronization signal is used by the terminal device to synchronize the frequency domain and time domain of the downlink. The downlink reference signal is used by the terminal device to perform propagation path estimation / propagation path correction of the downlink physical channel. For example, the downlink reference signal is used to demodulate the PBCH, PDSCH, and PDCCH. The downlink reference signal can also be used by the terminal device to measure the downlink channel state (CSI measurement).

[0045] The downlink physical channel and the downlink physical signal are also collectively referred to as the downlink signal. The uplink physical channel and the uplink physical signal are also collectively referred to as the uplink signal. The downlink physical channel and the uplink physical channel are also collectively referred to as the physical channel. The downlink physical signal and the uplink physical signal are also collectively referred to as the physical signal.

[0046] The BCH, UL-SCH, and DL-SCH are transport channels. A channel used in the MAC layer is called a transport channel. The unit of the transport channel used in the MAC layer is also called a transport block (TB) or a MAC protocol data unit (PDU). A transport block is a unit of data that the MAC layer delivers to the physical layer. In the physical layer, the transport block is mapped to a codeword, and encoding and other processes are performed for each codeword.

[0047] 2 is a schematic block diagram of the configuration of a base station device 10 according to this embodiment. The base station device 10 includes an upper layer processing unit (upper layer processing step) 102, a control unit (control step) 104, a transmitter (transmitting step) 106, a transmit antenna 108, a receive antenna 110, and a receiver (receiving step) 112. The transmitter 106 generates a physical downlink channel in accordance with the logical channel input from the upper layer processing unit 102. The transmitter 106 includes a coding unit (coding step) 1060, a modulation unit (modulation step) 1062, a downlink control signal generator (downlink control signal generation step) 1064, a downlink reference signal generator (downlink reference signal generation step) 1066, a multiplexing unit (multiplexing step) 1068, and a radio transmitter (radio transmitting step) 1070. The receiver 112 detects (demodulates, decodes, etc.) the physical uplink channel and inputs the detected content to the upper layer processing unit 102. The receiving unit 112 is composed of a radio receiving unit (radio receiving step) 1120, a propagation path estimation unit (propagation path estimation step) 1122, a demultiplexing unit (demultiplexing step) 1124, an equalization unit (equalization step) 1126, a demodulation unit (demodulation step) 1128, and a decoding unit (decoding step) 1130.

[0048] The upper layer processing unit 102 performs processing of layers higher than the physical layer, such as a Medium Access Control (MAC) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, and a Radio Resource Control (RRC) layer. The upper layer processing unit 102 generates information required to control the transmitting unit 106 and the receiving unit 112, and outputs the information to the control unit 104. The upper layer processing unit 102 outputs downlink data (such as DL-SCH), system information (MIB, SIB), and the like to the transmitting unit 106. Note that the DMRS configuration information may be notified to the terminal device by system information (MIB or SIB) rather than by an upper layer such as RRC.

[0049] The upper layer processing unit 102 generates system information to be broadcast (MIB or part of SIB) or acquires it from an upper node. The upper layer processing unit 102 outputs the system information to be broadcast as BCH / DL-SCH to the transmitting unit 106. The MIB is allocated to the PBCH in the transmitting unit 106. The SIB is allocated to the PDSCH in the transmitting unit 106. The upper layer processing unit 102 generates system information (SIB) specific to the terminal device or acquires it from an upper node. The SIB is allocated to the PDSCH in the transmitting unit 106.

[0050] The upper layer processing unit 102 sets various RNTIs for each terminal device. The RNTIs are used for encryption (scrambling) of PDCCH, PDSCH, etc. The upper layer processing unit 102 outputs the RNTIs to the control unit 104, the transmission unit 106, and the reception unit 112.

[0051] The upper layer processing unit 102 generates or acquires from an upper node downlink data (transport block, DL-SCH) to be allocated to the PDSCH, terminal device-specific system information (System Information Block: SIB), RRC messages, MAC CE, and DMRS configuration information as system information such as SIB or MIB, or DMRS configuration information if not notified by DCI, and outputs the information to the transmitting unit 106. The upper layer processing unit 102 manages various setting information of the terminal device 20. Note that part of the radio resource control function may be performed in the MAC layer or physical layer.

[0052] The upper layer processing unit 102 receives information about the terminal device, such as functions (UE capabilities) supported by the terminal device, from the terminal device 20 (via the receiving unit 112). The terminal device 20 transmits its own functions to the base station device 10 using an upper layer signal (RRC signaling). The information about the terminal device includes information indicating whether the terminal device supports a predetermined function, or information indicating that the terminal device has completed installation and testing of the predetermined function. Whether the terminal device supports a predetermined function includes whether installation and testing of the predetermined function have been completed.

[0053] If a terminal device supports a predetermined function, the terminal device transmits information (parameters) indicating whether the predetermined function is supported. If a terminal device does not support a predetermined function, the terminal device may not transmit information (parameters) indicating whether the predetermined function is supported. In other words, whether the terminal device supports a predetermined function is notified by whether or not it transmits information (parameters) indicating whether the predetermined function is supported. Note that the information (parameters) indicating whether the predetermined function is supported may be notified using a single bit of 1 or 0.

[0054] The upper layer processing unit 102 acquires the DL-SCH from the decoded uplink data (including the CRC) from the receiving unit 112. The upper layer processing unit 102 performs error detection on the uplink data transmitted by the terminal device. For example, the error detection is performed in the MAC layer.

[0055] The control unit 104 controls the transmitting unit 106 and the receiving unit 112 based on various setting information input from the upper layer processing unit 102 / receiving unit 112. The control unit 104 generates downlink control information (DCI) based on the setting information input from the upper layer processing unit 102 / receiving unit 112, and outputs the DCI to the transmitting unit 106. For example, the control unit 104 sets the frequency allocation of the DMRS (even or odd subcarriers in the case of DMRS configuration 1, or one of the 0th to 2nd sets in the case of DMRS configuration 2) in consideration of the setting information related to the DMRS input from the upper layer processing unit 102 / receiving unit 112 (whether DMRS configuration 1 or DMRS configuration 2), and generates the DCI.

[0056] The control unit 104 determines the MCS of the PUSCH in consideration of the channel quality information (CSI measurement result) measured by the channel estimation unit 1122. The control unit 104 determines an MCS index corresponding to the MCS of the PUSCH. The control unit 104 includes the determined MCS index in the uplink grant.

[0057] The transmitter 106 generates the PBCH, PDCCH, PDSCH, downlink reference signal, etc. in accordance with signals input from the upper layer processing unit 102 / control unit 104. The encoder 1060 performs encoding (including repetition) on the BCH, DL-SCH, etc. input from the upper layer processing unit 102 using a coding scheme predetermined / determined by the upper layer processing unit 102, such as a block code, a convolutional code, a turbo code, a polar code, or an LDPC code. The encoder 1060 punctures the coded bits based on the coding rate input from the control unit 104. The modulator 1062 data-modulates the coded bits input from the encoder 1060 using a modulation scheme (modulation order) predetermined / input from the control unit 104, such as BPSK, QPSK, 16QAM, 64QAM, or 256QAM. The modulation order is based on the MCS index selected by the control unit 104.

[0058] The downlink control signal generator 1064 adds a CRC to the DCI input from the controller 104. The downlink control signal generator 1064 encrypts (scrambles) the CRC using the RNTI. Furthermore, the downlink control signal generator 1064 performs QPSK modulation on the DCI to which the CRC has been added, to generate a PDCCH. The downlink reference signal generator 1066 generates a sequence known to the terminal device as a downlink reference signal. The known sequence is determined according to a predetermined rule based on a physical cell identifier for identifying the base station device 10, etc.

[0059] The multiplexing unit 1068 multiplexes the modulation symbols of each channel input from the PDCCH / downlink reference signal / modulation unit 1062. That is, the multiplexing unit 1068 maps the modulation symbols of each channel of the PDCCH / downlink reference signal to resource elements. The resource elements to be mapped are controlled by downlink scheduling input from the control unit 104. A resource element is the smallest unit of physical resources consisting of one OFDM symbol and one subcarrier. A plurality of resource elements constitute a resource block (RB), and scheduling is applied using the RB as the smallest unit. When MIMO transmission is performed, the transmitting unit 106 is provided with coding units 1060 and modulation units 1062 for the number of layers. In this case, the upper layer processing unit 102 sets an MCS for each transport block of each layer.

[0060] The radio transmitting unit 1070 performs an Inverse Fast Fourier Transform (IFFT) on the multiplexed modulation symbols to generate OFDM symbols. The radio transmitting unit 1070 adds a cyclic prefix (CP) to the OFDM symbols to generate baseband digital signals. The radio transmitting unit 1070 then converts the digital signals to analog signals, removes unnecessary frequency components by filtering, upconverts the signals to a carrier frequency, power amplifies the signals, and outputs the signals to the transmitting antenna 108 for transmission.

[0061] The receiver 112 detects (separates, demodulates, and decodes) a received signal from the terminal device 20 via the receive antenna 110 in accordance with instructions from the control unit 104, and inputs the decoded data to the upper layer processing unit 102 / control unit 104. The radio receiver 1120 down-converts the uplink signal received via the receive antenna 110 into a baseband signal, removes unnecessary frequency components, controls the amplification level so that the signal level is appropriately maintained, performs quadrature demodulation based on the in-phase and quadrature components of the received signal, and converts the quadrature-demodulated analog signal into a digital signal. The radio receiver 1120 removes a portion corresponding to the CP from the converted digital signal. The radio receiver 1120 performs a fast Fourier transform (FFT) on the signal from which the CP has been removed to extract a frequency-domain signal. The frequency-domain signal is output to the demultiplexer 1124.

[0062] The demultiplexing unit 1124 separates the signal input from the radio receiving unit 1120 into signals such as a PUSCH, a PUCCH, and an uplink reference signal based on uplink scheduling information (uplink data channel allocation information, etc.) input from the control unit 104. The separated uplink reference signal is input to a channel estimating unit 1122. The separated PUSCH and PUCCH are output to an equalization unit 1126.

[0063] The channel estimator 1122 estimates a frequency response (or a delay profile) using an uplink reference signal. The frequency response result obtained by channel estimation for demodulation is input to the equalizer 1126. The channel estimator 1122 measures uplink channel conditions (measures RSRP (Reference Signal Received Power), RSRQ (Reference Signal Received Quality), and RSSI (Received Signal Strength Indicator)) using the uplink reference signal. The measured uplink channel conditions are used to determine the MCS for the PUSCH, etc.

[0064] The equalization unit 1126 performs a process of compensating for the influence of the propagation path using the frequency response input from the propagation path estimation unit 1122. As a compensation method, any existing propagation path compensation method can be applied, such as a method of multiplying an MMSE weight or an MRC weight, or a method of applying MLD. The demodulation unit 1128 performs a demodulation process based on information on a modulation method that is predetermined or instructed by the control unit 104.

[0065] The decoding unit 1130 performs decoding processing on the output signal of the demodulation unit based on information about a predetermined coding rate / a coding rate instructed by the control unit 104. The decoding unit 1130 inputs the decoded data (UL-SCH, etc.) to the upper layer processing unit 102.

[0066] 3 is a schematic block diagram showing the configuration of a terminal device 20 in this embodiment. The terminal device 20 includes an upper layer processing unit (upper layer processing step) 202, a control unit (control step) 204, a transmitter (transmitting step) 206, a transmitting antenna 208, a receiving antenna 210, and a receiver (receiving step) 212.

[0067] The upper layer processing unit 202 performs processing of the Medium Access Control (MAC) layer, the Packet Data Protocol (PDCP) layer, the Radio Link Control (RLC) layer, and the Radio Resource Control (RRC) layer. The upper layer processing unit 202 manages various setting information of the terminal device itself. The upper layer processing unit 202 notifies the base station device 10 via the transmitting unit 206 of information indicating the terminal device functions supported by the terminal device itself (UE Capability). The upper layer processing unit 202 notifies the UE Capability by RRC signaling.

[0068] Upper layer processing unit 202 acquires decoded data such as DL-SCH and BCH from receiving unit 212. Upper layer processing unit 202 generates HARQ-ACK from the error detection result of the DL-SCH. Upper layer processing unit 202 generates SR. Upper layer processing unit 202 generates UCI including HARQ-ACK / SR / CSI (including CQI report). Furthermore, when DMRS configuration information has been notified by an upper layer, upper layer processing unit 202 inputs information about the DMRS configuration to control unit 204. Upper layer processing unit 202 inputs the UCI and UL-SCH to transmitting unit 206. Note that some of the functions of upper layer processing unit 202 may be included in control unit 204.

[0069] The control unit 204 interprets downlink control information (DCI) received via the receiving unit 212. The control unit 204 controls the transmitting unit 206 in accordance with the scheduling, MCS index, TPC (Transmission Power Control), and the like of the PUSCH acquired from the DCI for uplink transmission. The control unit 204 controls the receiving unit 212 in accordance with the scheduling, MCS index, and the like of the PDSCH acquired from the DCI for downlink transmission. Furthermore, the control unit 204 identifies the frequency allocation of the DMRS in accordance with information on the frequency allocation (port number) of the DMRS included in the DCI for downlink transmission and the DMRS configuration information input from the upper layer processing unit 202.

[0070] The transmitting unit 206 includes an encoding unit (encoding step) 2060, a modulation unit (modulation step) 2062, an uplink reference signal generating unit (uplink reference signal generating step) 2064, an uplink control signal generating unit (uplink control signal generating step) 2066, a multiplexing unit (multiplexing step) 2068, and a radio transmitting unit (radio transmitting step) 2070.

[0071] The coding unit 2060 performs coding such as convolutional coding, LDPC coding, polar coding, turbo coding, etc. on the uplink data (UL-SCH) input from the upper layer processing unit 202 under the control of the control unit 204 (according to the coding rate calculated based on the MCS index).

[0072] The modulation unit 2062 modulates the coded bits input from the coding unit 2060 using a modulation method specified by the control unit 204, such as BPSK, QPSK, 16QAM, 64QAM, or 256QAM, which is predetermined for each modulation method / channel (to generate modulation symbols for the PUSCH).

[0073] In accordance with instructions from the control unit 204, the uplink reference signal generation unit 2064 generates a sequence determined by a predetermined rule (formula) based on a physical cell identity (PCI, also referred to as Cell ID, etc.) for identifying the base station device 10, a bandwidth in which the uplink reference signal is allocated, a cyclic shift, parameter values ​​for generating a DMRS sequence, and frequency allocation, etc.

[0074] The uplink control signal generator 2066, in accordance with instructions from the controller 204, encodes the UCI, performs BPSK / QPSK modulation, and generates modulation symbols for the PUCCH.

[0075] When a higher layer parameter (frequencyHopping) related to frequency hopping in Rel-15 is set, the value can be set to mode 1 or mode 2. Mode 2 is inter-slot hopping, and when multiple slots are used for transmission, the frequency is changed for each slot. On the other hand, mode 1 is intra-slot hopping, and when one or more slots are used for transmission, the slot is divided into a first half and a second half, and transmission is performed at different frequencies between the first half and the second half. As for frequency allocation in frequency hopping, the radio resource allocation in the frequency domain notified by DCI or RRC is applied to the first hop, and the frequency allocation for the second hop is assigned to radio resources shifted by the value set in the higher layer parameter (frequencyHoppingOffset) related to the frequency hopping amount from the radio resources used in the first hop.

[0076] The multiplexing unit 2068 multiplexes modulation symbols for PUSCH, modulation symbols for PUCCH, and uplink reference signals for each transmit antenna port (DMRS port) (i.e., each signal is mapped to a resource element) in accordance with uplink scheduling information from the control unit 204 (such as the transmission interval in CS (Configured Scheduling) for uplink included in the RRC message, frequency domain and time domain resource allocation included in the DCI, etc.).

[0077] Here, we will explain CS (configured scheduling). There are two types of transmission without dynamic grant. One is configured grant type 1, which is given by RRC and saved as configured grant. The other is configured grant type 2, which is given by PDCCH and saved and cleared as configured grant based on L1 signaling indicating configured grant activation or deactivation. Type 1 and Type 2 are configured by RRC per serving cell and per BWP. Multiple configurations can be active simultaneously only in different serving cells. For Type 2, activation and deactivation are independent between serving cells. For the same serving cell, the MAC entity is configured with either Type 1 or Type 2. When Type 1 is configured, RRC configures the following parameters: cs-RNTI: CS-RNTI for retransmission periodicity: configured grant type 1 periodicity timeDomainOffset: Offset of the resource relative to SFN=0 in the time domain timeDomainAllocation: Allocation of configured grant in the time domain, including the parameter startSymbolAndLength nrofHARQ-Processes: Number of HARQ processes Also, when Type 2 is configured, RRC configures the following parameters: cs-RNTI: CS-RNTI for activation, deactivation, and retransmission periodicity: configured grant type 2 periodicity nrofHARQ-Processes: Number of HARQ processes That is, ConfiguredGrantConfig is used to configure uplink transmission without dynamic grant according to two schemes: the actual uplink grant is configured via RRC in Configured Grant Type 1, and is given via PDCCH processed with CS-RNTI in Configured Grant Type 2.

[0078] The parameter repK configured by the higher layer defines the number of repetitions applied to the transmitted transport block. The parameter repK-RV configured by the higher layer indicates the redundancy version pattern applied to the repetitions. If repK-RV is not configured (given), the redundancy version of each actual repetition in the configured grant is set to 0. Otherwise, for the nth transmission opportunity in all actual repetitions (including omitted actual repetitions) among the K nominal repetitions, transmission associated with the (mod(n-1, 4)+1)th value in the configured RV sequence (redundancy version pattern) is performed. Furthermore, the first transmission of a transport block begins at the first transmission opportunity of the K repetitions if the configured RV sequence is {0, 2, 3, 1}. If the configured RV sequence is {0, 3, 0, 3}, the first transmission begins at any of the K repetitions associated with RV=0. If the configured RV sequence is {0, 0, 0, 0}, the first transmission begins at any of the K repetitions except the last transmission opportunity when K=8. For any RV sequence, the repetition terminates after K repetitions, the last transmission opportunity among the K repetitions within the period P, or when an uplink grant for scheduling the same transport block is received within the period P, whichever comes first. In Rel-15, the terminal device is not expected to configure a time period for K repetitions longer than the time period calculated by the period P. For both Type 1 and Type 2 PUSCH transmissions via configured grants, when the terminal device configures repK>1, the terminal device repeats the transport block over repK consecutive slots. In this case, the terminal device applies the same symbol configuration to each slot. If the terminal device's procedure for determining the slot configuration determines that the symbol in the configured slot is a downlink symbol, transmission in that slot is omitted for multi-slot PUSCH transmissions. When repK is configured, the value can be set to 1, 2, 4, or 8. However, if the RRC parameter itself is not present, transmission is performed with a repetition count of 1.Furthermore, repK-RV can be set to any one of {0, 2, 3, 1}, {0, 3, 0, 3}, and {0, 0, 0, 0}. Note that signals of different redundancy versions generated from the same transport block are signals composed of the same transport block (information bit sequence), but at least some of the composed coded bits are different.

[0079] In NR Release 16, PUSCH repetition type B is specified. Except for PUSCHs that transmit CSI reports without transport blocks, the nominal number of repetitions is given by the higher layer parameter numberofrepetitions. The slot where PUSCH transmission starts is defined as K. s , the number of symbols per slot is N symb If the start symbol for the beginning of the slot is S and the number of consecutive symbols counted from the symbol S assigned as PUSCH is L, the slot where the nominal repetition starts is K s +ceil((S+n·L) / N symb ), the start symbol for the beginning of the slot is mod(S+n·L,N symb ) and the slot where the nominal iteration ends is given by K s +ceil((S+(n+1)·L-1) / N symb ), the end symbol for the beginning of the slot is mod(S+(n+1)·L-1,N symb ) is given by

[0080] For PUSCH repetition type B, after determining invalid symbols due to TDD configuration or received downlink control information for each of the K nominal repetitions, the remaining symbols are considered as potentially valid symbols for PUSCH repetition type B transmission. If the number of potentially valid symbols for PUSCH repetition type B transmission in a nominal repetition is greater than zero, the nominal repetition constitutes one or more actual repetitions, where each actual repetition constitutes a set of consecutive valid symbols used for PUSCH repetition type B transmission in a slot. An actual repetition by one symbol is omitted except when L=1. An actual repetition is omitted based on other conditions. Redundancy versions are applied based on the number of actual repetitions.

[0081] Inter-repetition frequency hopping in PUSCH repetition type B will now be explained. The start RB in an actual repetition within the nth nominal repetition is determined by the start RB in the uplink BWP when mod(n, 2) = 0, and is determined by the start RB in the uplink BWP, the frequency hopping offset notified by RRC signaling, and the bandwidth of the uplink BWP when mod(n, 2) = 1. On the other hand, in inter-slot frequency hopping, the start RB is determined based on a certain slot number.

[0082] In PUSCH mapping type B, a DMRS is placed at the beginning of a slot. Figure 4 shows an example of DMRS placement described in Non-Patent Document 2. In Figure 4, D represents a downlink symbol, G represents a guard symbol, and U represents an uplink symbol, with DMRS symbols indicated by diagonal lines. As a result, in the current specifications, there is a bias in the placement of DMRSs across S and U slots. This is because DMRS cannot be shared between S and U slots, i.e., joint channel estimation cannot be applied, and therefore a DMRS must be placed at the beginning of the U slot. However, the DMRS placement in the current specifications poses a problem in that the channel estimation accuracy varies depending on the data symbol. For example, the last symbol of the U slot is temporally distant from the DMRS, resulting in low channel estimation accuracy. However, the last symbol of the S slot is contiguous with the DMRS of the S slot and also with the DMRS at the beginning of the U slot, so high channel estimation accuracy can be expected. However, there is a possibility that errors will occur across the entire packet (coding block, transport block) due to the low-accuracy last data symbol of the U slot. Therefore, Non-Patent Document 2 proposes smart DMRS allocation as a DMRS allocation suitable for joint channel estimation, as shown in Fig. 4. In smart DMRS allocation, a DMRS is allocated at the beginning of an allocation, and the DMRSs are allocated at approximately equal intervals (constant intervals) within the allocation, which makes it less likely that data symbols with low channel estimation accuracy will be generated compared to the current specifications.

[0083] Non-Patent Document 2 does not disclose signaling for smart DMRS allocation or specific DMRS allocation criteria. However, it is conceivable to set parameters related to joint channel estimation and determine whether to apply joint channel estimation based on the parameters. When joint channel estimation is applied, the DMRS allocation according to the current specifications (up to Release 16) results in a large deviation in channel estimation accuracy. Therefore, by performing smart DMRS allocation instead of the current specifications, it is possible to improve transmission performance. Note that the scope for applying joint channel estimation, i.e., the number of symbols over which DMRSs are shared in time, may be set by signaling other than the RRC signaling for joint channel estimation. Note that the scope for application may be set as a parameter of the RRC signaling for joint channel estimation.

[0084] However, the DMRS allocation in the current specifications allows for the application of multi-user MIMO, in which resources are shared at the same frequency and time between multiple terminal devices with the same slot configuration. Applying multi-user MIMO can improve system throughput (cell throughput). Even when smart DMRS allocation is used, joint channel estimation can be configured and multi-user MIMO can be applied between transmitting devices with the same DMRS configuration. However, joint channel estimation must be configured for multiple terminals participating in multi-user MIMO, and the DMRS allocation must be the same. This means that the number of terminal devices that can participate in multi-user MIMO is limited, reducing the possibility of applying multi-user MIMO. This results in reduced cell throughput. Note that while multi-user MIMO is used as an example here, other technologies, such as multi-user superposition transmission (MUST) and non-orthogonal multiple access (NOMA), are not limited to multi-user MIMO as long as they allow multiple terminal devices to share radio resources. The same can be said for other technologies. Furthermore, when considering making the DMRS orthogonal to transmissions (which may be downlink transmission, uplink transmission, sidelink transmission, or any other link) of terminals (or other base stations) in other cells, it is necessary to match the settings so that the DMRS arrangement is the same as that of terminal devices in other cells, which requires cooperation between base station devices.

[0085] Therefore, it is desirable to be able to apply DMRS allocation according to the current specifications even when joint channel estimation is applied. That is, by providing RRC signaling specifying DMRS allocation in addition to RRC signaling (parameters, elements, information elements) that configures the application of joint channel estimation, it becomes possible to coordinate DMRS allocation with other terminal devices, facilitating the application of multi-user MIMO and the like. As a result, cell throughput can be increased. Note that the above two settings do not necessarily require the application of separate signaling. For example, signaling related to joint channel estimation may be configured as RRC signaling, and the DMRS allocation according to the current specifications and smart DMRS allocation may be configured as parameters of the signaling. When the signaling is configured by RRC, transmission is performed using a DMRS transmission method (such as maintaining a constant phase) for performing joint channel estimation regardless of the value. This makes it possible to apply / non-apply joint channel estimation and configure DMRS allocation when joint channel estimation is applied without increasing the RRC signaling. Note that, although the above description has been given using RRC signaling as an example, the present invention is not limited to RRC signaling and can also be applied to dynamic signaling using DCI. Furthermore, whether the setting is performed by RRC signaling or by DCI may be changed depending on the scheduling method. For example, in the case of a scheduling method called configured grant scheduling type 1 in which resources for transmission by a terminal device are allocated only by RRC signaling, the application of joint channel estimation may be configured by RRC signaling, and in the case of a scheduling method called configured grant scheduling type 2 or dynamic scheduling in which resources for transmission by a terminal device are allocated by DCI, the application of joint channel estimation may be configured by DCI. However, in the above, the application of joint channel estimation may be configured by DCI only in the case of dynamic scheduling.In this way, by enabling the configuration for joint channel estimation and the configuration for DMRS allocation to be set separately, it is possible to match the DMRS allocation among multiple terminal devices. As a result, opportunities for applying multi-user MIMO increase, and cell throughput can be increased.

[0086] Repetitive transmission is an important technology for achieving low latency because it allows data decoding for each repetitive transmission, enabling error detection during the repetitive transmission. However, when considering the entire repetitive transmission, it is possible to improve transmission characteristics by lowering the coding rate rather than by using repetitive transmission. Therefore, transmitting one TB (transport block) using multiple slots is considered. Non-Patent Document 3 proposes switching between repetitive transmission and single-TB transmission using dynamic signaling. This allows repetitive transmission to be applied when low latency is required, and batch coding and transmission using 1 TB to improve transmission characteristics, enabling control according to QoS.

[0087] If the same DMRS allocation as for repeated transmission is applied when transmitting 1TB, the DMRS will be biased when considering the entire allocated resource, resulting in bias in channel estimation accuracy. Therefore, when transmitting 1TB across multiple slots using dynamic signaling, a DMRS allocation different from the current DMRS allocation is applied. This makes it possible to obtain good transmission characteristics with a small amount of control information.

[0088] The above will be explained using the drawings. Figure 5 shows an example. The upper part of Figure 5 shows an example of repeat transmission. The figure shows an example where the actual repetition is three times, consisting of eight symbols, two symbols, and six symbols, respectively. Note that Figure 5 shows an example where PUSCH mapping type B is used and the DMRS addition position is set to "pos3." Figure 6 shows a table showing DMRS positions up to Release 16. As shown in Figure 6, when PUSCH mapping type B and the DMRS addition position is set to "pos3," the positions are "l0, 3, 6" for eight symbols, "l0" for two symbols, and "l0, 4" for six symbols. For PUSCH mapping type B, since "l0 = 0" is specified according to the NR specifications, DMRS symbols are placed in the positions indicated by diagonal lines in Figure 5. The lower part of Figure 5 shows an example where 1TB is transmitted using allocated resources with multiple repeat transmissions or multiple slot transmissions, rather than repeated transmission. The figure follows the specifications up to NR Release 16 and shows an example where the DMRS is determined every 14 symbols at most. Since the allocation is 16 symbols, it is divided into 14 symbols and 2 symbols. As shown in Figure 6, when the DMRS addition position is "pos3" with PUSCH mapping type B, the DMRS symbols are placed at positions "10, 3, 6, 9" when the allocation is 14 symbols, and at position "10" when the allocation is 2 symbols. As a result, the DMRS allocation for 1TB transmission has less DMRS imbalance (only one data symbol between DMRSs) than the DMRS allocation for repeat transmission shown at the top of Figure 5. Note that in the example of Figure 5, the number of DMRS symbols is one less for 1TB. Figure 7 shows another example. Figure 7 shows an example when "pos0" is set as the DMRS addition position with PUSCH mapping type B. The example in Figure 7 also has less DMRS imbalance (only one data symbol between DMRSs). In this way, when switching between repeat transmission and 1TB transmission using dynamic signaling, the DMRS allocation also changes. This allows DMRS allocation to be switched without additional signaling. Although the example of dynamic signaling has been shown above, higher layer signaling such as RRC signaling may be used instead of dynamic signaling.For example, RRC parameters for 1 TB transmission may be set, and when the RRC parameters for 1 TB transmission are set, smart DMRS allocation may be used for DMRS allocation. Alternatively, whether to use repeated transmission or 1 TB may be set by RRC signaling, and DMRS allocation may be notified by dynamic signaling using DCI. Alternatively, RRC parameters (information elements) related to smart DMRS allocation may be defined, and when the RRC parameters (information elements) related to smart DMRS allocation are set, smart DMRS allocation may be applied. Furthermore, one of multiple parameter sets may be set as the RRC parameter related to smart DMRS allocation, and one value from the parameter set may be specified. The parameter set may specify the number of consecutive slots to which smart DMRS allocation is applied. By dividing the signaling in this manner, it becomes possible to dynamically change the DMRS allocation depending on the status of other terminal devices. Note that, although an example in which smart DMRS is applied to radio resources for transmission at one TB has been shown, the present invention is not limited to this, and smart DMRS may be applied to allocated radio resources separated at slot boundaries. When smart DMRS is applied, in the corresponding DMRS, each DMRS symbol is transmitted with the same power and the same phase (within a predetermined range).

[0089] Next, a conventional method for determining the transport block size will be explained. First, when the retransmission is not due to a retransmission request, the control unit of the terminal device determines the number of resource elements in a slot (N RE ) is determined as follows: First, the number of resource elements (RE) in one physical resource block (PRB) allocated for the PUSCH (N' RE ) to N' RE =N SC ×N symb -N DMRS -N oh where N SC is the number of frequency domain subcarriers in one physical resource block, and 12, N symbis the number of symbols in the PUSCH allocation, N DMRS is the number of REs for DMRS per PRB indicated by RRC signaling or dynamic signaling, N oh is the overhead configured by RRC signaling. If N oh If not set, N oh is assumed to be 0. For PUSCH repetition type B, N DMRS is determined assuming a nominal repetition of L symbols (duration) without segmentation. Next, the terminal determines the total number of REs (N RE ) to N RE =min(156,N' RE )×n PRB where n PRB is the total number of PRBs allocated to the terminal device. RE Using the quantization-free intermediate variable N info Calculate N info is N info =N RE ×R×Q m ×ν, where R is the target coding rate, Q m is the modulation order, calculated from the MCS index and MCS table notified by RRC signaling or DCI. ν is the number of transmission layers. The intermediate variable N without quantization info If is less than or equal to 3284, the quantized intermediate variable N' info N' info =max(24, 2n×floor(N info / 2 n )) where n = max(3, floor(log2(N info ))-6). Using Figure 11, N' info The closest value that does not exceed the quantization intermediate variable N is determined as the TBS. info The case of >3284 will be omitted here, but we will use the table shown in Figure 11 to info NR has adopted a specification that calculates the value based on the formula.

[0090] Next, a method for determining the transport block size in this embodiment will be described. When repeated transmission is performed, the conventional method for determining the TBS is applied to the first repetition. When batch TB transmission is performed by higher layer signaling and / or dynamic signaling from the base station, the N used to calculate the TBS is RE By changing N info One way is to use a nominal number of iterations X for allocation allocation and change N' RE =X×(N SC ×N symb -N DMRS )-N oh There is a method to determine it based on N' RE =X×(N SC ×N symb -N DMRS -N oh ) and N oh Alternatively, N' may be multiplied by X, where X may be the actual number of repetitions rather than the nominal number of repetitions. RE =N SC ×N' symb -N DMRS -N oh As, N' symb N symb For example, if there is signaling for repetition and also a setting for collective TB, the number of symbols used for one PUSCH transmission is defined as N' symb For example, in Figure 5, symb is the number of symbols included in the actual repetition 1, which is 8, but in the case of bulk TB, N' symb = 16. This also means that N' symb N symb can be defined as different from

[0091] N DMRS It is also necessary to set N DMRS = 5. However, N DMRSis a value set based on one slot, and the current specifications do not assume a number of symbols exceeding 14 OFDM symbols. Therefore, if an allocation of more than 14 symbols is made, divide it into 14 symbol intervals and set N DMRS may be set. At this time, N' symb may be set to a value of 14 or less, and N' symb is the number of DMRSs, N DMRS In this case, N DMRS = 4. Note that the reference value is not fixed to 14, and may be set by RRC signaling or the like.

[0092] The radio transmitting unit 2070 performs an IFFT (Inverse Fast Fourier Transform) on the multiplexed signal to generate an OFDM symbol. The radio transmitting unit 2070 adds a CP to the OFDM symbol to generate a baseband digital signal. The radio transmitting unit 2070 then converts the baseband digital signal to an analog signal, removes unnecessary frequency components, up-converts the signal to a carrier frequency, power amplifies the signal, and transmits the signal to the base station device 10 via the transmitting antenna 208.

[0093] The receiving unit 212 is composed of a radio receiving unit (radio receiving step) 2120, a demultiplexing unit (demultiplexing step) 2122, a propagation path estimating unit (propagation path estimating step) 2144, an equalization unit (equalization step) 2126, a demodulation unit (demodulation step) 2128, and a decoding unit (decoding step) 2130.

[0094] The radio receiving unit 2120 down-converts the downlink signal received via the receiving antenna 210 into a baseband signal, removes unnecessary frequency components, controls the amplification level so that the signal level is maintained appropriately, performs quadrature demodulation based on the in-phase and quadrature components of the received signal, and converts the quadrature-demodulated analog signal into a digital signal. The radio receiving unit 2120 removes a portion corresponding to the CP from the converted digital signal, performs FFT on the signal from which the CP has been removed, and extracts a frequency domain signal.

[0095] The demultiplexing unit 2122 separates the extracted frequency domain signal into a downlink reference signal, PDCCH, PDSCH, and PBCH. The channel estimating unit 2124 estimates a frequency response (or delay profile) using a downlink reference signal (DM-RS, etc.). The frequency response result obtained by channel estimation for demodulation is input to the equalization unit 1126. The channel estimating unit 2124 measures uplink channel conditions (measures RSRP (Reference Signal Received Power), RSRQ (Reference Signal Received Quality), RSSI (Received Signal Strength Indicator), and SINR (Signal to Interference plus Noise power Ratio)) using a downlink reference signal (CSI-RS, etc.). The measurement of the downlink channel conditions is used to determine an MCS for a PUSCH, etc. The measurement result of the downlink channel conditions is used to determine a CQI index, etc.

[0096] The equalizer 2126 generates equalization weights based on the MMSE standard from the frequency response input from the channel estimator 2124. The equalizer 2126 multiplies the input signals (PUCCH, PDSCH, PBCH, etc.) from the demultiplexer 2122 by the equalization weights. The demodulator 2128 performs demodulation processing based on information on a modulation order that is determined in advance or instructed by the control unit 204.

[0097] The decoding unit 2130 performs decoding processing on the output signal of the demodulation unit 2128 based on information about a predetermined coding rate / a coding rate instructed by the control unit 204. The decoding unit 2130 inputs the decoded data (DL-SCH, etc.) to the upper layer processing unit 202.

[0098] (Second embodiment) In repetitive transmission, the base station device notifies the terminal device of the reference repetition unit (number of OFDM symbols) L and the number of repetitions K via RRC signaling or DCI. However, when considering uplink transmission, L × K symbols are not necessarily reserved consecutively for the uplink. In other words, in the case of TDD (Time Division Multiplexing), downlink (DL) and guard symbol allocation are required, making it impossible to reserve uplink resources consecutively, and some (or all) of the allocated resources may be unusable. Specifications up to Release 16, as shown in Figure 8, specify the nominal repetition, including invalid symbols due to DL allocation, and define the actual repetition taking the invalid symbols into account. Here, when the repetition unit L is set to a value of 2 or more, if only one symbol can be reserved for actual repetitive transmission based on the nominal repetition, as shown in the figure, the actual repetitive transmission is not performed and the transmission is skipped (omitted). However, this does not apply when L = 1. This is thought to be because, if joint channel estimation is not applied, repetitive transmission of only DMRS symbols is meaningless. On the other hand, when performing joint channel estimation, the repetitions of transmitting only the DMRS symbol can also be used for demodulating the data before and after the repetitions. Therefore, Non-Patent Document 2 proposes that even when L=2 or more and only one symbol can be secured for actual repetitive transmission, as shown in Figure 9, transmission should not be omitted, and DMRS should be transmitted and used for joint channel estimation.

[0099] However, when only DMRS is transmitted in repeated transmission consisting of one (single) symbol, in the case of PUSCH mapping type B (repetition type B), the first symbol of the next repetition is also DMRS, resulting in an excess of DMRS. Therefore, as shown in FIG. 10, data transmission using a single symbol under predetermined conditions will be described below.

[0100] For example, when settings related to joint channel estimation are performed by RRC signaling, and the number of symbols in actual repetition is 1 for L=2 or more, the one symbol can be used to transmit a data symbol instead of a DMRS, thereby avoiding excessive DMRS and improving transmission performance. Note that one OFDM symbol may be configured with an OFDM symbol including both DMRS and data. While the above description is given for the case of PUSCH mapping type B (and repetition type B), this may also be applied to the case of PUSCH mapping type A. In the case of PUSCH mapping type A, the first symbol of transmission is not necessarily a DMRS, so that when the number of symbols in actual repetition is 1, a data symbol is transmitted. Note that while FIG. 10 shows an example in which repetition is performed, one transport block may be transmitted with one PUSCH instead of actual repetition, by RRC signaling and / or dynamic signaling.

[0101] As described above, the redundancy version is changed for each repetition. However, when a DMRS is transmitted in a repetitive transmission consisting of one (single) symbol, it is not considered an actual repetition, and the redundancy version indicating the puncture pattern in the coded bit sequence may not be counted. However, when an OFDM symbol containing both a DMRS and a data signal is transmitted, the redundancy version may be counted. Furthermore, in a repetitive transmission consisting of one (single) symbol, if the repetition is the last transmission, or if the next OFDM symbol is transmitted at a different frequency (subcarrier) due to frequency hopping, no transmission, data transmission, or OFDM transmission consisting of DMRS and data may be performed instead of DMRS transmission. Note that even if the frequency offset related to frequency hopping is set to 0 and transmission is actually performed at the same frequency, if frequency hopping is configured by RRC signaling, etc., no transmission, data transmission, or OFDM transmission consisting of DMRS and data may be performed instead of DMRS transmission.

[0102] The program running on the device according to the present invention may be a program that controls a central processing unit (CPU) or the like to cause a computer to function so as to realize the functions of the above-described embodiments according to the present invention. The program or the information handled by the program is temporarily loaded into a volatile memory such as a random access memory (RAM) during processing, or stored in a nonvolatile memory such as a flash memory or a hard disk drive (HDD), and is read, modified, or written by the CPU as needed.

[0103] Note that a part of the device in the above-described embodiment may be realized by a computer. In this case, a program for realizing the functions of the embodiment may be recorded on a computer-readable recording medium. The program recorded on this recording medium may be read into a computer system and executed to realize the functions. The "computer system" here refers to a computer system built into the device, and includes hardware such as an operating system and peripheral devices. Furthermore, the "computer-readable recording medium" may be any of a semiconductor recording medium, an optical recording medium, a magnetic recording medium, etc.

[0104] Furthermore, the term "computer-readable recording medium" may include a medium that dynamically stores a program for a short period of time, such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, or a medium that stores a program for a fixed period of time, such as volatile memory within a computer system that serves as a server or client in such a case. The program may also be one that realizes part of the above-mentioned functions, or one that can realize the above-mentioned functions in combination with a program already stored in the computer system.

[0105] Furthermore, each functional block or feature of the device used in the above-described embodiments may be implemented or performed by an electrical circuit, typically an integrated circuit or multiple integrated circuits. The electrical circuit designed to perform the functions described herein may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or a combination thereof. The general-purpose processor may be a microprocessor, or a conventional processor, controller, microcontroller, or state machine. The electrical circuit may be composed of digital circuits or analog circuits. Furthermore, if advances in semiconductor technology result in the emergence of integrated circuit technology that replaces current integrated circuits, integrated circuits based on that technology may also be used.

[0106] The present invention is not limited to the above-described embodiment. Although an example of a device has been described in the embodiment, the present invention is not limited to this and can be applied to terminal devices or communication devices such as stationary or non-movable electronic devices installed indoors or outdoors, for example, AV equipment, kitchen equipment, cleaning / washing equipment, air conditioning equipment, office equipment, vending machines, and other household appliances.

[0107] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the invention. Furthermore, the present invention is susceptible to various modifications within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. Furthermore, configurations in which elements described in the above embodiments are substituted with elements that achieve the same effect are also included. [Industrial Applicability]

[0108] The present invention is suitable for use in a base station apparatus, a terminal apparatus, and a communication method.

Claims

1. A terminal device that transmits to a base station device, an upper layer processing unit that receives upper layer signaling including two parameters, a repetition unit and a repetition number, from the base station device; a control unit that switches between a first transmission that performs repeated transmission using the two parameters and a second transmission that performs transmission of one transport block using radio resources allocated by the two parameters, using the higher layer signaling and a predetermined field included in downlink control information; a multiplexing unit that switches between a DMRS arrangement associated with the first transmission and a DMRS arrangement associated with the second transmission according to a predetermined field included in the downlink control information; A terminal device comprising:

2. The multiplexing unit arranges at least one reference signal for each repetition when DMRS arrangement related to the first transmission is performed, and arranges at least one reference signal in radio resources allocated by the two parameters when DMRS arrangement related to the second transmission is performed. The terminal device according to claim 1.

3. 2. The terminal device according to claim 1, wherein when the multiplexing unit performs DMRS allocation related to the second transmission, the multiplexing unit divides the radio resources allocated by the two parameters into 14 symbols and allocates the DMRS to predetermined positions of the divided symbols.

4. A base station device that receives a signal transmitted by a terminal device, An upper layer processing unit that generates upper layer signaling for the terminal device, the upper layer signaling including two parameters, a repetition unit and a repetition number; a downlink control signal unit that uses a predetermined field included in downlink control information to notify switching between a first transmission in which repeated transmission is performed using the two parameters and a second transmission in which one transport block is transmitted using radio resources allocated by the two parameters, and switching between a DMRS allocation associated with the first transmission and a DMRS allocation associated with the second transmission; A base station device comprising:

5. 5. The base station apparatus according to claim 4, wherein the downlink control signal unit notifies that at least one reference signal is to be allocated for each repetition when DMRS related to the first transmission is allocated, and that at least one reference signal is to be allocated in the radio resources allocated by the two parameters when DMRS related to the second transmission is allocated.

6. 5. The base station apparatus according to claim 4, wherein, when performing DMRS allocation related to the second transmission, the downlink control signal unit divides the radio resources allocated by the two parameters into 14 symbols and allocates DMRSs at predetermined positions of the divided symbols.

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