Terminal device and base station device

Abstract

According to the present invention, during repeated transmissions, on the assumption that a repeated transmission signal and a reference signal can be shared, transmission is performed by changing the frequency of the reference signals in accordance with a redundancy version of each repeated transmission. When the redundancy version is zero, DMRS's are placed as set by RRC signaling. When the redundancy version is other than zero, the DMRS's are reduced from the placement set by RRC signaling.

Description

Technical Field

[0001] The present invention relates to a terminal device, a base station device, and a communication method thereof. This application claims priority to Japanese Patent Application No. 2020-134327 filed in Japan on August 7, 2020, the content of which is incorporated herein by reference.

Background Art

[0002] In a communication system of NR (New Radio) standardized by 3GPP (Third Generation Partnership Project), in a slot composed of a plurality of OFDM symbols, an OFDM symbol including one or a plurality of DMRS (Demodulation Reference Signal) is inserted according to the specification. A receiver that has received the transmitted slot performs channel estimation using the DMRS in the slot and demodulates the data signal in the slot.

[0003] Also, in NR Release 15, for improving communication reliability and expanding coverage, slot - to - slot repeated transmission is standardized. In slot - to - slot repeated transmission, the same data can be repeatedly transmitted in a plurality of slots. However, since a plurality of slots are required for repeated transmission, there is a problem in terms of latency. Therefore, in NR Release 16, in - slot repeated transmission is standardized. In in - slot repeated transmission, a plurality of repetition units can be set and transmitted within a slot.

[0004] In the specifications up to Rel - 16, the DMRS that can be used for channel estimation is limited within a repetition unit or within a slot. However, by using DMRSs included in different repetition units or different slots, the channel estimation accuracy can be significantly improved. Therefore, in NR Release 17, consideration is being given to DMRS sharing (DMRS bundling) that enables the use of DMRSs included in different repetition units or different slots. (Non - Patent Document 1)

[0005] DMRS sharing (DMRS bundling) is effective not only during low-speed movement but also during high-speed movement.

Prior Art Documents

Non-Patent Documents

[0006]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] Although the proposal of DMRS sharing has been made in 3GPP, the method of actually introducing it into the system has not been studied. Also, as a method of expanding coverage, not only DMRS sharing but also other technologies can be considered.

[0008] One aspect of the present invention has been made in view of such circumstances, and the object is to expand coverage by changing the policy method of DMRS and the control information related to DMRS.

Means for Solving the Problems

[0009] The configurations of the base station apparatus, the terminal apparatus, and the communication method according to one aspect of the present invention for solving the above-described problems are as follows.

[0010] (1) One aspect of the present invention is a terminal device that communicates with a base station device by means of repeated transmission, the terminal device comprising an upper layer processing unit that sets the number of repetitions and the redundancy version in the repeated transmission, and a slot configuration unit that configures a slot, wherein the slot configuration unit changes the number of reference signals in each repeated transmission based on the redundancy version in the repeated transmission. (2) One aspect of the present invention is that, in a repeated transmission in which a value other than 0 is set as the redundancy version, the slot configuration unit includes a smaller number of reference signals than the reference signals in a repeated transmission in which 0 is set as the redundancy version. (3) One aspect of the present invention is that the slot configuration unit transmits a reference signal only in a repeated transmission in which 0 is set as the redundancy version. (4) One aspect of the present invention is a base station device that communicates with a terminal device by means of repeated transmission, the base station device comprising an upper layer processing unit that sets the number of repetitions and the redundancy version in the repeated transmission, and a slot configuration unit that configures a slot, wherein the slot configuration unit changes the number of reference signals in each repeated transmission based on the redundancy version in the repeated transmission. (5) One aspect of the present invention is that, in a repeated transmission in which a value other than 0 is set as the redundancy version, the slot configuration unit includes a smaller number of reference signals than the reference signals in a repeated transmission in which 0 is set as the redundancy version. (6) One aspect of the present invention is that the slot configuration unit transmits a reference signal only in a repeated transmission in which 0 is set as the redundancy version.

Advantages of the Invention

[0011] According to one or more aspects of the present invention, it is possible to improve communication reliability or expand the communication coverage.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0013] The communication system according to this embodiment includes a base station apparatus (cell, small cell, serving cell, component carrier, eNodeB, Home eNodeB, gNodeB) and a terminal device (terminal, mobile terminal, UE: User Equipment). In this communication system, in the case of the downlink, the base station apparatus serves as a transmission apparatus (transmission point, transmission antenna group, transmission antenna port group, TRP (Tx / Rx Point)), and the terminal device serves as a reception apparatus (reception point, reception terminal, reception antenna group, reception antenna port group). In the case of the uplink, the base station apparatus serves as a reception apparatus, and the terminal device serves as a transmission apparatus. The communication system is also applicable to D2D (Device-to-Device, sidelink) communication. In that case, both the transmission apparatus and the reception apparatus are terminal devices.

[0014] The communication system is not limited to data communication between a terminal device and a base station device that involves human intervention. That is, it can also be applied to forms of data communication that do not require human intervention, such as MTC (Machine Type Communication), M2M communication (Machine-to-Machine Communication), communication for IoT (Internet of Things), NB-IoT (Narrow Band-IoT), etc. (hereinafter referred to as MTC). In this case, the terminal device becomes an MTC terminal. The communication system can use a multi-carrier transmission method such as CP-OFDM (Cyclic Prefix - Orthogonal Frequency Division Multiplexing) in the uplink and downlink. When upper layer parameters regarding the Transform precoder are set in the uplink, the communication system applies Transform precoding, that is, uses a transmission method such as DFTS-OFDM (Discrete Fourier Transform Spread - Orthogonal Frequency Division Multiplexing, also referred to as SC-FDMA) that applies DFT. In the following, the case where the OFDM transmission method is used in the uplink and downlink will be described, but it is not limited to this, and other transmission methods can be applied.

[0015] The base station device and the terminal device in this embodiment can communicate in a frequency band called a so-called licensed band for which a usage permission (license) has been obtained from the country or region where the wireless carrier provides services, and / or in a frequency band called a so-called unlicensed band that does not require a usage permission (license) from the country or region.

[0016] 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".

[0017] (First Embodiment) FIG. 1 is a diagram showing a configuration example of a communication system 1 according to the present embodiment. The communication system 1 in the present embodiment includes a base station device 10 and a terminal device 20. Coverage 10a is a range (communication area) in which the base station device 10 can be connected (communicate) with the terminal device 20 (also called a cell). Note that the base station device 10 can accommodate a plurality of terminal devices 20 in the coverage 10a.

[0018] In FIG. 1, the uplink radio communication r30 includes at least the following uplink physical channels. The uplink physical channels are used to transmit information output from the upper layer. · Physical Uplink Control Channel (PUCCH) · Physical Uplink Shared Channel (PUSCH) · Physical Random Access Channel (PRACH)

[0019] 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, the downlink data refers to Downlink transport block, Medium Access Control Protocol Data Unit: MAC PDU, Downlink-Shared Channel: DL-SCH, Physical Downlink Shared Channel: PDSCH, etc. ACK / NACK is also referred to as a signal indicating HARQ-ACK (Hybrid Automatic Repeat request ACKnowledgement), HARQ feedback, HARQ response, or HARQ control information, delivery confirmation.

[0020] 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 are composed of 1 or 2 OFDM symbols, and the other PUCCHs are composed of 4 to 14 OFDM symbols. Also, PUCCH format 0 and PUCCH format 1 are composed of 12 subcarriers in bandwidth. Also, in PUCCH format 0, 1-bit (or 2-bit) ACK / NACK is transmitted using resource elements of 12 subcarriers and 1 OFDM symbol (or 2 OFDM symbols).

[0021] Uplink control information includes a scheduling request (SR) used to request a PUSCH (Uplink-Shared Channel: UL-SCH) resource for initial transmission. The scheduling request indicates a request for a UL-SCH resource for initial transmission.

[0022] Uplink control information includes downlink channel state information (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 the precoding of the physical downlink shared channel.

[0023] In NR, upper layer parameter RI restrictions can be set. There are multiple setting parameters for the RI restriction. One is the type 1 single panel RI restriction, which is composed of 8 bits. The type 1 single panel RI restriction, 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). When r i is zero (i is 0, 1, … 7), PMI and RI reporting corresponding to the precoder associated with the i + 1 layer are not allowed. In addition to the type 1 single panel RI restriction, the RI restriction has a type 1 multi-panel RI restriction, which is composed of 4 bits. The type 1 multi-panel RI restriction, which is a bitmap parameter, forms a bit sequence r4, r3, r2, r1. Here, r4 is the MSB, and r0 is the LSB. When r i is zero (i is 0, 1, 2, 3), PMI and RI reporting corresponding to the precoder associated with the i + 1 layer are not allowed.

[0024] The CQI can use an index (CQI index) indicating a suitable modulation method (e.g., QPSK, 16QAM, 64QAM, 256QAMAM, etc.), coding rate, and frequency utilization efficiency in a predetermined band. The terminal device selects a CQI index from the CQI table that the transport block of the PDSCH will be able to receive without exceeding a block error rate (BLER) = 0.1. However, when a predetermined CQI table is set by upper layer signaling, a CQI index that the transport block will be able to receive without exceeding a BLER = 0.00001 is selected from the CQI table.

[0025] The PUSCH is a physical channel used to transmit uplink data (Uplink Transport Block, Uplink-Shared Channel: UL-SCH), and as a transmission method, CP-OFDM or DFT-S-OFDM is applied. The PUSCH may be used to transmit control information such as HARQ-ACK for downlink data and / or channel state information 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.

[0026] The PUSCH is used to transmit Radio Resource Control (RRC) signaling. RRC signaling is also referred to as RRC message / RRC layer information / RRC layer signal / RRC layer parameter / RRC information element. RRC signaling is information / signal processed in the radio resource control layer. The RRC signaling transmitted from the base station device may be common signaling for a plurality of terminal devices within the cell. The RRC signaling transmitted from the base station device may be dedicated signaling (also referred to as dedicated signaling) for a certain terminal device. That is, user device specific (user device specific) information is transmitted using dedicated signaling for a certain terminal device. The RRC message may include the UE Capability of the terminal device. UE Capability is information indicating functions supported by the terminal device.

[0027] The PUSCH is used to transmit MAC CE (Medium Access Control Element). The MAC CE is information / signal processed (transmitted) in the Medium Access Control layer. For example, the power headroom may be included in the MAC CE and reported via the PUSCH. That is, the field of the MAC CE is used to indicate the level of the power headroom. The RRC signaling and / or the MAC CE are also referred to as higher layer signaling. The RRC signaling and / or the MAC CE are included in the transport block.

[0028] 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 the initial connection establishment procedure, handover procedure, connection re-establishment procedure, synchronization for uplink transmission (timing adjustment), and indicating a request for PUSCH (UL-SCH) resources.

[0029] In uplink wireless communication, an uplink reference signal (UL RS) is used as an uplink physical signal. The uplink reference signal includes a demodulation reference signal (DMRS), a sounding reference signal (SRS), a phase tracking reference signal (PTRS), etc. The DMRS is related to the transmission of the physical uplink shared channel / physical uplink control channel. For example, when the base station device 10 demodulates the physical uplink shared channel / physical uplink control channel, it uses the demodulation reference signal to perform channel estimation / channel correction.

[0030] The SRS is not related to the transmission of the physical uplink shared channel / physical uplink control channel. The base station device 10 uses the SRS to measure the uplink channel state (CSI Measurement).

[0031] 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.

[0032] In FIG. 1, in the downlink wireless communication of r31, at least the following downlink physical channels are used. The downlink physical channel is used to transmit the information output from the upper layer. · Physical Broadcast Channel (PBCH) · Physical Downlink Control Channel (PDCCH) · Physical Downlink Shared Channel (PDSCH)

[0033] The PBCH is used to notify the master information block (Master Information Block: MIB, Broadcast Channel: BCH) commonly used in the terminal device. The MIB is one of the system information. For example, the MIB includes the downlink transmission bandwidth setting and the system frame number (SFN: System Frame number). The MIB may include information indicating at least a part of the number of the slot in which the PBCH is transmitted, the number of the subframe, and the number of the radio frame.

[0034] The PDCCH is used to transmit downlink control information (DCI). Multiple formats (also referred to as DCI formats) based on the usage are defined for the downlink control information. The DCI format may be defined based on the type and number of bits of the DCI that constitutes one DCI format. Each format is used according to the usage. 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).

[0035] One downlink assignment is used for scheduling one PDSCH within one serving cell. The downlink grant may be used at least for scheduling the PDSCH within the same slot as the slot in which the downlink grant is transmitted. The downlink assignment includes downlink control information such as frequency domain resource allocation for the PDSCH, time domain resource allocation, MCS (Modulation and Coding Scheme) for the PDSCH, NDI (New Data Indicator) indicating initial transmission or retransmission, information indicating the HARQ process number in the downlink, and Redudancy version indicating the amount of redundancy added to the codeword during error correction coding. The codeword is the 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. Note that each DCI format for downlink data transmission includes the information (fields) necessary for its usage among the above information.

[0036] One uplink grant is used to notify the terminal device of the scheduling of one PUSCH within one serving cell. The uplink grant includes uplink control information such as information regarding resource block allocation for transmitting the PUSCH (resource block allocation and hopping resource allocation), time domain resource allocation, information regarding the MCS of the PUSCH (MCS / Redundancy version), information regarding DMRS ports, information regarding retransmission of the PUSCH, TPC commands for the PUSCH, downlink channel state information (Channel State Information: CSI) requests (CSI request), etc. The uplink grant may also include information indicating the HARQ process number in the uplink, information indicating the redundancy version, transmission power control (TPC: Transmission Power Control) commands for the PUCCH, and TPC commands for the PUSCH. Note that the DCI format for each uplink data transmission includes the information (fields) necessary for its use among the above information.

[0037] The OFDM symbol number (position) for transmitting the DMRS symbol is given by the signaled period between the first OFDM symbol of the slot and the last OFDM symbol of the PUSCH resource scheduled in that slot if intra-frequency hopping is not applied and PUSCH mapping type A is used. If intra-frequency hopping is not applied and PUSCH mapping type B is used, the OFDM symbol number (position) for transmitting the DMRS symbol is given by the scheduled PUSCH resource period. If intra-frequency hopping is applied, it is given by the period per hop. For PUSCH mapping type A, only the case where the higher layer parameter indicating the position of the first DMRS is 2 and the higher layer parameter indicating the additional number of DMRSs is 3 is supported. Also, for PUSCH mapping type A, the 4-symbol period is applicable only when the higher layer parameter indicating the position of the first DMRS is 2.

[0038] The PDCCH is generated by adding a Cyclic Redundancy Check (CRC) to the downlink control information. In the PDCCH, the CRC parity bits are scrambled (exclusive logical sum operation, also called masking) using a predetermined identifier. The parity bits are scrambled with a C-RNTI (Cell-Radio Network Temporary Identifier), CS (Configured Scheduling)-RNTI, Temporary C-RNTI, P (Paging)-RNTI, SI (System Information)-RNTI, or RA (Random Access)-RNTI, SP-CSI (Semi-Persistent Channel State-Information)-RNTI, 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 (such as MCS and radio resource allocation) included in the PDCCH scrambled with the CS-RNTI is included in the upper layer parameters related to CS, and CS is activated (configured) by the upper 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 quasi-static CSI reporting. The MCS-C-RNTI is used when selecting a low spectral efficiency MCS table.

[0039] 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 Block: SIB). Part or all of the SIB can be included in the RRC message.

[0040] The PDSCH is used to transmit RRC signaling. The RRC signaling transmitted from the base station device may be common (cell-specific) to a plurality of terminal devices within the cell. That is, the information common to the user devices within the cell is transmitted using cell-specific RRC signaling. The RRC signaling transmitted from the base station device may be a dedicated message (also referred to as dedicated signaling) for a certain terminal device. That is, the user device-specific (user device unique) information is transmitted using a dedicated message for a certain terminal device.

[0041] The PDSCH is used to transmit MAC CE. The 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).

[0042] In the downlink wireless communication of FIG. 1, the synchronization signal (SS) and the downlink reference signal (DL RS) are used as the downlink physical signals. The downlink physical signals are not used to transmit the information output from the upper layer, but are used by the physical layer.

[0043] The synchronization signal is used by the terminal device to achieve synchronization in the frequency domain and time domain of the downlink. The downlink reference signal is used by the terminal device to perform channel estimation / channel 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 channel state (CSI measurement) of the downlink.

[0044] The downlink physical channel and the downlink physical signal are collectively referred to as the downlink signal. Also, the uplink physical channel and the uplink physical signal are collectively referred to as the uplink signal. Also, the downlink physical channel and the uplink physical channel are collectively referred to as the physical channel. Also, the downlink physical signal and the uplink physical signal are collectively referred to as the physical signal.

[0045] The BCH, UL-SCH, and DL-SCH are transport channels. The channels used in the MAC layer are referred to as transport channels. The unit of the transport channel used in the MAC layer is also referred to as a transport block (TB) or a MAC PDU (Protocol Data Unit). A transport block is the unit of data that the MAC layer delivers to the physical layer. In the physical layer, the transport block is mapped to codewords, and encoding processing and the like are performed for each codeword.

[0046] FIG. 2 is a schematic block diagram of the configuration of the base station apparatus 10 according to the present embodiment. The base station apparatus 10 includes an upper layer processing unit (upper layer processing step) 102, a control unit (control step) 104, a transmission unit (transmission step) 106, a transmission antenna 108, a reception antenna 110, and a reception unit (reception step) 112. The transmission unit 106 generates a physical downlink channel according to the logical channel input from the upper layer processing unit 102. The transmission unit 106 includes an encoding unit (encoding step) 1060, a modulation unit (modulation step) 1062, a downlink control signal generation unit (downlink control signal generation step) 1064, a downlink reference signal generation unit (downlink reference signal generation step) 1066, a multiplexing unit (multiplexing step) 1068, and a radio transmission unit (radio transmission step) 1070. The reception unit 112 detects a physical uplink channel (such as demodulation and decoding), and inputs the content to the upper layer processing unit 102. The reception unit 112 includes a radio reception unit (radio reception 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.

[0047] The upper layer processing unit 102 performs processing of upper 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 necessary for controlling the transmission unit 106 and the reception unit 112, and outputs it to the control unit 104. The upper layer processing unit 102 outputs downlink data (such as DL-SCH) and system information (MIB, SIB) to the transmission unit 106. Note that the DMRS configuration information may be notified to the terminal device by system information (MIB or SIB) instead of by notification from an upper layer such as RRC.

[0048] The upper layer processing unit 102 generates the system information (a part of MIB or SIB) to be broadcasted or obtains it from the upper node. The upper layer processing unit 102 outputs the system information to be broadcasted to the transmission unit 106 as BCH / DL-SCH. The MIB is arranged in the PBCH at the transmission unit 106. The SIB is arranged in the PDSCH at the transmission unit 106. The upper layer processing unit 102 generates the system information (SIB) specific to the terminal device or obtains it from the upper layer. The SIB is arranged in the PDSCH at the transmission unit 106.

[0049] The upper layer processing unit 102 sets various RNTIs for each terminal device. The RNTI is used for encryption (scrambling) such as PDCCH and PDSCH. The upper layer processing unit 102 outputs the RNTI to the control unit 104 / transmission unit 106 / reception unit 112.

[0050] The upper layer processing unit 102 generates the downlink data (transport block, DL-SCH) arranged in the PDSCH, the system information (System Information Block: SIB) specific to the terminal device, the RRC message, the MAC CE, and the DMRS configuration information. If it is not notified by system information such as SIB and MIB or DCI, the DMRS configuration information, etc. are generated or obtained from the upper node and output to the transmission unit 106. The upper layer processing unit 102 manages various setting information of the terminal device 20. Note that a part of the functions of radio resource control may be performed by the MAC layer or the physical layer.

[0051] The upper layer processing unit 102 receives information regarding the terminal device, such as the functions supported by the terminal device (UE capability), from the terminal device 20 (via the receiving unit 112). The terminal device 20 transmits information about its own functions to the base station device 10 by means of an upper layer signal (RRC signaling). The information regarding the terminal device includes information indicating whether the terminal device supports a predetermined function or information indicating the completion of the introduction and testing of a predetermined function. Whether the terminal device supports a predetermined function includes whether the introduction and testing of the predetermined function have been completed.

[0052] When the terminal device supports a predetermined function, the terminal device transmits information (parameters) indicating whether it supports the predetermined function. When the terminal device does not support a predetermined function, the terminal device may not transmit information (parameters) indicating whether it supports the predetermined function. That is, whether the terminal device supports a predetermined function is notified by whether it transmits information (parameters) indicating whether it supports the predetermined function. Note that the information (parameters) indicating whether the terminal device supports a predetermined function may be notified using 1 or 0 bits.

[0053] The upper layer processing unit 102 obtains the DL-SCH from the decoded uplink data (including 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 at the MAC layer.

[0054] The control unit 104 controls the transmission unit 106 and the reception unit 112 based on various setting information input from the upper layer processing unit 102 / reception unit 112. The control unit 104 generates downlink control information (DCI) based on the setting information input from the upper layer processing unit 102 / reception unit 112 and outputs it to the transmission unit 106. For example, the control unit 104 considers the setting information regarding DMRS (whether it is DMRS configuration 1 or DMRS configuration 2) input from the upper layer processing unit 102 / reception unit 112, and sets the frequency arrangement of DMRS (even subcarriers or odd subcarriers in the case of DMRS configuration 1, and either the 0th to 2nd sets in the case of DMRS configuration 2), and generates DCI.

[0055] The control unit 104 determines the MCS of the PUSCH in consideration of the channel quality information (CSI Measurement result) measured by the propagation path estimation unit 1122. The control unit 104 determines the MCS index corresponding to the MCS of the PUSCH. The control unit 104 includes the determined MCS index in the uplink grant.

[0056] The transmission unit 106 generates a PBCH, PDCCH, PDSCH, and downlink reference signal, etc., according to the signals input from the upper layer processing unit 102 / control unit 104. The encoding unit 1060 encodes BCH, DL-SCH, etc. input from the upper layer processing unit 102 using a predetermined / encoding method determined by the upper layer processing unit 102, such as block coding, convolutional coding, turbo coding, polar coding, LDPC coding, etc. (including repetition). The encoding unit 1060 punctures the encoded bits based on the coding rate input from the control unit 104. The modulation unit 1062 data-modulates the encoded bits input from the encoding unit 1060 using a predetermined / modulation method (modulation order) input from the control unit 104, such as BPSK, QPSK, 16QAM, 64QAM, 256QAM, etc. The modulation order is based on the MCS index selected by the control unit 104.

[0057] The downlink control signal generation unit 1064 adds a CRC to the DCI input from the control unit 104. The downlink control signal generation unit 1064 encrypts (scrambles) the CRC using an RNTI. Further, the downlink control signal generation unit 1064 performs QPSK modulation on the DCI to which the CRC has been added to generate a PDCCH. The downlink reference signal generation unit 1066 generates a known sequence as a downlink reference signal by the terminal device. The known sequence is obtained according to a rule predetermined based on a physical cell identifier for identifying the base station device 10 or the like.

[0058] 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 PDCCH / downlink reference signal to the modulation symbols of each channel to resource elements. The resource elements to be mapped are controlled by the downlink scheduling input from the control unit 104. A resource element is the smallest unit of physical resource composed of one OFDM symbol and one subcarrier. Note that a resource block (RB) is composed of a plurality of resource elements, and scheduling is applied with the RB as the smallest unit. Note that when performing MIMO transmission, the transmission unit 106 has an encoding unit 1060 and a modulation unit 1062 with the number of layers. In this case, the upper layer processing unit 102 sets the MCS for each transport block of each layer.

[0059] The wireless transmission unit 1070 performs an inverse fast Fourier transform (IFFT) on the multiplexed modulation symbols and the like to generate an OFDM symbol. The wireless transmission unit 1070 adds a cyclic prefix (CP) to the OFDM symbol to generate a baseband digital signal. Further, the wireless transmission unit 1070 converts the digital signal into an analog signal, removes extra frequency components by filtering, up-converts to a carrier frequency, amplifies the power, and outputs the signal to the transmission antenna 108 for transmission.

[0060] According to the instruction of the control unit 104, the receiving unit 112 detects (separates, demodulates, and decodes) the received signal from the terminal device 20 via the receiving antenna 110, and inputs the decoded data to the upper layer processing unit 102 / control unit 104. The radio receiving unit 1120 converts the uplink signal received via the receiving antenna 110 into a baseband signal by down-conversion, removes unnecessary frequency components, controls the amplification level so that the signal level is appropriately maintained, performs quadrature demodulation based on the in-phase component and the quadrature component of the received signal, and converts the quadrature-demodulated analog signal into a digital signal. The radio receiving unit 1120 removes the portion corresponding to the CP from the converted digital signal. The radio receiving unit 1120 performs a Fast Fourier Transform (FFT) on the signal with the CP removed to extract the signal in the frequency domain. The signal in the frequency domain is output to the multiplexing separation unit 1124.

[0061] Based on the uplink scheduling information (such as uplink data channel allocation information) input from the control unit 104, the multiplexing separation unit 1124 separates the signal input from the radio receiving unit 1120 into signals such as PUSCH, PUCCH, and uplink reference signals. The separated uplink reference signal is input to the propagation path estimation unit 1122. The separated PUSCH and PUCCH are output to the equalization unit 1126.

[0062] The propagation path estimation unit 1122 estimates the frequency response (or delay profile) using the uplink reference signal. The frequency response result estimated for demodulation is input to the equalization unit 1126. The propagation path estimation unit 1122 measures the uplink channel condition (measurement of RSRP (Reference Signal Received Power), RSRQ (Reference Signal Received Quality), RSSI (Received Signal Strength Indicator)) using the uplink reference signal. The measurement of the uplink channel condition is used for determining the MCS for PUSCH, etc.

[0063] Equalizer unit 1126 performs processing to compensate for the influence in the propagation path from the frequency response input from the propagation path estimation unit 1122. As a compensation method, any existing propagation path compensation such as a method of multiplying MMSE weights or MRC weights, or a method of applying MLD can be applied. Demodulation unit 1128 performs demodulation processing based on information on the modulation method determined in advance / instructed from control unit 104.

[0064] Decoder unit 1130 performs decoding processing on the output signal of the demodulation unit based on information on the coding rate determined in advance / instructed from control unit 104. Decoder unit 1130 inputs the decoded data (such as UL-SCH) to upper layer processing unit 102.

[0065] FIG. 3 is a schematic block diagram showing the configuration of the terminal device 20 in the present embodiment. The terminal device 20 includes an upper layer processing unit (upper layer processing step) 202, a control unit (control step) 204, a transmission unit (transmission step) 206, a transmission antenna 208, a reception antenna 210, and a reception unit (reception step) 212.

[0066] The upper layer processing unit 202 performs processing of the medium access control (MAC) layer, packet data convergence protocol (PDCP) layer, radio link control (RLC) layer, and radio resource control (RRC) layer. The upper layer processing unit 202 manages various setting information of its own terminal device. The upper layer processing unit 202 notifies the base station device 10 of information (UE Capability) indicating the functions of the terminal device supported by its own terminal device via the transmission unit 206. The upper layer processing unit 202 notifies UE Capability by RRC signaling.

[0067] The upper layer processing unit 202 acquires the decoded data such as DL-SCH and BCH from the receiving unit 212. The upper layer processing unit 202 generates HARQ-ACK from the error detection result of the DL-SCH. The upper layer processing unit 202 generates SR. The upper layer processing unit 202 generates UCI including HARQ-ACK / SR / CSI (including CQI report). Also, when the DMRS configuration information is notified by the upper layer, the upper layer processing unit 202 inputs the information regarding the DMRS configuration to the control unit 204. The upper layer processing unit 202 inputs the UCI and UL-SCH to the transmitting unit 206. Note that a part of the functions of the upper layer processing unit 202 may be included in the control unit 204.

[0068] The control unit 204 interprets the downlink control information (DCI) received via the receiving unit 212. The control unit 204 controls the transmitting unit 206 according to the PUSCH scheduling / MCS index / TPC (Transmission Power Control), etc. obtained from the DCI for uplink transmission. The control unit 204 controls the receiving unit 212 according to the PDSCH scheduling / MCS index, etc. obtained from the DCI for downlink transmission. Further, the control unit 204 specifies the frequency arrangement of the DMRS according to the information regarding the frequency arrangement (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.

[0069] The transmitting unit 206 is configured to include an encoding unit (encoding step) 2060, a modulation unit (modulation step) 2062, an uplink reference signal generation unit (uplink reference signal generation step) 2064, an uplink control signal generation unit (uplink control signal generation step) 2066, a multiplexing unit (multiplexing step) 2068, and a radio transmitting unit (radio transmission step) 2070.

[0070] The symbolization unit 2060 performs convolutional coding, LDPC coding, polar coding, turbo coding, etc. on the uplink data (UL-SCH) input from the upper layer processing unit 202 according to the control of the control unit 204 (according to the coding rate calculated based on the MCS index).

[0071] The modulation unit 2062 modulates the coded bits input from the symbolization unit 2060 with a modulation method predetermined for each modulation method / channel such as BPSK, QPSK, 16QAM, 64QAM, 256QAM, etc. instructed by the control unit 204 (generates modulation symbols for PUSCH).

[0072] The uplink reference signal generation unit 2064 generates a sequence obtained by a predetermined rule (formula) based on the physical cell identifier (referred to as physical cell identity: PCI, Cell ID, etc.) for identifying the base station apparatus 10, the bandwidth for arranging the uplink reference signal, the cyclic shift, the parameter values for generating the DMRS sequence, and further the frequency arrangement, etc., according to the instruction of the control unit 204.

[0073] The uplink control signal generation unit 2066 encodes UCI, performs BPSK / QPSK modulation according to the instruction of the control unit 204, and generates modulation symbols for PUCCH.

[0074] When the upper layer parameter (frequencyHopping) related to the frequency hopping of Rel-15 is set, the values that can be set are Mode 1 or Mode 2. Mode 2 is inter-slot hopping, which is a mode in which when transmitting using multiple slots, the frequency is changed for each slot. On the other hand, Mode 1 is intra-slot hopping, which is a mode in which when transmitting using one or more slots, the slot is divided into the first half and the second half, and the frequency is changed for the first half and the second half for transmission. As for the 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 to allocate radio resources shifted by the value set by the upper layer parameter (frequencyHoppingOffset) related to the frequency hopping amount with respect to the radio resources used in the first hop.

[0075] The multiplexing unit 2068 multiplexes (i.e., each signal is mapped to a resource element) the modulation symbols for PUSCH, the modulation symbols for PUCCH, and the uplink reference signal for each transmission antenna port (DMRS port) according to the uplink scheduling information from the control unit 204 (such as the transmission interval in CS (Configured Scheduling) for the uplink included in the RRC message, and the frequency domain and time domain resource allocation included in DCI).

[0076] Here, an explanation of CS (configured scheduling) will be given. There are two types of transmissions without dynamic grants. One is configured grant type 1 given by RRC and stored as a configured grant, and the other is configured grant type 2 given by PDCCH and stored and cleared as a configured grant based on L1 signaling indicating configured grant activation or deactivation. Type 1 and type 2 are set by RRC for each serving cell and for each BWP. Multiple settings can only be active simultaneously in different serving cells. Regarding type 2, activation and deactivation are independent between serving cells. For the same serving cell, the MAC entity is set with either type 1 or type 2. When type 1 is set, RRC sets the following parameters. · cs-RNTI: CS-RNTI for retransmission · periodicity: Period of configured grant type 1 · timeDomainOffset: Offset of the resource regarding SFN = 0 in the time domain · timeDomainAllocation: Allocation of the configured grant in the time domain including the parameter startSymbolAndLength · nrofHARQ-Processes: Number of HARQ processes. Also, when type 2 is set, RRC sets the following parameters. · cs-RNTI: CS-RNTI for activation, deactivation, and retransmission · periodicity: Period of configured grant type 2 · nrofHARQ-Processes: The number of HARQ processes, i.e., ConfiguredGrantConfig, is used to configure uplink transmission without dynamic grants according to two methods. The actual uplink grant is set via RRC for Configured Grant type 1 and given via PDCCH processed with CS-RNTI for Configured Grant type 2.

[0077] The parameter repK set at the upper layer defines the number of repetitions applied to the transmitted transport block. repK-RV indicates the redundancy version pattern applied to the repetition. For the n-th transmission opportunity during K repetitions, the transmission associated with the (mod(n - 1, 4)+1)-th value in the set RV sequence (redundancy version pattern) is performed. Also, the first transmission of a transport block starts at the first transmission opportunity of K repetitions when the set RV sequence is {0, 2, 3, 1}. When the set RV sequence is {0, 3, 0, 3}, it starts at any transmission opportunity of K repetitions associated with RV = 0. When the set RV sequence is {0, 0, 0, 0}, it starts at any transmission opportunity of K repetitions except the last transmission opportunity when K = 8. For any RV sequence, the repetition terminates when it first reaches any of the following: after K repeated transmissions, at the last transmission opportunity during K repetitions within the period P, or when receiving an uplink grant for scheduling the same transport block within the period P. In Rel-15, the terminal device does not expect a time period for K repeated transmissions longer than the time period calculated by the period P. For both type 1 and type 2 PUSCH transmissions by the configured grant, when the terminal device sets repK>1, the terminal device repeats the transport block across consecutive slots of repK. At this time, the terminal device applies the same symbol arrangement in each slot. If the terminal device's procedure for determining the slot configuration determines the symbols of the arranged slot as downlink symbols, the transmission in that slot is omitted for PUSCH transmissions across multiple slots. When repK is set, it can be set to any of 1, 2, 4, or 8 as a value. However, when the RRC parameter itself does not exist, the number of repetitions is set to 1 for transmission. Also, repK-RV can be set to any of {0, 2, 3, 1}, {0, 3, 0, 3}, {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 encoded bits that make them up are different. In NR Release 16, the inter-slot repetition is named PUSCH repetition type B. In the Release 16 specification, for PUSCH repetition type B, after determining the invalid symbols for each of the K nominal repetitions, the remaining symbols are regarded as potential valid symbols for PUSCH repetition type B. If the number of potential valid symbols for PUSCH repetition type B is greater than 0 for a certain nominal repetition, that nominal repetition constitutes one or more actual repetitions. Here, each actual repetition constitutes a set of consecutive potential valid symbols that can be used for PUSCH repetition type B within one slot. An actual repetition consisting of one symbol is omitted unless the symbol length L is 1. The actual repetitions are omitted according to specific conditions. The redundancy version applied to the n-th actual repetition (including the count of the omitted actual repetitions) is determined according to the table described in the specification.

[0078] If DMRS sharing (DMRS bundling) being considered in 3GPP is applied, DMRS can be shared among the above-mentioned slots. However, if DMRS sharing is applied to all transmission slots, there are problems such as the terminal being unable to change the phase of the transmission signal. Therefore, a solution to the above problem is shown below. Settings related to DMRS sharing are transmitted by RRC signaling or signaling by DCI. When settings related to DMRS sharing are made in the terminal, information regarding the time-domain slot of DMRS is notified to the terminal device by separate RRC signaling or signaling by DCI. The terminal device performs transmission so that DMRS sharing can be applied by the base station device, which is the receiver, for the number of slots determined by the information regarding the time-domain slot from the first transmission slot. In other words, transmission is performed so as to be regarded as QCL (Quasi-Colocation). That is, transmission is performed so that the amplitude and phase of the propagation path do not change (so as not to be discontinuous) among slots. Figure 4 is a diagram for explaining a case where the number of repeated transmissions is 4 and 2 slots are set as the DMRS sharing period by upper layer signaling such as RRC. In the case of the figure, it shows that the transmission device performs transmissions with DMRS sharing in the first and second slots, and further performs transmissions with DMRS sharing also in the third and fourth slots. In this case, the second slot and the third slot are consecutive slots, but DMRS sharing cannot be applied. Note that even when 4 times of repeated transmission is applied, and the terminal device starts transmission from the second time without performing the first transmission and performs a total of 3 times of repeated transmission up to 4 times of repetition, in actual transmission, slots satisfying QCL are determined based on the repetition number specified by the base station instead of actual transmission. However, when specified by separate control information, counting may start from actual transmission. Also, the slots specified by the information regarding the time-domain slot may be transmitted so as to be non-consecutive and non-continuous slots to be QCL. Whether transmission from other than the first time of the assigned repetition is enabled or disabled may be set by RRC signaling.

[0079] In NR, slot - inner frequency hopping / slot - to - slot frequency hopping / repetition - to - repetition frequency hopping are specified. However, if DMRS sharing is applied even at the frequency - hopped frequencies, the transmission characteristics generally deteriorate significantly in a frequency - selective fading environment. Therefore, when the above - mentioned hopping is applied by RRC signaling or the like, even if the offset amount of hopping is 0, regardless of the RRC signaling settings regarding DMRS sharing, it may be acceptable not to apply DMRS sharing. Note that instead of completely not applying it, it may also be acceptable to apply DMRS sharing at each hopped frequency. That is, for example, in FIG. 5 showing an example of slot - to - slot repetition transmission where slot - to - slot hopping is applied, for the first slot and the third slot using the same frequency, and the second slot and the fourth slot, DMRS sharing may be applied respectively.

[0080] In the above, the explanation was made assuming slot - to - slot repetition, but it is not limited to slot - to - slot repetition and may be applied to in - slot repetition. In this case, the setting regarding DMRS sharing by RRC signaling or signaling by DCI is based on the repetition unit rather than the slot, that is, the number of repetitions within the slot. Furthermore, QCL may be limited to within one slot of in - slot repetition, and it may be acceptable not to consider QCL for repetitions outside the slot.

[0081] When DMRS sharing is possible, channel compensation can be performed using DMRSs included in other slots, so it is not always necessary to insert a DMRS within a slot. When no DMRS is inserted, more information bits or parity bits can be transmitted, thereby reducing the communication error rate and leading to improved quality or coverage. For example, when a setting regarding DMRS reduction is made by control information such as RRC signaling, a configuration can be adopted where a DMRS is inserted only in the first repetition and not inserted in the repetitions after the second time, enabling more information bits or parity bits to be transmitted. However, if transmission starts from the second time among the repetitions specified by the base station device, no DMRS will be transmitted. A configuration is adopted where DMRSs are arranged only in slots (repetitions) with RV = 0 and not in slots (repetitions) with RV other than 0. The above will be described with reference to FIG. 6. The upper part of FIG. 6 shows the case where the RV pattern in repeated transmission is {0, 0, 0, 0}. The figure shows a 4-slot repetition, with the DMRS symbols within the slots indicated by diagonal lines and the data OFDM symbols patterned with dots. When the RV pattern is {0, 0, 0, 0}, DMRSs are transmitted in all slots. Next, when the RV pattern is {0, 3, 0, 3}, DMRSs are transmitted in the first and third slots and not included in the second and fourth slots. When the RV pattern is {0, 2, 3, 1}, DMRS is transmitted only in the first slot and not included in the second, third, and fourth slots. That is, in NR, it is not specified in the specification to start repeated transmission from a slot (repetition) with RV other than 0, so transmission must always start from a slot with RV = 0. This can avoid performing only transmissions without DMRS. Here, although a configuration is adopted where no DMRS is included in slots with RV other than 0, it may not be a completely non-inclusive configuration but rather a reduced one. For example, only front-loaded DMRSs can be transmitted, and all or part of the additional DMRSs set by RRC can be reduced.Information regarding the reduction criteria may be notified by RRC signaling. However, when the above transmission is performed in the case where in-slot frequency hopping / inter-slot frequency hopping / inter-repetition frequency hopping is applied, there is a problem that DMRS is not transmitted in the offset hop. Therefore, when any of the above frequency hopping is applied, a setting regarding DMRS sharing by RRC is performed, and even when DMRS sharing is effective, it may be configured to transmit DMRS for each repetition (slot). Note that regarding DMRS reduction, information regarding the time domain slot of the DMRS is also notified and set by RRC signaling or signaling by DCI, and it may be configured to apply for each set slot (repetition) and transmit DMRS outside the set slot.

[0082] The wireless transmission unit 2070 performs IFFT (Inverse Fast Fourier Transform) on the multiplexed signal to generate OFDM symbols. The wireless transmission unit 2070 adds a CP to the OFDM symbols to generate a baseband digital signal. Further, the wireless transmission unit 2070 converts the baseband digital signal into an analog signal, removes extra frequency components, converts it to a carrier frequency by up-conversion, amplifies the power, and transmits it to the base station device 10 via the transmission antenna 208.

[0083] The receiving unit 212 includes a wireless receiving unit (wireless receiving step) 2120, a demultiplexing unit (demultiplexing step) 2122, a propagation path estimation unit (propagation path estimation step) 2144, an equalization unit (equalization step) 2126, a demodulation unit (demodulation step) 2128, and a decoding unit (decoding step) 2130.

[0084] The wireless receiving unit 2120 converts the downlink signal received via the receiving antenna 210 into a baseband signal by down-conversion, removes unnecessary frequency components, controls the amplification level so that the signal level is properly maintained, performs quadrature demodulation based on the in-phase component and the quadrature component of the received signal, and converts the quadrature-demodulated analog signal into a digital signal. The wireless receiving unit 2120 removes the portion corresponding to the CP from the converted digital signal, performs an FFT on the signal with the CP removed, and extracts the signal in the frequency domain.

[0085] The multiplexing separation unit 2122 separates the extracted signal in the frequency domain into a downlink reference signal, PDCCH, PDSCH, and PBCH. The propagation path estimation unit 2124 estimates the frequency response (or delay profile) using the downlink reference signal (such as DM-RS). The frequency response result estimated for the propagation path for demodulation is input to the equalization unit 1126. The propagation path estimation unit 2124 measures the uplink channel status (measurement of RSRP (Reference Signal Received Power), RSRQ (Reference Signal Received Quality), RSSI (Received Signal Strength Indicator), SINR (Signal to Interference plus Noise power Ratio)) using the downlink reference signal (such as CSI-RS). The measurement of the downlink channel status is used for determining the MCS for PUSCH, etc. The measurement result of the downlink channel status is used for determining the CQI index, etc.

[0086] The equalization unit 2126 generates an equalization weight based on the MMSE norm from the frequency response input from the propagation path estimation unit 2124. The equalization unit 2126 multiplies the input signal (such as PUCCH, PDSCH, PBCH) from the multiplexing separation unit 2122 by the equalization weight. The demodulation unit 2128 performs demodulation processing based on the modulation order information determined in advance / indicated from the control unit 204.

[0087] The decoding unit 2130 performs a decoding process on the output signal of the demodulation unit 2128 based on the information on the coding rate that is determined in advance and instructed by the coding rate / control unit 204. The decoding unit 2130 inputs the decoded data (such as DL-SCH) to the upper layer processing unit 202. (Second Embodiment)

[0088] In the first embodiment, on the premise of DMRS sharing, the criteria for DMRS sharing and the reduction of DMRS were described. In the second embodiment, a method for reducing the error rate in repeated transmission without assuming DMRS sharing will be described.

[0089] In configured grant scheduling type 2, settings such as the allocation period and the number of repetitions are performed by RRC signaling, and the remaining transmission parameters (MCS and used resource blocks) are notified by PDCCH (DCI), and configured grant scheduling type 2 is activated. After that, generally, transmission will be performed with the same settings for a while. To deactivate configured grant scheduling type 2, predetermined parameters of PDCCH (DCI) are set to predetermined values and notified to the terminal device.

[0090] As described above, in configured grant scheduling type 2, the parameters set by PDCCH will be used continuously for a certain period of time. When the situation changes significantly, the parameters can be changed by reactivating by transmitting PDCCH again. However, after the change, the transmission parameters set by PDCCH will also be used continuously for a certain period of time. In particular, regarding the information on precoding (beamforming) when the terminal has a plurality of antenna ports, since the optimal value is likely to change, it is difficult to set the optimal value when there is a time difference between PDCCH transmission and actual data transmission.

[0091] Therefore, in the case of repeated transmission in configured grant scheduling, it is conceivable to apply different precoding for each repetition. That is, when configured grant scheduling type 2 is set by RRC and DCI, if a separate setting regarding precoding cycling is applied by RRC signaling, the specified precoding index is used for the first transmission, and for the second and subsequent repetitions, different precoding is applied according to a preset precoding pattern. However, one precoding pattern may be defined, or the base station may specify from among a plurality of patterns by control information. Also, when set by RRC, it may be possible not to use the notified precoding but to use the precoding determined by the terminal device. At this time, it may be restricted to apply the same precoding. (Third Embodiment)

[0092] In NR, the maximum spatial multiplexing is 8 in the case of DMRS configuration 1 and 12 in the case of DMRS configuration 2. This is because DMRS (front loaded DMRS) can only be arranged in two consecutive OFDM symbols. Up to NR Rel-16, when DMRS is allocated to three or more consecutive OFDM symbols, there is a problem that the OFDM symbols (resource elements) available for data transmission are limited and the transmission rate decreases.

[0093] If DMRS sharing can be applied in NR Rel-17, for example, even if the ratio of DMRS increases in one repeated transmission, if DMRS can be reduced in the second and subsequent repetitions, overall, spatial multiplexing can be increased without increasing the ratio of DMRS.

[0094] For the above implementation, for example, even when an RRC parameter (1 or 2) for setting the number of front-loaded DMRS up to Rel16 is set, if an RRC parameter for Rel-17 (an integer of 3 or more) is set, the DMRS is arranged according to the RRC parameter for Rel-17 (an integer of 3 or more). However, it is not limited to this. For example, the true number of DMRS may be determined by multiplying the number set by the RRC parameter set in Rel-17 by the number of front-loaded DMRS in the RRC parameter of Rel-16. In addition, there may be separate restrictions when slot inner frequency hopping or slot inner repetition (transmission) is applied. This is because when the above technology is applied, the number of consecutive allocated OFDM symbols decreases, so the insertion loss of DMRS becomes too large, or all of the DMRS symbols set within the allocation cannot be arranged at all.

[0095] A program that operates in an apparatus according to an aspect of the present invention may be a program that controls a Central Processing Unit (CPU) or the like to function a computer so as to realize the functions of the above-described embodiments according to an aspect of the present invention. The program or information handled by the program is temporarily read into a volatile memory such as a Random Access Memory (RAM) during processing, or stored in a non-volatile memory such as a flash memory or a Hard Disk Drive (HDD), and read, corrected, and written by the CPU as necessary.

[0096] Note that a part of the device in the above-described embodiment may be implemented by a computer. In that 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 be realized. Here, the "computer system" refers to a computer system built in the device and including hardware such as an operating system and peripheral devices. Also, the "computer-readable recording medium" may be any of a semiconductor recording medium, an optical recording medium, a magnetic recording medium, etc.

[0097] Furthermore, the "computer-readable recording medium" includes those that hold a program dynamically for a short 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, and those that hold a program for a certain time, such as a volatile memory inside a computer system that serves as a server or a client in that case. Also, the above program may be for realizing a part of the aforementioned functions, and may further be realized in combination with a program already recorded in the computer system for realizing the aforementioned functions.

[0098] In addition, each functional block or various features of the apparatus used in the above-described embodiments can be implemented or executed by an electric circuit, that is, typically an integrated circuit or a plurality of integrated circuits. The electric circuit designed to execute the functions described in this specification may include a general-purpose use processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gates or transistor logic, discrete hardware components, or a combination thereof. The general-purpose use processor may be a microprocessor, or may be a conventional type processor, controller, microcontroller, or state machine. The above-described electric circuit may be composed of a digital circuit or an analog circuit. Further, when an integrated circuit technology that replaces the current integrated circuit appears due to the progress of semiconductor technology, it is also possible to use an integrated circuit based on such technology.

[0099] Note that the invention of the present application is not limited to the above-described embodiments. In the embodiments, an example of the apparatus has been described, but the invention of the present application is not limited thereto, and it can be applied to stationary or non-mobile electronic devices installed indoors and outdoors, for example, terminal devices or communication devices such as AV devices, kitchen devices, cleaning and washing devices, air conditioning devices, office devices, vending machines, and other household appliances.

[0100] As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and design changes and the like within the scope not departing from the gist of the present invention are also included. Further, one aspect of the present invention can be variously modified within the scope shown in 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. In addition, a configuration in which elements described in the above embodiments and elements having the same effect are replaced with each other is also included.

Industrial Applicability

[0101] One aspect of the present invention is suitable for use in a base station device, a terminal device, and a communication method.

Explanation of Signs

[0102] 10 Base station device 20 Terminal device 10a Range where the base station device 10 can be connected to the terminal device 102 Upper layer processing unit 104 Control unit 106 Transmission unit 108 Transmission antenna 110 Reception antenna 112 Reception unit 1060 Encoding unit 1062 Modulation unit 1064 Downlink control signal generation unit 1066 Downlink reference signal generation unit 1068 Multiplexing unit 1070 Wireless transmission unit 1120 Wireless reception unit 1122 Propagation path estimation unit 1124 Multiplexing separation unit 1126 Equalization unit 1128 Demodulation unit 1130 Decoding unit 202 Upper layer processing unit 204 Control unit 206 Transmission unit 208 Transmission antenna 210 Reception antenna 212 Reception unit 2060 Encoding unit 2062 Modulation unit 2064 Uplink reference signal generation unit 2066 Uplink control signal generation unit 2068 Multiplexing unit 2070 Wireless transmission unit 2120 Wireless reception unit 2122 Multiplexing separation unit 2124 Propagation path estimation unit 2126 Equalization unit 2128 Demodulation unit 2130 Decoding unit

Claims

1. A terminal device that communicates with a base station device by means of iterative transmission, comprising a higher layer processing unit that sets the number of iterations and the redundancy version in the iterative transmission, and a slot configuration unit that constitutes a slot, wherein the slot configuration unit changes the number of reference signals in each iterative transmission based on the redundancy version in the iterative transmission.

2. The terminal device according to Claim 1, wherein in iterative transmissions with a redundancy version set to a value other than 0, the slot configuration unit includes a smaller number of reference signals than in iterative transmissions with a redundancy version set to 0.

3. The terminal device according to Claim 1, wherein the slot configuration unit transmits reference signals only in iterative transmissions with a redundancy version set to 0.

4. A base station device that communicates with a terminal device by means of iterative transmission, comprising a higher layer processing unit that sets the number of iterations and the redundancy version in the iterative transmission, and a slot configuration unit that constitutes a slot, wherein the slot configuration unit changes the number of reference signals in each iterative transmission based on the redundancy version in the iterative transmission.

5. The base station device according to Claim 4, wherein in iterative transmissions with a redundancy version set to a value other than 0, the slot configuration unit includes a smaller number of reference signals than in iterative transmissions with a redundancy version set to 0.

6. The base station device according to Claim 4, wherein the slot configuration unit transmits reference signals only in iterative transmissions with a redundancy version set to 0.

Images