Communication method and communication device

Abstract

A communication method of the present disclosure includes performing sidelink communication with a first communication device. The communication method includes performing scheduling of resources for performing sidelink communication using a first PSCCH. The communication method includes transmitting a second PSCCH different from the first PSCCH on a scheduled resource.

Description

Technical Field

[0001] The present disclosure relates to a communication method and a communication device. Background Art

[0002] Sidelink communication is known as a form of cellular communication. In recent years, in order to enable the use of sidelink communication inexpensively and easily, a technology for implementing sidelink communication using an unlicensed frequency band has been developed.

[0003] Citation List

[0004] Non-patent literature

[0005] Non-patent document 1: "R1-2205034, Qualcomm,"Physical Channel Design for Sidelink on Unlicensed Spectrum", 3GPP TSG-RAN WG1#109e, May 2022", [online], [retrieved on June 27, 2022], Internet https: / / www.3gpp.org / ftp / tsg_ran / WG1_RL1 / TSGR1_109-e / Docs / R1-2205034.zip Summary of the invention

[0006] Technical issues

[0007] When using an unlicensed band, a communication device is required to perform LBT and transmit a signal immediately after successfully acquiring COT. On the other hand, in cellular communication, data transmission starts in a predetermined scheduling time unit (eg, time slot).

[0008] Therefore, when the COT acquisition timing and the time slot start timing do not match, a reservation signal which is not data but is only used to occupy the channel is transmitted from the COT acquisition timing to the time slot start position.

[0009] Since the reservation signal does not include data, if the interval until the next slot boundary after COT acquisition is long, the transmission interval of the reservation signal is long, and the frequency utilization efficiency deteriorates.

[0010] Therefore, the present disclosure proposes a communication method and a communication device capable of further suppressing the degradation of frequency utilization efficiency.

[0011] Note that the above-mentioned problem or purpose is only one of multiple problems or purposes that can be solved or achieved by multiple embodiments disclosed in this specification.

[0012] Solutions to the Problem

[0013] The communication method of the present disclosure includes performing sidelink communication with a first communication device. The communication method includes using a first PSCCH to perform scheduling of resources for performing sidelink communication. The communication method includes sending a second PSCCH different from the first PSCCH on the scheduled resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a diagram for explaining an overview of a communication method according to an embodiment of the present disclosure.

[0015] Figure 2 is a diagram showing a configuration example of a communication system according to an embodiment of the present disclosure.

[0016] Figure 3 is a diagram showing a configuration example of a management device according to an embodiment of the present disclosure.

[0017] Figure 4 is a diagram showing a configuration example of a base station according to an embodiment of the present disclosure.

[0018] Figure 5 is a diagram showing a configuration example of a relay station according to an embodiment of the present disclosure.

[0019] Figure 6 is a diagram showing a configuration example of a terminal device according to an embodiment of the present disclosure.

[0020] Figure 7 is a diagram showing an example of a frame configuration of NR.

[0021] Figure 8 is a diagram showing an overview of sidelink communication.

[0022] Fig. 9 is a diagram showing an example of a frame configuration of a side link.

[0023] Fig.10 is a diagram showing an example of a frame configuration of a side link.

[0024] Fig.11 is a diagram showing a resource pool for a sidelink.

[0025] Fig.12 It is a diagram for explaining a resource allocation pattern.

[0026] Fig.13 is a diagram showing an example of multi-slot scheduling of a PDSCH.

[0027] Fig.14 is a diagram showing an example of multi-slot scheduling of a PUSCH.

[0028] Fig.15is a diagram for explaining four types of LBT categories.

[0029] Fig.16 is a diagram showing a frame-based configuration of a frame-based device.

[0030] Fig.17 is a diagram showing an example of reservation signaling in a sidelink.

[0031] Fig.18 is a diagram showing an example of mini-slot scheduling in a sidelink.

[0032] Fig.19 is a diagram showing an example of scheduling in a sidelink of an unlicensed band.

[0033] Fig. 20 is a diagram showing an example of multi-slot scheduling in a sidelink of an unlicensed band according to an embodiment of the present disclosure.

[0034] Fig.21 is a diagram illustrating another example of multi-slot scheduling in a sidelink of an unlicensed band according to an embodiment of the present disclosure.

[0035] Fig. 22 is a diagram illustrating another example of a configuration of a physical channel in a sidelink of an unlicensed band according to an embodiment of the present disclosure.

[0036] Fig.23 is a diagram illustrating another example of a configuration of a physical channel in a sidelink of an unlicensed band according to an embodiment of the present disclosure.

[0037] Fig.24 is a diagram showing an example of a second PSCCH in multi-slot scheduling according to an embodiment of the present disclosure.

[0038] Fig.25 is a diagram illustrating an example of a monitoring / sensing period adjustment method according to an embodiment of the present disclosure.

[0039] Fig.26 is a diagram illustrating another example of a monitoring / sensing period adjustment method according to an embodiment of the present disclosure.

[0040] Fig. 27 is a diagram illustrating another example of a monitoring / sensing period adjustment method according to an embodiment of the present disclosure.

[0041] Fig.28 is a diagram illustrating another example of a monitoring / sensing period adjustment method according to an embodiment of the present disclosure.

[0042] Fig.29is a diagram illustrating an example of a hidden terminal problem in a sidelink of an unlicensed band.

[0043] Fig.30 A diagram showing an example of transmitting COT information in a sidelink of an unlicensed band according to an embodiment of the present disclosure.

[0044] Fig.31 is a diagram illustrating an example of transmission of COT information according to an embodiment of the present disclosure.

[0045] Fig.32 is a diagram illustrating another example of transmission of COT information according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0046] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Note that in the embodiments described below, the same parts are denoted by the same reference numerals, and redundant descriptions are omitted.

[0047] In addition, unless otherwise specified, the techniques, functions, methods, configurations, processes and all other descriptions described below are applicable to LTE and NR.

[0048] In this specification and the drawings, multiple components having substantially the same functional configuration may be distinguished by adding different numbers after the same reference numerals. For example, multiple components having substantially the same functional configuration may be distinguished as terminal devices 401, 402, and 403 as needed. However, when it is not particularly necessary to distinguish each of the multiple components having substantially the same functional configuration, only the same reference numerals are added. For example, when it is not necessary to particularly distinguish terminal devices 401, 402, and 403, terminal devices 401, 402, and 403 may be referred to as terminal device 40.

[0049] One or more embodiments (including examples and variations) described below can be implemented independently. On the other hand, at least a portion of the multiple embodiments described below can be appropriately combined with at least a portion of other embodiments and implemented. These multiple embodiments can include new features that are different from each other. Therefore, these multiple embodiments can help solve different purposes or problems, and can achieve different effects from each other.

[0050] <<1.Overview>>

[0051] Radio access technologies (RATs) such as Long Term Evolution (LTE) and New Radio (NR) have been studied in the 3rd Generation Partnership Project (3GPP) (registered trademark). LTE and NR are types of cellular communication technologies, and enable mobile communication of terminal devices by arranging multiple areas covered by base stations in a cell shape. At this time, a single base station can manage multiple cells.

[0052] Note that in the following description, it is assumed that "LTE" includes LTE-A (LTE-Advanced), LTE-A Pro (LTE-Advanced Pro), and E-UTRA (Evolved Universal Terrestrial Radio Access). NR includes NRAT (New Radio Access Technology) and FE-UTRA (Further E-UTRA). In the following description, a cell suitable for LTE is referred to as an LTE cell, and a cell suitable for NR is referred to as an NR cell.

[0053] NR is the next (fifth) generation radio access technology (RAT) of LTE. NR is a radio access technology that can handle various use cases including eMBB (enhanced mobile broadband), mMTC (massive machine type communication) and URLLC (ultra-reliable and low latency communication). NR is studied for a technical framework suitable for usage scenarios, demand conditions, deployment scenarios, etc. in these use cases.

[0054] In 3GPP (registered trademark), sidelink communication for public safety and vehicle-to-everything communication (V2X) is introduced as a main use case. In recent years, the use of sidelink communication has been expected not only for V2X but also for commercial use communication. Examples of commercial use communication include XR (VR (virtual reality), AR (augmented reality) or MR (mixed reality)) games, real-time sharing of XR content, media sharing, wireless network sharing, industrial IoT (Internet of Things) networks, and home networks.

[0055] Commercial use communication requires providing cheap and easy services in addition to high quality. Therefore, in this embodiment, sidelink communication using an unlicensed band is considered. An unlicensed band is a band that can be used by anyone. Therefore, when an unlicensed band is used, cheap and easy service provision can be achieved. Note that unlicensed bands are sometimes referred to as unlicensed spectrum, licensed shared bands, shared spectrum, or cells with CCA. Operations using unlicensed bands are sometimes referred to as operations with shared spectrum.

[0056] When using an unlicensed band, a communication device is required to perform LBT and transmit a signal immediately after successfully acquiring COT. On the other hand, in cellular communication, data transmission starts in a predetermined scheduling time unit (eg, time slot).

[0057] Therefore, when the COT acquisition timing and the time slot start timing do not match, a reservation signal which is not data but is only used to occupy the channel is transmitted from the COT acquisition timing to the time slot start position.

[0058] A predetermined scheduling time unit has multiple lengths. For example, in cellular communications, a time slot is specified. In addition, in NR, scheduling can be performed in a time interval shorter than a time slot. For example, in the downlink and uplink of NR, scheduling can be performed with any length from 2 symbols to 13 symbols in a time slot including 14 symbols. Scheduled time intervals shorter than a time slot are sometimes referred to as mini slots or sub slots.

[0059] By introducing mini slots into the sidelink communication in the unlicensed band, the length of the reservation signal described above can be further reduced. However, since control information is included in each mini slot, if scheduling is performed in units of mini slots, the overhead for sending control information increases. This increase in overhead may lead to deterioration of communication quality and deterioration of frequency utilization efficiency.

[0060] Therefore, a method of suppressing the increase in the overhead of control information by enabling a communication device to perform scheduling in units of mini slots and in units of time slots can be conceived. However, in this case, other communication devices that communicate in one scheduling time unit (e.g., time slot) may ignore control information sent in other scheduling time units (e.g., mini slots).

[0061] As described above, if other communication devices ignore the control information transmitted by the communication device, the other communication devices may start communication in the communication section scheduled by the communication device, and the communication efficiency in the sidelink communication deteriorates.

[0062] Therefore, in this embodiment, the above-mentioned problem is solved by using a method of performing side link communication using two different PSCCHs.

[0063] Figure 1 1 is a diagram for describing an overview of a communication method according to an embodiment of the present disclosure. Figure 1 As shown, when performing sidelink communication with a first communication device, the communication device schedules PSSCH using resource S for performing sidelink communication using a first PSCCH. The communication device transmits a second PSCCH different from the first PSCCH using the scheduled resource S.

[0064] As described above, since the communication device sends a second PSCCH different from the first PSCCH used to perform scheduling, even if other communication devices ignore the first PSCCH, other communication devices can receive the second PSCCH. Another communication device can use the second PSCCH to check the resources scheduled by the communication device. Therefore, in the sidelink communication, the communication efficiency (frequency utilization efficiency) can be further improved.

[0065] <<2. Configuration of communication system>>

[0066] First, the configuration of the communication system 1 will be specifically described with reference to the drawings.

[0067] <Overall Configuration of Communication System>

[0068] Figure 2 1 is a diagram showing a configuration example of a communication system 1 according to an embodiment of the present disclosure. The communication system 1 includes a management device 10, a base station 20, a relay station 30, and a terminal device 40. The communication system 1 provides a user with a wireless network capable of performing mobile communications by configuring wireless communication devices of the communication system 1 that operate in collaboration. The wireless network in this embodiment is composed of, for example, a wireless access network and a core network. Note that in this embodiment, the wireless communication device is a device having a wireless communication function. Figure 2 In the illustrated example, the base station 20, the relay station 30, and the terminal device 40 correspond to wireless communication devices. In the following description, the wireless communication device is sometimes simply referred to as a communication device.

[0069] The communication system 1 may include a plurality of management devices 10, a plurality of base stations 20, a plurality of relay stations 30, and a plurality of terminal devices 40. Figure 2 In the example shown, the communication system 1 includes management devices 101 and 102 as the management device 10, and includes base stations 201 and 202 as the base station 20. The communication system 1 includes relay stations 301 and 302 and the like as the relay station 30, and includes terminal devices 401, 402, and 403 and the like as the terminal device 40.

[0070] Note that the devices in the figure can be considered as devices in a logical sense, that is, part of the devices in the figure can be implemented by a virtual machine (VM), a container (container), etc., which can be implemented on the same hardware physically.

[0071] Note that the communication system 1 can support radio access technologies (RATs) such as LTE (Long Term Evolution) and NR (New Radio). LTE and NR are types of cellular communication technologies, and enable mobile communication of the terminal device 40 by arranging multiple areas covered by the base station 20 in a cell shape.

[0072] Note that the wireless access scheme used by the communication system 1 is not limited to LTE and NR, and may be another wireless access scheme such as W-CDMA (Wideband Code Division Multiple Access) or CDMA2000 (Code Division Multiple Access 2000).

[0073] The base station 20 or the relay station 30 configuring the communication system 1 may be a ground station or may be a non-ground station. The non-ground station may be a satellite station or may be an aircraft station. In the case where the non-ground station is a satellite station, the communication system 1 may be a bent pipe (transparent) type mobile satellite communication system.

[0074] Note that in this embodiment, the ground station (also referred to as a ground base station) refers to the base station 20 (including the relay station 30) installed on the ground. Here, "ground" is the ground in a broad sense, including not only land but also underground, above water, and underwater. Note that in the following description, the description of "ground station" can be replaced by "gateway".

[0075] Note that the base station 20 in LTE is sometimes referred to as an eNodeB (evolved Node B) or an eNB. The NR base station 20 is sometimes referred to as a gNodeB or a gNB. In LTE and NR, the terminal device 40 (also referred to as a mobile station or a terminal) is sometimes referred to as a user equipment (UE). Note that the terminal device 40 is a type of communication device and is also referred to as a mobile station or a terminal.

[0076] In this embodiment, the concept of communication equipment includes not only portable mobile equipment (terminal equipment) such as portable terminals, but also equipment installed in a structure or a mobile body. The structure or mobile body itself can be considered as a communication equipment. The concept of communication equipment includes not only terminal equipment 40, but also base stations 20 and relay stations 30. Communication equipment is a type of processing equipment and information processing equipment. Communication equipment can also be referred to as a sending device or a receiving device.

[0077] In the following description, the configuration of the devices configuring the communication system 1 is specifically described. Note that the configuration of the devices described below is merely an example. The configuration of the devices may be different from the configuration explained below.

[0078] <2.1. Configuration of management equipment>

[0079] Subsequently, the configuration of the management device 10 is explained.

[0080] The management device 10 is a device that manages a wireless network. For example, the management device 10 is a device that manages the communication of the base station 20. The management device 10 may be, for example, a device having the function of an MME (Mobility Management Entity). The management device 10 may be a device having the function of an AMF (Access and Mobility Management Function) and / or an SMF (Session Management Function). Of course, the functions of the management device 10 are not limited to MME, AMF, and SMF. The management device 10 may be a device having the function of an NSSF (Network Slice Selection Function), an AUSF (Authentication Server Function), a PCF (Policy Control Function), and an UDM (Unified Data Management). The management device 10 may be a device having the function of an HSS (Home Subscriber Server).

[0081] Note that the management device 10 may have a function of a gateway. For example, the management device 10 may have a function of an S-GW (Serving Gateway) or a P-GW (Packet Data Network Gateway). The management device 10 may have a function as a User Plane Function (UPF).

[0082] The core network is composed of multiple network functions. The network functions can be aggregated into one physical device, or can be distributed to multiple physical devices. That is, the management device 10 can be dispersedly arranged in multiple devices. In addition, the distributed arrangement can be controlled to be dynamically executed. The base station 20 and the management device 10 constitute a network and provide wireless communication services to the terminal device 40. The management device 10 is connected to the Internet. The terminal device 40 can use various services provided via the Internet via the base station 20.

[0083] Note that the management device 10 may not always be a device that configures the core network. For example, it is assumed that the core network is a core network of W-CDMA (Wideband Code Division Multiple Access) or CDMA2000 (Code Division Multiple Access 2000). In this case, the management device 10 may be a device that functions as an RNC (Radio Network Controller).

[0084] Figure 3 1 is a diagram showing a configuration example of a management device 10 according to an embodiment of the present disclosure. The management device 10 includes a communication unit 11, a storage unit 12, and a control unit 13. Note that Figure 3 The configuration shown in is a functional configuration. The hardware configuration may be different from the functional configuration. The functions of the management device 10 may be statically or dynamically distributed and implemented in multiple physically separated components. For example, the management device 10 may be composed of multiple server devices.

[0085] The communication unit 11 is a communication interface for communicating with other devices. The communication unit 11 may be a network interface or may be a device connection interface. For example, the communication unit 11 may be a LAN (Local Area Network) interface, such as a NIC (Network Interface Card), or may be a USB (Universal Serial Bus) interface configured by a USB host controller, a USB port, etc. The communication unit 11 may be a wired interface or a wireless interface. The communication unit 11 functions as a communication device of the management device 10. The communication unit 11 communicates with the base station 20, etc., according to the control of the control unit 13.

[0086] The storage unit 12 is a data readable / writable storage device, such as a DRAM (dynamic random access memory), an SRAM (static random access memory), a flash memory, or a hard disk. The storage unit 12 is used as a storage device for the management device 10. The storage unit 12 stores, for example, the connection status of the terminal device 40. For example, the storage unit 12 stores the status of the RRC (radio resource control) of the terminal device 40 or the status of the ECM (EPS connection management) or the 5G system CM (connection management). The storage unit 12 can be used as a local memory for storing the location information of the terminal device 40.

[0087] The control unit 13 is a controller that controls the units of the management device 10. The control unit 13 is implemented by a processor such as a CPU (central processing unit), an MPU (microprocessing unit), or a GPU (graphics processing unit). For example, the control unit 13 is implemented by a processor executing various programs stored in a storage device inside the management device 10, which uses a RAM (random access memory) or the like as a working area. Note that the control unit 13 can be implemented by an integrated circuit such as an ASIC (application-specific integrated circuit) or an FPGA (field programmable gate array). CPU, MPU, GPU, ASIC, and FPGA can all be regarded as controllers.

[0088] <2.2. Base Station>

[0089] The base station 20 is a communication device that operates a cell and provides wireless communication services to one or more terminal devices 40 located within the coverage area of ​​the cell. The cell operates according to any wireless communication scheme such as LTE or NR. The base station 20 is connected to the core network. The core network is connected to the packet data network through a gateway device.

[0090] Note that the base station 20 may be configured by a set of multiple physical or logical devices. For example, in an embodiment of the present disclosure, the base station 20 may be distinguished into multiple devices of a BBU (baseband unit) and a RU (radio unit), and may be interpreted as an aggregate of multiple devices. Further or optionally, in an embodiment of the present disclosure, the base station 20 may be either or both of the BBU and the RU. The BBU and the RU may be connected via a predetermined interface (e.g., eCPRI). Additionally or alternatively, the RU may be referred to as a remote radio unit (RRU) or a radio DoT (RD). Further or optionally, the RU may correspond to the gNB-DU explained below. Further or optionally, the BBU may correspond to the gNB-CU explained below. Alternatively, the RU may be connected to the gNB-DU explained below. Furthermore, the BBU may correspond to a combination of the gNB-CU and the gNB-DU explained below. Further or optionally, the RU may be a device formed integrally with an antenna. The antenna included in the base station 20 (e.g., an antenna formed integrally with the RU) may adopt an advanced antenna system and support MIMO (e.g., FD-MIMO) and beamforming. In an advanced antenna system, an antenna included in the base station 20 (eg, an antenna integrally formed with the RU) may include, for example, 64 transmit antenna ports and 64 receive antenna ports.

[0091] A plurality of base stations 20 may be connected to each other. One or more base stations 20 may be included in a radio access network (RAN). That is, the base station 20 may be simply referred to as a RAN, a RAN node, an AN (access network), or an AN node. The RAN in LTE is referred to as EUTRAN (Enhanced Universal Terrestrial RAN). The RAN in NR is referred to as NGRAN. The RAN in W-CDMA (UMTS) is referred to as UTRAN. The base station 20 of LTE is referred to as an eNodeB (Evolved Node B) or an eNB. That is, the EUTRAN includes one or more eNodeBs (eNBs). The base station 20 of NR is referred to as a gNodeB or a gNB. That is, the NGRAN includes one or more gNBs. In addition, the EUTRAN may include a gNB (en-gNB) connected to a core network (EPC) in an LTE communication system (EPS). Similarly, the NGRAN may include an ng-eNB connected to a core network 5GC in a 5G communication system (5GS). In addition or alternatively, when the base station 20 is an eNB, a gNB, etc., the base station 20 may be referred to as a 3GPP access. Further or alternatively, when the base station 20 is a wireless access point (e.g., a WiFi (registered trademark) access point), the base station 20 may be referred to as a non-3GPP access. Further or alternatively, the base station 20 may be an optical extension device referred to as an RRH (remote radio head), and further or alternatively, when the base station 20 is a gNB, the base station 20 may be referred to as a combination of a gNB CU (central unit) and a gNB DU (distributed unit) or any one of the gNB CU and the gNB DU. In order to communicate with the UE, the gNB CU (central unit) hosts multiple upper layers (e.g., RRC, SDAP, and PDCP) of the access layer. On the other hand, the gNB-DU hosts multiple lower layers (e.g., RLC, MAC, and PHY) of the access layer. That is, among the messages and information explained below, RRC signaling (e.g., various SIBs including MIB and SIB1, RRCSetup message, and RRCReconfiguration message) may be generated by the gNB-CU, and on the other hand, the DCI and various physical channels (e.g., PDCCH and PBCH) explained below may be generated by the gNB-DU. Alternatively, in RRC signaling, for example, part of the configuration (configuration information) such as IE: cellGroupConfig may be generated by the gNB-DU, while the rest of the configuration may be generated by the gNB-CU. These configurations (configuration information) may be sent and received by the F1 interface explained below. The base station 20 may be configured to be able to communicate with another base station 20. For example, when the multiple base stations 20 are a combination of eNBs or eNBs and en-gNBs, the base stations 20 may be connected via an X2 interface. In addition or alternatively, when the multiple base stations 20 are a combination of gNBs or gn-eNBs and gNBs, the devices may be connected via an Xn interface.In addition or alternatively, when the multiple base stations 20 are a combination of gNB CU (central unit) and gNB DU (distributed unit), the devices can be connected through the F1 interface explained above. The messages / information (RRC signaling or DCI information and physical channels) explained below can be transmitted between the multiple base stations 20 (e.g., via X2, Xn or F1 interface).

[0092] In addition, as described above, the base station 20 can be configured to manage multiple cells. The cell provided by the base station 20 is called a serving cell. The serving cell includes a PCel l (primary cell) and a SCel l (secondary cell). When providing dual connectivity (e.g., EUTRA-EUTRA dual connectivity, EUTRA-NR dual connectivity (ENDC), EUTRA-NR dual connectivity of 5GC, NR-EUTRA dual connectivity (NEDC) or NR-NR dual connectivity) to a UE (e.g., a terminal device 40), zero or one or more SCel l provided by the PCel l and the MN (master node) is referred to as a primary cell group. In addition, the serving cell may include a PSCel l (primary secondary cell or primary SCG cell). That is, when dual connectivity is provided to a UE, the PSCel l and zero or one or more SCel l provided by the SN (secondary node) are referred to as a secondary cell group (SCG). Unless a special setting is performed (e.g., PUCCH on SCel l), the physical uplink control channel (PUCCH) is sent by the PCel l and the PSCel l, but not by the SCel l. A radio link failure is also detected in PCel l and PSCel l, but no radio link failure is detected in SCel l (may not be detected). As described above, since PCel l and PSCel l have special roles in the serving cell, PCel l and PSCel l are also referred to as special cells (SpCel l). One downlink component carrier and one uplink component carrier can be associated with a cell. The system bandwidth corresponding to a cell can be divided into multiple bandwidth parts. In this case, one or more bandwidth parts (BWP) can be set for the UE, and one bandwidth part can be used for the UE as an active BWP. The wireless resources (e.g., frequency band, parameter set (subcarrier spacing), time slot format (time slot configuration)) that the terminal device 40 can use can be different for each cell, each component carrier or each BWP.

[0093] Figure 4 2 is a diagram showing a configuration example of a base station 20 according to an embodiment of the present disclosure. The base station 20 includes a wireless communication unit 21, a storage unit 22, and a control unit 23. Note that Figure 4The configuration shown in is a functional configuration. The hardware configuration may be different from this configuration. The functions of the base station 20 may be implemented in a distributed manner in a plurality of physically separated components.

[0094] The wireless communication unit 21 is a signal processing unit for wirelessly communicating with other wireless communication devices (e.g., terminal device 40). The wireless communication unit 21 operates under the control of the control unit 23. The wireless communication unit 21 is applicable to one or more wireless access schemes. For example, the wireless communication unit 21 is applicable to both NR and LTE. In addition to NR or LTE, the wireless communication unit 21 may be applicable to W-CDMA or CDMA2000. The wireless communication unit 21 may be applicable to automatic retransmission technology such as HARQ (Hybrid Automatic Repeat Request).

[0095] The wireless communication unit 21 includes a transmission processing unit 211, a reception processing unit 212, and an antenna 213. The wireless communication unit 21 may include a plurality of transmission processing units 211, a plurality of reception processing units 212, and a plurality of antennas 213. Note that when the wireless communication unit 21 is applicable to a plurality of wireless access schemes, the units of the wireless communication unit 21 may be configured separately for each wireless access scheme. For example, the transmission processing unit 211 and the reception processing unit 212 may be configured separately by LTE and NR. The antenna 213 may be composed of a plurality of antenna elements (e.g., a plurality of patch antennas). In this case, the wireless communication unit 21 may be configured to be capable of performing beamforming. The wireless communication unit 21 may be configured to be capable of performing polarization beamforming using vertically polarized waves (V polarized waves) and horizontally polarized waves (H polarized waves).

[0096] The transmission processing unit 211 performs transmission processing of downlink control information and downlink data. For example, the transmission processing unit 211 encodes the downlink control information and downlink data input from the control unit 23 using a coding method such as block coding, convolutional coding, Turbo coding, etc. Here, as coding, coding by polar code or coding by LDPC code (low-density parity check code) can be performed. Then, the transmission processing unit 211 modulates the coded bits using a predetermined modulation scheme such as BPSK, QPSK, 16QAM, 64QAM or 256QAM. In this case, the signal points on the constellation do not always need to be equidistant. The constellation can be a non-uniform constellation (NUC). Then, the transmission processing unit 211 multiplexes the modulation symbols and downlink reference signals of the channel, and arranges the multiplexed symbols and the multiplexed downlink reference signals in predetermined resource elements. Then, the transmission processing unit 211 performs various signal processing on the multiplexed signals. For example, the transmission processing unit 211 performs processing such as conversion to the frequency domain by fast Fourier transform, adding a guard interval (cyclic prefix), generating a baseband digital signal, converting to an analog signal, orthogonal modulation, up-conversion, removing extra frequency components, and power amplification. The signal generated by the transmission processing unit 211 is transmitted from the antenna 213.

[0097] The receiving processing unit 212 processes the uplink signal received via the antenna 213. For example, the receiving processing unit 212 performs down-conversion, removal of unnecessary frequency components, control of amplification level, orthogonal demodulation, conversion to digital signals, removal of guard intervals (cyclic prefixes), extraction of frequency domain signals by fast Fourier transform, etc. on the uplink signal. Then, the receiving processing unit 212 separates uplink channels such as PUSCH (physical uplink shared channel) and PUCCH (physical uplink control channel) and uplink reference signals from the processed signals. In addition, the receiving processing unit 212 demodulates the received signal for the modulation symbols of the uplink channel using a modulation scheme such as BPSK (binary phase shift keying) or QPSK (quadrature phase shift keying). The modulation scheme used for demodulation may be 16QAM (quadrature amplitude modulation), 64QAM, or 256QAM. In this case, the signal points on the constellation do not always need to be equidistant. The constellation may be a non-uniform constellation (NUC). The reception processing unit 212 performs a decoding process on the coded bits of the demodulated uplink channel. The decoded uplink data and uplink control information are output to the control unit 23.

[0098] Antenna 213 is an antenna device (antenna unit) that converts electric current and radio waves into each other. Antenna 213 can be configured by one antenna element (e.g., one patch antenna), or can be configured by multiple antenna elements (e.g., multiple patch antennas). When antenna 213 is configured by multiple antenna elements, wireless communication unit 21 can be configured to be able to perform beamforming. For example, wireless communication unit 21 can be configured to generate a directional beam by controlling the directivity of a radio signal using multiple antenna elements. Note that antenna 213 can be a dual-polarized antenna. When antenna 213 is a dual-polarized antenna, wireless communication unit 21 can use vertical polarized waves (V polarized waves) and horizontal polarized waves (H polarized waves) when sending radio signals. Then, wireless communication unit 21 can control the directivity of radio signals sent using vertical polarized waves and horizontal polarized waves. In addition, wireless communication unit 21 can send and receive spatially multiplexed signals via multiple layers including multiple antenna elements.

[0099] The storage unit 22 is a data readable / writable storage device, such as a DRAM, an SRAM, a flash memory, or a hard disk. The storage unit 22 is used as a storage device of the base station 20.

[0100] The control unit 23 is a controller that controls the units of the base station 20. The control unit 23 is implemented by a processor such as a CPU (central processing unit) or an MPU (microprocessing unit). For example, the control unit 23 is implemented by the processor executing various programs stored in a storage device inside the base station 20, wherein the base station uses a RAM (random access memory) or the like as a working area. Note that the control unit 23 can be implemented by an integrated circuit such as an ASIC (application-specific integrated circuit) or an FPGA (field programmable gate array). CPU, MPU, ASIC, FPGA can all be regarded as controllers. In addition to or instead of the CPU, the control unit 23 can be implemented by a GPU (graphics processing unit).

[0101] like Figure 4 As shown, the control unit 23 includes an acquisition unit 231, a sending unit 232 and a communication control unit 233. The modules constituting the control unit 23 (acquisition unit 231 to communication control unit 233) are functional modules representing the functions of the control unit 23 respectively. These functional modules can be either software modules or hardware modules. For example, each of the above functional modules can be either a software module implemented by software (including microprograms) or a circuit module on a semiconductor chip (bare die). Of course, each functional module can be a processor or an integrated circuit. The configuration method of the functional modules is optional. Note that the control unit 23 can be composed of functional units different from the above functional modules. The operation of the control unit 23 can be the same as the operation of the modules of the control unit 43 of the terminal device 40.

[0102] <2.3. Relay Station Configuration>

[0103] The relay station 30 is a device used as a relay station of the base station 20. The relay station 30 is a type of the base station 20. The relay station 30 is a type of information processing device. The relay station 30 may be replaced with a relay base station. In addition, the relay station 30 may be a device called a repeater (e.g., an RF repeater, an intelligent repeater, a network-controlled repeater, or a smart surface).

[0104] The relay station 30 is capable of wireless communication such as NOMA communication with the terminal device 40. The relay station 30 relays the communication between the base station 20 and the terminal device 40. Note that the relay station 30 can be configured to be capable of wireless communication with other relay stations 30 and other base stations 20. The relay station 30 can be a ground station device or can be a non-ground station device. The relay station 30 configures the radio access network RAN ​​in conjunction with the base station 20.

[0105] Note that the relay station 30 in this embodiment can be a fixed device, a movable device, or a floating device. In addition, the size of the coverage range of the relay station 30 in this embodiment is not limited to a specific size. For example, the cell covered by the relay station 30 can be a macro cell, a micro cell, or a small cell.

[0106] If the relay function is satisfied, the relay station 30 in this embodiment is not limited to the device to which it is installed. For example, the relay station 30 may be installed on a terminal device 40 such as a smart phone, may be installed on a car, train or human-powered vehicle, may be installed on a balloon, airplane or drone, may be installed on a traffic light, sign, street light, etc., or may be installed on a household appliance such as a television, a game console, an air conditioner, a refrigerator or a lighting fixture.

[0107] In addition, the configuration of the relay station 30 can be similar to the configuration of the base station 20 explained above. For example, similar to the above-mentioned base station 20, the relay station 30 can be a device installed in a mobile body, or it can be the mobile body itself. As described above, the mobile body can be a mobile terminal such as a smart phone or a cellular phone. The mobile body can be a mobile body that moves on land (in a narrow sense, on the ground), or it can be a mobile body that moves underground. Of course, the mobile body can be a mobile body that moves on water, or it can be a mobile body that moves underwater. The mobile body can be a mobile body that moves in the atmosphere, or it can be a mobile body that moves outside the atmosphere. The relay station 30 can be a ground station device or can be a non-ground station device. At this time, the relay station 30 can be an aircraft station or a satellite station.

[0108] The size of the coverage of the relay station 30 may be a large size such as a macro cell size or a small size such as a pico cell size, such as the size of the coverage of the base station 20. Naturally, the size of the coverage of the relay station 30 may be an extremely small size such as a femto cell size. The relay station 30 may have a beamforming capability. In this case, for the relay station 30, a beamforming cell or service area may be formed for each cell.

[0109] Figure 5 3 is a diagram showing a configuration example of a relay station 30 according to an embodiment of the present disclosure. The relay station 30 includes a wireless communication unit 31, a storage unit 32, and a control unit 33. Note that Figure 5 The configuration shown in is a functional configuration. The hardware configuration may be different from this configuration. The functions of the relay station 30 may be implemented in a distributed manner in a plurality of physically separated components.

[0110] The wireless communication unit 31 is a wireless communication interface for wireless communication with other wireless communication devices (e.g., base station 20, terminal device 40, and other relay stations 30). The wireless communication unit 31 is applicable to one or more wireless access schemes. For example, the wireless communication unit 31 is suitable for both NR and LTE. In addition to NR or LTE, the wireless communication unit 31 may be suitable for W-CDMA or CDMA2000. The wireless communication unit 31 includes a transmission processing unit 311, a reception processing unit 312, and an antenna 313. The wireless communication unit 31 may include a plurality of transmission processing units 311, a plurality of reception processing units 312, and a plurality of antennas 313. Note that when the wireless communication unit 31 is applicable to a plurality of wireless access schemes, each unit of the wireless communication unit 31 may be configured separately for each wireless access scheme. For example, the transmission processing unit 311 and the reception processing unit 312 may be separately configured by LTE and NR. The configuration of the transmission processing unit 311, the reception processing unit 312, and the antenna 313 is similar to the configuration of the transmission processing unit 211, the reception processing unit 212, and the antenna 213 described above. Note that the wireless communication unit 31 may be configured to be able to perform beamforming like the wireless communication unit 21 .

[0111] The storage unit 32 is a storage device capable of reading and writing data, such as a DRAM, an SRAM, a flash memory, or a hard disk. The storage unit 32 serves as a storage device of the relay station 30.

[0112] The control unit 33 is a controller that controls the units of the relay station 30. The control unit 33 is implemented by a processor such as a CPU, an MPU, or a GPU. For example, the control unit 33 is implemented by the processor executing various programs stored in a storage device inside the relay station 30, and the relay station 30 uses a RAM or the like as a working area. Note that the control unit 33 can be implemented by an integrated circuit such as an ASIC or an FPGA. CPU, MPU, GPU, ASIC, and FPGA can all be regarded as controllers. The operation of the control unit 33 can be the same as the operation of the control unit 23 of the base station 20.

[0113] like Figure 5 As shown, the control unit 33 includes an acquisition unit 331, a sending unit 332 and a communication control unit 333. The modules (acquisition unit 331 to communication control unit 333) constituting the control unit 33 are functional modules representing the functions of the control unit 33 respectively. These functional modules can be either software modules or hardware modules. For example, each of the above functional modules can be either a software module implemented by software (including microprograms) or a circuit module on a semiconductor chip (bare die). Of course, each functional module can be a processor or an integrated circuit. The configuration method of the functional module is optional. Note that the control unit 33 can be configured by functional units different from the above functional modules. The operation of the control unit 33 can be the same as the operation of the modules of the control unit 23 of the base station 20.

[0114] Note that the relay station 30 may be an IAB relay node. The relay station 30 operates as an IAB-MT (mobile terminal) of an IAB donor node for providing backhaul, and operates as an IAB-DU (distributed unit) of a terminal device 40 for providing access. The IAB donor node may be, for example, a base station 20, and operates as an IAB-CU (central unit).

[0115] <2.4. Terminal equipment configuration>

[0116] The terminal device 40 is a wireless communication device that wirelessly communicates with other communication devices such as the base station 20 and the relay station 30. The terminal device 40 is, for example, a mobile phone, a smart device (smart phone or tablet), a PDA (personal digital assistant), or a personal computer. The terminal device 40 may be a device such as a commercial camera including a communication function, or may be a motorcycle, a mobile relay vehicle, etc. loaded with a communication device such as an FPU (field pickup unit). The terminal device 40 may be an M2M (machine to machine) device or an IoT (Internet of Things) device.

[0117] Note that the terminal device 40 can perform NOMA communication with the base station 20. The terminal device 40 can use automatic retransmission technology such as HARQ when communicating with the base station 20. The terminal device 40 is capable of performing sidelink communication with other terminal devices 40. The terminal device 40 is also capable of using automatic retransmission technology such as HARQ when performing sidelink communication. Note that the terminal device 40 is also capable of performing NOMA communication in communication (sidelink) with other terminal devices 40. The terminal device 40 is capable of LPWA communication with other communication devices (for example, the base station 20 and other terminal devices 40). The wireless communication used by the terminal device 40 may be wireless communication using millimeter waves. Note that the wireless communication (including sidelink communication) used by the terminal device 40 may be wireless communication using radio waves, or may be wireless communication using infrared or visible light (optical wireless).

[0118] The terminal device 40 may be a mobile device. A mobile device is a movable wireless communication device. At this time, the terminal device 40 may be a wireless communication device installed in a mobile body, or may be the mobile body itself. For example, the terminal device 40 may be a vehicle moving on a road such as a car, a bus, a truck, or a motorcycle, a vehicle moving on rails installed on a track of a train, etc., or a wireless communication device loaded on a vehicle. Note that the mobile body may be a mobile terminal, or may be a mobile body moving on land (on the ground in a narrow sense), underground, on water, or underwater. The mobile body may be a mobile body moving within the atmosphere, such as a drone or a helicopter, or may be a mobile body moving outside the atmosphere, such as an artificial satellite.

[0119] The terminal device 40 can be connected to multiple base stations 20 or multiple cells at the same time to perform communication. For example, when one base station 20 supports a communication area via multiple cells (e.g., pCel l, sCel l), the multiple cells can be bundled so that the base station 20 and the terminal device 40 can communicate using carrier aggregation (CA) technology, dual connection (DC) technology, or multi-connection (MC) technology. Alternatively, the terminal device 40 and multiple base stations 20 can communicate using coordinated multi-point transmission and reception (CoMP) technology via cells of different base stations 20.

[0120] Figure 6 4 is a diagram showing a configuration example of a terminal device 40 according to an embodiment of the present disclosure. The terminal device 40 includes a wireless communication unit 41, a storage unit 42, and a control unit 43. Note that Figure 6 The components shown in are functional configurations. The hardware configuration may be different from this configuration. The functions of the terminal device 40 may be distributed and implemented in a plurality of physically separate components.

[0121] The wireless communication unit 41 is a signal processing unit for wirelessly communicating with other wireless communication devices (e.g., the base station 20, the relay station 30, and other terminal devices 40). The wireless communication unit 41 operates according to the control of the control unit 43. The wireless communication unit 41 includes a transmission processing unit 411, a reception processing unit 412, and an antenna 413. The configuration of the wireless communication unit 41, the transmission processing unit 411, the reception processing unit 412, and the antenna 413 may be the same as the configuration of the wireless communication unit 21, the transmission processing unit 211, the reception processing unit 212, and the antenna 213 of the base station 20. The wireless communication unit 41 may be configured to be able to perform beamforming like the wireless communication unit 21. In addition, like the wireless communication unit 21, the wireless communication unit 41 may be configured to be able to transmit and receive spatially multiplexed signals.

[0122] The storage unit 42 is a data readable / writable storage device, such as a DRAM, an SRAM, a flash memory, or a hard disk. The storage unit 42 is used as a storage device of the terminal device 40.

[0123] The control unit 43 is a controller that controls each unit of the terminal device 40. The control unit 43 is implemented by a processor such as a CPU, an MPU, etc. For example, the control unit 43 is implemented by the processor executing various programs stored in a storage device inside the terminal device 40, and the terminal device 40 uses a RAM, etc. as a working area. Note that the control unit 43 can be implemented by an integrated circuit such as an ASIC or an FPGA. The CPU, MPU, ASIC, and FPGA can all be regarded as controllers. The control unit 43 can be implemented by a GPU as a supplement or replacement for the CPU.

[0124] like Figure 6 As shown, the control unit 43 includes an acquisition unit 431, a sending unit 432 and a communication control unit 433. The modules (acquisition unit 431 to communication control unit 433) constituting the control unit 43 are functional modules respectively representing the functions of the control unit 43. These functional modules can be either software modules or hardware modules. For example, each of the above-mentioned functional modules can be either a software module implemented by software (including microprograms) or a circuit module on a semiconductor chip (bare die). Of course, each functional module can be a processor or an integrated circuit. Note that the control unit 43 can be configured in a functional unit different from the above-mentioned functional modules. The configuration method of the functional module is optional. The operation of the control unit 43 can be the same as the operation of the modules of the control unit 23 of the base station 20.

[0125] <<3. Basic Operations of Communication System>>

[0126] The above describes the configuration of the communication system 1. Before describing the operation of the communication system 1 in the present embodiment in detail, the basic operation of the communication system 1 is described.

[0127] (Radio frame configuration)

[0128] Subsequently, as a configuration example of a radio frame, a frame configuration example of NR is described. Figure 7 is a diagram showing an example of a frame configuration of NR.

[0129] A radio frame (radio frame) configured by 10 ms includes two half frames (not shown). The time interval of the half frame is 5 ms. Each half frame includes five subframes.

[0130] In addition, one subframe is configured by one or more time slots. In the case of normal CP, one time slot is configured by fourteen symbols, and in the case of extended CP, one time slot is configured by twelve symbols.

[0131] The radio resources in this embodiment are configured by one or more resource elements (REs). A resource element is defined by one symbol and one subcarrier.

[0132] A resource block is defined by twelve consecutive subcarriers in frequency. A physical resource block (PRB) is defined as a resource block within a BWP (Bandwidth Part). A virtual resource block (VRB) is used for mapping between the output complex valued signal and the physical resource block.

[0133] (Subcarrier Spacing)

[0134] In NR, the SCS (subcarrier spacing) of OFDM can be changed. In TS 38.211, Table 4.2-1 is defined, which shows a corresponding table of the parameter μ indicating the OFDM parameter set, SCS, and cyclic prefix. Table 1 is a table showing the corresponding table. SCS is set to 2 μ NR up to Rel-16 supports up to 120kHz SCS for data transmission and up to 240kHz SCS for SS / PBCH blocks.

[0135] (Table 1) Supported send parameter sets

[0136] μ <![CDATA[Δf=2 μ · / 15[kHz]]]> Cyclic prefix 0 15 ordinary 1 30 ordinary 2 60 Normal, Extended 3 120 ordinary 4 240 ordinary

[0137] (Time Slot)

[0138] In NR, the slot length and symbol length decrease as the OFDM parameter set increases. In TS38.211, a corresponding table of the parameter μ indicating the OFDM parameter set, the number of symbols per slot, the number of slots per radio frame, and the number of slots per subframe is defined in Table 4.3.2-1. Table 2 is a table showing the corresponding table. Although the number of symbols per slot is a fixed fourteen symbols, no matter what μ is, the number of slots per radio frame and the number of slots per subframe change according to μ.

[0139] (Table 2) Number of OFDM symbols per slot for normal cyclic prefix, slots per frame, and slots per subframe

[0140] μ N slot symbol N frames, μ time slots N subframes, μ time slots 0 14 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14 160 16

[0141] <Frequency Range>

[0142] In NR, a predetermined frequency is defined as a frequency range (FR). A frequency of 0.41 GHz or higher and 7.125 GHz or lower is defined as a frequency range 1 (FR1, a first frequency range).

[0143] A frequency of 24.25 GHz or higher and 71 GHz or lower is defined as a frequency range 2 (FR2, a second frequency range). In FR2, a frequency of 24.25 GHz or higher and 52.6 GHz or lower is defined as a frequency range 2-1 (FR2-1), and a frequency of 52.6 GHz or higher and 71 GHz or lower is defined as a frequency range 2-2 (FR2-2).

[0144] <3.1. Sidelink Communication>

[0145] <3.1.1. Sidelink Communication Overview>

[0146] Figure 8 2 is a diagram showing an overview of sidelink communication. The use cases of sidelink communication are roughly divided into two. The first case is a case where two or more terminal devices 40 exist inside a cell C configured by a base station 20. The second case is a case where at least one of the two or more terminal devices 40 is located inside the cell C, and another terminal device 40 is located outside the cell C.

[0147] At this time, the terminal device 40 existing in the cell C can communicate with the base station 20 in addition to the sidelink communication. Therefore, the terminal device 40 existing inside the cell C functions as a relay station 30 that relays the base station 20 and the terminal device 40 existing outside the cell C.

[0148] Note that the presence of the terminal device 40 inside the cell C means that the terminal device 40 is in a state where the quality of the downlink signal received from the base station 20 is equal to or higher than a predetermined standard. That is, the presence of the terminal device 40 outside the cell C means that the terminal device 40 is in a state where the quality of the downlink signal received from the base station 20 is equal to or lower than a predetermined standard.

[0149] The presence of the terminal device 40 in the cell C also means that the terminal device 40 is in a state where it can decode the predetermined downlink channel received from the base station 20 with a predetermined probability or higher. That is, the presence of the terminal device 40 outside the cell C means that the terminal device 40 is in a state where it cannot decode the predetermined downlink channel received from the base station 20 with a predetermined probability or higher.

[0150] In the following description, the terminal device 40 that receives information about the sidelink communication from the base station 20 and transmits the sidelink control channel is sometimes referred to as a transmitting device 40T, and the other terminal devices 40 are sometimes referred to as receiving devices 40R (first terminal device, second terminal device, and other terminal devices) (for example, see Figure 8 ).

[0151] <3.1.2. Sidelink Communication Details>

[0152] Sidelink communication is direct communication between a terminal device 40 and a terminal device 40 different from the terminal device 40. In the sidelink communication, a resource pool is set in the terminal device 40. The resource pool is a candidate resource for time and frequency resources for transmission and reception of the sidelink. The terminal device 40 selects resources for transmission and reception of the sidelink from the resource pool and performs sidelink communication. Since the sidelink communication is performed using uplink resources (uplink subframes or uplink component carriers), the resource pool is also set in the uplink subframes or uplink component carriers.

[0153] The sidelink physical channels include PSCCH (Physical Sidelink Control Channel), PSSCH (Physical Sidelink Shared Channel) and PSFCH (Physical Sidelink Feedback Channel).

[0154] Fig. 9 and Fig.10 is a diagram showing an example of a frame configuration of a sidelink. Fig. 9 The configuration shown in is a frame configuration of the sidelink in the case where the PSCCH has a two-symbol configuration, the DMRS has a two-symbol allocation, and the PSFCH is absent. Fig.10 The configuration shown in is a frame configuration of the sidelink in the case where the PSCCH has a three-symbol configuration, the DMRS has a three-symbol allocation, and the PSFCH exists.

[0155] PSCCH is used to send Sidelink Control Information (SCI). PSCCH is configured by two symbols or three symbols. The mapping of information bits of the Sidelink Control Information is defined as the SCI format. The Sidelink Control Information includes Sidelink Grant. The Sidelink Grant is used to schedule the PSSCH.

[0156] PSSCH is used to send sidelink data (SL-SCH: Sidelink Shared Channel). PSSCH can also be used to send upper layer control information.

[0157] The PSFCH is used to feed back the HARQ response (HARQ-ACK or ACK / NACK) of the decoding result of the PSSCH to the transmitting device 40T.

[0158] The frame configuration of the sidelink includes an AGC symbol. The AGC symbol can be used for AGC (Automatic Gain Control) of the receiving end device. The AGC symbol is arranged in the first symbol transmitted.

[0159] Specifically, when PSSCH is transmitted, the AGC symbol is arranged in the first symbol, and when PSFCH is transmitted, the AGC symbol is arranged in the twelfth symbol. The AGC symbol is generated by copying the second symbol transmitted. That is, in the sidelink transmission, the first symbol and the second symbol transmitted are the same.

[0160] The frame configuration of the sidelink includes a guard symbol. In the sidelink, transmission and reception are switched by a guard symbol (guard time). The guard symbol is arranged in the fourteenth symbol. In addition, in the time slot in which the PSFCH is transmitted, the guard symbol is also arranged in the eleventh symbol.

[0161] In the terminal device 40, the resource pool is set from the base station 20 through the SIB or a dedicated RRC message. Alternatively, the resource pool is set by information about a resource pool preset in the terminal device 40. The time resource pool is indicated by the period information, the offset information, and the subframe bitmap information. The frequency resource pool is indicated by the start position of the resource block, the end position of the resource block, and the number of consecutive resource blocks.

[0162] (Sidelink resource pool)

[0163] Fig.11 : is a diagram showing a resource pool for a sidelink. In the sidelink, a resource pool (sidelink resource pool) is set as a resource for transmission of PSSCH and reception of PSSCH. On the frequency axis, the resource pool includes one or multiple consecutive subchannels. A subchannel includes one or multiple consecutive PRBs (physical resource blocks). The number of subchannels and the size of the subchannels are set by upper layer parameters.

[0164] Subchannels are used as resource allocation units of the frequency axis in the sidelink. Subchannel allocation for sidelink transmission is determined by the frequency resource allocation included in the SCI. Subchannels are indexed in ascending order of frequency.

[0165] The time slot set as the resource pool is indicated by a bitmap. The bits of the bitmap correspond to the time slots that can be set as the resource pool of the sidelink. For example, when the value of the bit indicates 1, the time slot corresponding to the bit is set as the resource pool. If the value of the bit indicates 0, the time slot corresponding to the bit is not set as the resource pool. The length of the bitmap is set by the upper layer.

[0166] A time slot including an S-SS (Sidelink-synchronization signal) / PSBCH (Physical Sidelink Broadcast Channel) block is not set as a resource pool. A time slot that does not semi-statically include a predetermined number of uplink symbols is not set as a resource pool. A reserved time slot is not set as a resource pool.

[0167] Note that the device that sets the resource pool may be a device other than the base station 20. Examples of the device other than the base station 20 include a representative terminal device 40 (a master terminal device or a leading terminal device).

[0168] (Sidelink Resource Allocation Scheme)

[0169] As resource allocation schemes for the sidelink, there are resource allocation mode 1 (Sidelink resource allocation mode 1) and resource allocation mode 2 (Sidelink resource allocation mode 2).

[0170] Resource allocation mode 1 is the way in which the base station 20 allocates resources for the terminal device 40 to transmit data on the sidelink physical channel (PSCCH or PSSCH).

[0171] Resource allocation mode 2 is a manner in which the terminal device 40 performs sensing by itself and selects resources for the terminal device 40 to send data on the sidelink physical channel.

[0172] (1) Resource allocation model 1

[0173] In resource allocation pattern 1, when a transmission packet is generated in terminal device 40, base station 20 selects a resource to be used for transmission of the packet from a resource pool, and allocates the resource.

[0174] In resource allocation mode 1, resources for sidelink transmission are specified by dynamic grant or RRC signaling transmitted from base station 20. Specifically, in resource allocation mode 1, for PSSCH transmission and PSCCH transmission, dynamic grant, configuration grant type 1 and configuration grant type 2 are supported.

[0175] In sidelink dynamic grant, PSSCH transmission is scheduled by DCI format 3_0. In sidelink configuration grant type 1, resources for PSSCH transmission are allocated by RRC signaling. In sidelink configuration grant type 2, the configuration grant is activated by DCI format 3_0. PSSCH transmission is performed using resources specified by RRC signaling.

[0176] In resource allocation pattern 1, since resource allocation is performed by the base station 20 every time a transmission packet is generated, the frequency of contention between sidelink communications can be reduced. On the other hand, a large amount of signaling overhead is required between the base station 20 and the terminal device 40.

[0177] (2) Resource Allocation Mode 2

[0178] In resource allocation mode 2, the resource pool is pre-allocated to the terminal device 40. Alternatively, in resource allocation mode 2, the resource pool is allocated by the base station 20 / network.

[0179] In resource allocation mode 2, the terminal device 40 can select the sidelink resource in the resource selection window and reserve the future sidelink resource based on the measurement result of the interference pattern in the sensing window and the reservation state of the sidelink resource in the sensing window. By using the prediction result, the terminal device 40 can select and reserve the sidelink resource that can be used for the transmission of the packet, that is, the sidelink resource that is predicted not to be used for the transmission of other packets.

[0180] In resource allocation pattern 2, although the signaling overhead between the base station 20 and the terminal device 40 is small, packet contention may occur.

[0181] In resource allocation pattern 2, resource allocation patterns are classified into the following four types.

[0182] Resource allocation mode 2(a)

[0183] Resource allocation mode 2(b)

[0184] Resource allocation model 2(c)

[0185] Resource allocation mode 2(d)

[0186] Resource allocation mode 2 (a) is a mode in which the terminal device 40 autonomously selects the transmission sidelink resource. Resource allocation mode 2 (b) is a mode in which the terminal device 40 assists the sidelink resource selection of another transmitting terminal. Resource allocation mode 2 (c) is a mode in which the sidelink transmission is performed by the configured grant. Resource allocation mode 2 (d) is a mode in which the terminal device schedules the sidelink transmission of another terminal device 40.

[0187] In the following description, four types of resource allocation modes are explained in detail.

[0188] [Resource Allocation Model 2(a)]

[0189] In resource allocation pattern 2(a), when a packet is generated in the terminal device 40, the terminal device 40 autonomously selects a sidelink resource to be used for transmission of the packet from a resource pool.

[0190] First, the terminal device 40 transmitting a packet performs sensing in order to find a sidelink resource for transmitting the packet from a resource pool. Then, the terminal device 40 selects a sidelink resource from the resource pool based on the result of the sensing.

[0191] Then, the terminal device 40 transmits the packet using the selected side link resource. At this time, the terminal device 40 reserves the side link resource for subsequent packet transmission as needed.

[0192] Resource allocation mode 2(a) can be applied to both a semi-persistent method, in which resources are selected for multiple sidelink transmissions with different transport blocks, and a dynamic method, in which resources are selected for each sidelink transmission of a transmission.

[0193] [Resource Allocation Model 2(b)]

[0194] In resource allocation pattern 2(b), the terminal device 40 assists in selecting a sidelink resource for another transmitting terminal.

[0195] [Resource Allocation Model 2(c)]

[0196] In resource allocation pattern 2(c), the sidelink transmission mode is set in the terminal device 40. The terminal device 40 selects a sidelink resource for transmission according to the set sidelink transmission mode.

[0197] The sidelink transmission mode is defined by the size, location and amount of time and frequency resources.

[0198] A plurality of sidelink transmission modes may be set. When only one sidelink transmission mode is set, the terminal device 40 does not perform sensing. On the other hand, when a plurality of sidelink transmission modes are set, the terminal device 40 performs sensing and selects a sidelink transmission mode based on the detection result.

[0199] In out-of-coverage operation, one or more sidelink transmission modes defined in each sidelink resource pool are pre-set. In in-coverage operation, one or more sidelink transmission modes defined in the corresponding sidelink resource pool are set from the base station 20.

[0200] [Resource Allocation Model 2(d)]

[0201] Resource allocation mode 2 (d) is applied to group-based sidelink communication including three or more terminal devices 40.

[0202] Fig.12 2(d) is a diagram for explaining resource allocation pattern 2. In the group, a representative terminal device 40P (a master terminal device or a leading terminal device) is defined.

[0203] The representative terminal device 40P reports information about other terminal devices 40S (slave terminal devices, secondary terminal devices, member terminal devices) in the group to the base station 20. The base station 20 provides resource pool settings and resource settings of the terminal devices 40S in the group via the representative terminal device 40P.

[0204] In resource allocation pattern 2(d), since the member terminal device 40S does not need to be directly connected to the base station 20, the signal overhead of the Uu link (the communication link between the base station 20 and the terminal device 40) can be reduced.

[0205] The terminal device 40 that can be used as the representative terminal device 40P and the functions that can be provided are determined according to the capabilities of the terminal device 40. The representative terminal device 40P can provide predetermined auxiliary information to the member terminal device 40S. Examples of the auxiliary information include resource pool settings, information about contention, COT sharing information, CSI, and information about congestion levels.

[0206] (Sensing in the sidelink)

[0207] In resource allocation mode 2, the sensing process is supported. SCI decoding and / or measurement of sidelink resources from another terminal device 40 is used as sensing in the sidelink.

[0208] In sensing based on SCI decoding, the terminal device 40 obtains information about the sidelink resources to be used contained in the SCI transmitted from other terminal devices 40. Based on the SCI information, the terminal device 40 determines the sidelink resources to be used for transmission while avoiding the resources that other terminal devices 40 plan to use.

[0209] In the sensing based on the measurement of the sidelink resource, the terminal device 40 performs L1 (layer 1) sidelink RSRP (reference signal received power) measurement based on the sidelink DMRS (demodulation RS). When the measured RSRP is higher than a predetermined threshold, the terminal device 40 recognizes that the measured sidelink resource is used for transmission by another terminal device 40, and determines the sidelink resource to be used for transmission while avoiding the sidelink resource.

[0210] As described above, the terminal device 40 selects or reselects the sidelink resource based on the result of the above-described sensing process.

[0211] <3.2. Multi-slot Scheduling>

[0212] The sidelink communication is explained above. Subsequently, multi-slot scheduling is explained.

[0213] In normal dynamic scheduling, one PDSCH or one PUSCH is scheduled by one PDCCH. Note that this normal dynamic scheduling is also called single-slot scheduling.

[0214] On the other hand, in NR, multiple PDSCHs or multiple PUSCHs can be scheduled through one PDCCH. This scheduling method is called multi-slot scheduling.

[0215] Fig.13 is a diagram showing an example of multi-slot scheduling of a PDSCH. Fig.13 In the example shown, one PDCCH schedules four PDSCHs over four consecutive time slots.

[0216] Fig.14 is a diagram showing an example of multi-slot scheduling of a PUSCH. Fig.14 In the example shown, one PDCCH schedules four PUSCHs from the next slot over four consecutive slots.

[0217] In multi-slot scheduling, the transmission blocks of PDSCH or PUSCH are different, that is, PDSCH or PUSCH can send different data.

[0218] When multi-slot scheduling is set, the number of slots to be scheduled can be specified by information on TDRA (Time Domain Resource Allocation) included in the DCI of one PDCCH. The value indicated by the information on TDRA is set by RRC signaling.

[0219] In multi-slot scheduling, the HARQ process number included in the DCI indicates the head PDSCH or PUSCH of the multi-slot scheduling.

[0220] In multi-slot scheduling, the HARQ process number of the PDSCH or PUSCH scheduled in the latter time slot is a value obtained by adding the indicated HARQ process number and the time slot offset from the beginning. Note that the modulo operation is performed with the number of HARQ processes so that the number of HARQ processes does not exceed the upper limit value of the number of HARQ processes (e.g., sixteen).

[0221] The NDI and RV included in the DCI are individually indicated for the time slots. On the other hand, in other fields included in the DCI, a common value is applied between a plurality of time slots to be scheduled.

[0222] The advantage of multi-slot scheduling is that since multiple PDSCHs or multiple PUSCHs can be scheduled through one PDCCH, multi-slot scheduling helps to reduce the overhead of control information.

[0223] Since the monitoring frequency of the PDCCH can be reduced, multi-slot scheduling also helps reduce power consumption of the terminal device 40. In addition, since the transmission gap for transmitting the PDCCH can be reduced in the unlicensed band, interruption of other wireless devices can be reduced.

[0224] <3.3. Use of unlicensed frequency bands>

[0225] The multi-slot scheduling is explained above. Subsequently, the use of the unlicensed band is explained.

[0226] (Channel access to unlicensed channels)

[0227] In order to use an unlicensed channel, a wireless device (e.g., base station 20 or terminal device 40) needs to perform channel access (channel access, medium access, or listen before talk) before sending a signal. Note that an unlicensed channel is a unit of a frequency band where channel access is performed. A channel can be represented as a carrier, a frequency carrier, a component carrier, a cell, a frequency band, an LBT band, etc.

[0228] In channel access, the wireless device performs power measurement of the channel (also called carrier sensing, sensing or CCA (Clear Channel Assessment)) and compares the measured power value of the channel with a power detection threshold (energy detection threshold).

[0229] When the measured power value of the channel is lower than the power detection threshold, the channel is determined to be idle. When the measured power value of the channel is higher than the power detection threshold, the channel is determined to be busy.

[0230] When the channel is determined to be idle in all sensing time slots, the wireless device can obtain the transmission right of the channel and transmit a signal. The transmission right of a channel may also be referred to as TxOP, transmit opportunity, COT or channel occupancy time.

[0231] In the following description, acquisition of the transmission right of a channel is sometimes referred to as acquisition of the channel.

[0232] The acquired channel can be used for transmission of other wireless devices. In this case, a grant is sent from the wireless device that has acquired the channel to another wireless device.

[0233] A wireless device that acquires a channel is sometimes called an initiating device. A wireless device that uses a channel acquired by another wireless device is sometimes called a responding device.

[0234] In 3GPP (registered trademark), four LBT categories are defined. In channel access, LBT corresponding to any one of the following LBT categories is performed.

[0235] Cat 1 LBT

[0236] LBT Category 2 (Cat 2LBT)

[0237] LBT Category 3 (Cat 3LBT)

[0238] LBT Category 4 (Cat 4LBT)

[0239] Fig.15 is a diagram for describing four types of LBT categories. LBT category 1 (Cat 1LBT) is a category without LBT. In LBT category 1, a gap is provided between transmission and transmission. LBT category 2 (Cat 2LBT) is a category in which random backoff is not performed. LBT category 3 (Cat 3LBT) is a category in which random backoff through a contention window with a fixed size is performed. LBT category 4 (Cat 4LBT) is a category in which random backoff through a contention window with a variable size is performed.

[0240] (Channel access process for unlicensed channels)

[0241] The channel access procedure is performed to access an unlicensed channel transmitted by the base station 20 or the terminal device 40. Channel access may also be referred to as medium access or LBT (Listen Before Talk).

[0242] During the channel access process of the load-based equipment (LBE), one or more channel sensing is performed. Based on the sensing result, it is determined whether the channel is idle (also known as unoccupied, available, or enabled) or busy (also known as occupied, unavailable, or disabled) (vacancy determination). In the channel sensing, the electric power of the channel within a predetermined waiting time is sensed.

[0243] The “channel access / channel access process of a load-based device” described above may also be referred to as a channel access process in dynamic channel access and dynamic channel occupancy.

[0244] Examples of the waiting time of the channel access procedure include a first waiting time (time slot), a second waiting time, a third waiting time (delay period), and a fourth waiting time.

[0245] A time slot is a unit of waiting time of the base station 20 and the terminal device 40 during the channel access process. The time slot is defined by, for example, 9 microseconds.

[0246] In the second waiting time, a time slot is inserted at the beginning. The second waiting time is defined by 16 microseconds, for example.

[0247] The delay period includes a second waiting time and a plurality of consecutive time slots after the second waiting time. The number of the plurality of consecutive time slots after the second waiting time is determined based on a priority level (channel access priority level) for satisfying QoS.

[0248] The fourth waiting time includes the second waiting time and a time slot after the second waiting time. The fourth waiting time is defined by 25 microseconds, for example.

[0249] The base station 20 or the terminal device 40 senses the predetermined channel during the period of the predetermined time slot. When the electric power detected by the base station 20 or the terminal device 40 for at least 4 microseconds within the predetermined time slot period is less than the predetermined power detection threshold, the predetermined time slot is considered to be idle. On the other hand, when the electric power is greater than the predetermined power detection threshold, the predetermined time slot is considered to be busy.

[0250] The channel access process includes a first channel access process, a second channel access process and a third channel access process. The first channel access process is performed using multiple time slots and delay periods. The second channel access process is performed using a second waiting time or a fourth waiting time. The third channel access process is performed using the second waiting time.

[0251] Parameters for channel access are determined based on the priority class. Examples of parameters for channel access include the minimum contention window, the maximum contention window, the maximum channel occupancy time, and the values ​​that the contention window can take. The priority level is determined by the value of the QCI (QoS Class Identifier) ​​or 5QI (5G QoS Identifier) ​​that handles QoS (Quality of Service).

[0252] Table 3 is an example of a correspondence table of parameters related to priority classes and channel access. Table 4 is an example of mapping between priority classes and QCI. Table 5 is an example of mapping between priority classes and 5QI.

[0253] (Table 3) Example of a correspondence table between priority levels and parameters related to channel intervention

[0254]

[0255] (Table 4) Example of mapping between priority level and QCI

[0256] Channel access priority level (p) QCI 1 1,3,5,65,66,69,70 2 2,7 3 4,6,8,9 4 In addition to the above

[0257] (Table 5) Example of mapping between priority levels and 5QI

[0258]

[0259] <Details of the First Channel Access Procedure>

[0260] The first channel access procedure (Type 1 channel access procedure) is classified as LBT Category 3 or LBT Category 4. In the first channel access procedure, the procedure described below is performed.

[0261] Step (0):

[0262] The sensing of the channel is performed during the delay period. If the channel is idle in the time slot during the delay period, the communication device proceeds with the process to step (1). Otherwise, the communication device proceeds with the process to step (6).

[0263] Step (1):

[0264] The communication device obtains the initial value of the counter. The initial value of the counter can take a value from 0 to the contention window CW. The initial value of the counter is randomly determined according to a uniform distribution. The communication device sets the initial value of the counter in the counter N and advances the process to step (2).

[0265] Step (2):

[0266] When the counter N is greater than 0 and subtraction of the counter N is selected, the communication device subtracts 1 from the counter N. Thereafter, the communication device advances the process to step (3).

[0267] Step (3):

[0268] The communication device increases the period of the time slot and remains on standby. In the additional time slot, the communication device performs channel sensing. When the additional time slot is idle, the communication device proceeds to step (4). Otherwise, the communication device proceeds to step (5).

[0269] Step (4):

[0270] When the counter N is 0, the communication device stops the process. Otherwise, the communication device advances the processing to step (2).

[0271] Step (5):

[0272] The communication device increases the delay period and remains on standby. The communication device performs channel sensing until it detects that any one of the time slots included in the additional delay period is busy or it can be detected that all the time slots included in the additional delay period are idle. Thereafter, the communication device advances the process to step (6).

[0273] Step (6):

[0274] When it is sensed that the channel is idle in all time slots included in the additional delay period, the communication device returns the process to step (4). Otherwise, the communication device returns the process to step (5).

[0275] After stopping in step (4), the communication device performs transmission including data such as PDSCH and PUSCH in the channel.

[0276] After step (4) stops, transmission may not be performed in the channel. In this case, thereafter, when the channel is idle in all time slots and delay periods immediately before transmission, the communication device may perform transmission without performing the process explained above. On the other hand, when the channel is not idle in either the time slot or the delay period, after sensing that the channel is idle in all time slots in the additional delay period, the communication device returns the process to step (1).

[0277] (Details of the second channel access process)

[0278] The second channel access procedure (type 2 channel access procedure) is classified into LBT category 2. In the second channel access procedure, after the channel is considered idle as a result of sensing for at least the second waiting time or the fourth waiting time, transmission can be performed immediately. On the other hand, when the channel is considered not idle as a result of sensing for at least the second waiting time or the fourth waiting time, transmission is not performed. When the transmission interval is 16 microseconds or 25 microseconds, the second channel access procedure is applied.

[0279] The second channel access procedure in which the fourth waiting time is used is referred to as a type 2A channel access procedure. The second channel access procedure using the second waiting time is referred to as a type 2B channel access procedure.

[0280] (Details of the third channel access process)

[0281] The third channel access procedure (Type 2C channel access procedure) is classified into LBT Category 1. In the third channel access procedure, the channel is not sensed before transmission. The third channel access procedure is applied when the transmission interval is 16 microseconds or less.

[0282] (Collision window adaptive process)

[0283] In LBT category 4, a contention window adaptation process is performed.

[0284] The contention window CW used in the first channel access process is determined based on the contention window adaptation process. The value of the contention window CW is retained for each priority class. The contention window CW has a value between the minimum contention window and the maximum contention window. The minimum contention window and the maximum contention window are determined based on the priority class.

[0285] The adjustment of the value of the contention window CW is performed before step (1) of the first channel access process. When the ratio of NACK in the HARQ response corresponding to the shared channel of the reference HARQ process in at least one reference subframe (reference time slot or reference interval) of the contention window adaptation process is higher than a threshold, the value of the contention window CW is increased. Otherwise, the value of the contention window CW is set to the value of the minimum contention window. For example, 90% is set as the threshold. For example, the value of the contention window CW is increased based on the formula CW=2*(CW+1)-1.

[0286] The reference interval is defined as an interval from the start of occupying the channel to the end of the first time slot including at least one unicast PDSCH or the end of the first transmission burst including at least one unicast PDSCH.

[0287] (Details of the channel access procedure in downlink)

[0288] When performing downlink transmission including PDSCH, PDCCH, and / or EPDCCH (Enhanced PDCCH) in an unlicensed channel, the base station 20 accesses the channel based on the first channel access procedure, and performs downlink transmission.

[0289] On the other hand, when performing downlink transmission including transmission of DRS (discovery RS) or DS (discovery signal) or discovery burst but not including PDSCH in unlicensed channel, base station 20 accesses the channel based on the second channel access procedure and performs downlink transmission. Note that the period of downlink transmission is preferably shorter than 1 millisecond.

[0290] (Details of channel access procedure in uplink)

[0291] In an unlicensed channel, when it is instructed to perform the first channel access procedure using an uplink grant for scheduling a PUSCH, the terminal device 40 performs the first channel access procedure before uplink transmission including the PUSCH.

[0292] When the second channel access procedure is instructed to be performed using the uplink grant for scheduling the PUSCH, the terminal device 40 performs the second channel access procedure before uplink transmission including the PUSCH.

[0293] For uplink transmissions that do not include PUSCH but include SRS, the terminal device 40 performs a second channel access procedure prior to the uplink transmission.

[0294] When the end of uplink transmission indicated by the uplink grant is within the uplink duration (UL duration), the terminal device 40 performs the second channel access procedure before uplink transmission regardless of the procedure type indicated by the uplink grant.

[0295] When uplink transmission is continued with the fourth waiting time inserted after the end of downlink transmission from the base station 20, the terminal device 40 performs the second channel access procedure before uplink transmission.

[0296] (NR channel access process)

[0297] During the channel access process in an unlicensed channel using NR, a communication device (transmitting station) can perform non-beamforming channel sensing and beamforming channel sensing.

[0298] Non-beamforming channel sensing is channel sensing by reception in which directivity is not controlled or channel sensing without directional information. Channel sensing without directional information is, for example, channel sensing in which measurement results are averaged in all directions. The communication device may not be able to identify the directivity (angle and direction) used in channel sensing.

[0299] Beamforming channel sensing is channel sensing received by directivity control or channel sensing with directional information. That is, beamforming channel sensing is channel sensing in which a receiving beam is directed to a predetermined direction. A communication device having a function of performing beamforming channel sensing can perform one or more channel sensing using different directivities.

[0300] By performing channel sensing with beamforming, the area detected by sensing becomes narrower. Therefore, the communication device can reduce the frequency of detecting a communication link that does not cause interference, and can reduce the problem of exposed terminals.

[0301] (Channel access for frame-based equipment (FBE))

[0302] In the channel access process of the frame-based equipment (FBE), channel sensing is performed once before transmission. Based on the result of the sensing, it is determined whether the channel is idle (idle, unoccupied, available, or enabled) or busy (busy, occupied, unavailable, or disabled) (idle determination). In the sensing of the channel, the electric power of the channel within a predetermined waiting time is sensed.

[0303] Note that the "channel access / channel access process of a frame-based device" explained above can also be called semi-static channel access or channel access process in semi-static channel occupation. The "channel access" explained above can also be called LBT (Listen Before Talk).

[0304] Fig.16 is a diagram showing a frame-based configuration for a frame-based device. The transmission and / or reception configuration for a frame-based device has a periodic timing referred to as a fixed frame period.

[0305] A fixed frame period is set in the channel access of a frame-based device. The fixed frame period is set to 1 millisecond to 10 milliseconds. The fixed frame period can be changed once within 200 milliseconds.

[0306] In channel access of a frame-based device, the device performs channel sensing immediately before starting to transmit from the head of a fixed frame period. The device performs sensing once using a time slot consisting of 9 microseconds or less. As a result of sensing the channel, when the power value is greater than a predetermined power detection threshold, the channel is considered busy. On the other hand, when the power value is less than the predetermined power detection threshold, the channel is idle and the device can perform transmission. The device can perform transmission during the channel occupancy time (COT). If the gap between multiple transmissions is 16 microseconds or less within the channel occupancy time, the device can perform multiple transmissions without performing sensing. On the other hand, when the interval between multiple transmissions exceeds 16 microseconds, the device needs to perform additional channel sensing. In additional channel sensing, similarly, sensing is performed once using one time slot.

[0307] The channel occupancy time in the channel access of the frame-based device does not exceed 95% of the fixed frame period. The idle period in the channel access of the frame-based device is equal to or greater than 5% of the fixed frame period. The idle period is 100 microseconds or longer.

[0308] Transmission of a response (ACK / NACK or HARQ-ACK) to transmission from a device may be performed in the channel occupation time.

[0309] (COT)

[0310] In the operation of the unlicensed band, the wireless communication device (hereinafter referred to as the communication device) performs LBT before signal transmission. When the channel is determined to be idle as a result of LBT, the channel can be occupied for a predetermined time. The predetermined time that the channel can be occupied after LBT is called COT.

[0311] In LBE, COT is defined as falling within the maximum channel occupancy time (Max COT) defined above in Table 3. In FBE, COT is defined as being within 95% of the fixed frame period.

[0312] The COT acquired by the communication device can be used for transmission by the receiving side communication device (hereinafter referred to as the receiving device). A communication device (responding device) different from the communication device (initiating device) that has acquired the COT for sending signals using the COT is called COT sharing. When the COT is shared, other communication devices also need to recognize the COT and the COT length.

[0313] The terminal device 40 is notified of the COT length (hereinafter referred to as base station start COT or base station acquisition COT) of the COT acquired by the base station 20 using DCI format 2_0. The terminal device 40 recognizes the length of the base station start COT based on the COT length indicator included in DCI format 2_0.

[0314] The terminal device 40 can implicitly identify the COT from the PDSCH scheduling received from the base station 20. The terminal device 40 can implicitly identify the COT from the downlink physical signal received from the base station 20 (DMRS, CSI-RS or PDCCH for SS / PBCH blocks).

[0315] The base station 20 is notified of the COT length of the COT (hereinafter referred to as the terminal device start COT or the terminal device acquisition COT) acquired by the terminal device 40 using the CG (Configuration Authorization)-UCI (Uplink Control Information). The base station 20 identifies the length of the start COT of the terminal device 40 based on the COT sharing information included in the CG-UCI.

[0316] <<4. Detailed operation of the communication system>>

[0317] The basic operation of the communication system 1 is explained above. Subsequently, the operation of the communication system 1 in the present embodiment is described in detail. Here, first, a problem in the case of performing sidelink communication in an unlicensed band is described. Subsequently, the operation of the communication system 1 in the present embodiment for solving the problem is described.

[0318] (question)

[0319] In the above-mentioned dynamic channel access in the unlicensed band, the communication device is required to perform LBT and transmit a signal immediately after successfully acquiring COT. On the other hand, in NR, data transmission starts in a predetermined scheduling time unit (e.g., time slot).

[0320] Therefore, when the COT acquisition timing and the time slot start timing do not match, a reservation signal which is not data but is only used to occupy the channel is transmitted from the COT acquisition timing to the time slot start position.

[0321] Fig.17 is a diagram showing an example of reservation signal transmission in a sidelink. Fig.17 An example of successfully acquiring the COT immediately after a slot boundary is shown.

[0322] In this case, the transmission device 40T transmits the reservation signal to the next slot boundary after COT acquisition. However, when the interval from COT acquisition to the next slot boundary is long, the transmission interval of the reservation signal is long, and the frequency utilization efficiency deteriorates.

[0323] As a method to solve this problem, it is conceivable to introduce mini slots in the sidelink, where the scheduling interval is shorter than the time slot. By introducing mini slots, the interval to the scheduling boundary is shortened, and the transmission interval of the reserved signal can also be shortened.

[0324] Fig.18 is a diagram showing an example of mini-slot scheduling in a sidelink. Fig.18 In the example shown, an example of introducing a mini-slot having a half length of a slot in the prior art is shown.

[0325] By introducing mini-slots, Fig.17 A portion of the interval for sending the reserved signal can also be used for data transmission, thereby improving the frequency utilization efficiency.

[0326] Mini-slot scheduling has the effect of shortening the transmission interval of the reservation signal, but has the following problems.

[0327] (1) Control the increase of expenses

[0328] In mini-slot scheduling, control information (first SCI and second SCI) of each mini-slot is included. The PSSCH carrying data in the mini-slot is scheduled based on the control information.

[0329] Therefore, compared with scheduling in time slots, the overhead required for control information increases, and this increase in overhead may lead to deterioration in communication quality or deterioration in frequency utilization efficiency.

[0330] (2) Increased monitoring / sensing frequency

[0331] In mini-slot scheduling, the scheduling period is shorter than that in a time slot. Therefore, the terminal device 40 needs to frequently blindly decode the control information (the first SCI and the second SCI) to check whether the control information is data addressed to the terminal device 40. When the monitoring frequency increases, the power consumption of the terminal device 40 may increase due to the increase in the processing load of the terminal device 40.

[0332] As described above, in the unlicensed band, it is preferable that the terminal device 40 continuously transmits a signal when acquiring a COT once. This is because when a transmission gap is formed in the COT, there is a possibility that other transmission interrupts the transmission.

[0333] Since continuously allocating resources after acquiring the COT is a general operation method, detailed scheduling is not required. Therefore, the terminal device 40 can make the scheduling unit and the sensing period different between the inside and the outside of the COT. By making the scheduling unit and the sensing period different, the terminal device 40 can obtain the advantages of both time slot scheduling and mini time slot scheduling.

[0334] The following is an example of the configuration of the sidelink physical channel for solving the above-mentioned problems (1) and (2).

[0335] Fig.19 1 is a diagram showing an example of scheduling in a sidelink of an unlicensed band. In the sidelink of an unlicensed band, when acquiring COT, the terminal device 40 schedules (transmits) the head sidelink communication in units of mini-slots. On the other hand, in the slots after the beginning of COT, the terminal device 40 schedules (transmits) the sidelink in units of slots.

[0336] Therefore, with Fig.18 Compared with the example shown in which all are scheduled in units of mini-slots, the overhead of control information (PSCCH and second SCI) is reduced.

[0337] (Solution in this embodiment)

[0338] In this embodiment, the communication system 1 adjusts the configuration and monitoring / sensing period of the sidelink physical channel based on the COT situation. Through the configuration and adjustment method according to this embodiment, the communication system 1 can further perform sidelink communication with higher communication efficiency in the unlicensed band.

[0339] [Sidelink physical channel configuration based on COT conditions]

[0340] First, the sidelink physical channel configuration based on the COT condition is described.

[0341] [Multi-slot scheduling via mini-slots at the beginning]

[0342] As an example of this embodiment, multi-slot scheduling is performed from the leading mini-slot to the trailing slots. The terminal device 40 can perform multi-slot scheduling for scheduling from the leading mini-slot to the trailing continuous slots. Therefore, compared with the scheduling based on the slot, the overhead of the control information is further reduced.

[0343] Specifically, for example, the leading mini-slot schedules the following slots in units of mini-slots.

[0344] Fig. 20 is a diagram showing an example of multi-slot scheduling in a sidelink of an unlicensed band according to an embodiment of the present disclosure. Fig. 20 The illustrated example shows a case where the terminal device 40 uses the PSCCH and the second SCI contained in the leading mini-slot after COT acquisition to schedule five PSSCHs for the same mini-slot and subsequent mini-slots.

[0345] exist Fig. 20 In the example shown, since the subsequent PSSCH is also scheduled in the mini-slot, fine scheduling on the time axis is possible.

[0346] As another example, for example, the leading mini-slot schedules the following slots in units of slots.

[0347] Fig.21 is a diagram showing another example of multi-slot scheduling in a sidelink of an unlicensed band according to an embodiment of the present disclosure. Fig.21 In the example shown, the terminal device 40 uses the PSCCH and the second SCI contained in the first mini-slot after COT acquisition to schedule three PSSCHs for the same mini-slot and subsequent slots.

[0348] exist Fig.21 In the example shown, since slot-based scheduling is performed in subsequent slots, the overhead of control information can be further reduced.

[0349] Here, in the above-mentioned mini-slot-based multi-slot scheduling, examples of information contained in the first SCI and the second SCI include information related to multi-slot scheduling and information related to operation in an unlicensed band.

[0350] Specific examples of the information included in the first SCI include the following information.

[0351] Information for reserving resources for multiple consecutive time slots (or mini-time slots)

[0352] COT length information

[0353] Information about the presence of the first SCI and / or the second SCI in the subsequent time slot (or mini-time slot)

[0354] Examples of information for reserving resources for a plurality of consecutive time slots (or a plurality of consecutive mini-time slots) include time resource allocation and / or resource reservation period for specifying a plurality of consecutive time slots.

[0355] Specific examples of the information included in the second SCI include information on PSSCH scheduling of a plurality of slots (NDI (New Data Indicator) or RV (Redundancy Version)).

[0356] Note that the format of the SCI indicating multi-slot scheduling in this example may be an SCI format other than the SCI formats 2-A, 2-B, and 2-C (eg, SCI format 2-D).

[0357] As described above, by including information indicating multi-slot scheduling in SCI (particularly, first SCI), single-slot scheduling and multi-slot scheduling can be switched dynamically. For each sidelink scheduling, other terminal devices 40 can be informed whether the scheduling is single-slot scheduling or multi-slot scheduling.

[0358] [PSCCH for Sensing]

[0359] As another example of this embodiment, it is conceivable to configure a physical channel that is not used for scheduling and transmits PSCCH (an example of a second PSCCH) for sensing other terminal devices 40. The PSCCH here is transmitted for sensing and may not be used for other purposes including scheduling.

[0360] As a difference between the PSCCH for scheduling and sensing in the prior art and the PSCCH for sensing, the PSCCH for sensing is not used for scheduling PSSCH. In other words, the PSCCH for sensing does not involve scheduling. In the following description, the PSCCH for sensing is also referred to as a PSCCH not involved in scheduling.

[0361] Fig. 22is a diagram illustrating another example of a configuration of a physical channel in a sidelink of an unlicensed band according to an embodiment of the present disclosure.

[0362] Fig. 22 The example shown in illustrates an example in which the terminal device 40 performs single-slot scheduling. PSCCH (an example of the first PSCCH) and the second SCI are arranged in the beginning mini-slot and the rear slot for scheduling and sensing. In addition, the PSCCH for sensing (an example of the second PSCCH) is arranged in the middle of the slot for sensing.

[0363] Fig.23 is a diagram illustrating another example of a configuration of a physical channel in a sidelink of an unlicensed band according to an embodiment of the present disclosure.

[0364] exist Fig.23 In the example shown, an example of multi-slot scheduling by the terminal device 40 is shown. In the leading mini-slot, a PSCCH (an example of the first PSCCH) and a second SCI for scheduling to the leading mini-slot and the subsequent slots are arranged. In addition, a PSCCH for sensing (the second PSCCH) is arranged at the beginning and in the middle of the slot for sensing.

[0365] like Fig. 22 and Fig.23 As shown, a PSCCH (first SCI) not used for scheduling can be arranged in the resources acquired through COT. As a result, the terminal device 40 can provide resource reservation information to other terminal devices 40 having different scheduling periods.

[0366] As Fig. 20 and Fig.21 The problem of the example shown is that if another terminal device 40 misses the PSCCH related to the head scheduling due to factors such as the sensing period and TDD restrictions, the rear resource reservation information cannot be identified. Therefore, it is assumed that there may be competition with the side link communication of other terminal devices 40 that missed the PSCCH related to the scheduling.

[0367] On the other hand, Fig. 22 and Fig.23 As shown, the sensing PSCCH is arranged where other terminal devices 40 are monitoring. Fig. 22 and Fig.23In the example shown, regardless of mini-slot scheduling, single-slot scheduling or multi-slot scheduling, the PSCCH for sensing is arranged according to the period (i.e., cycle) of the mini-slot. By setting the PSCCH for sensing at the same position as the PSCCH related to scheduling, other terminal devices 40 can receive the PSCCH for sensing. Therefore, even if other terminal devices 40 miss the PSCCH related to head scheduling, the rear resource reservation information can be identified from the PSCCH for sensing.

[0368] (Physical Configuration Example)

[0369] Next, an example of physical configuration of a sensing PSCCH (PSCCH not involved in scheduling) is described.

[0370] (First Physical Configuration Example)

[0371] As an example, the physical configuration of the PSCCH used for sensing (not involving the PSCCH for scheduling) is the same as the physical configuration of the PSCCH involved in scheduling. Specifically, the scrambling, modulation scheme, channel coding scheme and resource arrangement of the PSCCH used for sensing are preferably the same as the scrambling, modulation scheme, channel coding scheme and resource arrangement of the PSCCH involved in scheduling.

[0372] Therefore, the receiving device 40R can operate in the same receiving process until the decoding of the PSCCH succeeds regardless of the type of the PSCCH (first PSCCH or second PSCCH). That is, the receiving device 40R can decode the first PSCCH and the second PSCCH in the same receiving process.

[0373] On the other hand, in this example, it is preferable to transmit information (distinction information) for distinguishing the sensing PSCCH (second PSCCH) from the scheduling-related PSCCH (first PSCCH). For example, the distinction information is preferably included in the first SCI.

[0374] A specific example of the distinguishing information included in the first SCI includes the second-level SCI format. The receiving device 40R can recognize a PSCCH that is not designated as any second SCI format as a PSCCH for sensing using the second-level SCI format.

[0375] Specifically, when the second level SCI format indicates any one of 00, 01, 10, the receiving device 40R recognizes that the received PSCCH is a PSCCH related to scheduling. On the other hand, when the second level SCI format indicates 11, the receiving device 40R recognizes that the received PSCCH is a PSCCH for sensing.

[0376] Other specific examples of distinguishing information included in the first SCI include new fields. Notification of the new field is provided by using a reserved field (reserved, or "reserved", "reserved"). The transmitting device 40T can use the new field to specify whether the PSCCH is a PSCCH for sensing or a PSCCH related to scheduling.

[0377] Other specific examples of the distinguishing information included in the first SCI include an additional MCS table indicator. The transmitting device 40T may specify a PSCCH for sensing using 11 reserved in the additional MCS table indicator.

[0378] Specifically, when the additional MCS table indicator indicates any one of 00, 01, and 10, the receiving device 40R recognizes that the received PSCCH is a PSCCH related to scheduling. On the other hand, when the additional MCS table indicator indicates 11, the receiving device 40R recognizes that the received PSCCH is a PSCCH for sensing.

[0379] (Second physical configuration example)

[0380] As another example, the physical configuration of the PSCCH used for sensing (PSCCH not involved in scheduling) is different from the PSCCH involved in scheduling.

[0381] Specifically, between a PSCCH used for sensing (second PSCCH) and a PSCCH related to scheduling (first PSCCH), at least one of the following is different.

[0382] ·Scrambling sequence

[0383] Modulation scheme or coding rate

[0384] Channel coding scheme

[0385] Frequency (resource blocks or resource elements) or time (symbol) resource settings

[0386] CRC mask

[0387] Since the physical configurations of the first PSCCH and the second PSCCH are different, when the two PSCCHs are decoded in the same reception process, the reception device 40R successfully decodes one PSCCH but cannot decode the other PSCCH. The reception device 40R can distinguish the types of PSCCHs by failing to decode the other PSCCH.

[0388] Therefore, the transmitting device 40T does not need to include information (distinguishing information) for distinguishing the first PSCCH from the second PSCCH in the first SCI. Therefore, the overhead of control information can be reduced. On the other hand, the receiving device 40R attempts both the reception processing of the sensing PSCCH and the reception processing of the PSCCH involving scheduling.

[0389] Other specific examples of the case where the first PSCCH and the second PSCCH have different physical configurations include whether to perform scrambling. Specifically, scrambling is performed on a PSCCH for sensing (PSCCH not involved in scheduling), while scrambling is not performed on a PSCCH involved in scheduling.

[0390] Other specific examples of the case where the first PSCCH and the second PSCCH have different physical configurations include whether to apply a CRC mask. In particular, a CRC mask is applied to a sensing PSCCH, while a CRC mask is not applied to a PSCCH related to scheduling (or a CRC mask in which all bits are 0 is applied).

[0391] Other specific examples of the case where the first PSCCH and the second PSCCH have different physical configurations include resource settings. Specifically, the sensing PSCCH is not arranged in the first symbol (AGC symbol), and the PSCCH related to scheduling is also arranged in the first symbol (AGC symbol).

[0392] (Example of Characteristics of the Second PSCCH)

[0393] Examples of characteristics of a PSCCH used for sensing (not involving a scheduled PSCCH) include at least information related to resource reservation. On the other hand, information necessary for decoding a PSSCH may not be included in PSCCH sensing.

[0394] The PSCCH used for sensing is preferably not linked to the second SCI. That is, the second SCI is related to the PSCCH related to scheduling, but not to the PSCCH used for sensing.

[0395] As described above, the PSCCH for sensing may not include information necessary for decoding the PSSCH. That is, in the field of the first SCI included in the PSCCH for sensing, information about scheduling may not be transmitted.

[0396] Specifically, for example, the following information included in the sensing PSCCH is not used for decoding of the PSSCH.

[0397] Priority

[0398] DMRS mode

[0399] Second level SCI format

[0400] Beta_offset indicator

[0401] Number of DMRS ports

[0402] Modulation and coding scheme

[0403] Additional MCS table indicator

[0404] Furthermore, bits indicating these kinds of information on scheduling may be used for notification of other purposes. Examples of notification of other purposes include information on unlicensed bands (an example of unlicensed band information) and information on inter-terminal cooperation.

[0405] Specific examples of the information about the unlicensed frequency band include the following information.

[0406] COT information (COT length indicator and available RB set)

[0407] Information about LBT type and CP extension (ChannelAccess-CPext)

[0408] Information about the sensing period

[0409] Information about HARQ-ACK feedback timing

[0410] Specific examples of the information on inter-terminal cooperation include the following information.

[0411] · Preferred resources for other terminal devices 40

[0412] Non-preferred resources for other terminal devices 40

[0413] The preferred resource for other terminal devices 40 is a resource that is desired to be selected as a transmission resource for other terminal devices 40 in the sidelink because the terminal devices 40 are in a receivable state using the resource. On the other hand, the non-preferred resource for other terminal devices 40 is a resource that is not desired to be selected as a transmission resource for other terminal devices 40 in the sidelink because the terminal devices 40 are in a state where reception on the resource is difficult, such as a case of scheduled transmission or a sleep state.

[0414] Note that the PSCCH for sensing may not be transmitted every time. The base station 20 or the transmitting device 40T may determine whether to transmit the PSCCH for sensing.

[0415] Preferably, the receiving device 40R is also notified of the possibility of transmission of the PSCCH for sensing. The receiving device 40R starts monitoring operation of the PSCCH for sensing based on the possibility of transmission of the PSCCH for sensing. When notified that the PSCCH for sensing is not transmitted, the receiving terminal 40R receives only the PSCCH related to scheduling.

[0416] The transmission possibility of the PSCCH for sensing may be specified by the PSCCH involved in scheduling, or may be specified by RRC signaling.

[0417] Notification of the possibility of transmitting the PSCCH for sensing may be provided together with the setting for multi-slot scheduling. For example, when switching between mini-slot-based scheduling and slot-based scheduling or multi-slot scheduling is set, whether to transmit the PSCCH for sensing may be further set.

[0418] For example, in resource allocation mode 1, since the resources of the side link are controlled by the base station 20, the receiving device 40R does not need to perform sensing. That is, in a resource pool in which resource allocation mode 1 is set (resource allocation mode 2 is not set), the PSCCH for sensing may not be transmitted. In other words, when resource allocation mode 2 is set, the PSCCH for sensing may be transmitted.

[0419] Alternatively, when notification of the COT length is not provided, the PSCCH for sensing may not be used.

[0420] Alternatively, in the case of sidelink communication in which only one scheduling time unit is defined, since transmission and reception of the PSCCH of the prior art are sufficient, the PSCCH for sensing may not be used. For example, in sidelink communication in which only any one of mini-slot scheduling, single-slot scheduling, and multi-slot scheduling is applied, the PSCCH for sensing may not be used.

[0421] As described above, when the PSCCH for sensing is not needed, the transmitting device 40T may not transmit the PSCCH for sensing. Therefore, the communication system 1 can reduce the control overhead of the sidelink transmission.

[0422] The PSCCH used for sensing is preferably not arranged in the symbols of the DMRS.

[0423] When setting the transmission of the PSCCH for sensing, it is preferable to set the additional DMRS not to be transmitted. Alternatively, when setting the additional DMRS, the PSCCH for sensing is preferably arranged in a symbol that does not overlap with the DMRS symbol.

[0424] Alternatively, when a DMRS symbol overlaps with a PSCCH symbol for sensing, DMRS transmission is prioritized. That is, when an additional DMRS is set, the additional DMRS is transmitted and the PSCCH for sensing is discarded, and when the additional DMRS is not set, the PSCCH for sensing is transmitted.

[0425] The head symbol in which the PSCCH for sensing is arranged may be set by RRC signaling. The head symbol in which the PSCCH for sensing is arranged may be the same as the monitoring timing of the mini-slot.

[0426] The PSCCH used for sensing is not used to schedule the PSSCH. That is, the PSCCH used for sensing does not schedule PSSCH reception. PSSCH transmission is unrelated to the transmission of the PSCCH used for sensing.

[0427] (Resource mapping example of PSSCH in case of transmitting PSCCH for sensing)

[0428] Next, a physical configuration example of the PSSCH in the case where a PSCCH for sensing (not involving a PSCCH for scheduling) is transmitted is described.

[0429] like Fig. 22 and Fig.23 As shown, the PSCCH for sensing is transmitted using a part of the resources of the PSSCH. In this case, it is difficult to transmit the PSSCH on the resources to which the PSCCH for sensing is transmitted. Therefore, it is necessary to change the resource mapping of the PSSCH.

[0430] As an example of resource mapping of PSSCH, PSSCH is punctured in the resources in which PSCCH for sensing is arranged. Puncturing is a technique for extracting and transmitting a portion of a signal scheduled to be transmitted. In this example, the signal of PSSCH scheduled to be transmitted using the resources of PSCCH for sensing is not transmitted. The signal of PSSCH is overwritten on the signal of PSCCH.

[0431] As another example of resource mapping of PSSCH, PSSCH is rate matched considering the resources of PSCCH for sensing are arranged therein. Rate matching is a technique for performing rate control of codes in consideration of only available resources when unavailable resources are known in advance, and performing resource mapping while avoiding unavailable resources. In this example, rate control and resource mapping of PSSCH are performed under the assumption that the resources of PSCCH for sensing are resources that are unavailable for PSSCH.

[0432] [PSCCH for improving redundancy in multi-slot scheduling]

[0433] As another example of the present embodiment, a configuration of a physical channel can be assumed in which a PSCCH (an example of a second PSCCH) for providing notification of scheduling information is transmitted to the physical channel even from the middle of multi-slot scheduling.

[0434] Fig.24 is a diagram showing an example of a second PSCCH in multi-slot scheduling according to an embodiment of the present disclosure.

[0435] like Fig.24 As shown, the PSSCH is scheduled for the next two slots (the second and third slots) consecutive to the mini-slot by multi-slot scheduling using the first PSCCH and the second SCI. The first PSCCH and the second SCI are transmitted in the first mini-slot.

[0436] In addition, in the second time slot, the PSSCH is scheduled for the second and third time slots through multi-slot scheduling using the second PSCCH (redundant PSCCH) and the second SCI (redundant second SCI) corresponding to the second PSCCH.

[0437] In addition, in the third time slot, the PSSCH is scheduled for the third time slot through single time slot scheduling using the second PSCCH (redundant PSCCH) and the second SCI (redundant second SCI) corresponding to the second PSCCH.

[0438] like Fig.24 As shown, in multi-slot scheduling, in the rear time slot, control information (first SCI and second SCI) including scheduling information of the subsequent time slot of the rear time slot is also transmitted. Therefore, even when the previous PSCCH (for example, transmitted in the beginning mini-time slot) and the second SCI are missed, the terminal device 40 can receive the redundant PSCCH and the redundant second SCI in the rear. Therefore, the terminal device 40 can receive the remaining PSSCH in multi-slot scheduling.

[0439] In multi-slot scheduling, the redundant PSCCH and the redundant second SCI include at least the scheduling information of the remaining PSSCH. On the other hand, the redundant PSCCH and the redundant second SCI may not include the forward scheduling information.

[0440] As a specific example, in Fig.24 , when the HARQ process number of the second SCI of the mini slot indicates "0", the HARQ process number of the redundant second SCI of the second slot indicates "1". In this case, the HARQ process number of the redundant second SCI of the third slot is indicated as "2".

[0441] As another specific example, the second SCI of the mini slot includes NDI and RV corresponding to three PSSCHs to be scheduled. The redundant second SCI of the second slot includes NDI and RV corresponding to two PSSCHs to be scheduled. The redundant second SCI of the third slot includes NDI and RV corresponding to one PSSCH to be scheduled.

[0442] In the redundant PSCCH and redundant second SCI, control information intended to be different from the control information of the first PSCCH and the second SCI cannot be transmitted. For example, the time axis resource and frequency axis resource information indicated by the redundant PSCCH and redundant second SCI must not indicate resources different from those of the first PSCCH and the second SCI.

[0443] [Adjustment of monitoring / sensing period]

[0444] Subsequently, an adjustment method for the monitoring / sensing period is explained. The adjustment method is performed by the receiving device 40R, for example.

[0445] The operation of the receiving device 40R may also be switched according to the switching between the mini-slot-based scheduling and the slot-based scheduling or the multi-slot scheduling corresponding to the condition of the COT. For example, the receiving device 40R may change the monitoring / sensing period of the PSCCH by utilizing resources scheduled by the PSCCH (e.g., the first PSCCH) and unscheduled resources.

[0446] For example, when a notification that resources have been reserved by scheduling is provided, the reception device 40R may skip monitoring or sensing of the PSCCH (may not perform monitoring or sensing). Therefore, the reception device 40R can further reduce power consumption due to an increase in the PSCCH monitoring frequency.

[0447] (Adjustment method 1)

[0448] Fig.25 is a diagram showing an example of a method for adjusting a monitoring / sensing period according to an embodiment of the present disclosure. Fig.25 The following describes an adjustment method when the transmission device 40T switches between mini-slot-based scheduling and slot-based scheduling based on the COT status.

[0449] Before the transmitting device 40T transmits, the receiving device 40R performs monitoring / sensing at the transmission interval of the mini-slot.

[0450] On the other hand, after the transmitting device 40T obtains the COT and starts the sidelink communication, the transmitting device 40T performs scheduling based on the time slot. Therefore, when the communication through the transmitting device 40T is started, the receiving device 40R can perform monitoring / sensing at the transmission interval of the time slot and skip monitoring / sensing at the timing of the mini-time slot. As described above, the receiving device 40R can change the period (or "cycle") (mini-time slot / time slot) of monitoring the PSCCH for resources before the start of the sidelink communication (resources not scheduled in the first PSCCH) and resources after the start of the sidelink communication (resources scheduled in the first PSCCH).

[0451] In adjustment method 1, the receiving device 40R can adjust the monitoring / sensing period based on information about whether the PSSCH is based on mini-slot scheduling or slot scheduling in addition to the COT information of the transmitting device 40T. For example, even in COT, when mini-slot-based scheduling is performed, a monitoring / sensing period equivalent to that outside the COT is applied to the receiving device 40R.

[0452] (Adjustment method 2)

[0453] Fig.26 FIG. 1 is another example of a method for adjusting a monitoring / sensing period according to an embodiment of the present disclosure. For example, Fig.26 The following describes an adjustment method when the transmitting device 40T performs multi-slot scheduling.

[0454] Before the transmitting device 40T transmits, the receiving device 40R performs monitoring / sensing at the transmission interval of the mini-slot.

[0455] On the other hand, when the sidelink communication is started by acquiring the COT, the transmitting device 40T reserves a plurality of time slots by multi-slot scheduling. Fig.26 In the example shown, the transmitting device 40T uses the leading mini-slot to schedule four PSSCHs for the leading mini-slot and three slots following the mini-slot.

[0456] Since the reception device 40R having received the PSCCH related to scheduling in the mini-slot recognizes that the PSSCH is scheduled in the following three slots, the reception device 40R can skip monitoring / sensing in the slot scheduled by the PSCCH.

[0457] (Adjustment method 3)

[0458] When the transmitting device 40T uses the above-described PSCCH for sensing, the receiving device 40R can switch the monitoring / sensing period more efficiently.

[0459] Fig. 27FIG. 1 is a diagram showing another example of a method for adjusting a monitoring / sensing period according to an embodiment of the present disclosure. For example, Fig. 27 FIG. 4 shows an adjustment method in the case where the transmitting device 40T performs multi-slot scheduling. Fig. 27 In the present invention, the transmitting device 40T transmits the PSCCH for sensing.

[0460] Before the transmitting device 40T transmits, the receiving device 40R performs monitoring / sensing at the transmission interval of the mini-slot.

[0461] On the other hand, in the case where the COT is acquired and the sidelink communication is started, the transmitting device 40T reserves scheduling of a plurality of time slots by multi-slot scheduling.

[0462] exist Fig. 27 In the example shown, the transmitting device 40T uses the PSCCH ( Fig. 27 The first PSCCH in the mini-slot schedules four PSSCHs for the first mini-slot and the three slots after the mini-slot. Fig. 27 In the example, the transmitting device 40T transmits a PSCCH ( Fig. 27 The transmitting device 40T transmits a PSCCH for sensing at each of the beginning and the middle of the time slot.

[0463] The receiving device 40R that has received the PSCCH in the mini-slot can skip monitoring / sensing of the slot scheduled by the PSCCH.

[0464] However, if Fig. 27 As shown, when decoding (detection) of the PSCCH (first PSCCH) transmitted by the mini-slot fails, the receiving device 40R receives the PSCCH for sensing (second PSCCH) in the subsequent slot until successfully decoding (detecting) the PSCCH for sensing.

[0465] exist Fig. 27 In the example shown, the receiving device 40R fails to decode (detect) the first sensing PSCCH, but successfully decodes (detects) the next sensing PSCCH. Therefore, the receiving device 40R can skip monitoring / sensing the second scheduled time slot and subsequent time slots.

[0466] As described above, since the transmitting device 40T transmits the sensing PSCCH, even if the receiving device 40R fails to receive the scheduling PSCCH, the receiving device 40R can receive the sensing PSCCH in a subsequent time slot. The receiving device 40R can change (e.g., skip) the monitoring / sensing period based on the resource reservation information of the multi-slot scheduling included in the received sensing PSCCH.

[0467] Note that, as described above, the PSCCH for sensing may not be transmitted. In this case, adjustment method 1 or 2 may be applied. That is, the adjustment method may be dynamically switched according to whether the PSCCH for sensing can be transmitted.

[0468] (Adjustment method 4)

[0469] In the above adjustment method, the receiving device 40R skips sensing / monitoring. However, the receiving device 40R may skip decoding of the PSCCH. In this case, the receiving device 40R performs RSRP measurement without decoding the PSCCH.

[0470] Fig.28 FIG. 1 is another example of a method for adjusting a monitoring / sensing period according to an embodiment of the present disclosure. For example, Fig.28 The following describes an adjustment method when the transmission device 40T switches between mini-slot-based scheduling and slot-based scheduling based on the COT status.

[0471] The receiving device 40R frequently performs RSRP (Receive Power) measurement for resource sensing regardless of the COT status or the resource reservation status. On the other hand, the receiving device 40R skips decoding of the PSCCH with a high processing load according to the COT or resource reservation status.

[0472] For example, in Fig.28 In the embodiment, the receiving device 40R performs monitoring / sensing at the transmission interval of the mini-slot until the transmitting device 40T performs transmission.

[0473] After the transmitting device 40T acquires the COT and starts the sidelink communication, the transmitting device 40T schedules the time slot. Therefore, when the transmitting device 40T starts the communication, the receiving device 40R performs monitoring / sensing (decoding of PSCCH) at the transmission interval of the time slot, and skips the decoding of PSCCH at the timing of the mini-time slot. On the other hand, the receiving device 40R measures RSRP at the timing of the mini-time slot (the timing of skipping the decoding of PSCCH or the timing corresponding to the monitoring / sensing period before the start of the sidelink communication).

[0474] Note that the above description describes the case where the transmission device 40T switches between mini-slot-based scheduling and slot-based scheduling. The same is true when the transmission device 40T performs multi-slot scheduling. That is, when the transmission device 40T performs multi-slot scheduling, the receiving device 40R can also measure RSRP at the timing of the mini-slot while skipping the decoding of the PSCCH. The same is true when the transmission device 40T transmits the PSCCH for sensing.

[0475] Therefore, the receiving device 40R can continuously perform sensing regardless of whether the PSCCH is transmitted. The receiving device 40R can reduce power consumption by continuing to perform reception power measurement with a low processing load while reducing the number of PSCCH decodings with a high processing load.

[0476] [Sharing COT information in sidelink]

[0477] The operation of the above-mentioned communication system 1 is switched based on the COT information. Therefore, in the side link of the unlicensed band, the COT information needs to be shared between the terminal devices 40, and in the following description, the sharing method of the COT information in the side link is listed.

[0478] (Sharing method 1)

[0479] As an example of a sharing method of COT information in the side link, there is a method in which the transmission device 40T provides notification of COT information using PSCCH. The transmission device 40T that has acquired COT includes the acquired COT information (COT length, etc.) in PSCCH.

[0480] When the transmitting device 40T transmits the PSCCH including the COT information, the terminal device 40 other than the destination of the PSCCH (other terminal devices 40) can also recognize the COT information. Since the COT information is included in the PSCCH, the other terminal devices 40 can recognize the COT information earlier than other sharing methods described below.

[0481] (Sharing method 2)

[0482] As another example of sharing COT information in the sidelink, there is a method in which the transmission device 40T provides notification of COT information using the second SCI. The transmission device 40T having acquired the COT includes the acquired COT information (COT length, etc.) in the second SCI.

[0483] When the transmission device 40T transmits the easily expandable second SCI including the COT information, the terminal devices 40 other than the destination (other terminal devices 40) can also recognize the COT information.

[0484] (Sharing method 3)

[0485] As another example of sharing COT information in the side link, there is a method in which the transmitting device 40T provides notification of COT information using SL-SCH, the type of which is broadcast.

[0486] The transmitting device 40T transmits the COT information by broadcasting, thereby providing the COT information to all receivable terminal devices 40 (other terminal devices 40). The transmitting device 40T includes the COT information in the SL-SCH and provides notification of the COT information, thereby being able to transmit COT information having many bits.

[0487] [Adjustment of COT information of hidden terminal]

[0488] Even if the sensing period is adjusted based on the COT, loss of sidelink data may occur when there is transmission from the hidden terminal device 40H.

[0489] Fig.29 is a diagram showing an example of a hidden terminal problem in a sidelink of an unlicensed band. A transmitting device 40T (Tx UE) performs sidelink transmission to a receiving device 40R (Rx UE).

[0490] On the other hand, when the received power value is lower than the ED (Energy Detection) threshold of the LBT, the hidden terminal device 40H (hidden UE) recognizes that the channel is idle, and can perform sidelink transmission on the same resources as those of the transmitting device 40T. Therefore, there is a possibility that contention occurs between the transmitting device 40T and the hidden terminal device 40H.

[0491] In order to solve this problem, the receiving device 40R according to the embodiment of the present disclosure transmits the COT information of the sending device 40T to the hidden terminal device 40H.

[0492] Fig.30 A diagram showing an example of transmitting COT information in a sidelink of an unlicensed band according to an embodiment of the present disclosure.

[0493] like Fig.30 As shown, the transmitting device 40T performs sidelink transmission including COT information to the receiving device 40R (an example of the first communication device). The receiving device 40R transmits the COT information acquired from the transmitting device 40T to the hidden terminal device 40H (an example of the second communication device).

[0494] Therefore, the hidden terminal device 40H can recognize the COT information of the transmitting device 40T and can avoid contention of the side link.

[0495] As an example of a method of transmitting the COT information, there is a method in which the receiving device 40R notifies the hidden terminal of the COT information using the PSFCH.

[0496] Fig.31 is a diagram illustrating an example of transmission of COT information according to an embodiment of the present disclosure.

[0497] The transmitting device 40T (Tx UE) performs sidelink transmission after acquiring the COT. The receiving device 40R (Rx UE) transmits the PSFCH as a response to the initial sidelink transmission of the transmitting device 40T. Fig.31 In the example shown, the receiving device 40R transmits the PSFCH at the end of the leading mini-slot after COT acquisition.

[0498] Therefore, the receiving device 40R can transmit the COT information of the sending device 40T to the hidden terminal device 40H.

[0499] On the other hand, when the receiving device 40R does not successfully transmit the PSFCH, the hidden terminal device 40H may have already acquired the COT. Therefore, when the transmitting device 40T does not successfully receive the PSFCH, the transmitting device 40T may not perform transmission in the COT after the timing at which the transmitting device 40T is scheduled to receive the PSFCH. That is, upon failure to receive the COT information contained in the PSFCH, the transmitting device 40T is able to stop the sidelink communication in the acquired COT.

[0500] Therefore, the transmitting device 40T can avoid competition with the side link transmission of the hidden terminal device 40H.

[0501] As another example of a method of transmitting the COT information, there is a method in which the receiving device 40R notifies the hidden terminal device 40H of the COT information using the mini-slot PSSCH.

[0502] Fig.32 is a diagram illustrating another example of transmission of COT information according to an embodiment of the present disclosure.

[0503] The transmitting device 40T performs sidelink transmission after acquiring the COT. The receiving device 40R shares the COT of the transmitting device 40T and performs sidelink transmission including the COT information of the transmitting device 40T using the mini-slot.

[0504] exist Fig.32 In the example shown, the receiving device 40R performs sidelink transmission including PSCCH and PSSCH using the next mini-slot after the COT acquisition.

[0505] Therefore, the receiving device 40R can transmit the COT information of the sending device 40T to the hidden terminal device 40H.

[0506] On the other hand, when the receiving device 40R does not successfully perform the sidelink transmission, the hidden terminal device 40H may have acquired the COT. Therefore, when the transmitting device 40T does not successfully receive the sidelink communication from the receiving device 40R, the transmitting device 40T may not perform the transmission in the COT after the timing at which the transmitting device 40T is scheduled to receive the sidelink communication. That is, when the transmitting device 40T fails to receive the COT information transmitted by the receiving device 40R, the transmitting device 40T can stop the sidelink communication in the acquired COT.

[0507] Therefore, the transmitting device 40T can avoid competition with the side link transmission of the hidden terminal device 40H.

[0508] <<5. Other embodiments>>

[0509] The embodiments and application examples described above are examples, and various modifications and applications are possible.

[0510] For example, in the above-described embodiment, the terminal device 40 performs sidelink communication in an unlicensed frequency band. However, the frequency band in which the terminal device 40 performs sidelink communication is not limited to the unlicensed frequency band. The terminal device 40 may perform sidelink communication in a licensed frequency band. In this case, the transmitting device 40T may also transmit a second PSCCH different from the first PSCCH.

[0511] For example, in the embodiments described above, the control device that controls the base station 20 and the terminal device 40 may be implemented by a dedicated computer system, or may be implemented by a general-purpose computer system.

[0512] For example, the communication program for performing the above operation is distributed by being stored in a computer-readable recording medium such as an optical disk, a semiconductor memory, a magnetic tape, or a floppy disk. Then, for example, the program is installed in a computer, and the control device is configured by performing the above process. At this time, the control device may be a device (e.g., a personal computer) outside the base station 20 and the terminal device 40. The control device may be a device (e.g., a control unit 23 and 43) inside the base station 20 and the terminal device 40.

[0513] The above-mentioned communication program may be stored in a disk device included in a server device on a network such as the Internet, so that the communication program can be downloaded to a computer. The above-mentioned functions may be realized by the cooperation of an OS (operating system) and application software. In this case, a portion other than the OS may be stored in a medium and distributed, or a portion other than the OS may be stored in a server device so that the portion may be downloaded to a computer.

[0514] In the types of processing described in the embodiments, all or part of the processing described as being automatically performed may be performed manually, or all or part of the processing described as being manually performed may be automatically performed by a known method. In addition, except where otherwise noted, the processing procedures, specific names, and information including various data and parameters described in this document and shown in the accompanying drawings may be arbitrarily changed. For example, the various information shown in the drawings is not limited to the information shown.

[0515] The illustrated components of the device are conceptual in function and do not always need to be physically arranged as shown in the figure. That is, the specific form of distribution and integration of the device is not limited to the illustrated form, and all or part of it can be functionally or physically distributed and integrated in any unit according to various loads, usage conditions, etc. Note that such configuration by distribution and integration can be performed dynamically.

[0516] The above-described embodiments can be appropriately combined within a range in which the processing contents do not contradict each other.

[0517] For example, the present embodiment can be implemented as any configuration of a configuration device or system, such as a processor used as a system LSI (large scale integration) or the like, a module using multiple processors or the like, a unit using multiple modules or the like, a set obtained by further adding other functions to the unit, etc. (i.e., a configuration of a part of a device).

[0518] Note that in this embodiment, a system means a collection of multiple components (devices, modules (components), etc.). It is not important whether all components exist in the same housing. Therefore, multiple devices housed in separate housings and connected via a network and a device in which multiple modules are housed in one housing are both systems.

[0519] For example, the present embodiment may adopt a configuration of cloud computing in which one function is shared and processed cooperatively by a plurality of devices via a network.

[0520] <<6. Conclusion>>

[0521] Although the embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the above embodiments, and various changes can be made without departing from the gist of the present disclosure. Components in different embodiments and modifications can be appropriately combined.

[0522] The effects in the embodiments described in this specification are merely illustrative and not restrictive. Other effects may exist.

[0523] Note that the present technology can also adopt the following configurations.

[0524] (1) A communication method, comprising:

[0525] performing sidelink communications with a first communications device;

[0526] Scheduling of resources for performing sidelink communication is performed using a first PSCCH; and transmitting a second PSCCH different from the first PSCCH on the resources for which scheduling has been performed.

[0527] (2) The communication method as described in (1), wherein the second PSCCH is a PSCCH not involved in scheduling.

[0528] (3) The communication method as described in (2), wherein the second PSCCH is transmitted for sensing.

[0529] (4) The communication method as described in any one of (1) to (3), further including sending distinction information for distinguishing the first PSCCH from the second PSCCH.

[0530] (5) The communication method according to (4), wherein the distinguishing information is at least one of a second-level SCI format, a new field, and an additional MCS table indicator.

[0531] (6) The communication method as described in any one of (1) to (3), wherein a physical configuration of the second PSCCH is different from a physical configuration of the first PSCCH.

[0532] (7) The communication method according to (6), wherein

[0533] performing scrambling on the first PSCCH, and

[0534] No scrambling is performed on the second PSCCH.

[0535] (8) The communication method as described in (6) or (7), wherein a CRC mask is applied to the second PSCCH.

[0536] (9) The communication method as described in any one of (6) to (8), wherein the second PSCCH does not include information for decoding the PSCCH.

[0537] (10) The communication method as described in any one of (1) to (9), wherein the second SCI is associated with the first PSCCH and is not associated with the second PSCCH.

[0538] (11) The communication method as described in any one of (1) to (10), wherein when the sidelink communication is performed in resource allocation mode 2, a second PSCCH is transmitted.

[0539] (12) The communication method as described in any one of (1) to (11), wherein the second PSCCH is arranged in a symbol other than a DMRS symbol.

[0540] (13) The communication method as described in any one of (1) to (12), wherein the first PSCCH is used for scheduling of multiple time slots.

[0541] (14) The communication method according to any one of (1) to (13), wherein the sidelink communication is performed in an unlicensed frequency band.

[0542] (15) The communication method according to (14), wherein the second PSCCH includes unlicensed band information about the unlicensed band.

[0543] (16) The communication method according to (14) or (15), further comprising:

[0544] notifying the first communication device of COT information regarding the COT acquired in the unlicensed frequency band, wherein

[0545] The first communication device transmits the COT information to the second communication device.

[0546] (17) The communication method according to (16), wherein the first communication device transmits the COT information to the second communication device using a PSFCH.

[0547] (18) The communication method according to (16), wherein the first communication device transmits the COT information to the second communication device by performing sidelink transmission using resources scheduled by a PSCCH.

[0548] (19) The communication method according to any one of (16) to (18), further comprising stopping the sidelink communication in the acquired COT when reception of a signal including COT information transmitted by the first communication device fails.

[0549] (20) The communication method according to any one of (1) to (19), wherein the other communication device changes a period for monitoring the PSCCH using resources scheduled by the first PSCCH and resources that are not scheduled.

[0550] (21) The communication method according to (20), wherein the first communication device does not monitor the PSCCH on resources scheduled by the first PSCCH.

[0551] (22) A communication method according to (20) or (21), wherein, even when reception of the first PSCCH fails, when receiving the second PSCCH, the other communication device changes the period of monitoring the PSCCH on the resources scheduled by the first PSCCH.

[0552] (23) A communication method according to any one of (20) to (22), wherein the other communication device performs reception power measurement on resources scheduled by the first PSCCH at a timing corresponding to a monitoring period of the PSCCH on unscheduled resources.

[0553] (24) A communication method, comprising:

[0554] determining whether a second PSCCH different from the first PSCCH is used in sidelink communications performed between a transmitting device and a receiving device; and

[0555] The determination result is notified to the receiving device, wherein

[0556] The first PSCCH includes information related to scheduling of resources used when performing sidelink communication, and

[0557] The second PSCCH is sent on resources scheduled by the first PSCCH.

[0558] (25) A communication device comprising:

[0559] a communication unit that performs sidelink communication with the first communication device; and

[0560] a control unit that performs scheduling of resources for performing sidelink communication using a first PSCCH, and

[0561] A second PSCCH different from the first PSCCH is transmitted on the resources for which scheduling has been performed.

[0562] Reference numerals list

[0563] 1. Communication System

[0564] 20 base stations

[0565] 21, 41 wireless communication unit

[0566] 22, 42 storage units

[0567] 23,43Control unit

[0568] 40Terminal equipment

Claims

1. A communication method, comprising: performing sidelink communications with a first communications device; performing scheduling of resources for performing sidelink communication using a first PSCCH; as well as A second PSCCH different from the first PSCCH is transmitted on the resources for which scheduling has been performed.

2. The communication method according to claim 1, wherein: The second PSCCH is a PSCCH not involved in scheduling.

3. The communication method according to claim 3, wherein: The second PSCCH is sent for sensing. 4 . The communication method according to claim 1 , further comprising sending distinguishing information for distinguishing the first PSCCH from the second PSCCH.

5. The communication method according to claim 4, wherein the distinguishing information is in a second level SCI format.

6. The communication method according to claim 1, wherein: The physical configuration of the second PSCCH is different from the physical configuration of the first PSCCH.

7. The communication method according to claim 6, wherein performing scrambling on the first PSCCH, and No scrambling is performed on the second PSCCH.

8. The communication method according to claim 1, wherein: When the sidelink communication is performed in resource allocation mode 2, the second PSCCH is transmitted.

9. The communication method according to claim 1, wherein: The first PSCCH is used to schedule multiple time slots.

10. The communication method according to claim 1, wherein: The sidelink communication is performed in an unlicensed frequency band.

11. The communication method according to claim 10, wherein: The second PSCCH includes unlicensed band information about the unlicensed band.

12. The communication method according to claim 10, further comprising notifying the first communication device of COT information regarding the COT acquired in the unlicensed frequency band, wherein The first communication device transmits the COT information to the second communication device.

13. The communication method according to claim 12, further comprising stopping the sidelink communication in the acquired COT when reception of the signal including the COT information transmitted by the first communication device fails.

14. The communication method according to claim 1, wherein: The other communication device changes the period of monitoring the PSCCH using resources scheduled by the first PSCCH and unscheduled resources.

15. The communication method according to claim 14, wherein: The first communications device does not monitor the PSCCH on resources scheduled by the first PSCCH.

16. The communication method according to claim 14, wherein: Even when reception of the first PSCCH fails, another communication device changes the period for monitoring the PSCCH on the resources scheduled by the first PSCCH when receiving the second PSCCH.

17. The communication method according to claim 14, wherein: The other communication device performs reception power measurement on resources scheduled by the first PSCCH at a timing corresponding to a monitoring period of the PSCCH on non-scheduled resources.

18. A communication method, comprising: determining whether a second PSCCH different from the first PSCCH is used in sidelink communications performed between a transmitting device and a receiving device; as well as The determination result is notified to the receiving device, wherein The first PSCCH includes information related to scheduling of resources used when performing sidelink communication, and The second PSCCH is sent on resources scheduled by the first PSCCH.

19. A communication device comprising: a communication unit that performs sidelink communication with a first communication device; as well as a control unit that performs scheduling of resources for performing sidelink communication using a first PSCCH, and A second PSCCH different from the first PSCCH is transmitted on the resources for which scheduling has been performed.

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