Communication apparatus and communication method

Abstract

A communication device includes: a control circuit that, when a plurality of consecutive time resources are allocated in inter-terminal communication in an unlicensed band, allocates a signal to a guard interval that is set to the nth time resource among the nth time resource and the (n + 1) th time resource included in the plurality of time resources, allocates a signal to a guard interval that is set to the nth time resource among the nth time resource and the (n + 1) th time resource included in the plurality of time resources; and a transmission circuit that transmits a signal in the plurality of time resources.

Description

Technical Field

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

[0002] The expansion of the communication system called "5th Generation Mobile Communication System (5G)" has been studied. In 5G, the flexible provision of functions for various use cases requiring increased communication services, increased number of connected terminals, high reliability and low latency has been studied.

[0003] Prior art literature

[0004] Non-patent literature

[0005] Non-patent document 1: 3GPP, TR 38.885 V16.0.0, "Study on NR Vehicle-to-Everything (V2X)"

[0006] Non-patent document 2: RP-201385, “WID revision: NR sidelink enhancement,” LG Electronics, June 29-July 3, 2020

[0007] Non-patent document 3: RP-213678, “New WID on NR sidelink evolution,” OPPO, LG Electronics, Dec. 6-17, 2021

[0008] Non-patent document 4: 3GPP, TS 38.212 V17.2.0, “NR; Multiplexing and channel coding” Summary of the invention

[0009] However, there is still room for research on the effective utilization of communication resources in unlicensed bands.

[0010] The non-limiting embodiments of the present disclosure are helpful to provide a communication device and a communication method that can improve the utilization efficiency of communication resources in unlicensed frequency bands.

[0011] A communication device of one embodiment of the present disclosure includes: a control circuit, which, when a plurality of continuous time resources are allocated in terminal-to-terminal communication in an unlicensed frequency band, allocates a signal to the following protection interval, wherein the protection interval is a protection interval set for the nth time resource among the nth time resource and the n+1th time resource contained in the plurality of time resources; and a sending circuit, which sends the signal in the plurality of time resources.

[0012] It should be noted that these general or specific aspects may be implemented by a system, an apparatus, a method, an integrated circuit, a computer program or a recording medium, or may be implemented by any combination of systems, apparatuses, methods, integrated circuits, computer programs and recording media.

[0013] According to an embodiment of the present disclosure, the utilization efficiency of communication resources in an unlicensed frequency band can be improved.

[0014] Further advantages and effects of one embodiment of the present disclosure will be clearly presented in the specification and the drawings. These advantages and / or effects are provided by several embodiments, and the features described in the specification and the drawings, but not necessarily all of them need to be provided in order to obtain one or more of the same features. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a diagram showing an example of channel arrangement within a time slot.

[0016] Figure 2 This is a diagram showing an example of channel arrangement within a time slot when the channel is busy.

[0017] Figure 3 This is a block diagram showing a configuration example of a part of a base station.

[0018] Figure 4 This is a block diagram showing a configuration example of a part of a terminal.

[0019] Figure 5 This is a diagram showing an example of sidelink communication in Mode 1.

[0020] Figure 6 This is a diagram showing an example of sidelink communication in mode 1.

[0021] Figure 7 It is a diagram showing an example of channel arrangement within a time slot.

[0022] Figure 8 This is a diagram showing an example of sidelink communication in Mode 2.

[0023] Fig. 9 This is a block diagram showing a structural example of a terminal.

[0024] Fig.10 It is a diagram showing an example of channel arrangement within a time slot.

[0025] Fig.11 It is a diagram showing an example of channel arrangement within a time slot.

[0026] Fig.12 It is a diagram showing an example of channel arrangement within a time slot.

[0027] Fig.13 This is a block diagram showing a structural example of a terminal.

[0028] Fig.14 is a diagram of an exemplary architecture of a 3GPP NR system.

[0029] Fig.15 It is a schematic diagram showing the functional separation between NG-RAN (Next Generation-Radio Access Network) and 5GC (5th Generation Core).

[0030] Fig.16 This is a sequence diagram of the process of setting up / resetting an RRC (Radio Resource Control) connection.

[0031] Fig.17 It is a schematic diagram showing the utilization scenarios of large-capacity high-speed communications (eMBB: enhanced Mobile Broadband), multiple simultaneous machine-type communications (mMTC: massive Machine Type Communications) and high-reliability and ultra-low latency communications (URLLC: Ultra Reliable and Low Latency Communications).

[0032] Fig.18 is a block diagram representing an exemplary 5G system architecture for non-roaming scenarios. DETAILED DESCRIPTION

[0033] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0034] 3GPP (3rd Generation Partnership Project), an international standards organization, has studied the advancement of communication systems from two aspects: the advancement of LTE (Long Term Evolution) systems and New Radio (NR). 3GPP has previously studied the support of V2X (vehicle wireless communication technology) in the LTE system. It has also studied the support of V2X in NR, which can use a wider frequency band than LTE (for example, refer to non-patent document 1).

[0035] In addition, further expansion of communication using sidelink (SL) in addition to V2X is being studied (for example, see Non-Patent Document 2). V2X envisions communication between vehicles (V2V: Vehicle to Vehicle), between vehicles and infrastructure (V2I: Vehicle to Infrastructure), between vehicles and pedestrians (V2P: Vehicle to Pedestrian), and between vehicles and networks (V2N: Vehicle to Network).

[0036] In V2V, V2I, and V2P, terminals can directly send and receive signals using a side link or a link called "PC5" without going through a network with a base station (for example, a network via a base station). In V2N, communication is envisioned via a link called "Uu" between a base station and a terminal. It should be noted that a base station may be called a "gNB" in NR and an "eNB" in LTE. In addition, a terminal may also be called a "UE (User Equipment)".

[0037] In addition, the use of sidelink communication in an unlicensed band is also being studied (for example, refer to Non-Patent Document 3).

[0038] [NR Sidelink]

[0039] In the sidelink of NR, unicast, multicast and broadcast are supported in transmission and reception. As unicast, a one-to-one transmission from a transmitting terminal (e.g., also referred to as "Tx UE", "source UE" or "transmitting source terminal") to a receiving terminal (e.g., also referred to as "RxUE", "destination UE" or "destination terminal") is envisioned. As a multicast, transmission from a transmitting terminal to one or more receiving terminals included in a certain group is envisioned. As a broadcast, transmission from a transmitting terminal to an uncertain receiving terminal is envisioned.

[0040] In the sidelink of NR, a control signal called "SCI (Sidelink control information)" is sent and received. SCI is divided into first-stage SCI and second-stage SCI. The first-stage SCI is configured on the PSCCH (physical sidelink control channel). The second-stage SCI is configured on at least a part of the PSSCH (physical sidelink shared channel) that transmits and receives data. By dividing the SCI into two, the number of bits and size of the first-stage SCI can be reduced. In the sidelink, a terminal (for example, terminal A) has the following function, namely, receiving the PSCCH sent from other terminals different from terminal A, and after grasping the resource utilization status of other terminals, determining the resources for terminal A to send. This function is also called "sensing".

[0041] In addition, in the side link, signals are transmitted and received in the following channels.

[0042] -PSCCH (Physical Sidelink Control Channel): The first stage SCI (Sidelink Control Information) is configured in the PSCCH.

[0043] -PSSCH (Physical Sidelink Shared Channel): Data signals and the second stage SCI are configured in the PSSCH.

[0044] -PSFCH (Physical Sidelink Feedback Channel): A feedback signal for PSSCH is configured in PSFCH. The feedback signal represents, for example, ACK (Acknowledgement) or NACK (negative Acknowledgement), where ACK indicates successful reception of PSSCH and NACK indicates unsuccessful reception of PSSCH. The feedback signal can be applied to situations where PSSCH is unicast and multicast. In addition, after Release 17 (Rel.17: Release 17), for Inter-UE coordination, PSFCH is sometimes sent when a conflict is detected.

[0045] -PSBCH (physical SL broadcast channel): A broadcast signal is configured in the PSBCH. The SBCH is sent together with a synchronization signal. The synchronization signal is, for example, a sidelink primary synchronization signal (S-PSS: sidelink Primary synchronization signal) and / or a sidelink secondary synchronization signal (S-SSS: sidelink secondly synchronization signal). The SBCH sent together with the synchronization signal is also collectively referred to as an "S-SSB (sidelink synchronization signal block)".

[0046] It should be noted that the signal received and transmitted in the sidelink may also be referred to as a "sidelink signal". In addition, for example, "transmission of information (or, signal) configured on the PSCCH" is sometimes referred to as "transmission of the PSCCH" below. In addition, in the following description, the PSCCH may refer to a resource defined as the PSCCH, or may refer to information (or, signal) configured on a resource defined as the PSCCH. Other channels other than the PSCCH are sometimes referred to as the PSCCH.

[0047] Figure 1 This is a diagram showing an example of the configuration of PSCCH, PSSCH, and PSFCH within a time slot. Figure 1 The horizontal axis represents the time axis, and the vertical axis represents the frequency axis in PRB (physical resource block) units. Figure 1 Indicated in Figure 1 (a) and Figure 1 (b) These two examples.

[0048] It should be explained, such as Figure 1 As shown in (a), PSFCH can also be configured. Figure 1 As shown in (b), there is also a case where PSFCH is not configured according to the setting. When PSFCH is not configured, the area of ​​PSSCH can be increased.

[0049] The number of symbols of the sidelink signal in a time slot can be changed according to the settings. In addition, the configuration of the second-stage SCI will change according to the configuration of the DMRS (demodulation reference signal) of the PSSCH (not shown). The first-stage SCI is configured starting from the lowest frequency resource among the frequency resources allocated to the PSSCH. In the symbols before the leading symbols of the PSCCH and PSSCH, copies of the leading symbols of the PSCCH and PSSCH are configured for AGC (Auto gain control). In addition, as Figure 1 As shown in (a), a copy of the PSFCH is also arranged before the codeword of the PSFCH for AGC.

[0050] In addition, Figure 1 In (a), a protection interval (also called a "guard period" or "gap") for switching between transmission and reception is configured in the interval between PSSCH and PSFCH and in the interval after the last symbol of PSFCH. Figure 1 In (b), a guard period for switching between transmission and reception is arranged in a section after the last symbol of the PSSCH. The guard period may correspond to a section in which no signal is transmitted or received.

[0051] NR's sidelink communication has two modes called "Mode 1" and "Mode 2". In Mode 1, the base station determines (schedules) the resources used by the terminal in the sidelink and indicates the scheduling result to the terminal. In Mode 2, the terminal determines (or selects) the resources used in the sidelink from the resources in a predetermined resource pool. Mode 1 is used in an environment where it is assumed that the base station and the terminal are connected and the terminal communicating in the sidelink can receive instructions from the base station. Regarding Mode 2, the terminal can send in the sidelink even without instructions from the base station. Therefore, terminals under different operators and / or terminals outside the coverage of the base station can communicate in the sidelink.

[0052] For example, the resources used by the sidelink are set according to the SL BWP (Band width part) and the resource pool.

[0053] SL BWP specifies a frequency band that can be used in the sidelink, and is set separately from the downlink BWP (DL BWP: downlink BWP) and uplink BWP (UL BWP: Uplink BWP) set between the base station and the terminal (Uu). For example, the frequency band of SLBWP may overlap with UL BWP.

[0054] The resource pool is the resource in the SL BWP. The resources in the frequency direction and the time direction are specified according to the resource pool. For example, multiple resource pools can be set for one terminal. The frequency resources in the resource pool are divided into "subchannel" units, and the allocation of resources can be set in subchannel units. A subchannel contains multiple PRBs, and the PSSCH can be allocated in subchannel units that aggregate PRBs.

[0055] [NR-U: NR-Unlicensed)]

[0056] As communication capacity increases, 3GPP is also studying the use of unlicensed bands in addition to licensed bands. NR using unlicensed bands is also called "NR-U (unlicensed)". In NR-U, new and expanded actions are added to ensure fairness when mixed with other devices such as LAA (Licensed Assisted Access) based on Wifi (registered trademark) and / or LTE.

[0057] In the unlicensed band, in order to ensure fairness with other devices, the communication device (for example, the base station or terminal of NR-U) performs LBT (Listen Before Talk) and starts sending after confirming that other devices are not sending signals nearby. LBT can also be replaced by other expressions such as "carrier sensing" or "sensing". The communication device performs LBT, and after confirming that other devices are not sending signals nearby, it sets the channel occupancy time, namely COT (Channel Occupancy Time). Within the COT, the communication device can send and receive signals in DL (downlink) resources and UL (uplink) resources.

[0058] There are two application methods related to LBT. The first application method is LBE (Load Based Equipment). For LBE, the communication device implements Type 1 channel access (Type 1 channel access) (for example, also referred to as "category 4 LBT" or "Type 1 LBT") when obtaining COT. In addition, in addition to the front end of COT, the communication device can implement Type 2 channel access (Type 2 channel access) (for example, also referred to as "Type 2 LBT") and can start sending after implementation.

[0059] It should be noted that in the following description, a communication device (eg, a base station or a terminal) "starts transmitting after implementing LBT", which is equivalent to the communication device implementing LBT and starting transmitting after confirming that other devices are not transmitting signals nearby.

[0060] Table 1 shows an example of a sensing interval of LBT for obtaining a transmission right in DL in LBE and an applied interval.

[0061] [Table 1]

[0062]

[0063] For Type 2A, when the interval between two temporally consecutive resources is 25 μs, the terminal performs LBT within 25 μs. If the transmission of other devices is not confirmed during LBT, the terminal can start transmission.

[0064] For Type 2B, when the interval between two temporally consecutive resources is 16 μs, the terminal implements LBT within 16 μs. The terminal can start transmission without confirming transmission of other devices.

[0065] For Type 2C, when the interval between two consecutive resources in time is less than 16μs, the terminal can start sending without LBT. In addition, as an exception, for the transmission of DRS (Discovery reference signal), because the transmission time of DRS is short, it is possible to implement Type 2A LBT instead of Type 1 LBT and start sending.

[0066] The second application method is FBE (Frame Based Equipment). FBE is an application that assumes that other devices such as Wifi are not set up in the same space, fixes the frame period and implements LBT at the front end of the frame to obtain COT. For FBE, COT can only be obtained from the front end of the frame period (Fixed Frame Period). In addition, for FBE, it is stipulated that a non-transmission interval (idle period) of more than 5% is set according to the frame period.

[0067] The above explains NR-U.

[0068] In the following embodiments, an example of performing sidelink communication in an unlicensed band is described. NR using an unlicensed band is also called "SL-U (Sidelink unlicensed)".

[0069] In an unlicensed band, a terminal implements LBT and starts transmission without confirming transmission from other devices. On the other hand, in an unlicensed band, a terminal implements LBT and detects signals from other devices, and does not start transmission if transmission from other devices is confirmed. The situation where signals from other devices are detected is also called "busy (or, channel busy)", "unavailable", or "LBT failure".

[0070] In the case of LBT failure, the terminal cannot obtain the transmission right of the allocated resources or the selected resources even in the side link, and cannot start transmission.

[0071] Figure 2 This is a diagram showing an example of channel configuration in each time slot when LBT fails.

[0072] For example, Figure 2 (a) shows an example of a case where another device has started to transmit in a time slot before the time slot in which the terminal is expected to transmit (a time slot for which resources have been reserved). Figure 2 (b) shows an example of a case where another device has started to transmit in a symbol before the time slot in which the terminal is expected to transmit. Figure 2 (a) and Figure 2 As shown in (b) of FIG. 1 , the terminal implements LBT before the time slot in which it is expected to transmit, and because LBT fails, it cannot start transmitting the sidelink signal. Figure 2 As shown in (b), even if the terminal uses continuous time slots, even if it wants to implement LBT type 2 transmission in the COT, the transmission right may still be obtained by other devices.

[0073] In a non-limiting embodiment of the present disclosure, a method is described as follows, which allocates or selects the next resource when the terminal cannot obtain the transmission right in the sidelink communication of the unlicensed band. In addition, in a non-limiting embodiment of the present disclosure, a method is described as follows, which reduces the number of LBTs or the occurrence of LBT failures when the terminal uses continuous time slots in the sidelink communication of the unlicensed band.

[0074] In addition, although the sidelink communication is exemplified in each of the embodiments described below, the present disclosure is not limited to the sidelink communication.

[0075] [Overview of Communication System]

[0076] A communication system according to an embodiment of the present disclosure includes a base station 100 and a terminal 200 .

[0077] Figure 31 is a block diagram showing a configuration example of a part of the base station 100. Figure 3 In the base station 100 shown, the control unit controls the communication via the link called "Uu" between the terminal 200 and the base station 100. The communication unit transmits a signal via the link called "Uu" under the control of the control unit. In addition, the control unit may also perform control related to the side link communication between multiple terminals (for example, determining resources in mode 1).

[0078] Figure 4 2 is a block diagram showing a configuration example of a portion of the terminal 200 (eg, corresponding to a communication device). Figure 4 When the terminal 200 shown is allocated continuous time resources in the inter-terminal communication in the unlicensed frequency band, the control unit (e.g., corresponding to the control circuit) allocates the signal to the protection interval (e.g., protection period) set for the nth time resource and the n+1th time resource contained in the continuous time resource (e.g., time slot). The communication unit (e.g., corresponding to the communication circuit) transmits the signal in the continuous time resource. It should be noted that the transmitted signal may be, for example, a sidelink signal or a signal different from the sidelink signal.

[0079] (Implementation Method 1)

[0080] In this embodiment, when the terminal 200 fails to obtain the transmission right due to LBT failure, the base station 100 notifies the next resource or sets the resource that the terminal 200 can select. In this way, the terminal 200 can prepare resources for the signal that cannot be transmitted due to LBT failure.

[0081] An operation example of this embodiment will be described below.

[0082] [Action Example 1]

[0083] In operation example 1, an operation example in which resources are designated by the base station 100 in sidelink mode 1 will be described.

[0084] Figure 5 2 is a diagram showing an operation example in sidelink mode 1. Figure 5 The illustrated operation example shows an operation example when it is confirmed through LBT that other devices are not transmitting (when LBT is OK).

[0085] In mode 1, the base station 100 (gNB) indicates the resource allocation of the sidelink communication to the source terminal 200 (source UE). The resource allocation of the sidelink communication can be indicated by DCI format 3_0, for example. In addition, the base station 100 can also specify multiple resources of the sidelink to the terminal 200.

[0086] The transmission source terminal 200 transmits a sidelink signal such as PSCCH and / or PSSCH (hereinafter also referred to as "PSCCH / PSSCH") to the destination terminal 200 (destination UE) according to the resource allocation (e.g., resource pool, time resource (e.g., time slot), frequency resource (e.g., PRB)) indicated by the base station 100. The transmission source terminal 200 can, for example, indicate at least one resource indicated by DCI format 3_0 to the destination terminal 200 using PSCCH (SCI format 1A). In addition, the transmission source terminal 200 can start transmitting the sidelink signal when the result of LBT is LBT OK.

[0087] The destination terminal 200 receives the PSCCH / PSSCH from the transmission source terminal 200 , and when HARQ (Hybrid Automatic Repeat reQuest) feedback is set, for example, the destination terminal 200 transmits HARQ-ACK information including ACK or NACK to the transmission source terminal 200 using PSFCH resources.

[0088] The transmission source terminal 200 notifies the base station 100 of the information of the HARQ-ACK received from the destination terminal 200 via, for example, the PUCCH (Physical Uplink Control Channel) or the PUSCH (Physical Uplink Shared Channel).

[0089] It should be noted that it is also assumed that in the sidelink mode 1 of SL-U, the base station 100 does not perform LBT (or sensing) of the unlicensed band. Figure 5 In the sidelink mode 1, the transmission source terminal 200 performs LBT on the resources specified by the base station 100, and when the result of the LBT is LBT failure, the transmission of PSCCH / PSSCH in the sidelink is suspended. As a result, when the result of the LBT of the terminal 200 is that the transmission cannot be performed (for example, when the LBT fails), the base station 100 cannot determine that the terminal 200 cannot transmit the sidelink signal (for example, LBT fails). Therefore, in the sidelink mode 1, the base station 100 cannot allocate the next resource (or new resource) of the sidelink to the terminal 200.

[0090] Therefore, in Operation Example 1, the transmission source terminal 200 notifies the base station 100 of the LBT failure.

[0091] Figure 6 1 is a diagram showing an operation example in sidelink mode 1 of operation example 1.

[0092] exist Figure 6 In the example, the base station 100 (gNB) and Figure 5 Similarly, resource allocation for sidelink communication is instructed to the transmission source terminal 200 (source UE).

[0093] The transmission source terminal 200 performs LBT on the sidelink resources allocated by the base station 100. If the result of LBT is LBT failure, the transmission source terminal 200 stops the transmission of PSCCH / PSSCH in the sidelink. As a result, the destination terminal cannot detect (or detect) PSCCH and therefore does not receive PSSCH.

[0094] The transmission source terminal 200 transmits a notification of LBT failure (LBT failure indication) to the base station 100. The notification of LBT failure may be transmitted via an uplink (for example, PUCCH or PUSCH) between the transmission source terminal 200 and the base station 100, for example.

[0095] For example, after receiving the notification of LBT failure, the base station 100 may allocate (or reallocate) additional resources to the transmission source terminal 200 if necessary. The base station 100 instructs the transmission source terminal 200 on resource allocation for sidelink communication (resource (re-)allocation). In addition, for example, the base station 100 may not allocate additional resources to the transmission source terminal 200 based on the degree of congestion of other communications or the reliability of the transmitted signal.

[0096] When the base station 100 allocates new resources, the source terminal 200 performs LBT on the new resources. When the result of LBT is OK, the source terminal 200 uses the new resources to send PSCCH / PSSCH to the destination terminal 200. Figure 5 Similarly, the PSCCH / PSSCH from the transmission source terminal 200 is received, and when HARQ feedback is set, for example, the HARQ-ACK information including ACK or NACK is transmitted to the transmission source terminal 200 using the PSFCH resource. Figure 5 Similarly, the base station 100 is notified of the information of the HARQ-ACK received from the destination terminal 200 via, for example, the PUCCH or the PUSCH.

[0097] Thus, according to Operation Example 1, even when the LBT of the transmission source terminal 200 fails (when the transmission right cannot be obtained), by notifying the base station 100 of the LBT failure from the transmission source terminal 200, additional resources can be allocated for the transmission of the sidelink signal.

[0098] In addition, a new DCI format may be set for notification of sidelink mode 1 of SL-U.

[0099] Next, an example of a method in which the transmission source terminal 200 notifies the base station 100 of an LBT failure will be described.

[0100] Hereinafter, as an example, a case is described in which a resource for transmitting HARQ-ACK (information of ACK or NACK) received by the transmission source terminal 200 from the destination terminal 200 to the base station 100 is used as a resource for notifying LBT failure. In addition, the resource for notifying LBT failure is not limited to the resource for HARQ-ACK, and may be other resources.

[0101] <Notification method 1>

[0102] In notification method 1, the transmission source terminal 200 notifies the base station 100 of the LBT failure by not transmitting the HARQ-ACK (information of ACK or NACK) received from the destination terminal 200 to the base station 100 .

[0103] When the base station 100 does not receive the HARQ-ACK that is scheduled to be transmitted from the transmission source terminal 200 in the pre-specified resource, the base station 100 recognizes that there is a possibility that the LBT failure has occurred in the transmission source terminal 200 .

[0104] For example, when HARQ-ACK is transmitted from the transmission source terminal 200 to the base station 100 using PUCCH format 0, as shown in Table 2, the transmission source terminal 200 notifies the base station 100 of LBT failure by not transmitting PUCCH.

[0105] [Table 2]

[0106]

[0107] <Notification method 2>

[0108] In notification method 2, the transmission source terminal 200 transmits the same signal as NACK in the resource for transmitting the HARQ-ACK received from the destination terminal 200 to the base station 100, thereby notifying the base station 100 of the LBT failure.

[0109] For example, when HARQ-ACK is sent from the sending source terminal 200 to the base station 100 using PUCCH format 0, as shown in Table 3, the sending source terminal 200 notifies the base station 100 of the LBT failure by sending PUCCH format 0 using the same value as NACK (e.g., the value of sequence cyclic shift).

[0110] [Table 3]

[0111]

[0112] Base station 100 receives notification of LBT failure as HARQ-ACK received by source terminal 200 from destination terminal 200 in a pre-specified resource. Base station 100 does not distinguish between NACK and LBT failure in received PUCCH format 0, but can recognize that reception was unsuccessful in sidelink communication.

[0113] In addition, the PUCCH format used to notify LBT failure is not limited to PUCCH format 0. Even when a format different from PUCCH format 0 is used, or when a channel or signal different from PUCCH is used, LBT failure can be notified using the same signal as NACK.

[0114] <Notification method 3>

[0115] In notification method 3, the transmission source terminal 200 notifies the base station 100 of the LBT failure by allocating a signal different from ACK and NACK to the LBT failure in the resource for transmitting the HARQ-ACK received from the destination terminal 200 to the base station 100 .

[0116] For example, when HARQ-ACK is transmitted from the transmission source terminal 200 to the base station 100 using PUCCH format 0, the sequence cyclic shift m_cs=3 may be assigned to the LBT failure as shown in Table 4. In addition, m_cs=3 is an example, and LBT failure may be assigned to a sequence different from the sequence (m_cs) to which ACK and NACK are assigned, for example, m_cs=9 or other values ​​may be used.

[0117] [Table 4]

[0118]

[0119] The base station 100 receives the notification of LBT failure as HARQ-ACK received by the transmission source terminal 200 from the destination terminal 200 in a pre-specified resource. The base station 100 can distinguish between ACK and NACK and LBT failure in the received PUCCH format 0. For example, the base station 100 can separately determine the amount of resources allocated for retransmission of NACK and the amount of resources allocated for transmission of LBT failure (for example, the two resource amounts can also be different).

[0120] It should be noted that the PUCCH format for notifying LBT failure is not limited to PUCCH format 0. For example, a format different from PUCCH format 0, or a channel or signal different from PUCCH may be used.

[0121] For example, by allocating 2 bits to PUCCH or PUSCH in advance, and setting one of the states (for example, 4 states) represented by 2 bits as LBT failure, the LBT failure can be notified from the transmission source terminal 200 to the base station 100. The PUCCH or PUSCH is a resource for transmitting the HARQ-ACK received by the transmission source terminal 200 from the destination terminal to the base station 100. Table 5 shows an example of setting one of the states (for example, 4 states) represented by 2 bits (01) as LBT failure. In addition, although Table 5 shows a case where the state of 2 bits being 01 is set as LBT failure, LBT failure can also be set to other states.

[0122] [Table 5]

[0123] HARQ-ACK value 0(NACK) LBT failure 1(ACK) - 00 01 11 00

[0124] [Action Example 2]

[0125] In operation example 2, an operation example in which resources are designated by the base station 100 in sidelink mode 1 will be described.

[0126] In action example 2, when the LBT fails and the sidelink signal cannot be transmitted in the resource indicated by the base station 100, the transmission source terminal 200 of mode 1 selects resources for sidelink communication as in mode 2. In mode 1, the action of selecting resources as in mode 2 is sometimes expressed as "mode 2-like behavior".

[0127] As a result, the transmission source terminal 200 can perform sidelink communication in a resource different from the resource in which the LBT failed without waiting for an instruction on resource allocation from the base station 100 , thereby reducing delay.

[0128] For example, resources for a configured grant preset ((pre-)configured) by the base station may be set as resources selected by the source terminal 200 when LBT fails. For example, after LBT fails in a certain time slot, if there are resources that can be transmitted in the time slot after the time slot set by the base station 100, the source terminal 200 can implement LBT for the time slot, and if LBT is OK, use the resources in the time slot to send to the destination terminal 200.

[0129] When there are multiple time slots containing resources that can be transmitted, the transmission source terminal 200 may select a resource with a lower received power (e.g., RSRP (Reference Signal Received Power)) among multiple resources, similarly to the resource selection in mode 2. In addition, the resource selection is not limited to this, and a resource with a higher received power among multiple resources may be selected. In addition, the transmission source terminal 200 may also determine the resource based on communication quality information such as CQI (Channel Quality Indicator) feedback.

[0130] In addition, as another resource selection method, for example, even when the transmission source terminal 200 is not notified of resources for the configured grant by the base station 100, the transmission source terminal 200 can select resources in the same manner as the resource selection in mode 2 by the judgment of the transmission source terminal 200, and use the selected resources to transmit to the destination terminal 200. In addition, a method of randomly selecting resources from a plurality of resources called "random selection" can be applied instead of the resource selection in mode 2.

[0131] According to Action Example 2, even if the sending source terminal 200 fails in LBT (cannot obtain the sending right) and cannot implement sidelink transmission in the resources indicated by the base station 100, the sending source terminal 200 selects the resources for sidelink transmission, and the sending source terminal 200 can use the selected resources to send to the destination terminal 200 without waiting for instructions from the base station 100.

[0132] <Variation of Operation Example 2>

[0133] In the case of applying action example 2, the CP length called "cyclic prefix extension (CP) extension" can also be made different in mode 1 transmission using resources notified by the base station 100 (for example, mode 1 behavior (Mode 1 behavior)) and mode 2 transmission such as transmission using resources selected by the sending source terminal 200 (for example, behavior similar to mode 2).

[0134] For example, the longer the CP length is, and the earlier the expected start position of transmission is in the time direction, the easier it is to obtain the transmission right, and the terminal 200 is likely to start transmission during the channel sensing period of LBT by other terminals. Therefore, the longer the CP length is, the easier it is for the terminal 200 to use the resource for priority transmission.

[0135] Figure 7 This is a diagram showing an example of channel arrangement within a time slot in a variation of Operation Example 2.

[0136] For example, in the case where the resource priority notified by the base station 100 is Figure 7 As shown in (a) of FIG. 1 , the CP length in the transmission of mode 1 may be set to be longer than the CP length in the transmission of mode 2. Figure 7 As shown in (a) of FIG. 1 , in the transmission of mode 1, the channel can also be configured to be earlier than the front end of the time slot, and the transmission can be started earlier than the front end of the time slot. Figure 7 In (a), compared with transmission in mode 2, transmission in mode 1 has a higher possibility of LBT OK and is easier to be given priority.

[0137] In addition, as another method, in the case where the resource notified by the base station 100 is prioritized, as shown in FIG. Figure 7 As shown in (b) of FIG. 1 , it is also possible that the transmission of mode 1 starts from the front end of the time slot, while the transmission of mode 2 starts from the back end of the time slot. Figure 7 In (b), the possibility of LBT OK in mode 1 is higher than that in mode 2, and it is easy to give priority. For example, the transmission in mode 2 can also start from the end of the time slot by 1 codeword or in the middle of the first codeword. For example, in the case where the transmission in mode 2 starts from the middle of the first codeword, the CP length of the signal of the second codeword can be extended to the first codeword for transmission. In this way, the first codeword of the time slot becomes the codeword used by AGC. Although all or part of the codeword is not used for transmission, the transmission of mode 1 can be given priority, and the sensing time for the transmission of mode 1 can also be ensured.

[0138] It should be noted that Action Example 2 may be combined with Action Example 1. In this case, in Notification Method 2 or Notification Method 3 of Action Example 1, after receiving the notification of LBT failure, the base station 100 may recognize that the transmission source terminal 200 selected resources and performed communication in the sidelink.

[0139] [Action Example 3]

[0140] In operation example 3, an operation example in which resources are selected by the transmission source terminal 200 in sidelink mode 2 will be described.

[0141] In mode 2 where the transmission source terminal 200 selects resources, the transmission source terminal 200 notifies the destination terminal 200 that the LBT fails and the sidelink signal cannot be transmitted in the predetermined resource. Operation Example 3 is also applicable to transmission in mode 1.

[0142] Figure 8 This is a diagram showing an operation example of the transmission source terminal 200 and the destination terminal 200 in operation example 3.

[0143] exist Figure 8 In the example, the source terminal 200 (source UE) sends a sidelink signal (e.g., PSCCH / PSSCH) to the destination terminal 200 (destination UE). The first-stage SCI contained in the PSCCH can allocate multiple resources, for example, resources can also be reserved in the subsequent time slot. In addition, the source terminal 200 can start sending the sidelink signal when the LBT result is LBT OK.

[0144] After receiving the PSCCH / PSSCH, the destination terminal 200 recognizes that resources are allocated (reserved) even in other time slots later than the time slot in which the PSCCH / PSSCH is received. For example, when HARQ feedback is set, the destination terminal 200 uses the PSFCH resources to send HARQ-ACK including ACK or NACK to the transmission source terminal 200. The transmission source terminal 200 can perform retransmission control based on the HARQ-ACK from the destination terminal 200 (not shown).

[0145] In addition, Figure 8 In the transmission process, the transmission source terminal 200 uses, for example, the resources behind reserved by the first-stage SCI to perform transmission processing for the destination terminal 200. Here, for example, when the LBT result is LBT failure for the resources (for example, unlicensed band) reserved for transmission to the destination terminal 200, the transmission source terminal 200 does not transmit the sidelink signal.

[0146] In action example 3, when LBT fails for the reserved resources, the transmission source terminal 200 transmits information indicating that the sidelink signal cannot be transmitted in the reserved resources (e.g., notification of LBT failure) to the destination terminal 200. In addition, for example, in addition to the notification of LBT failure, the transmission source terminal 200 may also notify the destination terminal 200 of information related to the allocation (or reservation) of the newly added resources (additional resources).

[0147] For example, the PSFCH resource for the predetermined resource may be used to notify the LBT failure. Although the PSFCH resource is originally a resource for sending HARQ-ACK from the destination terminal 200 to the source terminal 200 (for example, in the case of LBT OK), in the case of LBT failure, it becomes a resource for notifying the LBT failure from the source terminal 200 to the destination terminal 200.

[0148] Table 6 shows an example of notification of LBT failure sent from the transmission source terminal 200 to the destination terminal 200. For example, as shown in Table 6, the occurrence of LBT failure and notification of no reservation of additional resources may be notified by the sequence cyclic shift of PSFCH = 0, and the occurrence of LBT failure and notification of reservation of additional resources may be notified by the sequence cyclic shift of PSFCH = 6.

[0149] [Table 6]

[0150]

[0151] In addition, it is also possible to set, when notifying the occurrence of LBT failure and notifying the reservation of new resources, for example, to reserve new resources after X time slots of the resources reserved in the pre-set setting (for example, the resources where the LBT failure occurred). For example, the value of X can be 4 time slots, 5 time slots, or 10 time slots, or other values.

[0152] In addition, the frequency resources in the newly added resources may also be the same as the frequency resources in the pre-set reserved resources. Thus, the frequency position in the newly added resources may not be notified, so even if the number of bits used to notify the LBT failure is 1 bit, the source terminal 200 can specify the position of the newly added resources (the resource position in the time direction and the frequency direction).

[0153] When the PSCCH / PSSCH is not received in the reserved resources, the destination terminal 200 attempts to receive the signal in the PSFCH resources corresponding to the reserved resources. Next, the destination terminal 200 receives the PSFCH from the source terminal 200, and upon receiving the notification of the occurrence of the LBT failure and the allocation instruction of the newly added resources, attempts to receive the PSCCH / PSSCH in the newly added resources. For example, when the destination terminal 200 receives the PSCCH / PSSCH in the newly added resources, it uses the PSFCH resources to send the HARQ-ACK containing ACK or NACK to the source terminal 200.

[0154] In the operation example 3, for example, when an LBT failure occurs, the terminal 200 can newly reserve resources that have not been reserved in advance, thereby ensuring transmission resources for the sidelink and reducing delay.

[0155] Furthermore, in operation example 3, when there is no need to add additional resources, for example, when it is sufficient to use the next reserved resources for transmission or when it is sufficient to reselect resources, it is not necessary to secure additional resources.

[0156] In addition, after receiving the notification of LBT failure, the destination terminal 200 is likely to be set to the receiving mode for receiving the newly reserved resources. In addition, even if the destination terminal 200 does not receive the notification of LBT failure, it is possible to receive the PSCCH / PSSCH from the transmission source terminal 200 as the allocation of new resources.

[0157] [Structure of Terminal 200]

[0158] Fig. 9 It is a block diagram showing a configuration example of the terminal 200 according to the present embodiment. Fig. 9 The terminal 200 shown includes a receiving unit 201, an LBT carrier monitoring unit 202, a signal separation unit 203, a demodulation unit 204, an error correction decoding unit 205, a control signal receiving unit 206, an LBT failure notification receiving unit 207, an error correction coding unit 208, a modulation unit 209, a control signal generating unit 210, an LBT failure notification generating unit 211, a signal distribution unit 212 and a sending unit 213.

[0159] In addition, at least one of the LBT carrier sensing unit 202, the signal separation unit 203, the demodulation unit 204, the error correction decoding unit 205, the control signal receiving unit 206, the LBT failure notification receiving unit 207, the error correction coding unit 208, the modulation unit 209, the control signal generating unit 210, the LBT failure notification generating unit 211 and the signal distribution unit 212 may be included in Figure 4 In addition, at least one of the receiving unit 201 and the sending unit 213 may be included in Figure 4 Communications Department shown.

[0160] In the sidelink communication, the terminal 200 may be a transmitting terminal (or a transmission source terminal) that transmits a sidelink signal, or may be a receiving terminal (or a destination terminal) that receives a sidelink signal.

[0161] The receiving unit 201 receives the received signal via the antenna and performs receiving processing such as down-conversion on the received signal. The received signal may be, for example, a sidelink signal including PSSCH / PSCCH. It should be noted that the sidelink signal may also include PSFCH. In addition, the received signal received by the receiving unit 201 may include a non-transmission interval and a signal different from the sidelink signal (for example, a downlink signal from the base station 100). The receiving unit 201 outputs the received signal after receiving processing to the LBT carrier monitoring unit 202 and the signal separation unit 203.

[0162] The LBT carrier sensing unit 202 performs carrier sensing (or, referred to as "LBT") based on the received signal input from the receiving unit 201. The LBT carrier sensing unit 202 can determine whether the channel state is "busy" (or, LBT failure) or "idle" (or, LBT OK) based on the received signal. In other words, the LBT carrier sensing unit 202 can determine whether the channel is available based on the received signal input from the receiving unit 201. The LBT carrier sensing unit 202 outputs information indicating the determined channel state to the LBT failure notification generating unit 211 and the transmitting unit 213.

[0163] The signal separation unit 203 outputs a received data signal from the received signal input from the receiving unit 201 to the demodulation unit 204. The received data signal is configured on the PSSCH, for example. In addition, the signal separation unit 203 separates the first-stage SCI configured on the PSCCH and the second-stage SCI configured on a part of the PSSCH from the received signal input from the receiving unit 201, and outputs the separated information to the control signal receiving unit 206. In addition, the signal separation unit 203 separates the LBT failure notification configured on the PSFCH from the received signal input from the receiving unit 201, and outputs the separated LBT failure notification to the LBT failure notification receiving unit 207.

[0164] The demodulation unit 204 performs a demodulation process on the reception data signal input from the signal separation unit 203. The demodulation unit 204 outputs a demodulated signal obtained by the demodulation process to the error correction decoding unit 205.

[0165] The error correction decoding unit 205 decodes the demodulated signal input from the demodulation unit 204, and outputs it as reception data.

[0166] The control signal receiving unit 206 determines (or grasps) resource allocation information including reserved resources based on the first-stage SCI included in the signal input from the signal separation unit 203. The control signal receiving unit 206 outputs the resource allocation information to the signal allocation unit 212, for example, so as to avoid overlapping with other resources. In addition, for example, the control signal receiving unit 206 determines (or grasps) the transmission ID and the reception ID based on the second-stage SCI included in the signal input from the signal separation unit 203. The control signal receiving unit 206 determines whether there is resource allocation to the terminal 200 based on the determined transmission ID or reception ID, and instructs the signal separation unit 203 to separate the received signal if there is resource allocation to the terminal 200.

[0167] The LBT failure notification receiving unit 207 receives the notification of LBT failure from the transmission source terminal contained in the signal input from the signal separation unit 203. In addition, when it is determined that additional resources are allocated based on the LBT failure notification, the LBT failure notification receiving unit 207 instructs the signal separation unit 203 to separate the received signal. It should be noted that the LBT failure notification receiving unit 207 can operate, for example, when the above-mentioned operation example 3 is applied.

[0168] The error correction coding unit 208 inputs a data signal, performs error correction coding on the data signal, and outputs the error correction coded data signal to the modulation unit 209 .

[0169] The modulation unit 209 modulates the data signal input from the error correction coding unit 208 , and outputs the modulated signal to the signal distribution unit 212 .

[0170] The control signal generation unit 210 generates the first stage SCI and the second stage SCI signals based on control information (not shown) and outputs the first stage SCI and the second stage SCI signals to the signal distribution unit 212 .

[0171] The LBT failure notification generating unit 211 generates information related to the notification of LBT failure based on the information input from the LBT carrier sensing unit 202 when LBT fails in the time slot where transmission is expected. For example, in the case of the above-mentioned action example 1, the LBT failure notification generating unit 211 can generate information related to the LBT failure notification sent to the base station 100. In addition, for example, in the case of the above-mentioned action example 3, the LBT failure notification generating unit 211 can determine whether to allocate additional resources and generate a signal indicating whether the additional resources are allocated. The LBT failure notification generating unit 211 outputs the generated signal to the signal allocation unit 212.

[0172] The signal allocation unit 212 allocates the modulated signal input from the modulation unit 209 to the resources. At this time, the signal allocation unit 212 may also consider the signal input from the control signal generation unit 210 and allocate the signal to the resources. In addition, the signal allocation unit 212 allocates the signal input from the LBT failure notification generation unit 211 to the resources. For example, in the case of the above-mentioned action example 1, the signal allocation unit 212 may allocate the signal input from the LBT failure notification generation unit 211 to the PUCCH or PUSCH. In addition, for example, in the case of the above-mentioned action example 3, the signal allocation unit 212 may allocate the signal input from the LBT failure notification generation unit 211 to the PSFCH. After performing resource allocation, the signal allocation unit 212 outputs the transmission signal to the transmission unit 213.

[0173] When the sensing result obtained from the LBT carrier sensing unit 202 indicates an idle state, the transmission unit 213 performs transmission processing such as up-conversion on the transmission signal input from the signal distribution unit 212, and transmits the processed transmission signal via the antenna.

[0174] The operation example of this embodiment has been described above.

[0175] Thus, in this embodiment, when the LBT fails, the terminal 200 notifies the base station 100 of the LBT failure, and the terminal 200 selects a resource, or notifies the destination terminal of the LBT failure (including reserving new resources), thereby allocating the next resource. Thus, even if the terminal 200 cannot obtain the transmission right, it can use the next resource to transmit the sidelink signal. Thus, according to this embodiment, the utilization efficiency of the sidelink communication resources in the unlicensed band can be improved.

[0176] (Implementation Method 2)

[0177] In this embodiment, the terminal 200a transmits and receives the sidelink signal using a plurality of consecutive time slots in the sidelink communication.

[0178] Hereinafter, an allocation method for continuously allocating a plurality of time slots and a transmission method using a plurality of continuous time slots (hereinafter also referred to as "continuous time slots") will be described.

[0179] For example, the transmission source terminal 200a can notify the allocation of consecutive time slots using SCI transmitted in PSCCH / PSSCH. Two methods are described as examples of the notification method of the allocation of consecutive time slots.

[0180] [Notification method 1]

[0181] In notification method 1, the allocation of continuous time slots can be notified by SCI format 1-A (for example, refer to Non-Patent Document 4).

[0182] For example, the allocation of consecutive time slots may be notified using "Time resource assignment" included in SCI format 1-A. SCI format 1-A is defined in the standard as follows (for example, refer to Non-Patent Document 4).

[0183] As defined in clause 8.1.5 of [6, TS 38.214], "Time resource assignment" is 5 bits when the value of the higher layer parameter sl-MaxNumPerReserve is configured to 2; otherwise 9 bits when the value of the higher layer parameter sl-MaxNumPerReserve is configured to 3, as defined in clause 8.1.5 of [6, TS 38.214].

[0184] For example, in "Time Resource Allocation", in addition to reserving the PSSCH in the same slot as the slot in which the PSCCH (SCI format 1-A) is transmitted, the PSSCH in the next two slots can also be reserved. In this case, in "Time Resource Allocation", the nearest two slots can be specified.

[0185] According to notification method 1, continuous time slots can be allocated according to existing parameters or formats.

[0186] [Notification method 2]

[0187] In notification method 2, a notification field indicating allocation of consecutive time slots may be newly added to SCI format 1-A, or may also be defined as a new SCI format.

[0188] For example, as a method of notifying continuous time slots, a notification indicating that K time slots including the time slot for transmitting the SCI format are continuously transmitted may be added to the SCI format.

[0189] For example, in the case of allocating continuous transmission of three time slots, namely time slot N, time slot N+1 and time slot N+2, as shown in Table 7, the number of time slots may be allocated in the inverse order of the time slot, and the number of remaining continuous time slots at the time point when the SCI is transmitted may be notified. For example, in Table 7, K=3 may be notified for time slot N, K=2 may be notified for time slot N+1, and K=1 may be notified for time slot N+2.

[0190] [Table 7]

[0191]

[0192] Alternatively, for example, 1 bit may be used to notify whether or not the time slot after the time slot in which the SCI is transmitted is also continuously allocated. For example, in the case of allocating three time slots, namely, time slot N, time slot N+1, and time slot N+2, for continuous transmission, as shown in Table 8, for time slot N and time slot N+1, for which the subsequent time slot is also continuously allocated, 1 indicating that there is a subsequent time slot may be notified, and for time slot N+2, for which the subsequent time slot is not allocated, 0 indicating that there is no subsequent time slot may be notified.

[0193] [Table 8]

[0194]

[0195] An example of a notification method of allocation of continuous time slots has been described above.

[0196] Next, an operation example of sidelink communication in the case of notifying the allocation of consecutive time slots using these notification methods will be described.

[0197] [Action Example 1]

[0198] In operation example 1, when transmission is performed in continuous time slots, the transmission source terminal 200a also transmits PSSCH in the symbol of the interval corresponding to the guard period at the end of the time slot for the time slot in which continuous transmission is also performed in the subsequent time slots. For example, when the terminal 200a transmits in continuous time slots, the guard period at the end of the time slot may not be set in the time slot in which continuous transmission is also performed in the subsequent time slots.

[0199] For example, Fig.10 As shown, when three consecutive time slots of time slot N, time slot N+1 and time slot N+2 are allocated to terminal 200a, for time slot N and time slot N+1, the transmission source terminal 200a transmits PSSCH even in the code element of the last guard period. In addition, in time slot N+2, the transmission source terminal 200a sets the guard period to the last code element.

[0200] Thus, in operation example 1, when a plurality of consecutive time slots are allocated in the sidelink communication of the unlicensed band, the terminal 200a allocates the PSSCH to the interval of the following protection period, the interval of which is set to the nth time slot among the nth time slot and the n+1th time slot included in the plurality of time slots (for example, the subsequent time slots are also used for transmission. Fig.10 For example, the terminal 200a may allocate the PSSCH to the last time slot (in the last time slot) set in the continuous time slots. Fig.10 The protection period interval of different time slots (time slot N+2) is used, and the protection period can be set in the last time slot.

[0201] Thus, in the interval equivalent to the protection period during the continuous time slot transmission, the transmission source terminal 200a transmits the PSSCH, thereby reducing the probability that other systems or other devices obtain the transmission right. Thus, for the transmission source terminal 200, the probability of LBT failure can be reduced, and the probability that the transmission source terminal 200 can transmit in the continuous time slot can be increased.

[0202] Furthermore, when the terminal 200a performs continuous slot transmission, it is not necessary to perform LBT between the continuous slots, or it is possible to perform LBT type 2C. This can reduce the number of times the transmission source terminal 200 performs LBT.

[0203] Here, there may be a case where other terminals different from the terminal 200a that performs continuous time slot transmission use different PRBs in the same RB set as the RB set for the terminal 200a to transmit the sidelink signal, and transmit at the same time (for example, FDM (frequency division multiplexing) transmission). In this case, if the terminal 200a transmits the PSSCH in the codeword equivalent to the guard period, sometimes the other terminals will detect the signal (PSSCH) of the terminal 200a through the type 2 LBT in the guard period, and the LTB fails, and the transmission cannot be started.

[0204] Therefore, in operation example 1, the conditions for transmitting the PSSCH in the symbols of the guard period may be set as follows.

[0205] <Condition 1>

[0206] For condition 1, when all PRBs in the RB set are allocated in the allocation of PSSCH, action example 1 can be applied.

[0207] In the case where the sidelink signal is allocated to all PRBs in the RB set used to transmit the sidelink signal, the terminal 200a may allocate the sidelink signal (for example, the PSSCH) to the interval of the guard period.

[0208] Thus, assuming that other terminals are not transmitting simultaneously in the RB set, the terminal 200a can apply action example 1. For example, when other terminals are transmitting simultaneously in the RB set, the terminal 200a can prevent interference with LBT (e.g., type 2 LBT) of other terminals by not allocating sidelink signals to the interval of the protection period.

[0209] In addition, the RB set is a frequency unit set in units of, for example, 20 MHz, and is the minimum unit for performing LBT, and is also referred to as an "LBT set".

[0210] <Condition 2>

[0211] Regarding condition 2, when more than X% of PRBs in an RB set are allocated in allocation of PSSCH, action example 1 can be applied.

[0212] When the sidelink signal is allocated to PRBs above a threshold (eg, PRBs above X%) in the RB set for transmitting the sidelink signal, the terminal 200a may allocate the sidelink signal (eg, PSSCH) to the guard period interval.

[0213] Thus, the terminal 200a can determine that even if not all PRBs in the RB set are occupied, as long as the PRBs with a resource amount above the threshold are occupied, a terminal can also transmit in the RB set (other terminals may also fail LBT). For example, when the PRB allocation in the RB set is above X%, the terminal 200a can Fig.10 As shown, PSSCH is transmitted in the symbol equivalent to the protection period (without the setting of the protection period), and when the PRB allocation in the RB set is less than X%, as shown in Fig.11 As shown, a guard period is set (setting of a guard period is provided). For example, by setting a guard period and not allocating a sidelink signal to the interval of the guard period, it is possible to prevent interference with the LBT of other terminals (for example, type 2 LBT). For example, by setting a guard period, the transmission of terminal 200a does not affect the LBT of other terminals, and the subsequent time slots (for example, Fig.11 Time slot N+2) can be used for other terminals.

[0214] <Condition 3>

[0215] For condition 3, when PSSCH is allocated to the same PRB between consecutive time slots, action example 1 may be applied. For example, when PRBs to which PSSCH is allocated are different between consecutive time slots, action example 1 may not be applied.

[0216] In the case where the sidelink signal is allocated to the same PRB in each consecutive time slot, the terminal 200a may allocate the sidelink signal (eg, PSSCH) to the interval of the guard period.

[0217] For example, when the terminal 200a allocated with continuous time slots transmits in different PRBs in the same RB set in each continuous time slot, a protection period is set at the end of the time slot. Therefore, the transmission of the terminal 200a will not affect the LBT of other terminals, and multiple terminals can transmit continuously (or, multiplexed transmission) within the RB set.

[0218] The conditions for implementing the operation example 1 have been described above.

[0219] It should be noted that the signal transmitted in the codeword of the last guard period of the time slot may also be transmitted in a portion of the time equivalent to the codeword. In this case, the signal transmitted in the codeword of the guard period may also be a part of the repeated signal of the signal transmitted in the second codeword from the last.

[0220] In addition, the continuous time slots are not continuous time slots in the sidelink resource pool, but continuous time slots on the time axis.

[0221] [Action Example 2]

[0222] In operation example 2, terminal 200a receives SCI of slot N transmitted by another terminal, and when detecting that the "remaining COT duration" notified in slot N is K, it can determine that transmission is possible from the next slot N+1 to the consecutive K-1 slots.

[0223] For example, the continuous time slots may be set within the period of COT. In addition, the terminal 200a may set the guard period in at least the last time slot in the period of COT among the continuous time slots.

[0224] For example, Fig.12 As shown in FIG. 1 , when the remaining COT duration contained in the SCN of other terminals received in time slot N is K=3, terminal 200a can perform continuous time slot transmission from time slot N+1 to the consecutive 2 time slots (K-1 time slot), i.e., time slot N+2. Fig.12 As shown, terminal 200a can send PSSCH in the interval of the protection period of time slot N+1 and time slot N+2, and set the protection period in time slot N+2 (PSSCH may not be sent).

[0225] Thus, for example, the terminal 200a can limit the transmission of continuous time slots to the period of COT, thereby avoiding continuous transmission beyond COT. In addition, the terminal 200a can set a protection period at the end of COT. In this way, continuous transmission beyond COT is avoided, thereby maintaining fairness with other devices.

[0226] It should be noted that, when the remaining COT duration is insufficient for resources assumed to be continuously transmitted by the transmission source terminal 200a, the following method can be applied.

[0227] <Method 1>

[0228] The transmission source terminal 200a performs type 1 LBT without using the COT duration obtained from other terminals, and obtains a new COT. Thus, the terminal 200a can set (or obtain) a COT duration of a length for continuous transmission.

[0229] <Method 2>

[0230] The transmission source terminal 200a continuously transmits signals in K-1 time slots which are the remaining COT duration. Thus, the terminal 200a can transmit signals in the remaining time slots in the COT.

[0231] <Method 3>

[0232] After continuously transmitting signals in K-1 time slots as the remaining COT duration, the transmission source terminal 200a performs type 1 LBT to obtain a new COT and transmits the remaining signals. Thus, the terminal 200a can transmit signals with reduced delays in continuously transmitted signals compared to other methods.

[0233] Methods 1 to 3 have been described above.

[0234] As another method, when the transmission source terminal 200a performs continuous time slot transmission, the transmission source terminal 200a may obtain the COT and perform transmission. In this way, the COT duration for continuous transmission can be specified.

[0235] [Configuration Example of Terminal 200a]

[0236] Fig.13 It is a block diagram showing a configuration example of the terminal 200a according to the present embodiment. Fig.13 The terminal 200a shown includes a receiving unit 201, an LBT carrier monitoring unit 202, a signal separation unit 203, a demodulation unit 204, an error correction decoding unit 205, a control signal receiving unit 206, an error correction coding unit 208, a modulation unit 209, a control signal generating unit 210, a protection period setting unit 220, a signal allocation unit 212 and a sending unit 213.

[0237] Fig.13 The terminal 200a shown is connected to Fig. 9 Compared with the terminal 200 shown in the figure, the difference lies in that a protection period setting unit 220 is newly included, and the LBT failure notification receiving unit 207 and the LBT failure notification generating unit 211 are not included.

[0238] In addition, at least one of the LBT carrier sensing unit 202, the signal separation unit 203, the demodulation unit 204, the error correction decoding unit 205, the control signal receiving unit 206, the error correction coding unit 208, the modulation unit 209, the control signal generating unit 210, the protection period setting unit 220 and the signal distribution unit 212 may be included in Figure 4 In addition, at least one of the receiving unit 201 and the sending unit 213 may be included in Figure 4 Communications Department shown.

[0239] In the sidelink communication, the terminal 200a may be a transmitting terminal (or a transmission source terminal) that transmits a sidelink signal, or may be a receiving terminal (or a destination terminal) that receives a sidelink signal.

[0240] The receiving unit 201 receives the received signal via the antenna and performs receiving processing such as down-conversion on the received signal. The received signal may be, for example, a sidelink signal including PSSCH / PSCCH. It should be noted that the sidelink signal may also include PSFCH. In addition, the received signal received by the receiving unit 201 may include a non-transmission interval and a signal different from the sidelink signal (for example, a downlink signal from the base station 100). The receiving unit 201 outputs the received signal after receiving processing to the LBT carrier monitoring unit 202 and the signal separation unit 203.

[0241] The LBT carrier sensing unit 202 performs carrier sensing (or, referred to as "LBT") based on the received signal input from the receiving unit 201. The LBT carrier sensing unit 202 can determine whether the channel state is "busy" (or, LBT failure) or "idle" (or, LBT OK) based on the received signal input from the receiving unit 201. In other words, the LBT carrier sensing unit 202 can determine whether the channel is available based on the received signal input from the receiving unit 201. The LBT carrier sensing unit 202 outputs information indicating the determined channel state to the transmitting unit 213.

[0242] The signal separation unit 203 outputs a received data signal from the received signal input from the receiving unit 201 to the demodulation unit 204. The received data signal is configured on the PSSCH, for example. In addition, the signal separation unit 203 separates the first-stage SCI configured on the PSCCH and the second-stage SCI configured on a part of the PSSCH from the received signal input from the receiving unit 201, and outputs the separated information to the control signal receiving unit 206.

[0243] The demodulation unit 204 performs a demodulation process on the reception data signal input from the signal separation unit 203. The demodulation unit 204 outputs a demodulated signal obtained by the demodulation process to the error correction decoding unit 205.

[0244] The error correction decoding unit 205 decodes the demodulated signal input from the demodulation unit 204, and outputs it as reception data.

[0245] The control signal receiving unit 206 determines (or grasps) resource allocation information including reserved resources based on the first-stage SCI included in the signal input from the signal separation unit 203. The control signal receiving unit 206 outputs the resource allocation information to the protection period setting unit 220 and the signal allocation unit 212, for example, so as to avoid overlapping with other resources. In addition, for example, the control signal receiving unit 206 determines (or grasps) the transmission ID and the reception ID based on the second-stage SCI included in the signal input from the signal separation unit 203. The control signal receiving unit 206 determines whether there is resource allocation to the terminal 200 based on the determined transmission ID or reception ID, and instructs the signal separation unit 203 to separate the received signal if there is resource allocation to the terminal 200.

[0246] The error correction coding unit 208 inputs a data signal, performs error correction coding on the data signal, and outputs the error correction coded data signal to the modulation unit 209 .

[0247] The modulation unit 209 modulates the signal input from the error correction coding unit 208 , and outputs the modulated signal to the signal distribution unit 212 .

[0248] The control signal generation unit 210 generates the first stage SCI and the second stage SCI signals based on control information (not shown) and outputs the first stage SCI and the second stage SCI signals to the signal distribution unit 212 .

[0249] The protection period setting unit 220 determines whether to allocate continuous resources (for example, continuous time slots) based on the information of the transmission signal not shown in the figure and the information input from the control signal receiving unit 206. When allocating continuous resources, it instructs the signal allocation unit 212 on the setting of the protection period (for example, whether it is set or not).

[0250] The signal allocation unit 212 allocates the modulated signal input from the modulation unit 209 to the resource. At this time, the signal allocation unit 212 may also consider the signal input from the control signal generation unit 210 and allocate the signal to the resource. In addition, the signal allocation unit 212 determines the number of symbols of the PSSCH (or the presence or absence of the setting of the guard period) based on the information input from the guard period setting unit 220, and allocates the resource. After performing the resource allocation, the signal allocation unit 212 outputs the transmission signal to the transmission unit 213.

[0251] When the sensing result obtained from the LBT carrier sensing unit 202 indicates an idle state, the transmission unit 213 performs transmission processing such as up-conversion on the transmission signal input from the signal distribution unit 212, and transmits the processed transmission signal via the antenna.

[0252] The operation example of this embodiment has been described above.

[0253] As described above, in the second embodiment, when continuous time slots are allocated in the sidelink communication in the unlicensed band, the terminal 200a allocates the PSSCH to the following protection period, which is the protection period set to the nth time slot among the nth time slot and the n+1th time slot included in the continuous time slot. Thus, for example, when the terminal 200a uses the continuous time slot, it is possible to reduce the possibility that other devices obtain the transmission right in the interval of the continuous time slot and transmit the sidelink signal. Therefore, according to this embodiment, the utilization efficiency of the sidelink communication resources in the unlicensed band can be improved.

[0254] It should be noted that the signal transmitted in the codeword of the guard period is not limited to the PSSCH, and may be other signals.

[0255] In addition, when transmission is performed in continuous time slots and type 2A or type 2B channel sensing is required, the time interval for type 2A or type 2B in the guard period may also be set as the guard period.

[0256] Each embodiment has been described above.

[0257] [Transformation]

[0258] It should be noted that the operation examples of the above-mentioned embodiments may be used in combination.

[0259] In addition, the terminal that performs transmission and reception in the sidelink includes a terminal that performs transmission but not reception in the sidelink, a terminal that performs reception but not transmission, and a terminal that performs both transmission and reception.

[0260] In addition, when the setting related to the sidelink is preset, the setting method may be preset in the specification (standard) or in the SIM (Subscriber Identity Module). Alternatively, the setting related to the sidelink may be set in the application layer called "preset", or in the SIB (system information block) and / or other RRC (radio resource control) and other high layers called "configured", or in the MAC (Medium Access Control).

[0261] In addition, although the above embodiments show examples of sidelink communication, the present disclosure is not limited thereto. For example, in the above embodiments, PSCCH may be replaced with PDCCH, PSSCH may be replaced with PDSCH or PUSCH, PSFCH may be replaced with PUCCH, and PSBCH may be replaced with PBCH, and the present disclosure may be applied to the communication between the base station and the terminal.

[0262] In addition, the above-mentioned embodiments may be applied to mode 2 but not to mode 1, may be applied to both mode 1 and mode 2, or may be applied to mode 1 but not to mode 2. In addition, in each action example of the above-mentioned embodiments, the action example applied to mode 1 and the action example applied to mode 2 may be the same or different. For example, there may be an action example applied to mode 2 but not to mode 1.

[0263] In addition, when the above-mentioned embodiments are applied to Mode 1, the base station may instruct which type 2A, 2B, or 2C of the Type 2 LBT is to be selected in the licensed band.

[0264] In addition, although the above embodiments show examples of operations in the unlicensed band, the frequency band of the unlicensed band may vary from country to country or region to region. The frequency band of the unlicensed band illustratively includes the 5 GHz band (5150 MHz-5925 MHz), the 6 GHz band (5925 MHz-7125 MHz), and 52.6 GHz to 71 GHz.

[0265] In addition, whether or not the above-mentioned embodiments or operation examples can be used may be changed according to SCS.

[0266] In addition, Type 1 LBT and Type 2 LBT may also be referred to by other names in sidelink communication.

[0267] The SCI format transmitted in the PSCCH may be SCI format 1-A or a newly added SCI format.

[0268] In addition, the above-mentioned embodiments can also be applied to S-PSS / SSS / PSBCH.

[0269] Furthermore, in each of the above-described embodiments, in the case of multicast or broadcast, the destination terminal may be a plurality of terminals.

[0270] In addition, the guard band may also be referred to as an "intra-cell guard band".

[0271] In addition, the allocation of resources for sidelink communication illustrated in the above embodiments is an example, and the present disclosure is not limited to these allocations. For example, the resources for sidelink communication may also include signals, channels, and non-transmission intervals that are not illustrated. In addition, the width of the signals in the time direction and frequency direction shown in each figure is not limited to the illustrated examples. In addition, the size of the time slot, the size of the resource, the size of the channel, the size of the signal, etc. are not limited to the above examples.

[0272] In addition, although the above-mentioned embodiments show an example in which the CP length of the sidelink signal is lengthened by CP extension to adjust the length of the sidelink signal, the present disclosure is not limited thereto. Instead of lengthening the CP length, the length may be adjusted by adding a known signal.

[0273] In addition, in the above-mentioned embodiments, confirmation of the channel idle state may be replaced by expressions such as sensing (or monitoring) the channel idle state. In addition, the "channel" in this case may be replaced by other terms such as "carrier" or "resource".

[0274] In addition, the method of notifying the terminal 200 of control information from the base station 100 is not limited to the above example, and may be notified (or broadcast, indicated, set) by at least one of system information such as MIB and SIB, RRC control information, MAC control information, and downlink control information (DCI: Downlink Control Information), or may be pre-set to the terminal 200 or pre-specified in the standard.

[0275] The base station may be referred to as a “gNodeB” or a “gNB.” In addition, the terminal may also be referred to as a “UE.”

[0276] The time resource unit of time slot can also be replaced by other units such as system frame, time slot, mini-time slot, frame, subframe, block, etc.

[0277] In addition, the expression "...part" in the above-mentioned embodiments may be replaced by other expressions such as "...circuitry", "...device", "...unit" or "...module".

[0278] It should be noted that terms such as "interpret", "determine", "judge", "determine", "decide", "calculate", "grasp", "recognize", "confirm" or "understand" can be used interchangeably.

[0279] (Replenish)

[0280] The information indicating whether the terminal 200 supports the functions, actions or processes shown in the above-mentioned embodiments may be sent (or notified) by the terminal 200 to the base station 100 as capability information or capability parameters of the terminal 200, for example.

[0281] The capability information may also include the following information elements (IE: Information Element), which individually indicate whether the terminal 200 supports at least one of the functions, actions, and processes shown in the above embodiments. Alternatively, the capability information may also include the following information elements, which indicate whether the terminal 200 supports a combination of two or more of the functions, actions, and processes shown in the above embodiments.

[0282] The base station 100 may, for example, determine (or determine or assume) a function, action or process supported (or not supported) by the terminal 200 that sends the capability information based on the capability information received from the terminal 200. The base station 100 may implement an action, process or control corresponding to the result of the determination based on the capability information. For example, the base station 100 may control the sidelink communication between the terminals 200 based on the capability information received from the terminal 200.

[0283] It should be noted that the terminal 200 does not support a part of the functions, actions or processes shown in the above embodiments, which may also be replaced by limiting such a part of the functions, actions or processes in the terminal 200. For example, information or requests related to such limitations may also be notified to the base station 100.

[0284] The information related to the capability or limitation of the terminal 200 may be defined in the standard, for example, or may be implicitly notified to the base station 100 by being associated with information known to the base station 100 or information transmitted to the base station 100 .

[0285] (Control signal)

[0286] In the present disclosure, a downlink control signal (or downlink control information) associated with an embodiment of the present disclosure may be, for example, a signal (or information) sent in a physical downlink control channel (PDCCH: Physical Downlink Control Channel) of the physical layer, or a signal (or information) sent in a medium access control control element (MAC CE: Medium Access Control Control Element) or a radio resource control (RRC: Radio Resource Control) of a higher layer. In addition, the signal (or information) is not limited to the case of being notified by a downlink control signal, and may be pre-defined in a specification (or standard), or may be pre-set in a base station and a terminal.

[0287] In the present disclosure, an uplink control signal (or uplink control information) associated with an embodiment of the present disclosure may be, for example, a signal (or information) sent in a PUCCH of a physical layer, or a signal (or information) sent in a MAC CE or RRC of a higher layer. In addition, the signal (or information) is not limited to the case where it is notified by an uplink control signal, and may be pre-defined in a specification (or standard), or may be pre-set in a base station and a terminal. In addition, the uplink control signal may be, for example, changed to uplink control information (UCI: uplink control information), first stage (1st stage) sidelink control information (SCI: sidelink control information), or second stage (2nd stage) SCI.

[0288] (Base Station)

[0289] In one embodiment of the present disclosure, the base station may also be a transceiver point (TRP: Transmission Reception Point), a cluster head, an access point, a remote radio head (RRH: Remote Radio Head), an eNodeB (eNB), a gNodeB (gNB), a base station (BS: Base Station), a base transceiver station (BTS: Base Transceiver Station), a mother machine, a gateway, etc. In addition, in the sidelink communication, the terminal may also assume the role of the base station. In addition, the base station may also be replaced by a relay device that relays the communication between the high-level node and the terminal. In addition, the base station may also be replaced by a roadside device.

[0290] (Uplink / Downlink / Sidelink)

[0291] An embodiment of the present disclosure may also be applied to any link in the uplink, downlink and sidelink. For example, an embodiment of the present disclosure may also be applied to the physical uplink shared channel (PUSCH: Physical Uplink Shared Channel), physical uplink control channel (PUCCH: Physical UplinkControl Channel), physical random access channel (PRACH: Physical Random Access Channel) of the uplink, physical downlink shared channel (PDSCH: Physical Downlink Shared Channel), PDCCH, physical broadcast channel (PBCH: Physical Broadcast Channel) of the downlink, or physical sidelink shared channel (PSSCH: Physical Sidelink Shared Channel), physical sidelink control channel (PSCCH: Physical Sidelink Control Channel), physical sidelink broadcast channel (PSBCH: Physical SidelinkBroadcast Channel) of the sidelink.

[0292] It should be noted that PDCCH, PDSCH, PUSCH and PUCCH are examples of downlink control channels, downlink data channels, uplink data channels and uplink control channels, respectively. In addition, PSCCH and PSSCH are examples of sidelink control channels and sidelink data channels. In addition, PBCH and PSBCH are examples of broadcast channels, and PRACH is an example of a random access channel.

[0293] (Data Channel / Control Channel)

[0294] An embodiment of the present disclosure may also be applied to any channel in a data channel and a control channel. For example, the channel in an embodiment of the present disclosure may also be changed to one of PDSCH, PUSCH, PSSCH of a data channel, or PDCCH, PUCCH, PBCH, PSCCH, PSBCH of a control channel.

[0295] (Reference signal)

[0296] In one embodiment of the present disclosure, the reference signal is, for example, a signal known to both the base station and the mobile station, and is sometimes referred to as a "Reference Signal (RS)" or a "pilot signal". The reference signal may also be any one of a demodulation reference signal (DMRS), a channel state information-reference signal (CSI-RS), a tracking reference signal (TRS), a phase tracking reference signal (PTRS), a cell-specific reference signal (CRS), and a sounding reference signal (SRS).

[0297] (Time interval)

[0298] In one embodiment of the present disclosure, the unit of time resources is not limited to one of a time slot and a symbol or a combination thereof, and may be, for example, a frame, a superframe, a subframe, a time slot, a time slot subslot, a minislot, or a symbol, an OFDM (Orthogonal Frequency Division Multiplexing) symbol, a single carrier-frequency division multiplexing (SC-FDMA) symbol, or other time resource units. In addition, the number of symbols contained in one time slot is not limited to the number of symbols exemplified in the above-mentioned embodiment, and may be other numbers of symbols.

[0299] (frequency band)

[0300] An embodiment of the present disclosure may be applied to any of a licensed band and an unlicensed band.

[0301] (communication)

[0302] An embodiment of the present disclosure may be applied to any communication between a base station and a terminal (Uu link communication), between terminals (sidelink communication), and in-vehicle wireless communication technology (V2X: Vehicle to Everything). For example, the channel in an embodiment of the present disclosure may be changed to one of PSCCH, PSSCH, physical sidelink feedback channel (PSFCH: Physical Sidelink Feedback Channel), PSBCH, PDCCH, PUCCH, PDSCH, PUSCH, and PBCH.

[0303] In addition, an embodiment of the present disclosure can be applied to any network in a terrestrial network and a non-terrestrial network (NTN: Non-Terrestrial Network) using a satellite or a high altitude pseudo satellite (HAPS: High Altitude Pseudo Satellite). In addition, an embodiment of the present disclosure can also be applied to a terrestrial network such as a network with a large cell size and an ultra-wideband transmission network where the transmission delay is greater than the symbol length or the time slot length.

[0304] (Antenna port)

[0305] In one embodiment of the present disclosure, an antenna port refers to a logical antenna (antenna group) composed of one or more physical antennas. For example, an antenna port does not necessarily refer to a physical antenna, but sometimes refers to an array antenna composed of multiple antennas. For example, it may be that the antenna port is not specified to be composed of several physical antennas, but is specified as the minimum unit that the terminal can send a reference signal (reference signal). In addition, an antenna port is sometimes also specified as the minimum unit multiplied by the weight of a precoding vector.

[0306] <5G NR system architecture and protocol stack>

[0307] 3GPP is continuing work to implement the next version of fifth generation mobile technology (also referred to simply as "5G"), including the development of new radio access technology (NR) operating in the frequency range up to 100 GHz. The first version of the 5G standard was completed in late 2017, which enabled the transition to trial production of terminals (e.g., smartphones) compliant with the 5G NR standard and commercial deployment.

[0308] For example, the system architecture as a whole envisions a NG-RAN (Next Generation Radio Access Network) including gNBs. The gNB provides the UE-side termination of the protocols of the user plane (SDAP (Service Data Adaptation Protocol) / PDCP (Packet Data Convergence Protocol) / RLC (Radio Link Control) / MAC / PHY (Physical Layer)) and control plane (RRC) of the NG radio access. The gNBs are connected to each other through an Xn interface. In addition, the gNB is connected to the NGC (Next Generation Core) through a Next Generation (NG) interface, more specifically, to the AMF (Access and Mobility Management Function) (e.g., a specific core entity that executes the AMF) through an NG-C interface, and in addition, to the UPF (User Plane Function) (e.g., a specific core entity that executes the UPF) through an NG-U interface. Fig.14 Represents the NG-RAN architecture (for example, refer to 3GPP TS 38.300v15.6.0, section 4).

[0309] The protocol stack of the user plane of NR (e.g., refer to 3GPP TS 38.300, Section 4.4.1) includes the PDCP (Packet Data Convergence Protocol (see Section 6.4 of TS 38.300)) sublayer, the RLC (Radio Link Control (see Section 6.3 of TS 38.300)) sublayer and the MAC (Media Access Control (see Section 6.2 of TS 38.300)) sublayer terminated on the network side in the gNB. In addition, a sublayer (SDAP: Service Data Adaptation Protocol) of the new access stratum (AS: Access Stratum) has been introduced on PDCP (e.g., refer to Section 6.5 of 3GPP TS 38.300). In addition, a protocol stack of the control plane is defined for NR (e.g., refer to TS 38.300, Section 4.4.2). An overview of the functions of Layer 2 is described in Section 6 of TS 38.300. The functions of the PDCP sublayer, RLC sublayer and MAC sublayer are listed in Sections 6.4, 6.3 and 6.2 of TS 38.300 respectively. The functions of the RRC layer are listed in Section 7 of TS 38.300.

[0310] For example, the media access control layer handles multiplexing of logical channels, and scheduling including processing of various parameter sets and various functions associated with the scheduling.

[0311] For example, the physical layer (PHY) is responsible for coding, PHY HARQ (Physical Layer Hybrid Automatic Repeat Request) processing, modulation, multi-antenna processing, and mapping signals to appropriate physical time-frequency resources. In addition, the physical layer handles the mapping of transport channels to physical channels. The physical layer provides services to the MAC layer in the form of transport channels. A physical channel corresponds to a set of time-frequency resources used to send a specific transport channel, and each transport channel is mapped to a corresponding physical channel. For example, in the physical channel, the uplink physical channels include PRACH (Physical Random Access Channel), PUSCH (Physical Uplink Shared Channel), PUCCH (Physical Uplink Control Channel), and the downlink physical channels include PDSCH (Physical Downlink Shared Channel), PDCCH (Physical Downlink Control Channel), and PBCH (Physical Broadcast Channel).

[0312] The use cases / extended scenarios of NR may include enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine type communications (mMTC), which have various requirements in terms of data rate, latency, and coverage. For example, eMBB is expected to support peak data rates (20 Gbps in the downlink and 10 Gbps in the uplink) and effective (user-experienced) data rates that are about 3 times the data rates provided by IMT-Advanced (International Mobile Telecommunications-Advanced). On the other hand, in the case of URLLC, more stringent requirements are proposed for ultra-low latency (the latency of the user plane is 0.5 ms in UL and DL, respectively) and high reliability (within 1 ms, 1-10-5). Finally, in mMTC, preferably, a high connection density is required (1,000,000 devices / km in an urban environment). 2 ), wide coverage in harsh environments and extremely long battery life (15 years) for a cheap device.

[0313] Therefore, sometimes the parameter set of OFDM that is suitable for one use case (for example, subcarrier spacing (SCS: SubCarrier Spacing), OFDM codeword length, cyclic prefix (CP: Cyclic Prefix) length, number of codewords per scheduling interval) is invalid for other use cases. For example, in low-latency services, it is preferred that the codeword length is shorter than that of mMTC services (therefore, the subcarrier spacing is larger) and / or the number of codewords per scheduling interval (also called "TTI (Transmission Time Interval)") is small. Moreover, in extended scenarios where the delay spread of the channel is large, it is preferred that the CP length is longer than that of scenarios where the delay spread is short. The subcarrier spacing can also be optimized according to the situation to maintain the same CP overhead. The value of the subcarrier spacing supported by NR can be more than one. Correspondingly, subcarrier spacings of 15kHz, 30kHz, 60kHz... are currently considered. The codeword length Tu and the subcarrier spacing Δf are directly related according to the formula Δf=1 / Tu. Similar to the LTE system, the term “resource element” can be used to represent the minimum resource unit composed of one subcarrier with a length of one OFDM / SC-FDMA (Single-Carrier Frequency Division Multiple Access) symbol.

[0314] In the new wireless system 5G-NR, for each parameter set and each carrier, a resource grid of subcarriers and OFDM symbols is defined in the uplink and downlink. Each element of the resource grid is called a "resource element", which is determined based on the frequency index in the frequency domain and the symbol position in the time domain (refer to 3GPP TS 38.211v15.6.0).

[0315] <Functional separation between NG-RAN and 5GC in 5G NR>

[0316] Fig.15 Indicates the functional separation between NG-RAN and 5GC. The logical node of NG-RAN is gNB or ng-eNB. 5GC has logical nodes AMF, UPF and SMF (Session Management Function).

[0317] For example, gNB and ng-eNB host the following main functions:

[0318] - Radio Bearer Control, Radio Admission Control, Connection Mobility Control, and Radio Resource Management functions such as dynamically allocating (scheduling) resources to UEs in both uplink and downlink;

[0319] -IP (Internet Protocol) header compression, encryption and integrity protection of data;

[0320] - Selection of the AMF when attaching the UE in case the routing towards the AMF cannot be decided based on the information provided by the UE;

[0321] - Routing of user plane data towards UPF;

[0322] - Routing of control plane information towards the AMF;

[0323] -Set up and disconnect connections;

[0324] - Scheduling and sending of paging messages;

[0325] - Scheduling and sending of system broadcast information (AMF or operation, admission, maintenance function (OAM) as the originator);

[0326] - Settings for measurements and measurement reports for mobility and scheduling;

[0327] - Packet marking of the transmission class in uplink;

[0328] -Session management;

[0329] - Network slicing support;

[0330] - Management of QoS (Quality of Service) flows and mapping to data radio bearers;

[0331] - Support of UE in RRC_INACTIVE state;

[0332] -NAS (Non Access Stratum) message distribution function;

[0333] -Sharing of wireless access networks;

[0334] -Dual connection;

[0335] -Close collaboration between NR and E-UTRA (Evolved Universal Terrestrial Radio Access).

[0336] The access and mobility management function (AMF) hosts the following main functions:

[0337] - Functionality to terminate non-access stratum (NAS) signaling;

[0338] -Security of NAS signaling;

[0339] - Security control of the access layer (AS);

[0340] -Core Network (CN) inter-node signaling for mobility between 3GPP access networks;

[0341] - the possibility of reaching the UE in idle mode (including the control and execution of paging retransmission);

[0342] - Management of the registration area;

[0343] -Support for intra-system and inter-system mobility;

[0344] -Access authentication;

[0345] - Access permission including roaming permission check;

[0346] -Mobility management control (subscription and policy);

[0347] - Network slicing support;

[0348] - Selection of Session Management Function (SMF).

[0349] In addition, the User Plane Function (UPF) hosts the following main functions:

[0350] - Anchor point for intra-RAT (Radio Access Technology) mobility / inter-RAT (Inter-RAT) mobility (where applicable);

[0351] - External PDU (Protocol Data Unit) session point for interconnection with data networks;

[0352] -Packet routing and forwarding;

[0353] -Policy rule enforcement for packet inspection and user plane;

[0354] - Business usage reporting;

[0355] - Uplink classifier for supporting routing of traffic towards data networks;

[0356] -BranchingPoint used to support multi-homed PDU session;

[0357] - QoS processing for the user plane (e.g., packet filtering, gating, UL / DL rate enforcement);

[0358] - Verification of uplink services (mapping of SDF (Service Data Flow) to QoS flows);

[0359] - Downlink packet buffering and downlink data notification triggering function.

[0360] Finally, the Session Management Function (SMF) hosts the following main functions:

[0361] -Session management;

[0362] -Allocation and management of UE IP addresses;

[0363] - UPF selection and control;

[0364] - Traffic steering configuration function in the user plane function (UPF) for directing traffic to the appropriate destination;

[0365] - Enforcement of policies and QoS in the control part;

[0366] -Notification of downlink data.

[0367] <RRC connection setup and re-setup process>

[0368] Fig.16 Represents several interactions between the UE, gNB and AMF (5GC entity) when the NAS part of the UE transitions from RRC_IDLE (RRC Idle) to RRC_CONNECTED (RRC Connected) (refer to TS 38.300v15.6.0).

[0369] RRC is a high-layer signaling (protocol) used for the configuration of UE and gNB. Through this transition, AMF prepares UE context data (which includes, for example, PDU session context, security keys, UE radio capabilities (UE Radio Capability), UE security capabilities (UE Security Capabilities), etc.), and sends it to gNB together with the initial context setup request (INITIAL CONTEXTSETUP REQUEST). Next, the gNB activates AS security together with the UE. The gNB sends a Security Mode Command (SecurityModeCommand) message to the UE, and the UE responds to the gNB with a Security Mode Complete (SecurityModeComplete) message to activate AS security. Then, the gNB sends an RRC Reconfiguration (RRCReconfiguration) message to the UE, and the gNB receives an RRC Reconfiguration Complete (RRCReconfigurationComplete) from the UE for the RRC Reconfiguration message, thereby reconfiguring the Signaling Radio Bearer 2 (SRB2) and the Data Radio Bearer (DRB). For signaling-only connections, since SRB2 and DRB are not configured, the steps related to RRC reconfiguration can be omitted. Finally, the gNB notifies the AMF of the completion of the setup process using the INITIAL CONTEXT SETUP RESPONSE.

[0370] Therefore, the present disclosure provides the following fifth generation core network (5GC) entity (e.g., AMF, SMF, etc.), which includes: a control circuit, which, when in action, establishes a next generation (Next Generation, NG) connection with a gNodeB (gNodeB); and a sending unit, which, when in action, sends an initial context setting message to the gNodeB via the NG connection to set a signaling radio bearer between the gNodeB and the user equipment (UE: User Equipment). Specifically, the gNodeB sends a radio resource control (RRC) signaling containing a resource allocation setting information element (IE: Information Element) to the UE via the signaling radio bearer. Then, the UE sends in the uplink or receives in the downlink based on the resource allocation setting.

[0371] <Application scenarios of IMT after 2020>

[0372] Fig.17Indicates several use cases for 5G NR. In the 3rd generation partnership project new radio (3GPP NR), three use cases supporting a wide range of services and applications conceived through IMT-2020 have been studied. The planning and development of the first phase of specifications for large-capacity high-speed communications (eMBB: enhanced mobile broadband) has been completed. In current and future work, in addition to gradually expanding support for eMBB, it also includes standardization for ultra-reliable and low-latency communications (URLLC: ultra-reliable and low-latency communications) and multiple simultaneous machine-type communications (mMTC: massive machine-type communications). Fig.17 Several examples of the conceptual use scenarios of IMT after 2020 are shown (for example, see ITU-R M.2083 Figure 2 ).

[0373] The use cases of URLLC have strict requirements related to performance such as throughput, latency (delay) and availability. The use cases of URLLC are conceived as an element technology for realizing future applications such as wireless control of industrial production processes or manufacturing processes, remote medical surgery, automation of power transmission and distribution in smart grids, and traffic safety. The ultra-high reliability of URLLC is supported by determining technologies that meet the requirements set by TR38.913. In version 15 of NR URLLC, as an important requirement, the target user plane latency is 0.5ms in UL (uplink) and 0.5ms in DL (downlink). The overall URLLC requirement for a packet transmission is that the block error rate (BLER) is 1E-5 for a packet size of 32 bytes when the user plane latency is 1ms.

[0374] Considering the physical layer, a number of possible approaches can be used to improve reliability. Current scope for improving reliability includes defining additional CQI (Channel Quality Indicator) tables for URLLC, more compact DCI formats, repetition of PDCCH, etc. However, as NR (an important prerequisite for NR URLLC) becomes more stable and further developed, the scope can be expanded to achieve ultra-high reliability. Specific use cases for NR URLLC in Release 15 include Augmented Reality / Virtual Reality (AR / VR), e-Health, e-Safety and critical applications.

[0375] In addition, the technical enhancements of the NR URLLC target are aimed at improving latency and increasing reliability. Technical enhancements for improving latency include configurable parameter sets, non-slot-based scheduling with flexible mapping, unauthorized (configured authorized) uplink, slot-level repetition in the data channel, and preemption in the downlink. Preemption means stopping the transmission of allocated resources and using the allocated resources for other transmissions that are requested later and must meet the necessary conditions of lower latency / higher priority. Therefore, the transmission that has been allowed will be replaced by the subsequent transmission. Preemption can be applied regardless of the specific service type. For example, the transmission of service type A (URLLC) can also be replaced by the transmission of service type B (eMBB, etc.). Technical enhancements related to reliability improvement include a dedicated CQI / MCS table for a target BLER of 1E-5.

[0376] The use case of mMTC (Massive Machine Type Communications) is characterized by the fact that typically there are a very large number of connected devices that send relatively small amounts of data that are not susceptible to latency. The devices are required to be low-priced and have very long battery life. From the NR point of view, utilizing very narrow bandwidth portions is one solution that can save power in the UE and extend its battery life.

[0377] As mentioned above, it is predicted that the room for reliability improvement in NR will be further expanded. It is one of the important requirements for all situations. For example, the important requirement related to URLLC and mMTC is high reliability or ultra-high reliability. From the wireless point of view and the network point of view, reliability can be improved in several mechanisms. In general, there are two to three important areas that may help improve reliability. These areas include compact control channel information, repetition of data channels / control channels, and diversity related to frequency domain, time domain and / or space domain. These areas can be used universally to improve reliability regardless of the specific communication scenario.

[0378] For NR URLLC, further use cases with stricter requirements are envisioned, such as factory automation, transportation, and power transmission. The strict requirements are high reliability (up to 10-6 reliability), high availability, packet size up to 256 bytes, time synchronization up to a few microseconds (μs) (the value can be set to 1μs or a few microseconds depending on the frequency range and short latency of around 0.5ms to 1ms (for example, 0.5ms latency in the user plane is set as the target) for the use case.

[0379] Moreover, regarding NR URLLC, from the perspective of the physical layer, there may be several technical enhancements. These technical enhancements include the enhancement of PDCCH (Physical Downlink Control Channel) related to compact DCI, repetition of PDCCH, and increased monitoring of PDCCH. In addition, the enhancement of UCI (Uplink Control Information) is related to the enhancement of enhanced HARQ (Hybrid Automatic Repeat Request) and CSI feedback. In addition, there may be enhancement of PUSCH related to frequency hopping at the mini-slot level and enhancement of retransmission / repetition. The term "mini-slot" refers to a transmission time interval (TTI) that contains fewer symbols than a slot (a slot has 14 symbols).

[0380] <QoS Control>

[0381] The 5G QoS (Quality of Service) model is based on QoS flows, supporting both QoS flows that require guaranteed bit rate (GBR: Guaranteed Bit Rate QoS flows) and QoS flows that do not require guaranteed bit rate (non-GBR QoS flows). Therefore, at the NAS level, QoS flows are the most fine-grained QoS divisions in a PDU session. QoS flows are determined within a PDU session based on the QoS flow ID (QFI: QoS Flow ID) transmitted by the encapsulation header via the NG-U interface.

[0382] For each UE, 5GC establishes one or more PDU sessions. For each UE, in conjunction with the PDU session, NG-RAN, for example, as described in the previous reference Fig.16 As described above, at least one data radio bearer (DRB) is established. In addition, the DRB added to the QoS flow of the PDU session can also be set later (when to set it depends on NG-RAN). NG-RAN maps packets belonging to various PDU sessions to various DRBs. NAS-level packet filters in UE and 5GC are used to associate UL packets and DL packets with QoS flows, and AS-level mapping rules in UE and NG-RAN associate UL QoS flows and DL QoS flows with DRBs.

[0383] Fig.18 Represents the non-roaming reference architecture of 5G NR (see TS23.501v16.1.0, section 4.23). Application Function (AF) (e.g., host Fig.17The 3GPP core network (an external application server for the 5G service illustrated) interacts with the 3GPP core network to provide services. For example, accessing the Network Exposure Function (NEF) to support applications that affect the routing of services, or interacting with the policy framework (refer to the Policy Control Function (PCF)) for policy control (for example, QoS control). Based on the operator's deployment, the operator considers that trusted application functions can interact directly with the associated network function (Network Function). Application functions that are not allowed by the operator to directly access network functions interact with associated network functions via NEF using an open framework to the outside.

[0384] Fig.18 It also represents further functional units of the 5G architecture, namely, Network Slice Selection Function (NSSF), Network Repository Function (NRF), Unified Data Management (UDM), Authentication Server Function (AUSF), Access and Mobility Management Function (AMF), Session Management Function (SMF) and Data Network (DN: Data Network, such as services provided by operators, Internet access or services provided by third parties). All or part of the core network functions and application services can also be deployed and operated in a cloud computing environment.

[0385] Therefore, the present disclosure provides the following application server (for example, AF of 5G architecture), which includes: a sending unit, which, in action, sends a request for QoS requirements for at least one of URLLC service, eMMB service and mMTC service to at least one of the functions of 5GC (for example, NEF, AMF, SMF, PCF, UPF, etc.) in order to establish a PDU session of a wireless bearer between a g-node B and a UE corresponding to the QoS requirements; and a control circuit, which, in action, uses the established PDU session to provide service.

[0386] The present disclosure can be implemented by software, hardware or software in cooperation with hardware. Each functional block used in the description of the above-mentioned embodiments is partially or entirely implemented as an LSI (Large Scale Integration) as an integrated circuit, and each process described in the above-mentioned embodiments may also be partially or entirely controlled by an LSI or a combination of LSIs. LSI may be composed of individual chips, or may be composed of one chip in a manner that includes part or all of the functional blocks. LSI may also include input and output of data. LSI may also be referred to as "IC (Integrated Circuit)", "System LSI", "Super LSI", "Ultra LSI" depending on the degree of integration.

[0387] The method of integrated circuitization is not limited to LSI, and can also be implemented by a dedicated circuit, a general-purpose processor or a dedicated processor. In addition, an FPGA (Field Programmable Gate Array) that can be programmed after LSI manufacturing, or a reconfigurable processor (Reconfigurable Processor) that can reconfigure the connection or setting of the circuit block inside the LSI can also be used. The present disclosure can also be implemented as digital processing or analog processing.

[0388] Furthermore, if integrated circuit technology that replaces LSI emerges as semiconductor technology advances or other technologies are derived, it is of course possible to use this technology to achieve integration of functional blocks. There is also the possibility of applying biotechnology, etc.

[0389] The present disclosure can be implemented in all kinds of devices, equipment, and systems (collectively referred to as "communication devices") with communication functions. The communication device may also include a wireless transceiver and a processing / control circuit. The wireless transceiver may also include a receiving unit and a transmitting unit, or perform the functions of these parts. The wireless transceiver (transmitting unit, receiving unit) may also include an RF (Radio Frequency) module and one or more antennas. The RF module may also include an amplifier, an RF modulator / demodulator, or a device similar to these. Non-limiting examples of communication devices include: phones (mobile phones, smart phones, etc.), tablets, personal computers (PCs) (laptops, desktops, notebook computers, etc.), cameras (digital cameras, digital video cameras, etc.), digital players (digital audio / video players, etc.), wearable devices (wearable cameras, smart watches, tracking devices, etc.), game consoles, e-book readers, telehealth / telemedicine (telehealth / medical prescription) equipment, vehicles or transportation vehicles with communication functions (cars, airplanes, ships, etc.), and combinations of the above-mentioned various devices.

[0390] Communication devices are not limited to portable or mobile devices, but also include all kinds of devices, equipment, and systems that cannot be carried or fixed. For example, they include: smart home devices (home appliances, lighting equipment, smart meters or meters, control panels, etc.), vending machines, and all other "things" that can exist on the IoT (Internet of Things) network.

[0391] The communication includes data communication performed by a cellular system, a wireless LAN (Local Area Network) system, a communication satellite system, etc., and also includes data communication performed by a combination of these systems.

[0392] In addition, the communication device also includes devices such as controllers or sensors connected or linked to the communication device that performs the communication function described in the present invention. For example, it includes a controller or sensor that generates a control signal or data signal used by the communication device that performs the communication function of the communication device.

[0393] In addition, the communication device includes infrastructure equipment that communicates with the above-mentioned non-limiting various devices or controls the above-mentioned various devices, such as base stations, access points, and all other devices, equipment, and systems.

[0394] A communication device of one embodiment of the present disclosure includes: a control circuit, which, when a plurality of continuous time resources are allocated in terminal-to-terminal communication in an unlicensed frequency band, allocates a signal to the following protection interval, wherein the protection interval is a protection interval set for the nth time resource among the nth time resource and the n+1th time resource contained in the plurality of time resources; and a sending circuit, which sends the signal in the plurality of time resources.

[0395] In one embodiment of the present disclosure, when the signal is allocated to all resource blocks in a resource block set used to transmit the signal, the control circuit allocates the signal to the guard interval.

[0396] In one embodiment of the present disclosure, when the signal is allocated to resource blocks greater than a threshold in a resource block set used to transmit the signal, the control circuit allocates the signal to the guard interval.

[0397] In one embodiment of the present disclosure, when the signal is allocated to the same frequency resource in each of the plurality of time resources, the control circuit allocates the signal to the guard interval.

[0398] In one embodiment of the present disclosure, the multiple time resources are set within a channel occupation time, and the control circuit sets the protection interval in at least a last time resource in the channel occupation time among the multiple time resources.

[0399] In one embodiment of the present disclosure, when multiple continuous time resources are allocated in terminal-to-terminal communication in an unlicensed frequency band, a signal is allocated to the following protection interval, which is a protection interval set to the nth time resource among the nth time resource and the n+1th time resource contained in the multiple time resources; and the signal is sent in the multiple time resources.

[0400] The disclosed contents of the specification, drawings, and abstract contained in the Japanese patent application No. 2022-127362 filed on August 9, 2022 are incorporated herein by reference in their entirety.

[0401] Industrial Applicability

[0402] One aspect of the present disclosure is useful for a wireless communication system.

[0403] Description of Reference Numerals

[0404] 100 base stations

[0405] 200, 200a terminal

[0406] 201 Receiving Department

[0407] 202 LBT Carrier Monitoring Unit

[0408] 203 Signal separation unit

[0409] 204 Demodulation Unit

[0410] 205 Error Correction Decoding Unit

[0411] 206 control signal receiving unit

[0412] 207 LBT failure notification receiving unit

[0413] 208 Error Correction Coding Unit

[0414] 209 Modulation Department

[0415] 210 Control signal generating unit

[0416] 211 LBT failure notification generation unit

[0417] 212 Signal Distribution Department

[0418] 213 Sending Department

[0419] 220 Protection period setting unit

Claims

1. A communication device, characterized in that: include: A control circuit, when a plurality of continuous time resources are allocated in inter-terminal communication in an unlicensed frequency band, allocates a signal to a protection interval set to a protection interval of the nth time resource among an nth time resource and an n+1th time resource included in the plurality of time resources; as well as The sending circuit sends the signal in the multiple time resources.

2. The communication device according to claim 1, wherein: When the signal is allocated to all resource blocks in a resource block set used to transmit the signal, the control circuit allocates the signal to the guard interval.

3. The communication device according to claim 1, wherein: When the signal is allocated to resource blocks equal to or larger than a threshold in a resource block set used to transmit the signal, the control circuit allocates the signal to the guard interval.

4. The communication device according to claim 1, wherein: When the signal is allocated to the same frequency resource in each of the plurality of time resources, the control circuit allocates the signal to the guard interval.

5. The communication device according to claim 1, wherein: The plurality of time resources are set within a channel occupation time, and the control circuit sets the guard interval in at least a last time resource in the channel occupation time among the plurality of time resources.

6. A communication method, characterized in that: The communication device performs the following processing: When a plurality of continuous time resources are allocated in inter-terminal communication in an unlicensed frequency band, a signal is allocated to a protection interval set to a protection interval of the nth time resource among an nth time resource and an n+1th time resource included in the plurality of time resources; as well as The signal is sent in the multiple time resources.

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