JP7745555B2 - Terminal device, base station device, and communication method - Google Patents

Description

The present invention relates to a terminal device, a base station device, and a communication method.
This application claims priority to Japanese Patent Application No. 2020-150234, filed on September 8, 2020, the contents of which are incorporated herein by reference.

A radio access method and radio network for cellular mobile communications (hereinafter referred to as "Long Term Evolution (LTE)" or "EUTRA: Evolved Universal Terrestrial Radio Access") is being studied by the 3rd Generation Partnership Project (3GPP). In LTE, base station devices are also called eNodeBs (evolved NodeBs), and terminal devices are also called UEs (User Equipment). LTE is a cellular communication system in which multiple areas covered by base station devices are arranged in the form of cells. A single base station device may manage multiple serving cells.

3GPP is currently studying and standardizing the next-generation standard (NR: New Radio) as a 5G communications method. NR is required to meet the requirements of three scenarios: eMBB (enhanced Mobile Broadband), mMTC (massive Machine Type Communication), and URLLC (Ultra Reliable and Low Latency Communication) within a single technology framework.

In addition, methods for improving coverage are being studied (Non-Patent Document 1). eMBB services and VoIP services are considered as target services. The uplink channels of PUSCH and PUCCH are considered to be channels requiring coverage improvement. Sequence-based DMRS-less noncoherent PUCCH transmission is being studied as a PUCCH method for transmitting and receiving more than one bit (Non-Patent Document 2).

"New SID on NR coverage enhancement", RP-193240, China Telecom, 3GPP TSG RAN Meeting #86, Sitges, Spain, December 9-12, 2019. "Potential techniques for coverage enhancements", R1-2004499, Qualcommm, 3GPP TSG RAN1 Meeting #101, e-Meeting, May 25th-June 5th, 2020.

To appropriately control data retransmission, the data receiver must provide appropriate feedback to the data transmitter, including data error detection results and data reception results (whether the received data was correct, whether the received data was erroneous, or whether the data was not received). The data transmitter retransmits data that was not properly received at the receiver based on the information provided as feedback from the data receiver. For example, the data transmitter is a base station device, the data receiver is a terminal device, the data is a transport block (transport block transmitted and received via PDSCH), and the data error detection results and reception results are HARQ-ACKs. Efficient communication is achieved by achieving appropriate retransmission control. To this end, it is necessary to be able to transmit and receive multiple HARQ-ACKs using sequence-based DMRS-less noncoherent PUCCH transmission. One aspect of the present invention provides a terminal device, a base station device, a communication method used in the terminal device, and a communication method used in the base station device, which perform efficient communication.

(1) In order to achieve the above object, one aspect of the present invention employs the following means. That is, a first aspect of the present invention is a terminal device comprising a processor and a memory for storing computer program code, which performs operations including selecting and transmitting a code sequence from among a plurality of code sequence candidates based on a combination of HARQ-ACKs for PDSCHs corresponding to each C-DAI value, and which uses a different candidate for each C-DAI value corresponding to the last received PDSCH.

(2) A second aspect of the present invention is a base station device comprising a processor and a memory for storing computer program code, which performs operations including detecting a code sequence transmitted from a terminal device from among a plurality of code sequence candidates, and determining a HARQ-ACK for a PDSCH corresponding to each C-DAI value from the detected code sequence, wherein a different candidate is used for each C-DAI value corresponding to the PDSCH last received by the terminal device.

(3) A third aspect of the present invention is a communication method used in a terminal device, comprising the steps of selecting and transmitting a code sequence from among a plurality of code sequence candidates based on a combination of HARQ-ACK for a PDSCH corresponding to each C-DAI value, wherein a different candidate is used for each C-DAI value corresponding to the last received PDSCH.

(4) A fourth aspect of the present invention is a communication method used in a base station device, comprising the steps of: detecting a code sequence transmitted from a terminal device from among a plurality of code sequence candidates; and determining, from the detected code sequence, a HARQ-ACK for a PDSCH corresponding to each C-DAI value; wherein a different candidate is used for each C-DAI value corresponding to the PDSCH last received by the terminal device.

According to one aspect of this invention, terminal devices can communicate efficiently. Also, base station devices can communicate efficiently.

1 is a conceptual diagram of a wireless communication system according to an aspect of the present embodiment. 10 is an example showing the relationship between N ^slot _symb , subcarrier spacing setting μ, slot setting, and CP setting according to one aspect of the present embodiment. 1 is a diagram illustrating an example of a configuration of a radio frame, a subframe, and a slot according to an aspect of the present embodiment. FIG. 2 is a schematic diagram illustrating an example of a resource grid in a subframe according to an aspect of the present embodiment. FIG. 10 is a diagram illustrating an example of the configuration of one REG according to one aspect of the present embodiment. FIG. 10 is a diagram illustrating an example of the configuration of a CCE according to one aspect of the present embodiment. A figure showing an example of the relationship between the number of REGs constituting a group of REGs and a mapping method of PDCCH candidates in one aspect of this embodiment. 1 is a schematic block diagram showing the configuration of a terminal device 1 according to one aspect of the present embodiment. FIG. 2 is a schematic block diagram showing the configuration of a base station device 3 according to one aspect of the present embodiment. A figure showing an example of multiple code sequence candidates corresponding to HARQ-ACK combinations for each C-DAI value. A figure showing an example of multiple code sequence candidates corresponding to HARQ-ACK combinations for each C-DAI value. A figure showing an example of multiple code sequence candidates corresponding to HARQ-ACK combinations for each C-DAI value. A figure showing an example of multiple code sequence candidates corresponding to HARQ-ACK combinations for each C-DAI value. A figure showing an example of multiple code sequence candidates corresponding to HARQ-ACK combinations for each C-DAI value. A figure showing an example of multiple code sequence candidates corresponding to HARQ-ACK combinations for each C-DAI value. A figure showing an example of multiple code sequence candidates corresponding to HARQ-ACK combinations for each C-DAI value.

The following describes an embodiment of the present invention.

"A and/or B" may be a term including "A", "B", or "A and B".

A parameter or information indicating one or more values may mean that the parameter or information includes at least a parameter or information indicating the one or more values. The upper layer parameter may be a single upper layer parameter. The upper layer parameter may be an information element (IE) including multiple parameters.

Figure 1 is a conceptual diagram of a wireless communication system according to one aspect of this embodiment. In Figure 1, the wireless communication system includes terminal devices 1A to 1C and base station devices 3A to 3B. Hereinafter, terminal devices 1A to 1C will also be referred to as terminal devices 1 (UE). Hereinafter, base station devices 3A to 3B will also be referred to as base station devices 3 (gNB).

The base station device 3 may be configured to include one or both of an MCG (Master Cell Group) and an SCG (Secondary Cell Group). The MCG is a group of serving cells including at least a PCell (Primary Cell). The SCG is a group of serving cells including at least a PSCell (Primary Secondary Cell). The PCell may be a serving cell assigned based on initial connection. The MCG may be configured to include one or more SCells (Secondary Cells). The SCG may be configured to include one or more SCells. The serving cell identity is a short identifier for identifying the serving cell. The serving cell identity may be provided by higher layer parameters.

The frame structure is explained below.

In a wireless communication system according to one aspect of this embodiment, at least Orthogonal Frequency Division Multiplex (OFDM) is used. An OFDM symbol is a time domain unit of OFDM. An OFDM symbol includes at least one or more subcarriers. The OFDM symbol may be converted into a time-continuous signal during baseband signal generation.

The subcarrier spacing (SCS) may be given by a subcarrier spacing Δf = 2 ^μ ·15 kHz. For example, the subcarrier spacing configuration μ may be set to any of 0, 1, 2, 3, 4, and/or 5. For a certain Bandwidth Part (BWP), the subcarrier spacing configuration μ may be given by a higher layer parameter.

In a wireless communication system according to an aspect of this embodiment, a time unit _Tc is used to express a length in the time domain. The time unit _Tc may be given by _Tc = 1/(Δf _max · N _f ). Δf _max may be the maximum subcarrier spacing supported in the wireless communication system according to an aspect of this embodiment. Δf _max may be Δf _max = 480 kHz. N _f may be N _f = 4096. The constant κ is κ = Δf _max · N _f / (Δf _ref N _f,ref ) = 64. Δf _ref may be 15 kHz. N _f,ref may be 2048.

The constant κ may be a value indicating the relationship between the reference subcarrier spacing and _Tc . The constant κ may be used for the length of the subframe. The number of slots included in the subframe may be determined based at least on the constant κ. Δf _ref is the reference subcarrier spacing, and N _f,ref is a value corresponding to the reference subcarrier spacing.

Downlink transmission and/or uplink transmission are composed of 10 ms frames. A frame is composed of 10 subframes. The length of a subframe is 1 ms. The frame length may be given regardless of the subcarrier spacing Δf. That is, the frame setting may be given regardless of μ. The subframe length may be given regardless of the subcarrier spacing Δf. That is, the subframe setting may be given regardless of μ.

For a certain subcarrier spacing setting μ, the number and index of slots included in a subframe may be given. For example, the first slot number n ^μ _s may be given in ascending order within the subframe in a range from 0 to N ^subframe,μ _slot −1. For a certain subcarrier spacing setting μ, the number and index of slots included in a frame may be given. For example, the second slot number n ^μ _s,f may be given in ascending order within the frame in a range from 0 to N ^frame,μ _slot −1. N ^slot _symb consecutive OFDM symbols may be included in one slot. N ^slot _symb may be given based at least on a slot configuration and/or a cyclic prefix (CP) configuration. The slot configuration may be provided by at least a higher layer parameter tdd-UL-DL-ConfigurationCommon. The CP configuration may be provided based at least on the higher layer parameter. The CP configuration may be provided based at least on dedicated RRC signaling. The first slot number and the second slot number are also referred to as slot numbers (slot indexes).

2A shows an example of the relationship between N ^slot _symb , subcarrier spacing setting μ, slot setting, and CP setting according to one aspect of the present embodiment. In FIG. 2A, when the slot setting is 0, the subcarrier spacing setting μ is 2, and the CP setting is normal CP (normal cyclic prefix), N ^slot _symb =14, N ^frame,μ _slot =40, and N ^subframe,μ _slot =4. 2B , when the slot setting is 0, the subcarrier spacing setting μ is 2, and the CP setting is extended cyclic prefix (CP), N ^slot _symb = 12, N ^frame,μ _slot = 40, and N ^subframe,μ _slot = 4. N ^slot _symb in slot setting 0 may correspond to twice the N ^slot _symb in slot setting 1.

Figure 3 shows an example of the configuration of a radio frame, subframe, and slot according to one aspect of this embodiment. In the example shown in Figure 3, the length of a slot is 0.5 ms, the length of a subframe is 1 ms, and the length of a radio frame is 10 ms. A slot may be a unit of resource allocation in the time domain. For example, a slot may be a unit to which one transport block is mapped. For example, a transport block may be mapped to one slot. Here, a transport block may be a unit of data transmitted within a predetermined interval (e.g., a transmission time interval (TTI)) specified by a higher layer (e.g., MAC: Medium Access Control, RRC: Radio Resource Control).

For example, the length of a slot may be determined by the number of OFDM symbols. For example, the number of OFDM symbols may be 7 or 14. The length of a slot may be determined based at least on the length of an OFDM symbol. The length of an OFDM symbol may vary based at least on the subcarrier spacing. The length of an OFDM symbol may also be determined based at least on the number of points in a Fast Fourier Transform (FFT) used to generate the OFDM symbol. The length of an OFDM symbol may also include the length of a cyclic prefix (CP) added to the OFDM symbol. Here, an OFDM symbol may also be referred to as a symbol. Furthermore, when a communication method other than OFDM is used in communication between the terminal device 1 and the base station device 3 (for example, when SC-FDMA or DFT-s-OFDM is used), the generated SC-FDMA symbols and/or DFT-s-OFDM symbols are also referred to as OFDM symbols. Furthermore, unless otherwise specified, OFDM includes SC-FDMA or DFT-s-OFDM.

For example, the slot length may be 0.125 ms, 0.25 ms, 0.5 ms, or 1 ms. For example, if the subcarrier spacing is 15 kHz, the slot length may be 1 ms. For example, if the subcarrier spacing is 30 kHz, the slot length may be 0.5 ms. For example, if the subcarrier spacing is 120 kHz, the slot length may be 0.125 ms. For example, if the subcarrier spacing is 15 kHz, the slot length may be 1 ms. For example, if the slot length is 0.125 ms, one subframe may consist of eight slots. For example, if the slot length is 0.25 ms, one subframe may consist of four slots. For example, if the slot length is 0.5 ms, one subframe may consist of two slots. For example, if the slot length is 1 ms, one subframe may consist of one slot.

Here, OFDM includes a multi-carrier communication method to which pulse shaping, PAPR reduction, out-of-band emission reduction, filtering, and/or phase processing (e.g., phase rotation) are applied. A multi-carrier communication method may also be a communication method in which a signal in which multiple subcarriers are multiplexed is generated/transmitted.

A radio frame may be given by the number of subframes. The number of subframes for a radio frame may be, for example, 10. A radio frame may be given by the number of slots.

The following explains physical resources.

An antenna port is defined by the fact that the channel through which symbols are transmitted at one antenna port can be estimated from the channel through which other symbols are transmitted at the same antenna port. If the large-scale properties of the channel through which symbols are transmitted at one antenna port can be estimated from the channel through which symbols are transmitted at another antenna port, the two antenna ports are said to be Quasi Co-Location (QCL). The large-scale properties may include at least the long-range properties of the channel. The large-scale characteristics may include at least some or all of delay spread, Doppler spread, Doppler shift, average gain, average delay, and beam parameters (spatial Rx parameters). The first antenna port and the second antenna port being QCL with respect to the beam parameters may be a case where a receive beam assumed by the receiver for the first antenna port is the same as a receive beam assumed by the receiver for the second antenna port. The first antenna port and the second antenna port being QCL with respect to the beam parameters may be a case where a transmit beam assumed by the receiver for the first antenna port is the same as a transmit beam assumed by the receiver for the second antenna port. The terminal device 1 may assume that two antenna ports are QCL if the large-scale characteristics of the channel through which symbols are transmitted at one antenna port can be estimated from the channel through which symbols are transmitted at another antenna port. The fact that two antenna ports are QCL may mean that the two antenna ports are assumed to be QCL.

For each subcarrier spacing configuration and set of carriers, a resource grid of N ^μ _RB,x N ^RB _sc subcarriers and N ^(μ) _symb N ^subframe,μ _symb OFDM symbols is provided. ^{N μ} _RB,x may refer to the number of resource blocks provided for the subcarrier spacing configuration μ for carrier x. N ^μ _RB,x may also refer to the maximum number of resource blocks provided for the subcarrier spacing configuration μ for carrier x. Carrier x may refer to either a downlink carrier or an uplink carrier. That is, x may be "DL" or "UL." N ^μ _RB is a term that includes N ^μ _RB,DL and/or N ^μ _RB,UL . N ^RB _sc may refer to the number of subcarriers included in one resource block. At least one resource grid may be provided for each antenna port p, and/or for each subcarrier spacing setting μ, and/or for each transmission direction setting. The transmission directions include at least a downlink (DL) and an uplink (UL). Hereinafter, a parameter set including at least the antenna port p, the subcarrier spacing setting μ, and some or all of the transmission direction settings is also referred to as a first radio parameter set. That is, one resource grid may be provided for each first radio parameter set.

In the downlink, a carrier included in the serving cell is called a downlink carrier (or downlink component carrier). In the uplink, a carrier included in the serving cell is called an uplink carrier (uplink component carrier). Downlink component carriers and uplink component carriers are collectively referred to as component carriers (or carriers).

Each element in the resource grid assigned for each first radio parameter set is referred to as a resource element. A resource element is identified by a frequency domain index k _sc and a time domain index l _sym . For a given first radio parameter set, a resource element is identified by a frequency domain index k _sc and a time domain index l _sym . A resource element identified by the frequency domain index k _sc and the time domain index l _sym is also referred to as a resource element (k _sc , l _sym ). The frequency domain index k _sc indicates any value from 0 to N ^μ _RB N ^RB _sc −1. N ^μ _RB may be the number of resource blocks assigned for the subcarrier spacing setting μ. ^{N RB} _sc is the number of subcarriers included in a resource block, and N ^RB _sc =12. The frequency domain index k _sc may correspond to the subcarrier index k _sc . The time domain index l _sym may correspond to the OFDM symbol index l _sym .

FIG. 4 is a schematic diagram illustrating an example of a resource grid in a subframe according to one aspect of this embodiment. In the resource grid of FIG. 4, the horizontal axis represents a time domain index l _sym and the vertical axis represents a frequency domain index k _sc . In one subframe, the frequency domain of the resource grid includes N ^μ _RB N ^RB _sc subcarriers. In one subframe, the time domain of the resource grid may include 14·2 ^μ OFDM symbols. One resource block includes N ^RB _sc subcarriers. The time domain of the resource block may correspond to one OFDM symbol. The time domain of the resource block may correspond to 14 OFDM symbols. The time domain of the resource block may correspond to one or more slots. The time domain of the resource block may correspond to one subframe.

The terminal device 1 may be instructed to transmit and receive using only a subset of the resource grid. The subset of the resource grid is also referred to as a BWP (Bandwidth Part), and the BWP may be determined based at least on upper layer parameters and/or part or all of the DCI. The BWP is also referred to as a Bandwidth Part (BP). In other words, the terminal device 1 may not be instructed to transmit and receive using the entire set of the resource grid. In other words, the terminal device 1 may be instructed to transmit and receive using some of the frequency resources within the resource grid. One BWP may be composed of multiple resource blocks in the frequency domain. One BWP may be composed of multiple contiguous resource blocks in the frequency domain. A BWP set for a downlink carrier is also referred to as a downlink BWP. A BWP set for an uplink carrier is also referred to as an uplink BWP.

One or more downlink BWPs may be configured for the terminal device 1. The terminal device 1 may attempt to receive a physical channel (e.g., PDCCH, PDSCH, SS/PBCH, etc.) in one of the one or more downlink BWPs. The one downlink BWP is also referred to as an activated downlink BWP.

One or more uplink BWPs may be configured for the terminal device 1. The terminal device 1 may attempt to transmit a physical channel (e.g., PUCCH, PUSCH, PRACH, etc.) in one of the one or more uplink BWPs. The one uplink BWP is also referred to as an activated uplink BWP.

A set of downlink BWPs may be configured for the serving cell. The set of downlink BWPs may include one or more downlink BWPs. A set of uplink BWPs may be configured for the serving cell. The set of uplink BWPs may include one or more uplink BWPs.

Higher layer parameters are parameters included in higher layer signals. The higher layer signals may be RRC (Radio Resource Control) signaling or MAC CE (Medium Access Control Control Element). Here, the higher layer signals may be RRC layer signals or MAC layer signals.

The higher layer signal may be common RRC signaling. The common RRC signaling may include at least some or all of the following features C1 to C3:
Feature C1) Mapped to the BCCH logical channel or the CCCH logical channel. Feature C2) Includes at least the radioResourceConfigCommon information element. Feature C3) Mapped to the PBCH.

The radioResourceConfigCommon information element may include information indicating a configuration commonly used in the serving cell. The configuration commonly used in the serving cell may include at least a PRACH configuration. The PRACH configuration may at least indicate one or more random access preamble indices. The PRACH configuration may at least indicate time/frequency resources for the PRACH.

The higher layer signaling may be dedicated RRC signaling, which may comprise at least some or all of the following features D1 to D2:
Feature D1) Mapped to DCCH logical channel Feature D2) Includes at least radioResourceConfigDedicated information element

The radioResourceConfigDedicated information element may include at least information indicating settings specific to the terminal device 1. The radioResourceConfigDedicated information element may include at least information indicating the settings of the BWP. The settings of the BWP may indicate at least the frequency resources of the BWP.

For example, the MIB, the first system information, and the second system information may be included in common RRC signaling. Furthermore, an upper layer message that is mapped to a DCCH logical channel and that includes at least the radioResourceConfigCommon information element may be included in common RRC signaling. Furthermore, an upper layer message that is mapped to a DCCH logical channel and that does not include the radioResourceConfigCommon information element may be included in dedicated RRC signaling. Furthermore, an upper layer message that is mapped to a DCCH logical channel and that includes at least the radioResourceConfigDedicated information element may be included in dedicated RRC signaling.

The first system information may at least indicate a time index of an SS (Synchronization Signal) block. The SS block is also referred to as an SS/PBCH block. The SS/PBCH block is also referred to as an SS/PBCH. The first system information may include at least information related to PRACH resources. The first system information may include at least information related to setting up an initial connection. The second system information may be system information other than the first system information.

The radioResourceConfigDedicated information element may include at least information related to PRACH resources. The radioResourceConfigDedicated information element may include at least information related to setting up an initial connection.

The following describes physical channels and physical signals related to various aspects of this embodiment.

An uplink physical channel may correspond to a set of resource elements carrying information generated in a higher layer. An uplink physical channel is a physical channel used in an uplink carrier. In a wireless communication system according to one aspect of the present embodiment, at least some or all of the following uplink physical channels are used:
・PUCCH (Physical Uplink Control Channel)
・PUSCH (Physical Uplink Shared Channel)
・PRACH (Physical Random Access CHannel)

PUCCH may be used to transmit uplink control information (UCI). The uplink control information includes part or all of a Hybrid Automatic Repeat request ACKnowledgement (HARQ-ACK) corresponding to a channel state information (CSI), a scheduling request (SR), a transport block (TB, MAC PDU: Medium Access Control Protocol Data Unit, DL-SCH: Downlink-Shared Channel, PDSCH: Physical Downlink Shared Channel). The uplink control information may include information not described above.

The HARQ-ACK may include at least a HARQ-ACK bit (HARQ-ACK information) corresponding to at least one transport block. The HARQ-ACK bit may indicate an ACK (acknowledgement) or a NACK (negative-acknowledgement) corresponding to one or more transport blocks. The HARQ-ACK may include at least a HARQ-ACK codebook including one or more HARQ-ACK bits. The HARQ-ACK bit corresponding to one or more transport blocks may correspond to a PDSCH including the one or more transport blocks. The HARQ-ACK bit may indicate an ACK or NACK corresponding to one Code Block Group (CBG) included in the transport block.

The scheduling request (SR) may be used at least to request PUSCH resources for the initial transmission. The scheduling request bit may be used to indicate either a positive SR or a negative SR. When the scheduling request bit indicates a positive SR, this is also referred to as "a positive SR being transmitted." A positive SR may indicate that PUSCH resources for the initial transmission are requested by the terminal device 1. A positive SR may indicate that a scheduling request is triggered by a higher layer. A positive SR may be transmitted when a scheduling request is instructed to be transmitted by a higher layer. When the scheduling request bit indicates a negative SR, this is also referred to as "a negative SR being transmitted." A negative SR may indicate that PUSCH resources for the initial transmission are not requested by the terminal device 1. A negative SR may indicate that no scheduling request is triggered by higher layers. A negative SR may be sent when no scheduling request is instructed to be sent by higher layers.

The channel state information may include at least some or all of a channel quality indicator (CQI), a precoder matrix indicator (PMI), and a rank indicator (RI). The CQI is an indicator related to the channel quality (e.g., propagation strength), the PMI is an indicator indicating the precoder, and the RI is an indicator indicating the transmission rank (or the number of transmission layers).

One or more PUCCH formats (e.g., PUCCH format 0 to PUCCH format 4, PUCCH format 5) may be supported for the PUCCH. The PUCCH format may be mapped to the PUCCH and transmitted. The PUCCH format may be transmitted on the PUCCH. Transmission of a PUCCH format may also mean transmission of the PUCCH.

PUSCH is used at least to transmit transport blocks (TB, MAC PDU, UL-SCH, PUSCH). PUSCH may be used at least to transmit some or all of the transport blocks, HARQ-ACK, channel state information, and scheduling requests. PUSCH is used at least to transmit random access message 3. PUSCH may also be used to transmit information not listed above.

The PRACH is used at least to transmit a random access preamble (random access message 1). The PRACH may be used at least to indicate some or all of the following: an initial connection establishment procedure, a handover procedure, a connection re-establishment procedure, synchronization (timing adjustment) for PUSCH transmission, and a request for resources for PUSCH. The random access preamble may be used to notify the base station device 3 of an index (random access preamble index) provided by a higher layer of the terminal device 1.

In Fig. 1, the following uplink physical signals are used in uplink wireless communication: The uplink physical signals may not be used to transmit information output from higher layers, but are used by the physical layer.
・UL DMRS (UpLink Demodulation Reference Signal)
・SRS (Sounding Reference Signal)
・UL PTRS (UpLink Phase Tracking Reference Signal)

UL DMRS is related to the transmission of PUSCH and/or PUCCH. UL DMRS is multiplexed with PUSCH or PUCCH. Base station device 3 may use UL DMRS to perform propagation path correction for PUSCH or PUCCH. Hereinafter, transmitting both PUSCH and UL DMRS related to the PUSCH will be simply referred to as transmitting PUSCH. Hereinafter, transmitting both PUCCH and UL DMRS related to the PUCCH will be simply referred to as transmitting PUCCH. UL DMRS related to PUSCH is also referred to as UL DMRS for PUSCH. UL DMRS related to PUCCH is also referred to as UL DMRS for PUCCH.

The SRS may not be related to the transmission of the PUSCH or PUCCH. The base station device 3 may use the SRS to measure the channel condition. The SRS may be transmitted at the end of a subframe in an uplink slot or a predetermined number of OFDM symbols from the end.

The UL PTRS may be a reference signal used at least for phase tracking. The UL PTRS may be associated with a UL DMRS group including at least antenna ports used for one or more UL DMRSs. The association of the UL PTRS with the UL DMRS group may be such that the antenna port of the UL PTRS and some or all of the antenna ports included in the UL DMRS group are at least QCL. The UL DMRS group may be identified based at least on the antenna port with the smallest index in the UL DMRS included in the UL DMRS group. The UL PTRS may be mapped to the antenna port with the smallest index among one or more antenna ports to which a codeword is mapped. When a codeword is mapped to at least the first layer and the second layer, the UL PTRS may be mapped to the first layer. The UL PTRS may not be mapped to the second layer. The index of the antenna port to which the UL PTRS is mapped may be given based at least on the downlink control information.

In addition, uplink physical signals not described above may also be used.

1, the following downlink physical channels are used in downlink wireless communication from the base station device 3 to the terminal device 1. The downlink physical channels are used by the physical layer to transmit information output from higher layers.
・PBCH (Physical Broadcast Channel)
・PDCCH (Physical Downlink Control Channel)
・PDSCH (Physical Downlink Shared Channel)

The PBCH is used at least to transmit the Master Information Block (MIB, BCH, Broadcast Channel). The PBCH may be transmitted based on a predetermined transmission interval. The PBCH may be transmitted at intervals of 80 ms. The PBCH may be transmitted at intervals of 160 ms. The content of the information contained in the PBCH may be updated every 80 ms. Some or all of the information contained in the PBCH may be updated every 160 ms. The PBCH may be composed of 288 subcarriers. The PBCH may be composed of 2, 3, or 4 OFDM symbols. The MIB may include information related to an identifier (index) of the synchronization signal. The MIB may include information indicating at least a portion of the slot number, subframe number, and/or radio frame number in which the PBCH is transmitted.

The PDCCH is used at least for transmitting downlink control information (DCI). The PDCCH may be transmitted including at least the downlink control information. The PDCCH may include the downlink control information. The downlink control information is also referred to as a DCI format. The downlink control information may include at least either a downlink grant (DL grant) or an uplink grant (UL grant). The DCI format used for scheduling the PDSCH is also referred to as a downlink DCI format. The DCI format used for scheduling the PUSCH is also referred to as an uplink DCI format. The downlink grant is also referred to as a downlink assignment (DL assignment) or a downlink allocation (DL allocation). The uplink DCI format includes at least one or both of DCI format 0_0 and DCI format 0_1.

DCI format 0_0 is configured to include at least some or all of 1A to 1F.
1A) DCI Format Identifier Field
1B) Frequency Domain Resource Assignment Field
1C) Time Domain Resource Allocation Field
1D) Frequency Hopping Flag Field
1E) MCS field (Modulation and Coding Scheme field)
1F) CSI request field

The DCI format specification field may be used at least to indicate to which of one or more DCI formats the DCI format containing the DCI format specification field corresponds. The one or more DCI formats may be based at least on some or all of DCI format 1_0, DCI format 1_1, DCI format 0_0, and/or DCI format 0_1.

The frequency domain resource allocation field may be used at least to indicate the allocation of frequency resources for a PUSCH scheduled by a DCI format including the frequency domain resource allocation field. The frequency domain resource allocation field is also referred to as an FDRA (Frequency Domain Resource Allocation) field.

The time domain resource allocation field may be used at least to indicate the allocation of time resources for a PUSH scheduled by a DCI format that includes the time domain resource allocation field.

The frequency hopping flag field may be used at least to indicate whether frequency hopping is applied to a PUSH scheduled by a DCI format that includes the frequency hopping flag field.

The MCS field may be used to indicate at least a modulation scheme and/or a target coding rate for a PUSCH scheduled by a DCI format including the MCS field. The target coding rate may be a target coding rate for a transport block of the PUSCH. The size of the transport block (TBS: Transport Block Size) may be determined based at least on the target coding rate.

The CSI request field is used at least to indicate the reporting of CSI. The size of the CSI request field may be a predetermined value. The size of the CSI request field may be 0, 1, 2, or 3.

DCI format 0_1 is configured to include at least some or all of 2A to 2H.
2A) DCI format specific field 2B) Frequency domain resource allocation field 2C) Time domain resource allocation field 2D) Frequency hopping flag field 2E) MCS field 2F) CSI request field
2G) BWP field (BWP field)
2H) UL DAI field (downlink assignment index)

The UL DAI field is used at least to indicate the transmission status of the PDSCH. If a dynamic HARQ-ACK codebook is used, the size of the UL DAI field may be 2 bits. The UL DAI field indicates the size of the HARQ-ACK codebook transmitted on the PUSCH. The UL DAI field indicates the number of HARQ-ACKs included in the HARQ-ACK codebook transmitted on the PUSCH. The UL DAI field indicates the number of PDSCHs for which the corresponding HARQ-ACK is included in the HARQ-ACK codebook transmitted on the PUSCH. The UL DAI field indicates the number of PDSCHs and SPS releases in which the corresponding HARQ-ACK is included in the HARQ-ACK codebook transmitted on the PUSCH.

The UL DAI field may indicate a value to which modulo arithmetic has been applied. An example in which the UL DAI field is 2 bits will be described. If the number of PDSCHs for which the corresponding HARQ-ACK is included in the HARQ-ACK codebook transmitted on the PUSCH is 0, the UL DAI field indicates "00". If the number of PDSCHs for which the corresponding HARQ-ACK is included in the HARQ-ACK codebook transmitted on the PUSCH is 1, the UL DAI field indicates "01". If the number of PDSCHs for which the corresponding HARQ-ACK is included in the HARQ-ACK codebook transmitted on the PUSCH is 2, the UL DAI field indicates "10". When the number of PDSCHs for which the corresponding HARQ-ACK is included in the HARQ-ACK codebook transmitted by the PUSCH is three, the UL DAI field indicates "11". When the number of PDSCHs for which the corresponding HARQ-ACK is included in the HARQ-ACK codebook transmitted by the PUSCH is four, the UL DAI field indicates "00". When the number of PDSCHs for which the corresponding HARQ-ACK is included in the HARQ-ACK codebook transmitted by the PUSCH is five, the UL DAI field indicates "01". When the number of PDSCHs for which the corresponding HARQ-ACK is included in the HARQ-ACK codebook transmitted by the PUSCH is six, the UL DAI field indicates "10". When the number of PDSCHs for which the corresponding HARQ-ACKs are included in the HARQ-ACK codebook transmitted on the PUSCH is 7, the UL DAI field indicates "11." In this example, a modulo operation using the value "4" is performed on the number of PDSCHs for which the corresponding HARQ-ACKs are included in the HARQ-ACK codebook transmitted on the PUSCH.

The terminal device 1 interprets the UL DAI field taking into account the total number of received PDSCHs. For example, the terminal device 1 receives four PDSCHs and receives a UL DAI field indicating "00". In this case, the terminal device 1 interprets the number of PDSCHs whose corresponding HARQ-ACKs are included in the HARQ-ACK codebook transmitted on the PUSCH indicated by the UL DAI field as four. For example, the terminal device 1 receives three PDSCHs and receives a UL DAI field indicating "00". In this case, the terminal device 1 interprets the number of PDSCHs whose corresponding HARQ-ACKs are included in the HARQ-ACK codebook transmitted on the PUSCH indicated by the UL DAI field as four, and determines that reception of one PDSCH has been missed.

The BWP field may be used to indicate the uplink BWP to which the PUSH scheduled by DCI format 0_1 is mapped.

The CSI request field is used at least to indicate the reporting of CSI. The size of the CSI request field may be based at least on the higher layer parameter ReportTriggerSize.

The downlink DCI format includes at least one or both of DCI format 1_0 and DCI format 1_1.

DCI format 1_0 is configured to include at least some or all of 3A to 3H.
3A) DCI Format Identifier Field
3B) Frequency Domain Resource Assignment Field
3C) Time Domain Resource Allocation Field
3D) Frequency hopping flag field
3E) MCS field (Modulation and Coding Scheme field)
3F) First CSI Request Field
3G) PDSCH-to-HARQ feedback timing indicator field
3H) PUCCH Resource Indicator Field

The timing indication field from the PDSCH to the HARQ feedback may be a field indicating timing K1. If the index of the slot containing the last OFDM symbol of the PDSCH is slot n, the index of the slot containing a PUCCH or PUSCH containing at least a HARQ-ACK corresponding to the transport block included in the PDSCH may be n+K1. If the index of the slot containing the last OFDM symbol of the PDSCH is slot n, the index of the slot containing the first OFDM symbol of the PUCCH or the first OFDM symbol of the PUSCH containing at least a HARQ-ACK corresponding to the transport block included in the PDSCH may be n+K1.

Hereinafter, the PDSCH-to-HARQ feedback timing indicator field (PDSCH-to-HARQ_feedback timing indicator field) may be referred to as the HARQ indication field.

The PUCCH resource indication field may be a field indicating the index of one or more PUCCH resources included in the PUCCH resource set.

DCI format 1_1 is configured to include at least some or all of 4A to 4J.
4A) DCI Format Identifier Field
4B) Frequency Domain Resource Assignment Field
4C) Time Domain Resource Allocation Field
4D) Frequency Hopping Flag Field
4E) MCS field (Modulation and Coding Scheme field)
4F) First CSI Request Field
4G) PDSCH-to-HARQ feedback timing indicator field
4H) PUCCH Resource Indicator Field
4J) BWP field

The BWP field may be used to indicate the downlink BWP to which the PDSCH scheduled by DCI format 1_1 is mapped.

DCI format 2_0 may be configured to include at least one or more slot format indicators (SFIs).

The downlink control information may include a slot format indicator (SFI). A pattern indicating whether each subframe (slot) among multiple subframes (slots) is an uplink subframe (slot), a downlink subframe (slot), or a flexible subframe (slot) may be transmitted and received using the downlink control information. The terminal device 1 may determine that a subframe (slot) not indicated by the received SFI is a flexible subframe (slot). If PUSCH transmission is scheduled for a flexible subframe (slot) by an UL grant, the terminal device 1 processes the flexible subframe (slot) as an uplink subframe (slot). If PUSCH transmission is not scheduled for a flexible subframe (slot) by an UL grant, the terminal device 1 monitors PDCCH candidates in the flexible subframe (slot) and performs processing to detect a DL assignment. When reception of the PDSCH is scheduled by a DL assignment in a flexible subframe (slot), the terminal device 1 processes the flexible subframe (slot) as a downlink subframe (slot).

For example, downlink control information including a downlink grant or an uplink grant is transmitted and received on the PDCCH, including a C-RNTI (Cell-Radio Network Temporary Identifier).

In various aspects of this embodiment, unless otherwise specified, the number of resource blocks refers to the number of resource blocks in the frequency domain.

A downlink grant is used for scheduling at least one PDSCH in one serving cell. A downlink grant is used for scheduling at least one PDSCH in the same slot as the slot in which the downlink grant is transmitted. A downlink grant may be used for scheduling a PDSCH in a slot different from the slot in which the downlink grant is transmitted. An uplink grant is used for scheduling at least one PUSH in one serving cell.

The downlink DCI format includes a field (C-DAI: Counter Downlink Assignment Index field) that indicates the cumulative number of transmitted PDCCHs. C-DAI may indicate the cumulative number of transmitted PDSCHs. For example, if the cumulative number of transmitted PDSCHs up to that point, including the transmitted PDSCH, is 1, the value of C-DAI is indicated as "1." For example, if the cumulative number of transmitted PDSCHs up to that point, including the transmitted PDSCH, is 8, the value of C-DAI is indicated as "8."

It should be noted that various DCI formats may further include fields different from the above-mentioned fields. For example, a field (NFI: New Feedback Indicator field) indicating whether or not HARQ-ACK information of the PDSCH has been correctly detected may be included. A field (NFI field) indicating whether or not to erase (flush) the HARQ-ACK bits stored in a recording medium such as a memory may be included. A field (NFI field) indicating whether or not to include retransmission of the transmitted HARQ-ACK codebook may be included. A field (PGI: PDSCH Group ID field) indicating the PDSCH group to which (linked to) the PDSCH scheduled by the DCI format belongs may be included. A field (RPGI: Request PDSCH Group ID field) indicating the PDSCH group to which transmission of HARQ-ACK information is instructed may be included. A field indicating the total number of PDCCHs to be transmitted (T-DAI: Total Downlink Assignment
The field may include a field (Index field).

The terminal device 1 may associate a PDSCH group identifier (PGI: PDSCH Group ID) with each PDSCH. The PGI of a certain PDSCH may be indicated based at least on the DCI format used to schedule the PDSCH. For example, a field indicating the PGI (PGI field) may be included in the DCI format. For example, a PDSCH group may be a set of PDSCHs having the same PGI (PDSCH group identifier). A PDSCH group may be one PDSCH, or a set of one or more PDSCHs associated with the same PGI. The number of PDSCH groups configured for the terminal device 1 may be 1, 2, 3, 4, or any other integer greater than or equal to 0.

The Requested PDSCH Group (RPG) may be a PDSCH group corresponding to the HARQ-ACK information to be transmitted (reported) via the next PUCCH or PUSCH. The RPG (Requested PDSCH Group) may include one PDSCH group or multiple PDSCH groups. The RPG indication may be indicated in the form of a bitmap corresponding to each PDSCH group based at least on the DCI format. The RPG may be indicated at least on the basis of the RPGI field included in the DCI format. The terminal device 1 may generate a HARQ-ACK codebook for the indicated RPG and transmit (report) it via the PUCCH or PUSCH.

The value of K1 (information or parameter indicated by the timing indication field from PDSCH to HARQ feedback) indicated by the DCI format included in the PDCCH may be numerical or non-numerical. Here, a numerical value means a value expressed by a number, for example, a value among {0, 1, 2, ... , 15}. A non-numerical value may mean a value other than a number or may mean that no number is indicated. The operation of numerical and non-numeric K1 values is explained below. For example, the PDSCH scheduled by the DCI format is transmitted by the base station device 3 in slot n and received by the terminal device 1. If the value of K1 indicated by the DCI format is numerical, the terminal device 1 may transmit (report) HARQ-ACK information corresponding to the PDSCH via the PUCCH or PUSCH in slot n+K1. If the value of K1 indicated by the DCI format is a non-numeric value, the terminal device 1 may postpone reporting of HARQ-ACK information corresponding to the PDSCH. If a non-numeric value of K1 is indicated by a DCI format including scheduling information for the PDSCH, the terminal device 1 may postpone reporting of HARQ-ACK information corresponding to the PDSCH. For example, the terminal device 1 may store the HARQ-ACK information in a recording medium such as a memory, and not transmit (report) the HARQ-ACK information via the next PUCCH or PUSCH, but may transmit (report) the HARQ-ACK information triggered based at least on a DCI format other than the above-mentioned DCI format.

A non-numeric value for K1 may be included in the sequence of upper layer parameters. The upper layer parameter may be the upper layer parameter dl-DataToUL-ACK. The upper layer parameter may be an upper layer parameter different from the upper layer parameter dl-DataToUL-ACK. The value of K1 may be a value indicated by the PDSCH to HARQ Feedback Timing Indicator field included in the DCI format in the sequence of upper layer parameters. For example, assuming that the sequence of upper layer parameters is set to {0, 1, 2, 3, 4, 5, 15, non-numeric value} and the number of bits in the PDSCH to HARQ Feedback Timing Indicator field is 3, a codepoint "000" in the PDSCH to HARQ Feedback Timing Indicator field may indicate a K1 value of 0, a codepoint "001" may indicate a K1 value of 1, and a codepoint "111" may indicate a non-numeric value for K1. For example, assuming that the sequence of higher layer parameters is set to {non-numeric value, 0, 1, 2, 3, 4, 5, 15} and the number of bits in the PDSCH to HARQ feedback timing indication field is 3, then the codepoint "000" in the PDSCH to HARQ feedback timing indication field may indicate that the value of K1 is non-numeric, the codepoint "001" may indicate that the value of K1 is 0, and the codepoint "111" may indicate that the value of K1 is 15.

One physical channel may be mapped to one serving cell. One physical channel may be mapped to one BWP configured on one carrier included in one serving cell.

The terminal device 1 may be configured with one or more control resource sets (CORESET: CONTrolREsourceSET). The terminal device 1 monitors the PDCCH in one or more control resource sets. Here, monitoring the PDCCH in one or more control resource sets may include monitoring one or more PDCCHs corresponding to each of the one or more control resource sets. Note that the PDCCH may include one or more PDCCH candidates and/or sets of PDCCH candidates. Furthermore, monitoring the PDCCH may include monitoring and detecting the PDCCH and/or the DCI format transmitted via the PDCCH.

The control resource set may be a time-frequency region to which one or more PDCCHs may be mapped. The control resource set may also be a region in which the terminal device 1 monitors the PDCCHs. The control resource set may be composed of contiguous resources (localized resources). The control resource set may also be composed of discontinuous resources (distributed resources).

In the frequency domain, the unit of mapping of the control resource set may be a resource block. For example, in the frequency domain, the unit of mapping of the control resource set may be six resource blocks. In the time domain, the unit of mapping of the control resource set may be an OFDM symbol. For example, in the time domain, the unit of mapping of the control resource set may be one OFDM symbol.

The mapping of the control resource set to resource blocks may be based at least on higher layer parameters, which may include a bitmap for a group of resource blocks (RBG), which may be given by six consecutive resource blocks.

The number of OFDM symbols constituting the control resource set may be determined based at least on higher layer parameters. For example, the starting positions of the OFDM symbols constituting the control resource set are notified from the base station device 3 to the terminal device 1 using higher layer signaling. For example, the ending positions of the OFDM symbols constituting the control resource set are notified from the base station device 3 to the terminal device 1 using higher layer signaling.

A certain control resource set may be a common control resource set. The common control resource set may be a control resource set configured in common for multiple terminal devices 1. The common control resource set may be assigned based on at least some or all of the MIB, the first system information, the second system information, the common RRC signaling, and the cell ID. For example, the time resources and/or frequency resources of the control resource set configured to monitor the PDCCH used for scheduling the first system information may be assigned based at least on the MIB.

The control resource set configured in the MIB is also referred to as CORESET #0. CORESET #0 may be the control resource set with index #0.

A control resource set may be a dedicated control resource set. The dedicated control resource set may be a control resource set configured to be used exclusively for the terminal device 1. The dedicated control resource set may be assigned based at least on dedicated RRC signaling and some or all of the value of the C-RNTI. Multiple control resource sets may be configured in the terminal device 1, and each control resource set may be assigned an index (control resource set index). One or more control channel elements (CCEs) may be configured within the control resource set, and each CCE may be assigned an index (CCE index).

A CCE may be configured to include one or more groups of REGs. A group of REGs is also called a REG bundle. The number of REGs constituting one REG group is called the bundle size. For example, the REG bundle size may be 1, 2, 3, or 6. In interleaved mapping, an interleaver may be applied on a REG bundle basis. The terminal device 1 may assume that the precoders applied to REs within a group of REGs are the same. The terminal device 1 can perform channel estimation by assuming that the precoders applied to REs within a group of REGs are the same. On the other hand, the terminal device 1 may assume that the precoders applied to REs between groups of REGs are not the same. In other words, the terminal device 1 does not have to assume that the precoders applied to REs between groups of REGs are the same. “Between groups of REGs” may be rephrased as “between two different groups of REGs.” The terminal device 1 can perform channel estimation assuming that the precoders applied to the REs between the groups of REGs are not the same.

The set of PDCCH candidates monitored by the terminal device 1 is defined in terms of a search space. In other words, the set of PDCCH candidates monitored by the terminal device 1 is given by the search space.

The search space may be configured to include one or more PDCCH candidates of one or more aggregation levels. The aggregation level of a PDCCH candidate may indicate the number of CCEs that make up the PDCCH. A PDCCH candidate may be mapped to one or more CCEs.

The number of CCEs constituting a PDCCH candidate is also referred to as the aggregation level (AL). When one PDCCH candidate is composed of an aggregation of multiple CCEs, one PDCCH candidate is composed of multiple CCEs with consecutive CCE numbers. A set of PDCCH candidates with aggregation level AL _X is also referred to as the search space for aggregation level AL _X. That is, the search space for aggregation level AL _X may be composed of one or more PDCCH candidates with aggregation level AL _X. Furthermore, a search space may include PDCCH candidates of multiple aggregation levels. For example, a CSS may include PDCCH candidates of multiple aggregation levels. For example, a USS may include PDCCH candidates of multiple aggregation levels. The set of aggregation levels of PDCCH candidates included in a CSS and the set of aggregation levels of PDCCH candidates included in a USS may be specified/configured, respectively.

The terminal device 1 may monitor at least one or more search spaces in slots where DRX (Discontinuous Reception) is not set. DRX may be provided based at least on higher layer parameters. The terminal device 1 may monitor at least one or more search space sets in slots where DRX is not set. Multiple search space sets may be configured in the terminal device 1. An index (search space set index) may be assigned to each search space set.

A search area set may be configured to include at least one or more search areas. Each search area may be assigned an index (search area index).

Each search area set may be associated with at least one control resource set. Each search area set may be included in one control resource set. Each search area set may be given an index of the control resource set associated with that search area set.

Search spaces may be of two types: CSS (Common Search Space) and USS (UE-specific Search Space). CSS may be a search space set in common for multiple terminal devices 1. USS may be a search space including settings used exclusively for individual terminal devices 1. CSS may be determined based at least on a synchronization signal, MIB, first system information, second system information, common RRC signaling, dedicated RRC signaling, cell ID, etc. USS may be determined at least on the value of dedicated RRC signaling and/or C-RNTI. CSS may be a search space set in resources (control resource elements) common to multiple terminal devices 1. USS may be a search space set in resources (control resource elements) for each individual terminal device 1.

The CSS may use a Type 0 PDCCH CSS for a DCI format scrambled by the SI-RNTI used to transmit system information in the primary cell, and a Type 1 PDCCH CSS for a DCI format scrambled by the RA-RNTI and TC-RNTI used for initial access. The CSS may use a Type 1 PDCCH CSS for a DCI format scrambled by the CC-RNTI used for unlicensed access. The terminal device 1 can monitor PDCCH candidates in these search areas. The DCI format scrambled by a specified RNTI may be a DCI format to which a CRC (Cyclic Redundancy Check) scrambled by a specified RNTI is added.

The information related to the reception of the PDCCH may include information related to an ID indicating the destination of the PDCCH. The ID indicating the destination of the PDCCH may be an ID used for scrambling the CRC bits added to the PDCCH. The ID indicating the destination of the PDCCH is also referred to as an RNTI (Radio Network Temporary Identifier). The information related to the reception of the PDCCH may include information related to an ID used for scrambling the CRC bits added to the PDCCH. The terminal device 1 can attempt to receive the PDCCH based at least on the information related to the ID included in the PBCH.

RNTI may include SI-RNTI (System Information - RNTI), P-RNTI (Paging - RNTI), C-RNTI (Common - RNTI), Temporary C-RNTI (TC-RNTI), RA-RNTI (Random Access - RNTI), CC-RNTI (Common Control - RNTI), and INT-RNTI (Interruption - RNTI). SI-RNTI is used at least for scheduling PDSCHs transmitted containing system information. P-RNTI is used at least for scheduling PDSCHs transmitted containing information such as paging information and/or system information change notifications. The C-RNTI is used at least for scheduling user data for the RRC-connected terminal device 1. The Temporary C-RNTI is used at least for scheduling the random access message 4. The Temporary C-RNTI is used at least for scheduling the PDSCH including data mapped to the CCCH in the logical channel. The RA-RNTI is used at least for scheduling the random access message 2. The CC-RNTI is used at least for transmitting and receiving control information for unlicensed access. The INT-RNTI is used at least for indicating pre-emption in the downlink.

In addition, the PDCCH and/or DCI included in the CSS may not include a CIF (Carrier Indicator Field) indicating which serving cell (or which component carrier) the PDCCH/DCI is scheduling the PDSCH or PUSCH for.

In addition, when carrier aggregation (CA), which aggregates multiple serving cells and/or multiple component carriers to perform communication (transmission and/or reception), is configured for the terminal device 1, the PDCCH and/or DCI included in the USS for a specified serving cell (specified component carrier) may include a CIF indicating which serving cell and/or which component carrier the PDCCH/DCI is scheduling the PDSCH or PUSCH for.

In addition, when communication is performed using one serving cell and/or one component carrier for terminal device 1, the PDCCH and/or DCI included in the USS does not need to include a CIF indicating which serving cell and/or which component carrier the PDCCH/DCI is scheduling the PDSCH or PUSCH for.

A common control resource set may include a CSS. A common control resource set may include both a CSS and a USS. A dedicated control resource set may include a USS. A dedicated control resource set may include a CSS.

The physical resources of the search area are composed of control channel components (CCEs: Control Channel Elements). A CCE is composed of a predetermined number of resource element groups (REGs: Resource Element Groups). For example, a CCE may be composed of six REGs. A REG may be composed of one OFDM symbol of one PRB (Physical Resource Block). In other words, a REG may be composed of 12 resource elements (REs: Resource Elements). A PRB is also simply referred to as an RB (Resource Block).

In other words, the terminal device 1 can detect the PDCCH and/or DCI for the terminal device 1 by blindly detecting the PDCCH candidates included in the search space within the control resource set.

The number of blind detections for one control resource set in one serving cell and/or one component carrier may be determined based on the type of search space for the PDCCH included in the control resource set, the type of aggregation level, and the number of PDCCH candidates. Here, the type of search space may include at least one of CSS and/or USS and/or UGSS (UE Group SS) and/or GCSS (Group CSS). The type of aggregation level indicates the maximum aggregation level supported for the CCEs that make up the search space, and may be specified/set from at least one of {1, 2, 4, 8, ..., X} (X is a predetermined value). The number of PDCCH candidates may indicate the number of PDCCH candidates for a certain aggregation level. In other words, the number of PDCCH candidates may be specified/set for each of multiple aggregation levels. Note that UGSS may be a search space commonly assigned to one or more terminal devices 1. The GCSS may be a search space to which DCI including parameters related to the CSS is mapped for one or more terminal devices 1. Note that the aggregation level indicates an aggregation level for a predetermined number of CCEs and is related to the total number of CCEs that make up one PDCCH and/or search space.

In addition, the size of the aggregation level may be associated with the coverage corresponding to the PDCCH and/or search area or the size of the DCI included in the PDCCH and/or search area (DCI format size, payload size).

Note that when the start position (start symbol) of the OFDM symbol of the PDCCH is set for one control resource set, and when PDCCHs in more than one control resource set can be detected within a specified period, the type of search space, type of aggregation level, and number of PDCCH candidates for the PDCCHs included in the control resource set may be set for the time domain corresponding to each start symbol. The type of search space, type of aggregation level, and number of PDCCH candidates for the PDCCHs included in the control resource set may be set for each control resource set, provided/set via DCI and/or higher layer signaling (RRC signaling), or predefined/set in a specification. Note that the number of PDCCH candidates may be the number of PDCCH candidates within the specified period. Note that the specified period may be 1 millisecond. The specified period may be 1 microsecond. The specified period may also be the period of one slot. The specified period may also be the period of one OFDM symbol.

Note that if there is more than one start position (start symbol) of the PDCCH OFDM symbol for one control resource set, that is, if there are multiple timings for blind detection (monitoring) of the PDCCH within a specified period, the type of search space, type of aggregation level, and number of PDCCH candidates for the PDCCH included in the control resource set may be set for the time domain corresponding to each start symbol. The type of search space, type of aggregation level, and number of PDCCH candidates for the PDCCH included in the control resource set may be set for each control resource set, or may be provided/set via DCI and/or higher layer signaling, or may be specified/set in advance by a specification.

In addition, as a way of indicating the number of PDCCCH candidates, the number to be reduced from a predetermined number of PDCCCH candidates may be specified/set for each aggregation level.

The terminal device 1 may transmit/notify the base station device 3 of capability information related to blind detection. The terminal device 1 may transmit/notify the base station device 3 of the number of PDCCH candidates that can be processed in one subframe as capability information related to PDCCH. The terminal device 1 may transmit/notify the base station device 3 of capability information related to blind detection if more than a predetermined number of control resource sets can be configured for one or more serving cells/component carriers.

The terminal device 1 may transmit/notify capability information related to blind detection to the base station device 3 if more than a specified number of control resource sets can be configured for a specified period of one or more serving cells/component carriers.

The capability information related to blind detection may include information indicating the maximum number of blind detections in a specified period. The capability information related to blind detection may also include information indicating that PDCCH candidates can be reduced. The capability information related to blind detection may also include information indicating the maximum number of control resource sets for which blind detection is possible in a specified period. The maximum number of control resource sets and the maximum number of serving cells and/or component carriers for which PDCCH monitoring is possible may each be set as individual parameters or as a common parameter. The capability information related to blind detection may also include information indicating the maximum number of control resource sets for which blind detection can be performed simultaneously in a specified period.

If the terminal device 1 does not support the capability to detect (blind detection) more than a predetermined number of control resource sets in a predetermined period, it does not need to transmit/notify capability information related to the blind detection. If the base station device 3 does not receive capability information related to the blind detection, it may configure the control resource sets so as not to exceed the predetermined number for blind detection and transmit a PDCCH.

The settings for the control resource set include a parameter indicating an index (ControlResourceSetId) that identifies the control resource set. The settings for the control resource set may also include a parameter indicating the frequency resource domain of the control resource set (the number of resource blocks that make up the control resource set). The settings for the control resource set may also include a parameter indicating the type of mapping from CCE to REG. The settings for the control resource set may also include the REG bundle size. RRC signaling may be used to send and receive messages indicating the settings for the control resource set. SIB may be used to send and receive messages indicating the settings for the control resource set. MIB may be used to send and receive messages indicating the settings for the control resource set.

The search area configuration includes a parameter indicating an index (search area index) that identifies the search area. The search area configuration includes a parameter indicating the index of the control resource set in which the search area is arranged. The search area configuration may include a parameter indicating the period and offset of the slot in which the search area is arranged. The search area configuration may include a parameter indicating the number of slots in which the search area is consecutively arranged. The search area configuration may include a parameter indicating the OFDM symbols in the slot in which PDCCH candidates are monitored. The search area configuration may include a parameter indicating the number of PDCCH candidates to be monitored per CCE aggregation level. The search area configuration may include a parameter indicating the DCI format in which monitoring is performed. The search area configuration may include a parameter indicating the type of search area (CSS or USS). RRC signaling may be used to transmit and receive messages indicating the search area configuration. SIB may be used to transmit and receive messages indicating the search area configuration. MIB may be used to transmit and receive messages indicating the search area configuration.

The PDSCH is used at least for transmitting/receiving transport blocks. The PDSCH may also be used at least for transmitting/receiving random access message 2 (random access response). The PDSCH may also be used at least for transmitting/receiving system information including parameters used for initial access.

In Figure 1, the following downlink physical signals are used in downlink wireless communication: The downlink physical signals may not be used to transmit information output from higher layers, but are used by the physical layer.
・Synchronization signal (SS)
・DL DMRS (DownLink DeModulation Reference Signal)
・CSI-RS (Channel State Information-Reference Signal)
・DL PTRS (DownLink Phase Tracking Reference Signal)

The synchronization signal is used by the terminal device 1 to synchronize the frequency domain and/or time domain of the downlink. The synchronization signal includes a PSS (Primary Synchronization Signal) and an SSS (Secondary Synchronization Signal).

An SS block (SS/PBCH block) is composed of at least some or all of the PSS, SSS, and PBCH.

DL DMRS is related to the transmission of PBCH, PDCCH, and/or PDSCH. DL DMRS is multiplexed onto PBCH, PDCCH, and/or PDSCH. The terminal device 1 may use the DL DMRS corresponding to the PBCH, PDCCH, or PDSCH to perform propagation path correction for the PBCH, PDCCH, or PDSCH. The terminal device 1 may determine that the base station device 3 is transmitting a signal based on detection of the DL DMRS.

The CSI-RS may be a signal used at least to calculate channel state information. The CSI-RS pattern assumed by the terminal device 1 may be given at least by higher layer parameters.

The PTRS may be a signal used at least for phase noise compensation. The PTRS pattern assumed by the terminal device 1 may be based at least on higher layer parameters and/or DCI.

A DL PTRS may be associated with a DL DMRS group that includes at least the antenna ports used for one or more DL DMRSs.

In addition, downlink physical signals not described above may also be used.

Downlink physical channels and downlink physical signals are also referred to as downlink signals. Uplink physical channels and uplink physical signals are also referred to as uplink signals. Downlink signals and uplink signals are collectively referred to as physical signals. Downlink signals and uplink signals are collectively referred to as signals. Downlink physical channels and uplink physical channels are collectively referred to as physical channels. Downlink physical signals and uplink physical signals are collectively referred to as physical signals.

BCH (Broadcast Channel), UL-SCH (Uplink-Shared Channel), and DL-SCH (Downlink-Shared Channel) are transport channels. Channels used in the Medium Access Control (MAC) layer are called transport channels. The unit of transport channel used in the MAC layer is also called a transport block (TB) or MAC PDU. In the MAC layer, HARQ (Hybrid Automatic Repeat reQuest) control is performed for each transport block. A transport block is the unit of data that the MAC layer delivers to the physical layer. In the physical layer, transport blocks are mapped to codewords, and modulation processing is performed for each codeword.

The base station device 3 and the terminal device 1 exchange (transmit and receive) higher layer signals at higher layers. For example, the base station device 3 and the terminal device 1 may transmit and receive RRC signaling (RRC message; RRC information) at the Radio Resource Control (RRC) layer. The base station device 3 and the terminal device 1 may also transmit and receive MAC Control Elements (CEs) at the MAC layer. Here, the RRC signaling and/or the MAC CE are also referred to as higher layer signaling.

PUSCH and PDSCH may be used at least to transmit RRC signaling and/or MAC CE. Here, the RRC signaling transmitted by the base station device 3 on the PDSCH may be signaling common to multiple terminal devices 1 in the serving cell. Signaling common to multiple terminal devices 1 in the serving cell is also referred to as common RRC signaling. The RRC signaling transmitted by the base station device 3 on the PDSCH may be signaling dedicated to a certain terminal device 1 (also referred to as dedicated signaling or UE-specific signaling). Signaling dedicated to a terminal device 1 is also referred to as dedicated RRC signaling. Upper layer parameters specific to the serving cell may be transmitted/received using signaling common to multiple terminal devices 1 in the serving cell or signaling dedicated to a certain terminal device 1. UE-specific higher layer parameters may be transmitted/received using signaling dedicated to a certain terminal device 1.

The BCCH (Broadcast Control Channel), CCCH (Common Control Channel), and DCCH (Dedicated Control Channel) are logical channels. For example, the BCCH is an upper layer channel used to transmit/receive MIBs. The CCCH (Common Control Channel) is an upper layer channel used to transmit/receive information common to multiple terminal devices 1. Here, the CCCH may be used, for example, for terminal devices 1 that are not RRC connected. The DCCH (Dedicated Control Channel) is an upper layer channel used at least to transmit/receive control information dedicated to the terminal device 1. Here, the DCCH may be used, for example, for a terminal device 1 that is RRC connected.

The BCCH in the logical channel may be mapped to the BCH, DL-SCH, or UL-SCH in the transport channel. The CCCH in the logical channel may be mapped to the DL-SCH or UL-SCH in the transport channel. The DCCH in the logical channel may be mapped to the DL-SCH or UL-SCH in the transport channel.

The UL-SCH in the transport channel may be mapped to the PUSCH in the physical channel. The DL-SCH in the transport channel may be mapped to the PDSCH in the physical channel. The BCH in the transport channel may be mapped to the PBCH in the physical channel.

Figure 5 is a diagram showing an example of the configuration of one REG according to one aspect of this embodiment. The REG may be composed of one OFDM symbol of one PRB. In other words, the REG may be composed of 12 consecutive REs in the frequency domain. Some of the REs constituting the REG may be REs to which downlink control information is not mapped. The REG may be composed of REs to which downlink control information is not mapped, or may be composed of REs to which downlink control information is not mapped. The REs to which downlink control information is not mapped may be REs to which a reference signal is mapped, REs to which a channel other than a control channel is mapped, or REs to which a control channel is not assumed to be mapped by the terminal device 1.

Figure 6 is a diagram showing an example of the configuration of a CCE according to one aspect of this embodiment. A CCE may be composed of six REGs. As shown in Figure 6(a), a CCE (CCE #0) may be composed of REGs that are contiguously mapped (such mapping may be referred to as localized mapping) (such mapping may be referred to as non-interleaved CCE-to-REG mapping) (such mapping may be referred to as non-interleaved mapping). Note that not all REGs constituting a CCE need to be contiguous in the frequency domain. For example, if all of the multiple resource blocks constituting a control resource set are not contiguous in the frequency domain, even if the numbers assigned to the REGs are contiguous, the resource blocks constituting each REG with consecutive numbers are not contiguous in the frequency domain. When a control resource set is composed of multiple OFDM symbols and multiple REGs constituting one CCE are arranged across multiple time intervals (OFDM symbols), a CCE (CCE #1) may be composed of a group of REGs that are mapped consecutively, as shown in Figure 6(b).

As shown in FIG. 6(c), a CCE (CCE #2) may be composed of REGs that are discontinuously mapped (such mapping may be referred to as distributed mapping) (such mapping may be referred to as interleaved CCE-to-REG mapping) (such mapping may be referred to as interleaved mapping). REGs that constitute a CCE may be discontinuously mapped to time-frequency resources using an interleaver. When a control resource set is composed of multiple OFDM symbols and multiple REGs that constitute one CCE are arranged across multiple time intervals (OFDM symbols), a CCE (CCE #3) may be composed of REGs that are discontinuously mapped by mixing REGs from different time intervals (OFDM symbols), as shown in FIG. 6(d). As shown in Figure 6(e), CCE (CCE #4) may be composed of REGs that are distributed and mapped in units of groups of multiple REGs. As shown in Figure 6(f), CCE (CCE #5) may be composed of REGs that are distributed and mapped in units of groups of multiple REGs.

Figure 7 is a diagram showing an example of REGs constituting a PDCCH candidate and the number of REGs constituting a REG group according to one aspect of this embodiment. In the example shown in Figure 7(a), a PDCCH candidate is mapped to one OFDM symbol, and three REG groups (REG groups) each containing two REGs are formed. In other words, in the example shown in Figure 7(a), one REG group is composed of two REGs. The number of REGs constituting a REG group in the frequency domain may include a divisor of the number of PRBs mapped in the frequency direction. In the example shown in Figure 7(a), the number of REGs constituting a REG group in the frequency domain may be 1, 2, 3, or 6.

In the example shown in Figure 7(b), the PDCCH candidates are mapped to two OFDM symbols, and three REG groups each containing two REGs are configured. In the example shown in Figure 7(b), the number of REGs configuring the frequency domain REG group may be either 1 or 3.

Below, an example configuration of a terminal device 1 relating to one aspect of this embodiment is described.

Figure 8 is a schematic block diagram showing the configuration of a terminal device 1 according to one aspect of this embodiment. As shown in the figure, the terminal device 1 includes a radio transceiver unit 10 and an upper layer processing unit 14. The radio transceiver unit 10 includes at least an antenna unit 11, an RF (Radio Frequency) unit 12, and part or all of a baseband unit 13. The upper layer processing unit 14 includes at least a medium access control layer processing unit 15 and part or all of a radio resource control layer processing unit 16. The radio transceiver unit 10 is also referred to as a transmitter, receiver, or physical layer processing unit.

The physical layer processing unit includes a decoding unit. The receiving unit (also referred to as the receiving processing unit) of the terminal device 1 receives the PDCCH. The decoding unit of the terminal device 1 decodes the received PDCCH. More specifically, the decoding unit of the terminal device 1 performs blind decoding processing on the received signal of the resource corresponding to the USS PDCCH candidate. The decoding unit of the terminal device 1 performs blind decoding processing on the received signal of the resource corresponding to the CSS PDCCH candidate. The receiving processing unit of the terminal device 1 monitors the PDCCH candidates within the control resource set. The receiving processing unit of the terminal device 1 monitors the PDCCH candidates within the control resource set.

The receiving processing unit of terminal device 1 monitors PDCCH candidates within the control resource set of the downlink frequency band (cell, component carrier, carrier) managed by base station device 3. The receiving unit of terminal device 1 receives the PDSCH. The receiving processing unit of terminal device 1 performs processing to receive the PDSCH in the downlink frequency band (cell, component carrier, carrier) managed by base station device 3. The receiving processing unit of terminal device 1 performs processing such as demodulation and decoding on the PDSCH. The receiving processing unit of terminal device 1 generates a HARQ-ACK for the decoded PDSCH. Based on a received C-DAI of a certain value, the receiving processing unit of terminal device 1 generates a HARQ-ACK for the PDSCH corresponding to a different C-DAI value. For example, if the reception processing unit of the terminal device 1 receives a C-DAI with a value of "3" immediately after receiving a C-DAI with a value of "1," it determines that it has failed to receive the PDSCH corresponding to the C-DAI with a value of "2" between the two, and generates a NACK as the HARQ-ACK for the PDSCH corresponding to the C-DAI with a value of "2." In other words, if the consecutively received C-DAI values are discontinuous, the reception processing unit of the terminal device 1 determines that it has failed to receive (detect) the PDCCH and PDSCH corresponding to the C-DAI with the values between the two. Furthermore, the reception processing unit of the terminal device 1 determines that it has not received the PDSCH corresponding to a C-DAI with a value greater than the last received C-DAI value, and generates (sets) DTX as the HARA-ACK. For example, if the maximum value of C-DAI is 8, and the last received C-DAI value is "5", the receiving processing unit of terminal device 1 determines that it did not receive (detect) PDSCHs corresponding to C-DAIs of "6", "7", and "8", and sets (generates) DTX for each of the HARQ-ACKs of PDSCHs corresponding to C-DAI values of "6", HARQ-ACKs of PDSCHs corresponding to C-DAI values of "7", and HARQ-ACKs of PDSCHs corresponding to C-DAI values of "8".

The transmitter (also referred to as the transmission processing unit) of terminal device 1 transmits a HARQ-ACK. The transmission processing unit of terminal device 1 transmits a HARQ-ACK for the PDSCH. The transmission processing unit of terminal device 1 transmits a HARQ-ACK in an uplink frequency band (cell, component carrier, carrier) managed by base station device 3. The transmission processing unit of terminal device 1 transmits a HARQ-ACK for the PDSCH in a downlink frequency band (cell, component carrier, carrier) managed by base station device 3. The transmission processing unit of terminal device 1 transmits a HARQ-ACK for the PDSCH in a downlink frequency band (cell, component carrier, carrier) managed by base station device 3 in an uplink frequency band (cell, component carrier, carrier) managed by base station device 3. The transmission processing unit of terminal device 1 selects a code sequence based on the combination of HARQ-ACKs corresponding to the PDSCH for each value of C-DAI generated by the reception processing unit. The number of code sequence candidates is set in the transmission processing unit of the terminal device 1 by the radio resource control layer processing unit 16. The transmission processing unit of the terminal device 1 selects a code sequence from the set code sequence candidates based on a combination of HARQ-ACK corresponding to the PDSCH for each C-DAI value. The transmission processing unit of the terminal device 1 transmits the PUCCH (PUCCH format 5) using the selected code sequence.

The upper layer processing unit 14 outputs uplink data (transport blocks) generated by user operations, etc. to the radio transceiver unit 10. The upper layer processing unit 14 processes the MAC layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, and RRC layer.

The media access control layer processing unit 15 provided in the upper layer processing unit 14 performs MAC layer processing.

The radio resource control layer processing unit 16 included in the upper layer processing unit 14 performs RRC layer processing. The radio resource control layer processing unit 16 manages various setting information/parameters of its own device. The radio resource control layer processing unit 16 sets various setting information/parameters based on upper layer signals received from the base station device 3. That is, the radio resource control layer processing unit 16 sets various setting information/parameters based on information indicating the various setting information/parameters received from the base station device 3. Note that the setting information may include information related to processing or setting of physical channels and physical signals (i.e., the physical layer), the MAC layer, the PDCP layer, the RLC layer, and the RRC layer. The parameters may be upper layer parameters.

The radio resource control layer processing unit 16 sets a control resource set based on RRC signaling received from the base station device 3. The radio resource control layer processing unit 16 sets a search space within the control resource set. The radio resource control layer processing unit 16 sets PDCCH candidates to be monitored within the control resource set. The radio resource control layer processing unit 16 sets the number of PDCCH candidates to be monitored within the control resource set. The radio resource control layer processing unit 16 sets an aggregation level for the PDCCH candidates to be monitored within the control resource set. The radio resource control layer processing unit 16 may set a maximum C-DAI value based on RRC signaling. For example, the maximum C-DAI value may be set to 4, 6, or 8. The maximum C-DAI value may be set to a value other than 4, 6, or 8, such as 10 or 12. The radio resource control layer processing unit 16 may set, in the reception processing unit, a number corresponding to the C-DAI at which a HARQ-ACK is generated. The radio resource control layer processing unit 16 may set the number of code sequence candidates for the transmission processing unit based on the maximum value of C-DAI. For example, if the maximum value of C-DAI is 4, the radio resource control layer processing unit 16 sets the transmission processing unit to use 16 code sequence candidates. For example, if the maximum value of C-DAI is 6, the radio resource control layer processing unit 16 sets the transmission processing unit to use 64 code sequence candidates. For example, if the maximum value of C-DAI is 8, the radio resource control layer processing unit 16 sets the transmission processing unit to use 256 code sequence candidates.

The wireless transceiver unit 10 performs physical layer processing such as modulation, demodulation, encoding, and decoding. The wireless transceiver unit 10 separates, demodulates, and decodes the received physical signals, and outputs the decoded information to the upper layer processing unit 14. The wireless transceiver unit 10 generates physical signals by modulating, encoding, and generating baseband signals (converting to time-continuous signals) from the data, and transmits them to the base station device 3.

The RF unit 12 converts the signal received via the antenna unit 11 into a baseband signal by quadrature demodulation (downconvert) and removes unnecessary frequency components. The RF unit 12 outputs the processed analog signal to the baseband unit.

The baseband unit 13 converts the analog signal input from the RF unit 12 into a digital signal. The baseband unit 13 removes the portion corresponding to the cyclic prefix (CP) from the converted digital signal, and performs a fast Fourier transform (FFT) on the CP-removed signal to extract the frequency domain signal.

The baseband unit 13 performs an inverse fast Fourier transform (IFFT) on the data to generate OFDM symbols, adds a CP to the generated OFDM symbols, generates baseband digital signals, and converts the baseband digital signals to analog signals. The baseband unit 13 outputs the converted analog signals to the RF unit 12.

The RF unit 12 uses a low-pass filter to remove unnecessary frequency components from the analog signal input from the baseband unit 13, up-converts the analog signal to a carrier frequency, and transmits it via the antenna unit 11. The RF unit 12 also amplifies the power. The RF unit 12 may also have a function to control the transmission power. The RF unit 12 is also referred to as a transmission power control unit.

The terminal device 1 receives the PDCCH. The terminal device 1 receives the PDSCH. The radio resource control layer processing unit 16 sets a control resource set. The radio resource control layer processing unit 16 sets a search space. The radio resource control layer processing unit 16 sets a control resource set based on RRC signaling. The radio resource control layer processing unit 16 sets the search space based on RRC signaling. The receiving unit of the terminal device 1 monitors multiple PDCCH candidates within the search space of the set control resource set. The receiving unit of the terminal device 1 monitors multiple PDCCH candidates within the search space of the set control resource set in a certain slot. The decoding unit of the terminal device 1 decodes the monitored PDCCH candidates. The decoding unit of the terminal device 1 decodes the received PDSCH.

The receiver of the terminal device 1 monitors a number of PDCCH candidates set based on RRC signaling within a search area of a control resource set in a certain slot. The receiver of the terminal device 1 monitors PDCCH candidates consisting of one or more OFDM symbols set based on RRC signaling within a search area of a control resource set in a certain slot. The receiver of the terminal device 1 monitors PDCCH candidates in a search area in the first half of a slot (e.g., the first OFDM symbol, or the first and second OFDM symbols, or the first, second, and third OFDM symbols). The receiving unit of the terminal device 1 monitors PDCCH candidates in a search region in the first half of a slot (for example, the first OFDM symbol, or the first and second OFDM symbols, or the first, second, and third OFDM symbols), and monitors PDCCH candidates in a search region in the second half of the slot (for example, the eighth OFDM symbol, or the eighth and ninth OFDM symbols, or the eighth, ninth, and tenth OFDM symbols). Note that the receiving unit of the terminal device 1 may set three or more search regions in a slot, each of which is a search region of a different OFDM symbol, and may monitor PDCCH candidates in a distributed manner within the slot.

Below, an example configuration of a base station device 3 relating to one aspect of this embodiment is described.

Figure 9 is a schematic block diagram showing the configuration of a base station device 3 according to one aspect of this embodiment. As shown in the figure, the base station device 3 includes a radio transceiver unit 30 and an upper layer processing unit 34. The radio transceiver unit 30 includes an antenna unit 31, an RF unit 32, and a baseband unit 33. The upper layer processing unit 34 includes a medium access control layer processing unit 35 and a radio resource control layer processing unit 36. The radio transceiver unit 30 is also referred to as a transmitter, receiver, or physical layer processing unit.

The upper layer processing unit 34 processes the MAC layer, PDCP layer, RLC layer, and RRC layer.

The media access control layer processing unit 35 provided in the upper layer processing unit 34 performs MAC layer processing.

The radio resource control layer processing unit 36 included in the upper layer processing unit 34 performs RRC layer processing. The radio resource control layer processing unit 36 generates downlink data (transport blocks), system information, RRC messages, MAC CEs, etc. to be allocated to the PDSCH, or acquires these from upper nodes, and outputs them to the radio transceiver unit 30. The radio resource control layer processing unit 36 also manages various setting information/parameters for each terminal device 1. The radio resource control layer processing unit 36 may set various setting information/parameters for each terminal device 1 via upper layer signals. In other words, the radio resource control layer processing unit 36 transmits/reports information indicating various setting information/parameters. Note that the setting information may include information related to processing or setting of physical channels and physical signals (i.e., the physical layer), the MAC layer, the PDCP layer, the RLC layer, and the RRC layer. The parameters may be upper layer parameters.

The radio resource control layer processing unit 36 sets a control resource set for the terminal device 1. Multiple PDCCH candidates are configured (set) within the set control resource set. The radio resource control layer processing unit 36 sets a search space for the terminal device 1.

The radio resource control layer processing unit 36 configures resources for transmitting HARQ-ACK to the terminal device 1. The radio resource control layer processing unit 36 of the base station device 3 configures resources for transmitting HARQ-ACK for the PDSCH in the downlink frequency band (cell, component carrier, carrier). The radio resource control layer processing unit 36 of the base station device 3 configures resources for transmitting HARQ-ACK for the PDSCH in the downlink frequency band (cell, component carrier, carrier) in the uplink frequency band (cell, component carrier, carrier). The radio resource control layer processing unit 36 may configure a maximum value for C-DAI to the terminal device 1. The base station device 3 may notify the terminal device 1 of the maximum value of C-DAI using RRC signaling. The radio resource control layer processing unit 36 may configure candidates for code sequences to be used for detection to the reception processing unit.

The functions of the radio transceiver unit 30 are similar to those of the radio transceiver unit 10, and therefore description thereof will be omitted where appropriate. The radio transceiver unit 30 also identifies the SS (search space) configured in the terminal device 1. The radio transceiver unit 30 identifies the search space within the control resource set configured in the terminal device 1. The radio transceiver unit 30 identifies the PDCCH candidates monitored in the terminal device 1 and identifies the search space. The radio transceiver unit 30 identifies which control channel elements each PDCCH candidate monitored in the terminal device 1 is configured from (identifies the numbers of the control channel elements from which the PDCCH candidate is configured). The radio transceiver unit 30 includes an SS identification unit, and the SS identification unit identifies the SS configured in the terminal device 1. The SS identification unit identifies one or more PDCCH candidates within the control resource set configured as the search space of the terminal device. The SS grasping unit grasps the PDCCH candidates (number of PDCCH candidates, PDCCH candidate numbers) configured in the search area of the control resource set of the terminal device 1.

The SS grasping unit grasps the configuration of the search area within the control resource set (the number of PDCCH candidates, the OFDM symbols of the PDCCH candidates, and the aggregation level of the PDCCH candidates). The transmitting unit of the radio transceiver unit 30 transmits the PDCCH to the terminal device 1 using the PDCCH candidates within the search area of the control resource set.

The SS identification unit may identify the configuration of the search region for a slot as follows: one or more PDCCH candidates are configured from the OFDM symbols in the first half of the slot (e.g., the first OFDM symbol, or the first and second OFDM symbols, or the first, second, and third OFDM symbols). The SS identification unit may identify the configuration of the search region for a slot as follows: one or more PDCCH candidates are configured from the OFDM symbols in the first half of the slot (e.g., the first OFDM symbol, or the first and second OFDM symbols, or the first, second, and third OFDM symbols), and one or more PDCCH candidates are configured from the OFDM symbols in the second half of the slot (e.g., the eighth OFDM symbol, or the eighth and ninth OFDM symbols, or the eighth, ninth, and tenth OFDM symbols). The SS identification unit may also identify three or more search regions in a slot, each search region being a different OFDM symbol.

The receiver (also referred to as the receiver processing unit) of base station device 3 receives the HARQ-ACK. The receiver processing unit of base station device 3 receives the HARQ-ACK for the PDSCH. The receiver processing unit of base station device 3 receives the HARQ-ACK in the uplink frequency band (cell, component carrier, carrier). The receiver processing unit of base station device 3 receives the HARQ-ACK for the PDSCH in the downlink frequency band (cell, component carrier, carrier). The receiver processing unit of base station device 3 receives the HARQ-ACK for the PDSCH in the downlink frequency band (cell, component carrier, carrier) in the uplink frequency band (cell, component carrier, carrier). The receiver processing unit of base station device 3 detects the PUCCH used to transmit the HARQ-ACK using candidate code sequences set in the radio resource control layer processing unit 36. The reception processing unit of the base station device 3 extracts (generates, determines) a HARQ-ACK for the PDSCH for each C-DAI value corresponding to the detected code sequence. The base station device 3 controls retransmission of the PDSCH based on the extracted HARQ-ACK. For example, the reception processing unit of the base station device 3 detects the correlation between the signal generated from each code sequence and the received signal, and determines that the code sequence with the highest correlation value was transmitted from the terminal device 1.

Each of the units designated by reference numerals 10 to 16 in the terminal device 1 may be configured as a circuit. Each of the units designated by reference numerals 30 to 36 in the base station device 3 may be configured as a circuit.

The terminal device 1 transmits uplink control information (UCI) to the base station device 3. The terminal device 1 may multiplex the UCI onto the PUCCH and transmit it. The terminal device 1 may multiplex the UCI onto the PUSCH and transmit it. The UCI may include at least one of downlink channel state information (CSI), a scheduling request (SR) indicating a request for PUSCH resources, and a Hybrid Automatic Repeat request ACKnowledgement (HARQ-ACK) for downlink data (Transport block, Medium Access Control Protocol Data Unit (MAC PDU), Downlink-Shared Channel (DL-SCH), Physical Downlink Shared Channel (PDSCH)).

HARQ-ACK may also be referred to as ACK/NACK, HARQ feedback, HARQ-ACK feedback, HARQ response, HARQ-ACK response, HARQ information, HARQ-ACK information, HARQ control information, and HARQ-ACK control information.

If downlink data is successfully decoded, an ACK for the downlink data is generated. If downlink data is not successfully decoded, a NACK for the downlink data is generated. The HARQ-ACK may include at least a HARQ-ACK bit corresponding to at least one transport block. The HARQ-ACK bit may indicate an ACK (ACKnowledgement) or a NACK (Negative-ACKnowledgement) corresponding to one or multiple transport blocks. The HARQ-ACK may include at least a HARQ-ACK codebook including one or more HARQ-ACK bits. The HARQ-ACK bit corresponding to one or multiple transport blocks may correspond to a PDSCH including the one or multiple transport blocks.

HARQ control for one transport block may be referred to as an HARQ process. One HARQ process identifier may be given for each HARQ process. The DCI format includes a field indicating the HARQ process identifier.

An NDI (New Data Indicator) is indicated in the DCI format for each HARQ process. For example, the NDI field is included in the DCI format (DL assignment) containing PDSCH scheduling information. The NDI field is 1 bit. The terminal device 1 stores (memorizes) the NDI value for each HARQ process. The base station device 3 stores (memorizes) the NDI value for each HARQ process for each terminal device 1. The terminal device 1 updates the stored NDI value using the NDI field of the detected DCI format. The base station device 3 sets the updated NDI value or the non-updated NDI value in the NDI field of the DCI format and transmits it to the terminal device 1. The terminal device 1 updates the stored NDI value using the NDI field of the detected DCI format for the HARQ process corresponding to the value of the HARQ process identifier field of the detected DCI format.

The terminal device 1 determines whether the received transport block is a new transmission or a retransmission based on the value of the NDI field in the DCI format (DL assignment). The terminal device 1 compares the value of the NDI previously received for the transport block of a certain HARQ process with the value of the detected NDI field in the DCI format, and if the value of the NDI field is toggled, determines that the received transport block is a new transmission. When transmitting a transport block for a new transmission in a certain HARQ process, the base station device 3 toggles the value of the NDI stored for that HARQ process and transmits the toggled NDI to the terminal device 1. When transmitting a transport block for a retransmission in a certain HARQ process, the base station device 3 does not toggle the value of the NDI stored for that HARQ process and transmits an untoggled NDI to the terminal device 1. The terminal device 1 compares the value of the NDI field of the detected DCI format with the value of the NDI previously received for the transport block of a certain HARQ process, and if the value of the NDI field of the detected DCI format has not been toggled (is the same), determines that the received transport block is a retransmission. Note that toggling here means switching to a different value.

The terminal device 1 may report HARQ-ACK information to the base station device 3 using a HARQ-ACK codebook in a slot indicated by the value of the HARQ indication field included in DCI format 1_0 corresponding to PDSCH reception or DCI format 1_1.

For DCI format 1_0, the value of the HARQ indication field may be mapped to a set of slot numbers (1, 2, 3, 4, 5, 6, 7, 8). For DCI format 1_1, the value of the HARQ indication field may be mapped to a set of slot numbers given by the higher layer parameter dl-DataToUL-ACK. The slot number indicated based at least on the value of the HARQ indication field may also be referred to as HARQ-ACK timing or K1. For example, a HARQ-ACK indicating the decoding status of PDSCH (downlink data) transmitted in slot n may be reported (transmitted) in slot n+K1.

dl-DataToUL-ACK indicates a list of HARQ-ACK timings for the PDSCH. The timing is the number of slots between the slot in which the PDSCH is received (or the slot containing the last OFDM symbol to which the PDSCH is mapped) and the slot in which the HARQ-ACK for the received PDSCH is transmitted. For example, dl-DataToUL-ACK is a list of 1, 2, 3, 4, 5, 6, 7, or 8 timings. If dl-DataToUL-ACK is a list of 1 timing, the HARQ indication field is 0 bits. If dl-DataToUL-ACK is a list of 2 timings, the HARQ indication field is 1 bit. If dl-DataToUL-ACK is a list of 3 or 4 timings, the HARQ indication field is 2 bits. When the dl-DataToUL-ACK is a list of 5, 6, 7, or 8 timings, the HARQ indication field is 3 bits. For example, the dl-DataToUL-ACK is configured from a list of timings with any value in the range from 0 to 31. For example, the dl-DataToUL-ACK is configured from a list of timings with any value in the range from 0 to 63.

The size of the dl-DataToUL-ACK is defined as the number of elements it contains. The size of the dl-DataToUL-ACK may be referred to as L _para . The index of the dl-DataToUL-ACK indicates the order (number) of the elements of the dl-DataToUL-ACK. For example, if the size of the dl-DataToUL-ACK is 8 (L _para = 8), the index of the dl-DataToUL-ACK is any of 1, 2, 3, 4, 5, 6, 7, or 8. The index of the dl-DataToUL-ACK may be given, indicated, or indicated by the value indicated by the HARQ indication field.

When the terminal device 1 is configured to monitor a PDCCH including DCI format 1_0 and not to monitor a PDCCH including DCI format 1_1, the HARQ-ACK timing value K1 may be some or all of (1, 2, 3, 4, 5, 6, 7, 8). When the terminal device 1 is configured to monitor a PDCCH including DCI format 1_1, the HARQ-ACK timing value K1 may be given by the upper layer parameter dl-DataToUL-ACK.

The Counter DAI field indicates the cumulative number of PDSCHs or transport blocks scheduled until the reception of the corresponding DCI format.

The Counter DAI indicates, for a given PDCCH monitoring opportunity in a serving cell among M PDCCH monitoring opportunities, the cumulative number of PDCCHs detected up to the PDCCH monitoring opportunity in the serving cell (or a value at least related to the cumulative number). The Counter DAI may also be referred to as a C-DAI. The C-DAI corresponding to a PDSCH may be indicated by a field included in the DCI format used for scheduling the PDSCH.

The following describes the HARQ-ACK transmission method in terminal device 1 and the HARQ-ACK reception method in base station device 3. Multiple code sequence candidates are used as the code sequence used to transmit PUCCH (PUCCH format 5). For example, 4, 8, 16, 32, 64, 128, or 256 code sequence candidates may be used. Terminal device 1 selects and transmits a code sequence from multiple code sequence candidates based on the HARQ-ACK combination for each C-DAI value. Base station device 3 recognizes (determines) the HARQ-ACK combination of the PDSCH for each C-DAI transmitted to terminal device 1 based on the received (detected) code sequence. Terminal device 1 selects and transmits a code sequence from multiple code sequence candidates based on the PDSCH HARQ-ACK combination corresponding to each C-DAI value. Based on the received (detected) code sequence, the base station device 3 recognizes (determines) the combination of HARQ-ACKs of the PDSCHs corresponding to the respective C-DAI values transmitted to the terminal device 1. When the terminal device 1 receives a PDSCH corresponding to a certain value of C-DAI, it sets ACK or NACK to the HARQ-ACK based on the error detection result of the transport block of that PDSCH. When the terminal device 1 does not receive a PDSCH corresponding to a certain value of C-DAI, it sets NACK or DTX to the HARQ-ACK for that PDSCH.

The multiple code sequence candidates are divided into multiple groups. A group of multiple code sequence candidates is formed for each value of the C-DAI last received by terminal device 1.

Figure 10 shows an example of multiple code sequence candidates corresponding to HARQ-ACK combinations for each C-DAI value. Figure 10 shows a case where 30 code sequence candidates are used for HARQ-ACK combinations with C-DAI values from 1 to 4. In Figure 10, a C-DAI with a value of 1 is shown as C-DAI "1," a C-DAI with a value of 2 is shown as C-DAI "2," a C-DAI with a value of 3 is shown as C-DAI "3," and a C-DAI with a value of 4 is shown as C-DAI "4." In Figure 10, Group 1 consists of two code sequence candidates, Group 2 consists of four code sequence candidates, Group 3 consists of eight code sequence candidates, and Group 4 consists of 16 code sequence candidates. Note that the group identification codes may differ from the values shown in Figure 10.

Group 1 is a set of multiple code sequence candidates to be used when the last C-DAI received by terminal device 1 is C-DAI "1". In Group 1, the HARQ-ACK with C-DAI "2", the HARQ-ACK with C-DAI "3", and the HARQ-ACK with C-DAI "4" are all DTX, and the code sequences correspond to the combinations of the HARQ-ACK with C-DAI "1" being an ACK and a NACK. Group 2 is a set of multiple code sequence candidates to be used when the last C-DAI received by terminal device 1 is C-DAI "2". In group 2, the HARQ-ACK with C-DAI "3" and the HARQ-ACK with C-DAI "4" are each DTX, and the code sequences correspond to the combinations of the HARQ-ACK with C-DAI "1" and the HARQ-ACK with C-DAI "2", respectively, for ACK and NACK. Group 3 is a plurality of code sequence candidates to be used when the C-DAI last received by the terminal device 1 is C-DAI "3". In group 3, the HARQ-ACK with C-DAI "4" is DTX, and the code sequences correspond to the combinations of the HARQ-ACK with C-DAI "1", the HARQ-ACK with C-DAI "2", and the HARQ-ACK with C-DAI "3", respectively, for ACK and NACK. Group 4 is a plurality of code sequence candidates to be used when the C-DAI last received by the terminal device 1 is C-DAI "4." In group 4, the code sequences correspond to the combinations of ACK and NACK, respectively, of HARQ-ACK with C-DAI "1," HARQ-ACK with C-DAI "2," HARQ-ACK with C-DAI "3," and HARQ-ACK with C-DAI "4."

Figure 11 is a diagram showing an example of multiple code sequence candidates corresponding to HARQ-ACK combinations for each C-DAI value. Figure 12 is a diagram showing an example of multiple code sequence candidates corresponding to HARQ-ACK combinations for each C-DAI value. Figures 11 and 12 show the case where 126 code sequence candidates are used for HARQ-ACK combinations for C-DAI values from 1 to 6. 11 and 12, a C-DAI with a value of 1 is written as C-DAI "1", a C-DAI with a value of 2 is written as C-DAI "2", a C-DAI with a value of 3 is written as C-DAI "3", a C-DAI with a value of 4 is written as C-DAI "4", a C-DAI with a value of 5 is written as C-DAI "5", and a C-DAI with a value of 6 is written as C-DAI "6". In FIG. 11, group 11 is made up of two code sequence candidates, group 12 is made up of four code sequence candidates, group 13 is made up of eight code sequence candidates, group 14 is made up of 16 code sequence candidates, and group 15 is made up of 32 code sequence candidates. In FIG. 12, group 16 is made up of 64 code sequence candidates. Note that the group identification codes may be different from the values written in FIGS. 11 and 12.

Group 11 is a set of multiple code sequence candidates to be used when the last C-DAI received by terminal device 1 is C-DAI "1." In group 11, the HARQ-ACK with C-DAI "2," the HARQ-ACK with C-DAI "3," the HARQ-ACK with C-DAI "4," the HARQ-ACK with C-DAI "5," and the HARQ-ACK with C-DAI "6" are all DTX, and the code sequences correspond to the combinations of the HARQ-ACK with C-DAI "1" being an ACK and a NACK. Group 12 is a set of multiple code sequence candidates to be used when the last C-DAI received by terminal device 1 is C-DAI "2." In group 12, the code sequences correspond to the combinations of HARQ-ACK with C-DAI "3", HARQ-ACK with C-DAI "4", HARQ-ACK with C-DAI "5", and HARQ-ACK with C-DAI "6", each of which is DTX, and HARQ-ACK with C-DAI "1" and HARQ-ACK with C-DAI "2", each of which is ACK and NACK. Group 13 is a plurality of code sequence candidates to be used when the C-DAI last received by terminal device 1 is C-DAI "3". In group 13, the HARQ-ACK with C-DAI "4", the HARQ-ACK with C-DAI "5", and the HARQ-ACK with C-DAI "6" are each DTX, and the code sequences correspond to the combinations of ACK and NACK for the HARQ-ACK with C-DAI "1", the HARQ-ACK with C-DAI "2", and the HARQ-ACK with C-DAI "3". Group 14 is a plurality of code sequence candidates to be used when the C-DAI last received by terminal device 1 is C-DAI "4". In group 14, the HARQ-ACK with C-DAI "5" and the HARQ-ACK with C-DAI "6" are each DTX, and the code sequences correspond to the combinations of ACK and NACK for the HARQ-ACK with C-DAI "1", the HARQ-ACK with C-DAI "2", the HARQ-ACK with C-DAI "3", and the HARQ-ACK with C-DAI "4". Group 15 is a plurality of code sequence candidates to be used when the C-DAI last received by terminal device 1 is C-DAI "5". In group 15, the HARQ-ACK with C-DAI "6" is DTX, and the code sequences correspond to the combinations of ACK and NACK for each of the HARQ-ACK with C-DAI "1", the HARQ-ACK with C-DAI "2", the HARQ-ACK with C-DAI "3", the HARQ-ACK with C-DAI "4", and the HARQ-ACK with C-DAI "5". Group 16 is a plurality of code sequence candidates to be used when the C-DAI last received by terminal device 1 is C-DAI "6". In group 16, the code sequences correspond to the combinations of ACK and NACK for each of the following: HARQ-ACK with C-DAI "1", HARQ-ACK with C-DAI "2", HARQ-ACK with C-DAI "3", HARQ-ACK with C-DAI "4", HARQ-ACK with C-DAI "5", and HARQ-ACK with C-DAI "6".

Figure 13 is a diagram showing an example of multiple code sequence candidates corresponding to HARQ-ACK combinations for each C-DAI value. Figure 14 is a diagram showing an example of multiple code sequence candidates corresponding to HARQ-ACK combinations for each C-DAI value. Figure 15 is a diagram showing an example of multiple code sequence candidates corresponding to HARQ-ACK combinations for each C-DAI value. Figure 16 is a diagram showing an example of multiple code sequence candidates corresponding to HARQ-ACK combinations for each C-DAI value. Figures 13 to 16 show the case where 510 code sequence candidates are used for HARQ-ACK combinations for C-DAI values from 1 to 8. 13 to 16, a C-DAI with a value of 1 is written as C-DAI "1", a C-DAI with a value of 2 is written as C-DAI "2", a C-DAI with a value of 3 is written as C-DAI "3", a C-DAI with a value of 4 is written as C-DAI "4", a C-DAI with a value of 5 is written as C-DAI "5", a C-DAI with a value of 6 is written as C-DAI "6", a C-DAI with a value of 7 is written as C-DAI "7", and a C-DAI with a value of 8 is written as C-DAI "8". In FIG. 13, group 101 is composed of two code sequence candidates, and group 102 is composed of four code sequence candidates. 14, group 106 is made up of 64 code sequence candidates. In FIG. 15, group 107 is made up of 128 code sequence candidates. In FIG. 16, group 108 is made up of 256 code sequence candidates. Note that the group identification codes may be different from those shown in FIGS. 13 to 16.

Group 101 is a set of multiple code sequence candidates to be used when the last C-DAI received by terminal device 1 is C-DAI "1." In group 101, the HARQ-ACK with C-DAI "2," the HARQ-ACK with C-DAI "3," the HARQ-ACK with C-DAI "4," the HARQ-ACK with C-DAI "5," the HARQ-ACK with C-DAI "6," the HARQ-ACK with C-DAI "7," and the HARQ-ACK with C-DAI "8" are all DTX, and the code sequences correspond to the combinations of the HARQ-ACK with C-DAI "1" being an ACK and a NACK. Group 102 is a set of multiple code sequence candidates to be used when the last C-DAI received by terminal device 1 is C-DAI "2." In group 102, the code sequences correspond to the combinations of HARQ-ACK with C-DAI "3", HARQ-ACK with C-DAI "4", HARQ-ACK with C-DAI "5", HARQ-ACK with C-DAI "6", HARQ-ACK with C-DAI "7", and HARQ-ACK with C-DAI "8", each of which is DTX, and HARQ-ACK with C-DAI "1" and HARQ-ACK with C-DAI "2", each of which is ACK and NACK. Group 103 is a plurality of code sequence candidates to be used when the C-DAI last received by terminal device 1 is C-DAI "3". In group 103, the code sequences correspond to the combinations of HARQ-ACK with C-DAI "4", HARQ-ACK with C-DAI "5", HARQ-ACK with C-DAI "6", HARQ-ACK with C-DAI "7", and HARQ-ACK with C-DAI "8", each of which is DTX, and HARQ-ACK with C-DAI "1", HARQ-ACK with C-DAI "2", and HARQ-ACK with C-DAI "3", each of which is ACK and NACK. Group 104 is a plurality of code sequence candidates to be used when the C-DAI last received by terminal device 1 is C-DAI "4". In group 104, the HARQ-ACK with C-DAI "5", the HARQ-ACK with C-DAI "6", the HARQ-ACK with C-DAI "7", and the HARQ-ACK with C-DAI "8" are each DTX, and the code sequences correspond to the combinations of ACK and NACK, respectively, for the HARQ-ACK with C-DAI "1", the HARQ-ACK with C-DAI "2", the HARQ-ACK with C-DAI "3", and the HARQ-ACK with C-DAI "4". Group 105 is a plurality of code sequence candidates to be used when the C-DAI last received by terminal device 1 is C-DAI "5". In group 105, the HARQ-ACK with C-DAI "6", the HARQ-ACK with C-DAI "7", and the HARQ-ACK with C-DAI "8" are each DTX, and the code sequences correspond to the combinations of ACK and NACK, respectively, for the HARQ-ACK with C-DAI "1", the HARQ-ACK with C-DAI "2", the HARQ-ACK with C-DAI "3", the HARQ-ACK with C-DAI "4", and the HARQ-ACK with C-DAI "5". Group 106 is a plurality of code sequence candidates to be used when the C-DAI last received by terminal device 1 is C-DAI "6". In group 106, the HARQ-ACK with C-DAI "7" and the HARQ-ACK with C-DAI "8" are each DTX, and the code sequences correspond to the combinations of ACK and NACK for the HARQ-ACK with C-DAI "1", the HARQ-ACK with C-DAI "2", the HARQ-ACK with C-DAI "3", the HARQ-ACK with C-DAI "4", the HARQ-ACK with C-DAI "5", and the HARQ-ACK with C-DAI "6". Group 107 is a plurality of code sequence candidates to be used when the C-DAI last received by terminal device 1 is C-DAI "7". In group 107, the HARQ-ACK with C-DAI "8" is DTX, and the code sequences correspond to the combinations of ACK and NACK for each of the HARQ-ACK with C-DAI "1", the HARQ-ACK with C-DAI "2", the HARQ-ACK with C-DAI "3", the HARQ-ACK with C-DAI "4", the HARQ-ACK with C-DAI "5", the HARQ-ACK with C-DAI "6", and the HARQ-ACK with C-DAI "7". Group 108 is a plurality of code sequence candidates to be used when the C-DAI last received by terminal device 1 is C-DAI "8". In group 108, the code sequences correspond to the combinations of ACK and NACK, respectively, of HARQ-ACK with C-DAI "1", HARQ-ACK with C-DAI "2", HARQ-ACK with C-DAI "3", HARQ-ACK with C-DAI "4", HARQ-ACK with C-DAI "5", HARQ-ACK with C-DAI "6", HARQ-ACK with C-DAI "7", and HARQ-ACK with C-DAI "8".

By using the above-described HARQ-ACK combinations for each C-DAI value and corresponding multiple code sequence candidates, terminal device 1 can notify base station device 3 of the HARQ-ACK for the PDSCH corresponding to each C-DAI value, and base station device 3 can detect the HARQ-ACK for the PDSCH corresponding to each C-DAI value. Because terminal device 1 selects a different code sequence for each last received C-DAI, base station device 3 can detect the last C-DAI value received by terminal device 1. If base station device 3 transmits a PDSCH but terminal device 1 does not receive that PDSCH, this means that terminal device 1 failed to detect the PDCCH corresponding to that PDSCH, and this can be utilized for adaptive control of PDCCH transmission by base station device 3. For example, the PDCCH detection accuracy at terminal device 1 can be improved by increasing the PDCCH transmission power or increasing the CCE aggregation level.

As explained above, one aspect of the present invention enables appropriate exchange of HARQ-ACK between the terminal device 1 and the base station device 3. As a result, the base station device 3 can appropriately control data retransmission. By realizing appropriate retransmission control, efficient communication is achieved.

The following describes various aspects of the device relating to one aspect of this embodiment.

(1) In order to achieve the above object, aspects of the present invention employ the following means. That is, a first aspect of the present invention is a terminal device comprising a processor and a memory for storing computer program code, which performs operations including selecting and transmitting a code sequence from among a plurality of code sequence candidates based on a combination of HARQ-ACKs for PDSCHs corresponding to each C-DAI value, and which uses a different candidate for each C-DAI value corresponding to the last received PDSCH.

(2) A second aspect of the present invention is a base station device comprising a processor and a memory for storing computer program code, which performs operations including detecting a code sequence transmitted from a terminal device from among a plurality of code sequence candidates, and determining a HARQ-ACK for a PDSCH corresponding to each C-DAI value from the detected code sequence, wherein a different candidate is used for each C-DAI value corresponding to the PDSCH last received by the terminal device.

(3) A third aspect of the present invention is a communication method used in a terminal device, comprising the steps of selecting and transmitting a code sequence from among a plurality of code sequence candidates based on a combination of HARQ-ACK for a PDSCH corresponding to each C-DAI value, wherein a different candidate is used for each C-DAI value corresponding to the last received PDSCH.

(4) A fourth aspect of the present invention is a communication method used in a base station device, comprising the steps of: detecting a code sequence transmitted from a terminal device from among a plurality of code sequence candidates; and determining, from the detected code sequence, a HARQ-ACK for a PDSCH corresponding to each C-DAI value; wherein a different candidate is used for each C-DAI value corresponding to the PDSCH last received by the terminal device.

The programs running on the base station device 3 and terminal device 1 relating to one aspect of the present invention may be programs (programs that cause a computer to function) that control a CPU (Central Processing Unit) or the like so as to realize the functions of the above-described embodiment relating to one aspect of the present invention. Information handled by these devices is temporarily stored in RAM (Random Access Memory) during processing, and then stored in various ROMs such as Flash ROM (Read Only Memory) or HDD (Hard Disk Drive), and is read, modified, and written by the CPU as needed.

In addition, a portion of the terminal device 1 and base station device 3 in the above-described embodiment may be implemented by a computer. In this case, the program for implementing this control function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed to implement the function.

Note that the term "computer system" here refers to a computer system built into the terminal device 1 or base station device 3, and includes hardware such as the OS and peripheral devices. Furthermore, "computer-readable recording media" refers to portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, as well as storage devices such as hard disks built into the computer system.

Furthermore, "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 cases. Furthermore, the above-mentioned program may be one that realizes part of the functions described above, or may be one that can realize the functions described above in combination with a program already stored in the computer system.

The terminal device 1 may comprise at least one processor and at least one memory containing computer program instructions (computer program). The memory and computer program instructions (computer program) may be configured to cause the terminal device 1 to perform the operations and processing described in the above embodiments using the processor. The base station device 3 may comprise at least one processor and at least one memory containing computer program instructions (computer program). The memory and computer program instructions (computer program) may be configured to cause the base station device 3 to perform the operations and processing described in the above embodiments using the processor.

Furthermore, the base station device 3 in the above-described embodiment can also be realized as a collection (device group) consisting of multiple devices. Each of the devices constituting the device group may have some or all of the functions or functional blocks of the base station device 3 related to the above-described embodiment. It is sufficient for the device group to have all of the functions or functional blocks of the base station device 3. Furthermore, the terminal device 1 related to the above-described embodiment can also communicate with the base station device as a collection.

Furthermore, the base station device 3 in the above-described embodiments may be an EUTRAN (Evolved Universal Terrestrial Radio Access Network) and/or an NG-RAN (NextGen RAN, NR RAN).Furthermore, the base station device 3 in the above-described embodiments may have some or all of the functions of an upper node for an eNodeB and/or a gNB.

Furthermore, some or all of the terminal device 1 and base station device 3 in the above-described embodiments may be realized as an LSI, which is typically an integrated circuit, or as a chipset. Each functional block of the terminal device 1 and base station device 3 may be individually formed into a chip, or some or all may be integrated into a chip. Furthermore, the integrated circuit method is not limited to LSI, and may be realized using a dedicated circuit or a general-purpose processor. Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology, it may also be possible to use an integrated circuit based on that technology.

In addition, in the above-mentioned embodiment, a terminal device is described as an example of a communication device, but the present invention is not limited to this and can also be applied to terminal devices or communication devices such as stationary or non-mobile electronic devices installed indoors or outdoors, such as AV equipment, kitchen equipment, cleaning/washing equipment, air conditioning equipment, office equipment, vending machines, and other household appliances.

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, various modifications of one aspect of the present invention are possible within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included within the technical scope of the present invention. Furthermore, configurations in which elements described in the above embodiments are substituted for elements that achieve the same effect are also included.

One aspect of the present invention can be used, for example, in communication systems, communication equipment (e.g., mobile phone devices, base station devices, wireless LAN devices, or sensor devices), integrated circuits (e.g., communication chips), or programs.

1 (1A, 1B, 1C) Terminal device 3 Base station device 10, 30 Radio transmission/reception unit 11, 31 Antenna unit 12, 32 RF unit 13, 33 Baseband unit 14, 34 Upper layer processing unit 15, 35 Medium access control layer processing unit 16, 36 Radio resource control layer processing unit

Claims (4)

A terminal device comprising a processor and a memory for storing computer program code,
one code sequence included in the plurality of code sequences corresponds to one group included in the plurality of groups, and based on a combination of HARQ-ACK for PDSCH corresponding to each C-DAI value, selecting and transmitting a code sequence from among a plurality of code sequence candidates in the group;
Performing an action including
A different group is used for each value of C-DAI corresponding to the last received PDSCH.
Terminal device. A base station device comprising a processor and a memory for storing computer program code,
one code sequence included in the plurality of code sequences corresponds to one group included in the plurality of groups, and a code sequence transmitted from a terminal device is detected from among the plurality of code sequence candidates;
determining a HARQ-ACK for a PDSCH corresponding to each C-DAI value from the detected code sequence;
Performing an action including
A different group is used for each value of C-DAI corresponding to the PDSCH last received in the terminal device.
Base station equipment. A communication method used in a terminal device, comprising:
a step of selecting and transmitting a code sequence from among a plurality of code sequence candidates based on a combination of HARQ-ACK for PDSCH corresponding to each C-DAI value, where one code sequence included in the plurality of code sequences corresponds to one group included in the plurality of groups;
Including,
A different group is used for each value of C-DAI corresponding to the last received PDSCH.
Communication method. A communication method used in a base station device,
a step of detecting a code sequence transmitted from a terminal device from among a plurality of code sequence candidates, wherein one code sequence included in the plurality of code sequences corresponds to one group included in the plurality of groups;
determining a HARQ-ACK for a PDSCH corresponding to each C-DAI value from the detected code sequence;
Including,
A different group is used for each value of C-DAI corresponding to the PDSCH last received in the terminal device.
Communication method.