Communication devices, communication methods, and integrated circuits

Abstract

This communication device comprises: a control circuit that allocates a signal to a resource allocation unit constituted by an interlace of consecutive numbers in a terminal communication in an unlicensed band; and a transmission circuit that transmits the signal.

Description

Communication device and communication method

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

[0002] The expansion of communication systems known as 5th Generation mobile communication systems (5G) is currently being considered. 5G is being considered to provide flexible functions for each use case that requires increased communication traffic, an increased number of connected devices, high reliability, and low latency.

[0003] 3GPP, TR 38.885 V16.0.0, “Study on NR Vehicle-to-Everything (V2X)”RP-201385, “WID revision: NR sidelink enhancement,” LG Electronics, June 29 - July 3, 2020RP-213678, “New WID on NR sidelink evolution,” OPPO, LG Electronics, Dec. 6 - 17, 20213GPP, TS 38.331 V17.1.0, “NR; Radio Resource Control (RRC) protocol specification (Release 17)”

[0004] However, there is room for further consideration regarding the effective use of communication resources in unlicensed bands.

[0005] Non-limiting embodiments of the present disclosure contribute to providing a communication device and a communication method that can improve the utilization efficiency of communication resources in unlicensed bands.

[0006] A communication device according to one embodiment of the present disclosure includes a control circuit that allocates signals to resource allocation units consisting of consecutively numbered interlaces in terminal-to-terminal communication in an unlicensed band, and a transmission circuit that transmits the signals.

[0007] These comprehensive or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

[0008] According to one embodiment of the present disclosure, it is possible to improve the utilization efficiency of communication resources in unlicensed bands.

[0009] Further advantages and benefits of certain aspects of the present disclosure will become apparent from the specification and drawings. Such advantages and / or benefits may be provided by some of the embodiments and features described in the specification and drawings, respectively, but not necessarily all of them may be provided to obtain one or more identical features.

[0010] 1. Diagram showing an example of channel allocation within a slot. 2. Diagram showing an example of channel allocation within a slot when a channel is busy. 3. Diagram showing an example of specifications regarding the frequency of signals in an unlicensed band. 4. Diagram showing an example of interlace allocation. 5. Block diagram showing an example of the configuration of a part of a base station. 6. Block diagram showing an example of the configuration of a part of a terminal. 7. Diagram showing an example of the allocation of PSCCH (physical sidelink control channel). 8. Diagram showing an example of the allocation of PSCCH. 9. Diagram showing an example of the allocation of VRB (Virtual Resource Block) and PRB (Physical Resource Block). 10. Block diagram showing an example of the configuration of a terminal. 11. Diagram showing an example of channel allocation within a slot. 12. Diagram showing an example of channel allocation within a slot. 13. Diagram showing an example of channel allocation within a slot. 14. Diagram showing an example of parameter setting related to PSFCH (physical sidelink feedback channel). 15. Diagram of an exemplary architecture of a 3GPP NR system. 16. Schematic diagram showing functional separation between NG-RAN and 5GC. 17. Sequence diagram of the procedure for setting up / resetting an RRC (Radio Resource Control) connection. Schematic diagram illustrating the use scenarios of 5G (Ultra Reliable and Low Latency Communications) and URLLC (Ultra Reliable and Low Latency Communications)

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0012] The 3GPP (3rd Generation Partnership Project), an international standardization organization, is studying the advancement of communication systems from both the perspective of the Long Term Evolution (LTE) system and New Radio (NR). 3GPP has first considered supporting V2X (vehicle to X) in the LTE system. NR, which can use a wider bandwidth than LTE, has also considered supporting V2X (see, for example, Non-Patent Document 1).

[0013] In addition to V2X, further expansion of communication using sidelink (SL) is being considered (see, for example, Non-Patent Document 2). V2X is expected to cover vehicle-to-vehicle (V2V: Vehicle to Vehicle), vehicle-to-infrastructure (V2I: Vehicle to Infrastructure), vehicle-to-pedestrian (V2P: Vehicle to Pedestrian), and vehicle-to-network (V2N: Vehicle to Network) communications.

[0014] In V2V, V2I, and V2P, signals can be transmitted and received directly between terminals using a link called a sidelink or PC5, without going through a network with a base station (for example, a network via a base station). In V2N, communication is assumed to occur via a link called Uu between a base station and a terminal. Note that a base station may be referred to as a gNB in ​​NR or an eNB in ​​LTE. Furthermore, a terminal may be referred to as a UE (User Equipment).

[0015] In addition, the use of sidelink communication in unlicensed bands is also being considered (see, for example, Non-Patent Document 3).

[0016] [NR Sidelink] NR sidelink supports unicast, groupcast, and broadcast transmission / reception. Unicast assumes one-to-one transmission from a transmitting terminal (also called Tx UE, source UE, or source terminal) to a receiving terminal (Rx UE, destination UE, or destination terminal). Groupcast assumes transmission from a transmitting terminal to one or more receiving terminals included in a certain group. Broadcast assumes transmission from a transmitting terminal without specifying a receiving terminal.

[0017] In the NR sidelink, a control signal called SCI (sidelink control information) is transmitted and received. The SCI is divided into a first-stage SCI and a second-stage SCI. The first-stage SCI is allocated to a PSCCH (physical SL control channel). The second-stage SCI is allocated to at least a portion of a PSSCH (physical SL shared channel) that transmits and receives data. Dividing the SCI into two parts can reduce the number of bits and size of the first-stage SCI. In the sidelink, a certain terminal (e.g., terminal A) has a function of receiving a PSCCH transmitted from another terminal other than terminal A, understanding the resource usage status of the other terminal, and then determining the resources that terminal A will use for transmission. This function is also called "sensing."

[0018] In the sidelink, signals are transmitted and received on the following channels: -PSCCH (physical SL control channel): 1st-stage SCI (Sidelink control information) is allocated in the PSCCH. -PSSCH (physical SL shared channel): Data signals and 2nd-stage SCI are allocated in the PSSCH. -PSFCH (physical SL feedback channel): Feedback signals for the PSSCH are allocated in the PSFCH. The feedback signals indicate, for example, an acknowledgement (ACK) indicating successful reception of the PSSCH or a negative acknowledgement (NACK) indicating unsuccessful reception of the PSSCH. The feedback signals can be applied when the PSSCH is unicast or groupcast. In addition, in Release 17 (Rel. 17) and later, the PSFCH may be transmitted as inter-UE coordination when a collision is detected. -PSBCH (physical SL broadcast channel): Broadcast signals are allocated in the PSBCH. The SBCH is transmitted together with a synchronization signal. The synchronization signal may be, for example, a sidelink primary synchronization signal (S-PSS) and / or a sidelink secondarily synchronization signal (S-SSS). The SBCH transmitted together with the synchronization signal is also referred to as a sidelink synchronization signal block (S-SSB).

[0019] Note that a signal transmitted and received in the sidelink may be referred to as a "sidelink signal." Also, for example, "transmission of information (or a signal) allocated to the PSCCH" may be abbreviated as "transmission of the PSCCH" hereinafter. Also, in the following description, the PSCCH may refer to a resource defined as the PSCCH, or may refer to information (or a signal) allocated to the resource defined as the PSCCH. Channels other than the PSCCH may also be abbreviated as the PSCCH.

[0020] Figure 1 shows an example of the arrangement of PSCCH, PSSCH, and PSFCH in a slot. The horizontal axis of Figure 1 represents the time axis, and the vertical axis represents the frequency axis in units of PRB (physical resource block). Figure 1 shows two examples, Figure 1(a) and Figure 1(b).

[0021] Note that the PSFCH may be arranged as shown in Figure 1(a). Alternatively, as shown in Figure 1(b), the PSFCH may not be arranged depending on the setting. If the PSFCH is not arranged, the PSSCH area may be increased.

[0022] The number of symbols of the sidelink signal in a slot may be variable depending on the setting. Furthermore, the arrangement of the 2nd-stage SCI may be changed depending on the arrangement of the PSSCH DMRS (demodulation reference signal), not shown. The 1st-stage SCI is arranged starting from the lowest frequency resource among the frequency resources to which the PSSCH is allocated. A copy of the first symbol of the PSCCH and PSSCH is arranged in the symbol before the first symbol of the PSCCH and PSSCH for AGC (Auto Gain Control). Furthermore, as shown in FIG. 1(a), a copy of the PSFCH is also arranged before the PSFCH symbol for AGC.

[0023] In addition, in FIG. 1(a), guard intervals (for example, guard periods or gaps) for switching between transmission and reception are arranged in the interval between the PSSCH and the PSFCH and in the interval after the last symbol of the PSFCH. In FIG. 1(b), a guard period for switching between transmission and reception is arranged in the interval after the last symbol of the PSSCH. The guard period may correspond to an interval in which no signals are transmitted or received.

[0024] NR sidelink communication has two modes, Mode 1 and Mode 2. In Mode 1, the base station determines (schedules) the resources to be used by the terminal on the sidelink and notifies the terminal of the scheduling result. In Mode 2, the terminal determines (or selects) the resources to be used on the sidelink from resources in a predetermined resource pool. Mode 1 is a state in which the base station and the terminal are connected, and is intended to be used in an environment in which the terminal communicating on the sidelink can receive instructions from the base station. In Mode 2, the terminal can transmit on the sidelink without instructions from the base station, so sidelink communication is possible with terminals under the control of different operators and / or terminals outside the base station's coverage.

[0025] The resources used for the sidelink are set, for example, by the SL BWP (Bandwidth part) and a resource pool.

[0026] The SL BWP specifies a frequency band that can be used for the sidelink and is set separately from the downlink BWP (DL BWP) and uplink BWP (UL BWP) set between the base station and the terminal (Uu). For example, the frequency band of the SL BWP may overlap with the UL BWP.

[0027] A resource pool is a resource within an SL BWP, and resources in the frequency direction and time direction are specified by the resource pool. For example, multiple resource pools may be configured for one terminal. The frequency resources within the resource pool are divided into units called "subchannels," and resource allocation can be configured for each subchannel. A subchannel includes multiple PRBs, and PSSCH allocation can be performed for each subchannel that groups together PRBs.

[0028] [NR-U (NR-Unlicensed)] With the increasing capacity of communications, 3GPP is also considering the use of unlicensed bands in addition to licensed bands. NR that utilizes unlicensed bands is also called NR-U (unlicensed). NR-U adds and enhances operations to maintain fairness when coexisting with other devices, such as Wi-Fi (registered trademark) and / or LTE-based Licensed Assisted Access (LAA).

[0029] In unlicensed bands, a communication device (e.g., an NR-U base station or terminal) performs LBT (Listen Before Talk) to maintain fairness with other devices, and starts transmission only after confirming that no other devices are transmitting signals nearby. LBT may be replaced with other terms such as carrier sense or sensing. After performing LBT and confirming that no other devices are transmitting signals nearby, a channel occupancy time (COT) is set for the communication device. Within the COT, the communication device can transmit and receive signals in downlink (DL) resources and uplink (UL) resources.

[0030] There are two operation methods for LBT. The first operation method is LBE (Load Based Equipment). In LBE, when a communication device acquires a COT, it performs Type 1 channel access (e.g., category 4 LBT or Type 1 LBT). In addition, except at the beginning of the COT, the communication device can perform Type 2 channel access (e.g., Type 2 LBT) and start transmission after performing this.

[0031] In the following description, when a communication device (e.g., a base station or a terminal) "starts transmission after performing LBT," this corresponds to the communication device starting transmission after performing LBT and confirming that no other devices are transmitting signals nearby.

[0032] Table 1 shows an example of the sensing interval of LBT for acquiring the transmission right in DL in LBE and the interval to be applied.

[0033] In Type 2A, if the interval between two consecutive resources is 25 μs, the terminal performs LBT within 25 μs. If the terminal does not confirm transmissions from other devices in the LBT, it can start transmission.

[0034] In Type 2B, if the interval between two consecutive resources is 16 μs, the terminal performs LBT within 16 μs. If the terminal does not confirm transmissions from other devices, it can start transmission.

[0035] In Type 2C, if the interval between two consecutive resources is less than 16 μs, the terminal can start transmission without LBT. As an exception, when transmitting a discovery reference signal (DRS), the terminal can start transmission by implementing Type 2A LBT instead of Type 1 LBT because the transmission time of the DRS is short.

[0036] The second operating method is FBE (Frame Based Equipment). FBE assumes that other devices such as Wi-Fi are not installed in the same space, and operates by fixing the frame period and performing LBT at the beginning of the frame to obtain the COT. In FBE, the COT can only be obtained from the beginning of the frame interval (Fixed Frame Period). FBE also stipulates that an idle period of 5% or more must be set for each frame interval.

[0037] The above is an explanation of NR-U.

[0038] In the following embodiments, an example of performing sidelink communication in an unlicensed band will be described. Sidelink communication utilizing an unlicensed band is also called SL-U (Sidelink unlicensed).

[0039] In unlicensed bands, a terminal performs LBT and starts transmission if it does not confirm transmissions from other devices. On the other hand, in unlicensed bands, a terminal performs LBT, detects signals from other devices, and does not start transmission if it confirms transmissions from other devices. The detection of signals from other devices is also called "busy (or channel busy)," "unavailable," or "LBT failure."

[0040] In the case of an LBT failure, even in the sidelink, the terminal cannot acquire the transmission right for the allocated resource or the selected resource and cannot start transmission.

[0041] FIG. 2 is a diagram showing an example of channel allocation within each slot in the case of an LBT failure.

[0042] For example, Figure 2(a) shows an example in which another device starts transmission in a slot before the slot in which the terminal is scheduled to transmit (a slot for which resources are reserved). Also, Figure 2(b) shows an example in which another device starts transmission in a symbol immediately before the slot in which the terminal is scheduled to transmit. As shown in Figures 2(a) and 2(b), the terminal performs LBT before the slot in which the terminal is scheduled to transmit, resulting in an LBT failure and thus unable to start transmitting a sidelink signal. For example, as shown in Figure 2(b), even if the terminal uses consecutive slots and attempts to transmit by performing LBT Type 2 in a COT, another device may still be able to acquire the transmission right.

[0043] Additionally, in unlicensed bands, ETSI (ETSI EN 301 893 V2.1.1 (2017-05)) stipulates that the Occupied Channel Bandwidth (OCB) must be 80% to 100% of the Nominal Channel Bandwidth (NCB). The requirement that the OCB must be 80% or more of the NCB is hereinafter referred to as the OCB requirement. When this OCB requirement is met, unlicensed band signals are transmitted using frequencies that are 80% or more of the NCB frequency band.

[0044] In the following description, the OCB requirement is that the OCB must satisfy 80% or more of the NCB, but the present disclosure is not limited to this. The OCB requirement that the OCB must satisfy 80% or more of the NCB is an example of a bandwidth restriction related to a frequency band.

[0045] Figure 3 shows an example of regulations regarding the frequencies of signals in unlicensed bands. "OCB 80%" in Figure 3 indicates that OCB occupies 80% or more of the frequency band of NCB. Note that in the following figures, "OCB 80%" also indicates that OCB occupies 80% or more of the frequency band of NCB.

[0046] The signal of the unlicensed band may be transmitted continuously using 80% or more of the frequency band of the NCB, as shown in Figure 3(a), or may be arranged so that the width at both ends of the frequency axis of the divided multiple resources is 80% or more of the frequency band of the NCB, as shown in Figure 3(b).

[0047] In NR-U and LAA, interlaced allocation is introduced to satisfy the OCB requirements in the frequency domain. In NR-U interlaced allocation, the NCB is set to a 20 MHz RB set (Resource Block set). Note that the NCB setting is not limited to 20 MHz.

[0048] Table 2 shows an example of the relationship between SCS (subcarrier spacing) and interlaces. FIG. 4 shows an example of interlace allocation. In Table 3, M indicates the number of interlaces, and N indicates the number of PRBs (Physical Resource Blocks) that make up one interlace. FIG. 4 shows an example of interlace allocation when the SCS is 30 kHz. In NR-U interlace allocation, as shown in Table 2 and FIG. 4, for example, when the SCS is 30 kHz, a 20 MHz band is divided into five (M=5) interlaces (interlaces #0 to #4), and one interlace is composed of 10 or 11 PRBs (N PRBs).

[0049] It is expected that interlace allocation will also be applied to sidelink communication in unlicensed bands. In sidelink communication in unlicensed bands, there is room for further study on the method of setting subchannels, which are units for allocating PSSCH, and interlace mapping.

[0050] In one non-limiting embodiment of the present disclosure, a method for configuring subchannel and interlace mapping in sidelink communication in an unlicensed band is described.

[0051] Although the embodiments described below exemplify sidelink communication, the present disclosure is not limited to sidelink communication. Furthermore, although the embodiments described below exemplify unlicensed bands, the present disclosure is not limited to unlicensed bands.

[0052] [Overview of Communication System] A communication system according to an embodiment of the present disclosure includes a base station 100 and a terminal 200.

[0053] Fig. 5 is a block diagram showing an example of the configuration of a portion of the base station 100. In the base station 100 shown in Fig. 5, a control unit controls communication between the terminal 200 and the base station 100 via a link called Uu. The communication unit transmits a signal via the link called Uu under the control of the control unit. The control unit may also perform control related to sidelink communication between multiple terminals (e.g., determining resources in Mode 1).

[0054] FIG. 6 is a block diagram showing a partial configuration example of terminal 200 (e.g., corresponding to a communication device). In terminal 200 shown in FIG. 6, a control unit (e.g., corresponding to a control circuit) allocates signals to resource allocation units (e.g., subchannels) consisting of consecutively numbered interlaces in terminal-to-terminal communication in an unlicensed band, and a communication unit (e.g., corresponding to a transmission circuit) transmits the signals. In addition, in terminal 200, a communication unit (e.g., corresponding to a reception circuit) receives signals allocated in resource allocation units (e.g., subchannels) consisting of consecutively numbered interlaces in terminal-to-terminal communication in an unlicensed band, and a control unit (e.g., corresponding to a control circuit) demodulates the signals. Note that the transmission signals may be, for example, sidelink signals or may be signals different from sidelink signals.

[0055] (Embodiment 1) In this embodiment, in sidelink communication of an unlicensed band, a subchannel, which is a resource allocation unit of a PSSCH, is configured from interlaces with consecutive interlace numbers (for example, interlaces adjacent in the frequency domain).

[0056] For example, when multiple terminals transmit using frequency division multiplexing (FDM), there is a possibility of radio wave leakage from transmissions of other terminals multiplexed within a band called in-band emission (IBE). According to this embodiment, by configuring subchannels using interlaces with consecutive interlace numbers, PSSCHs are allocated to interlaces that are consecutive in the frequency domain among multiple interlaces. This reduces the overlap between resources allocated to terminal 200 and resources allocated to other terminals, and reduces the effects of IBE (or the effects of interference with other terminals).

[0057] An example of operation according to this embodiment will be described below.

[0058] [Operation Example 1] In operation example 1, the interlaces (for example, interlace numbers) that make up each subchannel are set in the resource pool configuration.

[0059] Table 3 shows example settings of interlaces that make up subchannels. The example in Table 3 shows example settings of subchannels when the SCS is 15 kHz, 30 kHz, and 60 kHz. Table 3 also shows example settings of subchannels when the number of subchannels per RB set (e.g., 20 MHz) is 1, 2, 3, 4, 5, and 10. Note that the SCS and number of subchannels are not limited to the examples shown in Table 3.

[0060] For example, when SCS=15 kHz and 30 kHz, the interlaces may be set in the same way as those used in NR-U. For example, when SCS=15 kHz, 10 interlaces (e.g., interlaces #0 to #9) may be set in an RB set, and when SCS=30 kHz, 5 interlaces (e.g., interlaces #0 to #4) may be set in an RB set. Note that for SCS=60 kHz, there is no setting in NR-U, but for example, 3 interlaces (e.g., interlaces #0 to #2) may be set in an RB set.

[0061] For example, when there is one subchannel for a 20 MHz RB set (1 subchannel / 20 MHz), one subchannel is configured by all interlaces in each SCS.

[0062] Furthermore, for example, in a case where there are two subchannels for a 20 MHz RB set (2 subchannels / 20 MHz), with SCS=15 kHz, the 10 interlaces are divided into two, and one subchannel is formed by five interlaces with consecutive interlace numbers (e.g., interlaces #0 to #4 and interlaces #5 to #9). Furthermore, with SCS=30 kHz, since the number of interlaces cannot be evenly distributed (divided equally) to each subchannel, for example, the five interlaces may be divided into two, with consecutive interlace numbers, three (e.g., interlaces #0 to #2) and two (e.g., interlaces #3 and #4), and one subchannel may be formed by each of the divided interlaces. Similarly, with SCS=60 kHz, the three interlaces may be divided into two, with consecutive interlace numbers (e.g., interlaces #0 and #1) and one (e.g., interlace #2), and one subchannel may be formed by each of the divided interlaces.

[0063] Similarly, for example, in a 20 MHz RB set with three subchannels (3 subchannels / 20 MHz), since the number of interlaces cannot be evenly distributed to each subchannel with SCS=15 kHz, the 10 interlaces may be divided into three groups with consecutive interlace numbers: four (e.g., interlaces #0 to #3), three (e.g., interlaces #4 to #6), and three (e.g., interlaces #7 to #9), and one subchannel may be configured with each of the divided interlaces. Similarly, with SCS=30 kHz, since the number of interlaces cannot be evenly distributed to each subchannel, the five interlaces may be divided into three groups with consecutive interlace numbers: two (e.g., interlaces #0 and #1), two (e.g., interlaces #2 and #3), and one (e.g., interlace #4), and one subchannel may be configured with each of the divided interlaces. Furthermore, when SCS=60 kHz, three interlaces are divided into three, and one interlace constitutes one subchannel.

[0064] In Table 3, even when the number of subchannels included in the 20 MHz RB set is other than 4, 5, or 10, interlaces with consecutive interlace numbers are set for each subchannel.

[0065] For example, if the number of interlaces in an RB set is M and the number of subchannels set in a resource pool is C, the number of interlaces constituting each subchannel is M / C if it can be equally divided, and floor(M / C) or floor(M / C) + 1 if it cannot be equally divided. Here, Floor() is a function (floor function) that rounds down to the nearest integer.

[0066] In this way, by making it possible to variably set the sub-channel size (or the number of sub-channels) in a resource pool, it becomes possible to set a sub-channel size suitable for the purpose of each resource pool.

[0067] For example, when a larger amount of small data (e.g., data with a data volume less than a threshold value) is transmitted, such as when notifying sensing information, the sub-channel size may be set to a smaller size, and when a larger amount of data (e.g., data with a data volume greater than or equal to a threshold value) is transmitted, such as when transmitting large amounts of video, the sub-channel size may be set to a larger size.

[0068] The number of subchannels corresponds to the number of times that terminal 200 performing sidelink communication detects the PSCCH in a single period of time. For example, the fewer the number of subchannels, the more likely it is that terminal 200 will detect the PSCCH (e.g., the number of blind decoding (BD)).

[0069] Furthermore, the number of interlaces constituting each of the multiple subchannels included in an RB set may be different, as shown in Table 3. For example, when the number of 30 kHz subchannels is three, the number of interlaces may be two or one depending on the subchannel. This allows PSCCH / PSSCH allocation even if the interlace number and the subchannel number are not in a multiple relationship.

[0070] [Operation Example 2] In the unlicensed band, it is assumed that an intra-cell guard band is configured for each 20 MHz RB set (for example, at the boundary of the RB set). Whether or not to configure the intra-cell guard band may be notified to terminal 200 by higher layer signaling called (pre-)configured for each resource pool or for each terminal, or may be determined in advance by configuration.

[0071] When an intra-cell guard band is set, terminal 200 can confirm that a channel is not being used by LBT for a certain 20 MHz bandwidth, and even if it confirms that a channel is being used by LBT in an RB set 20 MHz bandwidth adjacent to that 20 MHz bandwidth, it can start transmission in the 20 MHz bandwidth where the channel is not being used.

[0072] For example, a case where the SL BWP is 100 MHz will be described. For example, when an intra-cell guard band is set, terminal 200 performs LBT for each 20 MHz RB set, and can start transmission in a channel where it has been confirmed by LBT that the channel is not in use. On the other hand, when an intra-cell guard band is not set, terminal 200 can start transmission in all RB sets within the SL BWP where it has been confirmed by LBT that the channel is not in use.

[0073] For example, when an intra-cell guard band is configured and consecutive RB sets (or adjacent RB sets) are assigned to terminal 200, terminal 200 may be able to transmit the PSSCH even in a PRB that forms the intra-cell guard band. For example, when LBT is OK in two adjacent RB sets, terminal 200 may transmit the PSSCH in the intra-cell guard band between the two RB sets.

[0074] In addition, when terminal 200 uses consecutive RB sets that are allocated, whether or not to allocate PSSCH to the intra-cell guard band between the RB sets may be (re-)configured for each resource pool or may be indicated by PSCCH.

[0075] Furthermore, for example, terminal 200 identifies the number of RB sets to be allocated by a signal in the PSCCH. Therefore, before receiving the PSCCH, terminal 200 does not know whether adjacent RB sets are allocated. Therefore, for example, the PSCCH does not need to be allocated in the intra-cell guard band.

[0076] There is also a guard band called an inter-cell guard band, which is placed at the edge of the SL-BWP or resource pool. PSCCH and PSSCH do not need to be placed in the inter-cell guard band. This can reduce the impact of out-of-band radiation on other cells.

[0077] [Operation Example 3] In Operation Example 3, an example of arrangement of PSCCH and / or PSSCH (hereinafter also referred to as "PSCCH / PSSCH") when interlace mapping is set for PSCCH and / or PSSCH will be described.

[0078] When the PSCCH is assigned to some of the PRBs constituting the subchannel assigned to the PSSCH, terminal 200 may assign the PSSCH to a PRB among the PRBs in the same symbol that is different from the PRB to which the PSCCH is assigned. In this case, the transmission power per PRB may be set to be the same for the PSCCH and the PSSCH in the multiple PRBs constituting the subchannel. This eliminates the difference in transmission power between symbols and eliminates the need for a time period called a tangent period for power adjustment between symbols.

[0079] Furthermore, the size of the PSSCH may be pre-configured for each resource pool, and may be specified by, for example, the number of PRBs or the interlace number.

[0080] An example of setting the PSSCH and PSCCH will be described below.

[0081] <Configuration Example 3A> In configuration example 3A, the size of the PSSCH is (pre-)configured for each resource pool. For example, the size of the PSSCH may be set to be selectable from 10, 12, 15, and 20 PRB, similar to the licensed band.

[0082] In setting example 3A, the PSCCH is allocated to the PRBs in the subchannel to which the PSSCH is allocated, in order from the PRB with the lowest PRB number. For example, the terminal 200 allocates the PSCCH included in the transmission signal to the PRB with the lowest PRB number among the multiple PRBs constituting the subchannel.

[0083] Fig. 7 is a diagram showing an example of channel allocation according to setting example 3A. Fig. 7 shows, as an example, a case where SCS = 30 kHz, and three subchannels are included per RB set (e.g., divided into three). In the example shown in Fig. 7, subchannel #0 includes interlaces #0 and #1, subchannel #1 includes interlaces #2 and #3, and subchannel #2 includes interlace #4.

[0084] In Fig. 7(a), source terminal 200 selects subchannel #0 (interlaces #0, #1) to transmit PSSCH. In this case, PSCCH may be allocated to a PRB with a lower PRB number (or a lower frequency) among the multiple PRBs that make up subchannel #0. As shown in Fig. 7(a), the higher the PRB number among the PRBs that make up subchannel #0, the less likely PSCCH is allocated to the PRB, and only PSSCH is allocated to the PRB.

[0085] 7(b), source terminal 200 selects subchannel #2 (interlace #4) to transmit the PSSCH. In this case, the PSCCH may be allocated to a PRB with a lower PRB number (or a lower frequency) among the PRBs that make up subchannel #2.

[0086] In the example of Figure 7, the number of PRBs (or the number of interlaces) included in subchannel #2 is smaller than that of subchannel #0. Therefore, in Figure 7(b), the PSCCH is allocated and transmitted over a wider frequency band than when subchannel #0 is allocated (e.g., Figure 7(a)). For example, when the number of PRBs in a subchannel is the same as the number of PRBs to which the PSCCH is allocated, the PSCCH is transmitted in all PRBs in the subchannel.

[0087] If the number of PRBs to which PSCCHs are assigned is greater than the number of PRBs in a subchannel, source terminal 200 cannot transmit all of the PSCCHs. In this case, for example, a restriction may be imposed in the resource pool configuration such that the number of PRBs to which PSCCHs are assigned is not set to be greater than the number of PRBs in a subchannel, and source terminal 200 may not need to transmit some of the PSCCHs.

[0088] In Fig. 7(c), source terminal 200 selects subchannels #1 and #2 to transmit PSSCH. If multiple subchannels are selected, PSCCH may be allocated to subchannel #1, which has the lower number, of subchannels #1 and #2. Furthermore, PSCCH may be allocated to PRBs with lower PRB numbers among PRBs constituting subchannel #1. As shown in Fig. 7(c), the higher the PRB number among PRBs constituting subchannel #1, the less likely PSCCH is allocated, and only PSSCH is allocated.

[0089] Also, in FIG. 7(c), no PSCCH is allocated to sub-channel #2 in source terminal 200. However, as shown in FIG. 7(b), there is a possibility that PSCCH transmission may be performed on sub-channel #2, and therefore other terminals (e.g., destination terminal 200) may attempt to receive PSCCH on each of sub-channel #0, sub-channel #1, and sub-channel #2.

[0090] Furthermore, for example, if the number of PRBs to which the PSCCH is assigned is greater than the number of PRBs in subchannel #n, source terminal 200 may transmit the PSCCH using PRBs in subchannel #n+1 in addition to the PRBs in subchannel #n. In this case, the PSCCH may be allocated to a PRB with a lower PRB number among the PRBs constituting subchannel #n+1.

[0091] Configuration example 3A has the advantage that the size of the PSCCH can be determined independently of the number of PRBs included in a subchannel and the number of PRBs included in an interlace. For example, even if the number of PRBs included in each subchannel is different, destination terminal 200 can identify the allocation of the PSCCH based on the number of PRBs to which the PSSCH is assigned.

[0092] <Configuration Example 3B> In configuration example 3B, the size of the PSSCH is (pre-)configured for each resource pool. For example, the size of the PSSCH may be set to be selectable from 10, 12, 15, and 20 PRB, similar to the licensed band.

[0093] In setting example 3B, the PSCCH is allocated in ascending order of PRB numbers among the PRBs included in the interlaces with the lowest interlace numbers among the interlaces included in the subchannel to which the PSSCH is allocated. For example, terminal 200 allocates the PSCCH included in the transmission signal to the PRB with the lowest PRB number included in the interlace with the lowest interlace number among the multiple PRBs constituting the subchannel.

[0094] Fig. 8 is a diagram showing an example of channel allocation according to setting example 3B. Fig. 8 shows an example where SCS = 30 kHz, with two subchannels included per RB set (e.g., divided into two). In the example shown in Fig. 8, subchannel #0 includes interlaces #0, #1, and #2, and subchannel #1 includes interlaces #3 and #4.

[0095] In Figure 8(a), source terminal 200 selects subchannel #0 (interlaces #0, #1, #2) to transmit PSSCH. In this case, of interlaces #0, #1, and #2 that make up subchannel #0, PSCCH is allocated to interlace #0, which has the lowest interlace number. Furthermore, PSCCH is allocated to a PRB with a lower PRB number (or lower frequency) among multiple PRBs included in interlace #0.

[0096] If the number of PRBs to which the PSCCH is allocated is greater than the number of PRBs included in interlace #0, the PSCCH may be allocated to interlace #1 in addition to interlace #0, as shown in Fig. 8(a). In this case, the PSCCH is allocated to a PRB with a lower PRB number (or a lower frequency) among the multiple PRBs included in interlace #1.

[0097] In Figure 8(b), source terminal 200 selects subchannel #1 (interlaces #3 and #4) to transmit the PSSCH. In this case, the PSCCH is allocated to interlace #3, which has the lowest interlace number, of interlaces #3 and #4 that make up subchannel #1. Furthermore, the PSCCH is allocated to a PRB with a lower PRB number (or a lower frequency) among the multiple PRBs included in interlace #3.

[0098] If the number of PRBs to which the PSCCH is allocated is greater than the number of PRBs included in interlace #3, the PSCCH may be allocated to interlace #4 in addition to interlace #3, as shown in Fig. 8(b). In this case, the PSCCH is allocated to a PRB with a lower PRB number (or a lower frequency) among the multiple PRBs included in interlace #4.

[0099] Configuration example 3B has the advantage that the size of the PSCCH can be determined independently of the number of PRBs included in a subchannel and the number of PRBs included in an interlace, as in configuration example 3A. For example, even if the number of PRBs included in each subchannel is different, destination terminal 200 can identify the allocation of the PSCCH based on the interlace to which the PSSCH is assigned and the number of PRBs.

[0100] In addition, in setting example 3B, compared to setting example 3A, the PSCCH is first placed in one interlace within the subchannel, so the PSCCH is transmitted in a distributed manner in the frequency direction, which has the advantage of a high frequency diversity effect.

[0101] <Configuration Example 3C> In configuration example 3C, the size of the PSSCH is (pre-)configured for each resource pool. For example, the size of the PSSCH may be set to be selectable from 10, 12, 15, and 20 PRB, similar to the licensed band.

[0102] In configuration example 3C, the size of the PSCCH is pre-configured as the number of interlaces (for example, a specified number) for each resource pool.

[0103] In setting example 3C, the PSCCH is allocated in ascending order of PRB numbers among the PRBs included in a prescribed number of interlaces with lower interlace numbers among the interlaces included in the subchannel to which the PSSCH is allocated. For example, terminal 200 allocates the PSCCH included in the transmission signal to PRBs with lower PRB numbers in a prescribed number of interlaces with lower interlace numbers among the multiple interlaces included in the subchannel.

[0104] In the following, as an example, a case where one interlace is (pre-)configured for the size (prescribed number) of the PSCCH will be described. Note that the size of the PSCCH may be two or more interlaces.

[0105] Fig. 9 is a diagram showing an example of channel allocation according to setting example 3C. Fig. 9 shows, as an example, a case where SCS = 30 kHz, and three subchannels are included per RB set (e.g., divided into three). In the example shown in Fig. 9, subchannel #0 includes interlaces #0 and #1, subchannel #1 includes interlaces #2 and #3, and subchannel #2 includes interlace #4.

[0106] 9(a), source terminal 200 selects subchannel #0 (interlaces #0 and #1) to transmit the PSSCH. In this case, the PSCCH is allocated to a PRB with a lower PRB number (or a lower frequency) among multiple PRBs constituting interlace #0, the interlace with the lower interlace number, among interlaces #0 and #1 included in subchannel #0.

[0107] Note that, if the number of PRBs included in each interlace is different, the number of PRBs to which the PSCCH is assigned (e.g., PSCCH size) may be adjusted to the smaller number of PRBs (e.g., the minimum value) among the numbers of PRBs included in each interlace. For example, in FIG. 9(a), if the number of PRBs included in interlace #0 is greater than the number of PRBs included in other interlaces, the PSCCH size may be set to the number of PRBs included in the other interlaces. In FIG. 9(a), the number of PRBs included in interlace #0 is greater than the number of PRBs included in each of the other interlaces #1 to #4, so the PSCCH size may be set to the number of PRBs in each of interlaces #1 to #4. For this reason, as shown in FIG. 9(a), the PSCCH is not allocated to the higher PRBs (or higher frequency PRBs) among the PRBs included in interlace #0.

[0108] In Figure 9(b), source terminal 200 selects subchannel #2 (interlace #4) to transmit the PSSCH. In this case, the PSCCH is allocated to PRBs with low PRB numbers in interlace #4 included in subchannel #2. In the example of Figure 9(b), the PSCCH is allocated to all PRBs included in interlace #4.

[0109] In FIG. 9(c), source terminal 200 selects subchannel #1 (interlaces #2 and #3) and subchannel #2 (interlace #4) to transmit the PSSCH. In this case, the PSCCH is allocated to subchannel #1, which has the lowest number, of subchannels #1 and #2. Furthermore, the PSCCH is allocated to the PRB with the lowest PRB number (or the lowest frequency) among multiple PRBs constituting interlace #2, which is the lowest interlace number, of interlaces #2 and #3 included in subchannel #1. In the example of FIG. 9(c), the PSCCH is allocated to all PRBs included in interlace #2.

[0110] Also, in FIG. 9(c), no PSCCH is allocated to sub-channel #2 in source terminal 200. However, as shown in FIG. 9(b), there is a possibility that PSCCH transmission may be performed on sub-channel #2. Therefore, other terminals (e.g., destination terminal 200) may attempt to receive PSCCH on each of sub-channel #0, sub-channel #1, and sub-channel #2.

[0111] According to setting example 3C, the PSCCH is allocated in interlace units, so even if the number of interlaces within a subchannel differs between subchannels, the allocation relationship between the PSCCH and interlaces in each subchannel is the same, facilitating reception of the PSCCH in destination terminal 200. For example, in the example shown in Fig. 9, in any of the cases in Fig. 9(a) to (c), the PSCCH is allocated to one interlace with a lower interlace number among the interlaces included in the subchannel to which the PSSCH is allocated.

[0112] <Configuration Example 3D> In configuration example 3D, mapping (allocation) from a VRB (Virtual Resource Block) to a PRB is performed.

[0113] FIG. 10 is a diagram illustrating an example of mapping from a VRB to a PRB.

[0114] In the VRB, for example, RBs within a subchannel may be arranged contiguously. In the example of Fig. 10, each of subchannels #0 to #2 may include four contiguous VRBs.

[0115] Also, the PSCCH may be arranged in, for example, consecutive VRBs. In the example of Fig. 10, the PSCCH is arranged in two consecutive VRBs with the lowest numbers among the subchannels #0 to #2.

[0116] In the VRB, the sidelink subchannel configuration in the licensed band and / or the frequency-direction contiguous allocation configuration without interlace mapping in the unlicensed band may be followed. Regarding the allocation of VRBs to PRBs, the interleaving rule or the interlacing rule may be pre-configured in the resource pool.

[0117] Also, in PRBs, subchannels may be allocated to partially contiguous PRBs and non-contiguous PRBs.

[0118] This VRB to PRB mapping allows the same design to be used for contiguous and non-contiguous (e.g., interlaced) PRB arrangements.

[0119] The PSCCH setting example of operation example 3 has been described above.

[0120] [Configuration of terminal 200] Fig. 11 is a block diagram showing an example configuration of terminal 200 according to this embodiment. Terminal 200 shown in Fig. 11 includes receiving section 201, LBT carrier sense section 202, signal separation section 203, demodulation section 204, error correction decoding section 205, control signal receiving section 206, error correction coding section 207, modulation section 208, control signal generation section 209, signal allocation section 210, and transmission section 211.

[0121] At least one of the LBT carrier sense unit 202, signal separation unit 203, demodulation unit 204, error correction decoding unit 205, control signal receiving unit 206, error correction coding unit 207, modulation unit 208, control signal generating unit 209, and signal allocation unit 210 may be included in the control unit shown in Fig. 6. At least one of the receiving unit 201 and the transmitting unit 211 may be included in the communication unit shown in Fig. 6.

[0122] In sidelink communication, the terminal 200 may be a transmitting terminal (or a source terminal) that transmits a sidelink signal, or a receiving terminal (or a destination terminal) that receives a sidelink signal.

[0123] The receiving unit 201 receives a received signal via an antenna and performs reception processing such as down-conversion on the received signal. The received signal may be, for example, a sidelink signal including a PSSCH / PSCCH. The sidelink signal may also include a PSFCH. The received signal received by the receiving unit 201 may also include a non-transmission interval or 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 reception processing to the LBT carrier sense unit 202 and the signal separation unit 203.

[0124] The LBT carrier sense unit 202 performs carrier sensing (also referred to as LBT) based on the received signal input from the receiving unit 201. The LBT carrier sense unit 202 may 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 sense unit 202 may determine whether the channel is available for use based on the received signal input from the receiving unit 201. The LBT carrier sense unit 202 outputs information indicating the determined channel state to the transmitting unit 211.

[0125] Signal separating section 203 outputs a received data signal, of the received signal input from receiving section 201, to demodulating section 204. The received data signal is mapped to, for example, a PSSCH. Furthermore, signal separating section 203 separates, from the received signal input from receiving section 201, a 1st stage SCI mapped to the PSCCH and a 2nd stage SCI mapped to part of the PSSCH, and outputs the separated information to control signal receiving section 206.

[0126] Demodulation section 204 performs demodulation processing on the received data signal input from signal separation section 203. Demodulation section 204 outputs the demodulated signal obtained by performing the demodulation processing to error correction decoding section 205.

[0127] The error correction decoder 205 decodes the demodulated signal input from the demodulator 204 and outputs it as received data.

[0128] The control signal receiving unit 206 identifies (or grasps) resource allocation information including reserved resources based on the 1st stage SCI included in the signal input from the signal separating unit 203. The control signal receiving unit 206 outputs the resource allocation information to the signal allocating unit 210, for example, so as to avoid overlap with other resources. Furthermore, for example, the control signal receiving unit 206 identifies (or grasps) a transmitting ID and a receiving ID based on the 2nd stage SCI included in the signal input from the signal separating unit 203. For example, the control signal receiving unit 206 determines whether or not there is a resource allocation addressed to the terminal 200 based on the identified transmitting ID or receiving ID, and if there is a resource allocation addressed to the terminal 200, instructs the signal separating unit 203 to separate the received signal.

[0129] The error correction coding section 207 receives the data signal, performs error correction coding on the data signal, and outputs the error correction coded data signal to the modulation section 208 .

[0130] Modulation section 208 modulates the signal input from error correction coding section 207 and outputs the modulated signal to signal allocation section 210 .

[0131] The control signal generating unit 209 generates first stage SCI and second stage SCI signals based on control information (not shown) and outputs the first stage SCI and second stage SCI signals to the signal allocating unit 210.

[0132] The signal allocating unit 210 allocates the modulated signal input from the modulating unit 208 to resources. At this time, the signal allocating unit 210 may allocate the signal to the resources taking into consideration the signal input from the control signal generating unit 209. For example, the signal allocating unit 210 may determine the allocation of the PSCCH for transmitting the 1st stage SCI based on the size of the PSCCH set for each resource pool. After allocating the resources, the signal allocating unit 210 outputs the transmission signal to the transmitting unit 211.

[0133] When the sensing result obtained from the LBT carrier sense unit 202 indicates an idle state, the transmission unit 211 performs transmission processing such as upconversion on the transmission signal input from the signal allocation unit 210, and transmits the transmission signal after transmission processing via the antenna.

[0134] An example of operation according to this embodiment has been described above.

[0135] As described above, in this embodiment, in sidelink communication in an unlicensed band, terminal 200 allocates PSCCH / PSSCH to subchannels formed by interlaces with consecutive numbers and transmits the PSCCH / PSSCH. This allows terminal 200 to appropriately set subchannel and interlace mapping in sidelink communication in an unlicensed band. For example, allocation in units of subchannels formed by interlaces with consecutive numbers can reduce the impact of interference between terminal 200 and other terminals. Therefore, this embodiment can improve resource utilization efficiency in sidelink communication in an unlicensed band.

[0136] In this embodiment, a case has been described in which a sub-channel is composed of interlaces with consecutive interlace numbers, but this is not limited to this, and a sub-channel may be composed of interlaces with non-consecutive interlace numbers, or may be composed of interlaces with both consecutive and non-consecutive interlace numbers.

[0137] Furthermore, in this embodiment, the case where the PSCCH is arranged in order from the lowest PRB number, lowest interlace number, and lowest subchannel number has been described, but this is not limited to this, and the PSCCH may be arranged, for example, for at least one of the PRB, interlace, and subchannel in order from the highest number (e.g., highest frequency), or may be arranged in order from the set sequence number.

[0138] (Embodiment 2) In this embodiment, a resource allocation method and a transmission method will be described when a plurality of time resources (for example, symbols) for detecting the PSCCH in destination terminal 200 are arranged within a slot.

[0139] In the licensed band, the arrangement position of the sidelink PSCCH is only at the beginning of a slot. In this embodiment, for example, in addition to the beginning of a slot, it is assumed that the PSCCH is arranged at other positions in the slot, and an additional PSCCH starting position (referred to as an additional PSCCH starting point or additional starting point) is set.

[0140] The number of additional starting points per slot is not limited to one, and multiple additional starting points may be set (or placed) in one slot.

[0141] An example of a case where an additional starting point is set will be described.

[0142] [Case 1] In case 1, as shown in FIG. 12 , source terminal 200 performs LBT, but the channel is being used by another system or another device (busy state or LBT failure), and so the transmission right cannot be acquired and PSCCH / PSSCH cannot be transmitted from the beginning of slot N+2.

[0143] In case 1, as shown in FIG. 12, the source terminal 200 performs LBT at an additional starting point in the middle of slot N+2, confirms that the channel is not being used by other systems or other devices, and if it acquires the right to transmit, it may transmit the PSCCH / PSSCH.

[0144] In case 1, the PSCCH may be allocated (or LBT may be performed) at the additional starting point in a slot in which pre-reserved resources are allocated. For example, the additional starting point may not be set in a slot in which pre-reserved resources are not allocated.

[0145] Furthermore, in Case 1, the length of the PSSCH (e.g., symbol length) is determined according to the starting position of the PSCCH. For example, when the PSCCH is arranged from the first symbol of a slot (e.g., a sidelink slot), the length of the PSSCH may be set to the same length as the slot. Furthermore, when the PSCCH is arranged from an additional starting point within the slot, the length of the PSSCH may be set to the interval from the additional starting point of the PSCCH to the end of the slot.

[0146] For example, when destination terminal 200 detects the PSCCH at the first symbol of a slot, it may determine that the length of the PSSCH is the same as the length of the slot. Furthermore, when destination terminal 200 detects the PSCCH at an additional starting point, it may determine that the length of the PSSCH is the interval from the additional starting point to the end of the slot. In this way, destination terminal 200 can determine the length of the PSCCH (PSCCH size) based on the position at which the PSCCH is detected within the slot, so information regarding the length of the PSSCH does not need to be reported to destination terminal 200.

[0147] [Case 2] Case 2 is a case where source terminal 200 reserves resources for slot N+1, as shown in FIG.

[0148] In case 2, as shown in FIG. 13, when the source terminal 200 confirms that there is no transmission from the beginning of slot N, it may perform LBT at an additional starting point in the middle of slot N and acquire the transmission right for slot N+1.

[0149] For example, when source terminal 200 acquires the right to transmit at the additional starting point of slot N, it may transmit the PSCCH / PSSCH from the additional starting point of slot N across the reserved resources of slot N+1. In this case, source terminal 200 may allocate the PSCCH at the additional starting point of slot N and in the first symbol of slot N+1, as shown in FIG.

[0150] As a result, source terminal 200 acquires the transmission right at an earlier timing than the reserved resources. Therefore, other terminals will not be able to transmit from a timing earlier than the reserved resources, and terminal 200 will be more likely to be able to transmit the PSCCH / PSSCH in the reserved resources. In other words, it is possible to reduce the probability that source terminal 200 will not be able to acquire the transmission right in the reserved resources and will cancel PSCCH / PSSCH transmission.

[0151] [Case 3] Case 3 is a case where the number of symbols that can be transmitted via PSSCH can be set to be shorter than the slot length, as shown in FIG.

[0152] In Case 3, the number of transmission symbols of the PSSCH can be set to be shorter than the slot length, and for example, multiple PSSCHs / PSCCHs can be allocated to the time resources within one slot.

[0153] For example, as shown in FIG. 14, the source terminal 200 may perform LBT at either or both of the beginning of slot N and an additional starting point in the middle of slot N, confirm that the channel is not being used by other systems or other devices, and if it acquires the right to transmit, it may transmit the PSCCH / PSSCH.

[0154] In case 3, source terminal 200 may notify destination terminal 200 of the length of the PSSCH via the PSCCH. For example, if the PSCCH length is 14 symbols, the PSSCH is arranged in all symbols within a slot, and if the PSCCH length is 7 symbols, the PSCCH is arranged in a minislot. Note that the length of the PSCCH is not limited to 14 symbols or 7 symbols, and may be other lengths.

[0155] The above describes examples of cases in which an additional starting point is set.

[0156] As in these cases, when the PSCCH can be detected at the additional starting point, the number of times (BD count) the PSCCH is detected within one slot can increase in destination terminal 200. As described above, since PSCCH detection is performed for each subchannel, the fewer the number of subchannels (for example, when they are limited), the fewer the number of PSCCH detections.

[0157] Therefore, in this embodiment, the number of subchannels to be set in a resource pool may be determined according to the setting of an additional starting point. For example, the number of subchannels when an additional starting point is set may be set to be smaller than the number of subchannels when an additional starting point is not set. Also, for example, the greater the number of start positions (e.g., first symbols and additional starting points) at which PSCCHs can be arranged in a slot, the smaller the number of subchannels that can be set in the slot may be set. In this way, when an additional starting point is set, the number of subchannels to be set in a resource pool may be limited.

[0158] Next, an example of the operation of terminal 200 according to this embodiment will be described.

[0159] [Operation Example 1] In Operation Example 1, an example of setting sub-channels according to the setting of an Additional starting point will be described.

[0160] <Setting Example 1A> When no additional starting point is set (or added), the number of subchannels that can be set in a slot is set to C.

[0161] For example, if the number of time resources for which PSCCH detection is attempted within one slot, including the additional starting point, is K, the number of subchannels that can be set within the slot may be set (e.g., limited) to C / K.

[0162] For example, as shown in Fig. 15(a), when an additional starting point is not set, the number of subchannels that can be set within a slot is C = 4. In Fig. 15(a), destination terminal 200 attempts to detect the PSCCH in C = 4 subchannels (e.g., subchannels #0 to #3) within the slot (e.g., the number of times the PSCCH is detected: 4).

[0163] Also, as shown in Figure 15(b), when the number of time resources for attempting to detect the PSCCH within one slot, including the additional starting point, is K = 2 (for example, the beginning of the slot and one additional starting point), the number of subchannels that can be set within the slot is set (limited) to C / K = 2. In Figure 15(b), destination terminal 200 attempts to detect the PSCCH on C / K = 2 subchannels (for example, subchannels #0 and #1) within the slot, for example, at each of the beginning of the slot and the additional starting point (for example, the number of times the PSCCH is detected: 4).

[0164] According to setting example 1A, even when a plurality of time resources for attempting to detect the PSCCH, including an additional starting point, are set, it is possible to suppress an increase in the number of times the PSCCH is detected per slot.

[0165] <Configuration Example 1B> In configuration example 1B, when there are K time resources for attempting to detect the PSCCH within one slot including the additional starting point, the number of times the PSCCH is detected, which corresponds to the number of subchannels multiplied by the number of time resources, may be set to a value that does not exceed the number of times that terminal 200 can receive the PDCCH transmitted from base station 100 per slot.

[0166] For example, the number of subchannels (or subchannel size) and the number of additional starting points may be set according to the set value of the number of times PSCCH is detected.

[0167] The number of times per slot that terminal 200 can receive the PDCCH transmitted from base station 100 may be set according to the capability or specifications of terminal 200, for example.

[0168] <Configuration Example 1C> In configuration example 1C, when an additional starting point is set, one subchannel is set within the RB set. Therefore, for example, a 20 MHz band equivalent to the RB set is set as one subchannel.

[0169] In this way, when an additional starting point is set, the subchannel size is set to be the same as the size of the RB set, thereby reducing the number of times the PSCCH is detected.

[0170] As a modified example of setting example 1C, a setting (or restriction) may be added such that when K or more additional starting points (e.g., a threshold) are set, one subchannel is set within an RB set.

[0171] In addition, in setting example 1C, the number of subchannels set when an additional starting point is set is not limited to one, and may be another number.

[0172] Operation example 1 has been described above.

[0173] [Operation Example 2] In Operation Example 2, a description will be given of an example of configuring a PSFCH when a plurality of PSSCHs, each having a length shorter than 14 symbols and also called a minislot, are transmitted within a slot, as in the above-described Case 3. For example, the arrangement of PSFCHs for a plurality of PSSCHs arranged on time resources within one slot is not defined in sidelink communication.

[0174] <Configuration Example 2A> In configuration example 2A, when an additional starting point is configured and there is a possibility of multiple PSSCH transmissions in the time resources within a slot, the PSFCH is not configured (or supported).

[0175] As a result, it is not necessary to set an association between the PSFCH and the PSSCH corresponding to the additional starting point.

[0176] Furthermore, since minislot transmission allows retransmission at short intervals, it is possible to perform retransmission based on channel quality without waiting for HARQ-ACK feedback via PSFCH. In this case, the impact of not configuring PSFCH on retransmission control can be reduced.

[0177] <Configuration Example 2B> In configuration example 2B, a PSFCH resource for an additional starting point may be configured (prepared).

[0178] The PSFCH resource for the PSSCH allocated by the PSCCH at the beginning of the slot may be set in accordance with, for example, "SL-PSFCH-Config" (e.g., FIG. 16 ) of the rules for PSFCH defined in Release 16 (Rel. 16) (e.g., Non-Patent Document 4), or a newly set mapping.

[0179] Furthermore, the PSFCH resource for the PSSCH allocated by the PSCCH arranged at the additional starting point may be newly configured. For example, the PSFCH resource for the PSSCH allocated by the PSCCH arranged at the additional starting point may be configured separately from the existing configuration as "sl-PSFCH-RB-Set" indicating the position of the PRB resource of the PSFCH among "sl-PSFCH-RB-Set-r16" in "SL-PSFCH-Config", as shown in FIG. 16 .

[0180] The "sl-PSFCH-RB-Set" is, for example, a parameter indicating PRBs used for transmitting and receiving the PSFCH. For example, the "sl-PSFCH-RB-Set" may indicate in a bitmap format whether each of multiple PRBs is used for transmitting and receiving the PSFCH. For example, at least one of the PRBs indicated by the sl-PSFCH-RB-Set may include a PSFCH resource for the PSSCH allocated by the PSCCH located at the additional starting point.

[0181] According to setting example 2B, it is possible to frequency-multiplex a PSFCH with a plurality of PSSCHs arranged in a slot.

[0182] Note that the PSFCH for a plurality of PSSCHs is not limited to being allocated to a plurality of resources on the frequency axis, but may also be allocated to a plurality of resources on the time axis.

[0183] <Configuration Example 2C> The PSFCH in sidelink communication in the licensed band is allocated to the second to last symbol of the slot, as shown in FIG. 1(a).

[0184] In configuration example 2C, when an additional starting point is set, a resource on the time axis within the slot in which the PSFCH is allocated may be newly set.

[0185] For example, as shown in Figure 17(a), a PSFCH may be placed before a PSCCH placed at an additional starting point. Alternatively, as shown in Figure 17(b), a new PSFCH may be placed before a PSFCH placed at the second-to-last symbol of a slot.

[0186] <Configuration Example 2D> In configuration example 2D, when an additional starting point is set and multiple PSSCHs can be transmitted on time resources within a slot, for the PSFCH corresponding to the PSSCH allocated by the first PSCCH among the multiple PSSCHs, resources may be set in accordance with the rules for PSFCHs defined in Rel. 16 or a newly defined mapping.

[0187] On the other hand, among the multiple PSSCHs in a slot, resources for the PSFCH for the PSSCH corresponding to the PSCCH arranged at the additional starting point are not arranged.

[0188] As a result, source terminal 200 receives feedback of HARQ-ACK for the PSSCH allocated by the first PSCCH, but does not receive feedback of HARQ-ACK for the PSSCH allocated by the PSCCH of the additional starting point. For example, source terminal 200 can use different PSCCHs depending on the application, such as using the PSCCH at the beginning of a slot when HARQ-ACK feedback is required, and using the PSCCH at the additional starting point when HARQ-ACK is not required.

[0189] The above describes an example of setting the PSFCH.

[0190] An example of operation according to this embodiment has been described above.

[0191] The operation example of this embodiment can be applied whether the arrangement of PRBs to which PSSCH is allocated is contiguous or whether it is interlaced mapping as in the first embodiment.

[0192] As described above, in this embodiment, terminal 200 sets an additional starting point within a slot, thereby increasing the number of times that the PSCCH can be transmitted within the slot (or the number of times that the PSCCH can be detected). As a result, for example, even if the LBT result at the beginning of the slot is busy (LBT failure), source terminal 200 can perform LBT at an additional starting point in the middle of the slot, thereby increasing the probability of acquiring the right to transmit. Alternatively, for example, source terminal 200 can transmit multiple PSSCHs within a slot, like mini-slots.

[0193] Therefore, according to this embodiment, it is possible to improve the utilization efficiency of resources for sidelink communication in unlicensed bands.

[0194] The above describes each embodiment.

[0195] [Variations] The operation examples of the above-described embodiments may be used in combination.

[0196] In addition, terminals that transmit and receive on the sidelink include terminals that transmit but do not receive on the sidelink, terminals that receive but do not transmit, and terminals that transmit and receive.

[0197] Furthermore, when the sidelink configuration is configured in advance, the configuration method may be to configure it in advance in a specification (standard) or in advance in a SIM (Subscriber Identity Module). Alternatively, the sidelink configuration may be configured in an application layer called "pre-configured," in a system information block (SIB) called "configured" and / or other higher layers such as RRC (radio resource control), or in MAC (Medium Access Control).

[0198] Furthermore, although the above-described embodiments have shown examples of sidelink communication, the present disclosure is not limited thereto. For example, in the above-described embodiments, the present disclosure may be applied to communication between a base station and a terminal by replacing the PSCCH with a PDCCH, the PSSCH with a PDSCH or a PUSCH, the PSFCH with a PUCCH, and the PSBCH with a PBCH.

[0199] Furthermore, each of the above-described 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. Furthermore, among the operation examples of each of the above-described embodiments, the operation example applied to Mode 1 and the operation example applied to Mode 2 may be the same or different. For example, there may be an operation example that is applied to Mode 2 but not to Mode 1.

[0200] Furthermore, when the above-described embodiments are applied to Mode 1, the base station may instruct in the licensed band which of Types 2A, 2B, and 2C to select in Type 2 LBT.

[0201] In addition, although the above-described embodiments have shown examples of operation in unlicensed bands, the frequency band of the unlicensed band may differ from country to country or from region to region. Exemplary unlicensed band frequency bands include the 5 GHz band (5150 MHz - 5925 MHz), the 6 GHz band (5925 MHz - 7125 MHz), and 52.6 GHz to 71 GHz.

[0202] Furthermore, whether or not each of the above embodiments or each of the operation examples can be used may be changed depending on the SCS.

[0203] In addition, Type 1 LBT and Type 2 LBT may be called by different names in sidelink communication.

[0204] The SCI format transmitted on the PSCCH may be SCI format 1-A or a newly added SCI format.

[0205] Furthermore, the above embodiment may be applied to S-PSS / SSS / PSBCH.

[0206] In addition, in each of the above embodiments, the destination terminal may refer to multiple terminals in the case of groupcast and broadcast.

[0207] The guard band may also be called an intra-cell guard band.

[0208] Furthermore, the resource allocations for sidelink communication illustrated in the above-described embodiments are merely examples, and the present disclosure is not limited thereto. For example, the resources for sidelink communication may include signals, channels, non-transmission periods, etc. that are not illustrated. Furthermore, the widths of the time and frequency directions of the signals illustrated in each figure are not limited to the illustrated examples. Furthermore, the slot sizes, resource sizes, channel sizes, signal sizes, etc. are not limited to the above-described examples.

[0209] In addition, in each of the above-described embodiments, the length of the sidelink signal is adjusted by lengthening the CP length of the sidelink signal using the CP extension, but the present disclosure is not limited to this. Instead of lengthening the CP length, the length may be adjusted by adding a known signal.

[0210] In addition, in each of the above-described embodiments, checking the availability of a channel may be replaced with an expression such as sensing (or monitoring) the availability of a channel. In this case, the term "channel" may be replaced with other terms such as "carrier" or "resource."

[0211] Furthermore, the method of notifying the control information from the base station 100 to the terminal 200 is not limited to the above-mentioned example, and may be notified (or reported, indicated, or set) by at least one of system information such as MIB and SIB, RRC control information, MAC control information, and downlink control information (DCI), or may be set in advance in the terminal 200, or may be specified in advance in a standard.

[0212] The base station may be referred to as a gNodeB or a gNB, and the terminal may be referred to as a UE.

[0213] The resource allocation unit for sidelink communication in unlicensed bands may be a unit other than a subchannel, or may have a name other than a subchannel.

[0214] A time resource unit such as a slot may be replaced with another unit such as a system frame, time slot, minislot, frame, subframe, or block.

[0215] Furthermore, the notation "... section" in the above-described embodiments may be replaced with other notations such as "... circuitry," "... device," "... unit," or "... module."

[0216] It should be noted that terms such as "interpretation," "identification," "judgment," "determination," "decision," "calculation," "grasp," "recognition," "confirmation," or "understanding" may be used interchangeably.

[0217] (Supplementary Note) Information indicating whether the terminal 200 supports the functions, operations, or processes described in the above-described embodiments may be transmitted (or notified) from the terminal 200 to the base station 100, for example, as capability information or capability parameters of the terminal 200.

[0218] The capability information may include an information element (IE) that individually indicates whether or not the terminal 200 supports at least one of the functions, operations, or processes described in the above-described embodiments. Alternatively, the capability information may include an information element that indicates whether or not the terminal 200 supports a combination of any two or more of the functions, operations, or processes described in the above-described embodiments.

[0219] For example, the base station 100 may determine (or decide or assume) functions, operations, or processes that the terminal 200 that transmitted the capability information supports (or does not support) based on the capability information received from the terminal 200. The base station 100 may perform operations, processes, or control according to the determination result based on the capability information. For example, the base station 100 may control sidelink communication between the terminals 200 based on the capability information received from the terminal 200.

[0220] Note that the fact that terminal 200 does not support some of the functions, operations, or processes described in the above-described embodiments may be interpreted as meaning that such some of the functions, operations, or processes are restricted in terminal 200. For example, information or a request regarding such restrictions may be notified to base station 100.

[0221] Information regarding the capabilities or limitations of terminal 200 may, for example, be defined in a standard, or may be implicitly notified to base station 100 in association with information known at base station 100 or information transmitted to base station 100.

[0222] (Control Signal) In the present disclosure, a downlink control signal (or downlink control information) related to an embodiment of the present disclosure may be, for example, a signal (or information) transmitted in a Physical Downlink Control Channel (PDCCH) of a physical layer, or a signal (or information) transmitted in a Medium Access Control Control Element (MAC CE) or Radio Resource Control (RRC) of a higher layer. Furthermore, the signal (or information) is not limited to being notified by a downlink control signal, but may be predefined in a specification (or standard) or preconfigured in a base station and a terminal.

[0223] In the present disclosure, an uplink control signal (or uplink control information) related to an embodiment of the present disclosure may be, for example, a signal (or information) transmitted in a PUCCH of a physical layer, or a signal (or information) transmitted in a MAC CE or RRC of a higher layer. Furthermore, the signal (or information) is not limited to being notified by an uplink control signal, but may be predefined in a specification (or standard) or preconfigured in a base station and a terminal. Furthermore, the uplink control signal may be replaced with, for example, uplink control information (UCI), 1st stage sidelink control information (SCI), or 2nd stage SCI.

[0224] (Base Station) In an embodiment of the present disclosure, the base station may be a Transmission Reception Point (TRP), a cluster head, an access point, a Remote Radio Head (RRH), an eNodeB (eNB), a gNodeB (gNB), a Base Station (BS), a Base Transceiver Station (BTS), a parent device, a gateway, or the like. In sidelink communication, a terminal may play the role of a base station. Instead of a base station, a relay device that relays communication between an upper node and a terminal may be used. Alternatively, a roadside unit may be used.

[0225] (Uplink / Downlink / Sidelink) An embodiment of the present disclosure may be applied to, for example, any of the uplink, downlink, and sidelink. For example, an embodiment of the present disclosure may be applied to a Physical Uplink Shared Channel (PUSCH), a Physical Uplink Control Channel (PUCCH), or a Physical Random Access Channel (PRACH) in the uplink, a Physical Downlink Shared Channel (PDSCH), a PDCCH, or a Physical Broadcast Channel (PBCH) in the downlink, or a Physical Sidelink Shared Channel (PSSCH), a Physical Sidelink Control Channel (PSCCH), or a Physical Sidelink Broadcast Channel (PSBCH) in the sidelink.

[0226] The PDCCH, PDSCH, PUSCH, and PUCCH are examples of a downlink control channel, a downlink data channel, an uplink data channel, and an uplink control channel, respectively. The PSCCH and PSSCH are examples of a sidelink control channel and a sidelink data channel. The PBCH and PSBCH are examples of a broadcast channel, and the PRACH is an example of a random access channel.

[0227] (Data Channel / Control Channel) An embodiment of the present disclosure may be applied to, for example, either a data channel or a control channel. For example, the channel in an embodiment of the present disclosure may be replaced with any of the data channels PDSCH, PUSCH, and PSSCH, or the control channels PDCCH, PUCCH, PBCH, PSCCH, and PSBCH.

[0228] (Reference Signal) In one embodiment of the present disclosure, a reference signal is, for example, a signal known by both a base station and a mobile station, and may also be called a Reference Signal (RS) or a pilot signal. The reference signal may be any 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), or a Sounding Reference Signal (SRS).

[0229] (Time Interval) In one embodiment of the present disclosure, the unit of time resource is not limited to one or a combination of slots and symbols, but may be, for example, a time resource unit such as a frame, a superframe, a subframe, a slot, a time slot subslot, a minislot, or a symbol, an Orthogonal Frequency Division Multiplexing (OFDM) symbol, or a Single Carrier-Frequency Division Multiplexing Access (SC-FDMA) symbol, or another time resource unit. Furthermore, the number of symbols included in one slot is not limited to the number of symbols exemplified in the above-mentioned embodiment, and may be another number of symbols.

[0230] (Frequency Band) An embodiment of the present disclosure may be applied to either a licensed band or an unlicensed band.

[0231] (Communication) An embodiment of the present disclosure may be applied to communication between a base station and a terminal (Uu link communication), communication between terminals (Sidelink communication), or Vehicle to Everything (V2X) communication. For example, the channel in an embodiment of the present disclosure may be replaced with any of PSCCH, PSSCH, Physical Sidelink Feedback Channel (PSFCH), PSBCH, PDCCH, PUCCH, PDSCH, PUSCH, or PBCH.

[0232] An embodiment of the present disclosure may be applied to a terrestrial network, a non-terrestrial network (NTN) using a satellite or a high altitude pseudo satellite (HAPS), or a terrestrial network in which transmission delay is large compared to the symbol length or slot length, such as a network with a large cell size or an ultra-wideband transmission network.

[0233] (Antenna Port) In one embodiment of the present disclosure, an antenna port refers to a logical antenna (antenna group) consisting of one or more physical antennas. For example, an antenna port does not necessarily refer to a single physical antenna, but may refer to an array antenna consisting of multiple antennas. For example, the number of physical antennas that an antenna port is composed of is not specified, and the antenna port may be specified as the smallest unit by which a terminal station can transmit a reference signal. Furthermore, an antenna port may also be specified as the smallest unit by which a weighting of a precoding vector is multiplied.

[0234] 5G NR System Architecture and Protocol Stack 3GPP continues work on the next release of fifth-generation cellular technology (also referred to simply as "5G"), which includes 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 at the end of 2017, allowing for the prototyping and commercial deployment of 5G NR-compliant devices (e.g., smartphones).

[0235] For example, the system architecture generally assumes a Next Generation - Radio Access Network (NG-RAN) including gNBs. The gNBs provide UE-side termination of NG radio access user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocols. The gNBs are connected to each other via an Xn interface. The gNBs are also connected to a Next Generation Core (NGC) via a Next Generation (NG) interface, more specifically to an Access and Mobility Management Function (AMF) (e.g., a specific core entity performing AMF) via an NG-C interface, and to a User Plane Function (UPF) (e.g., a specific core entity performing UPF) via an NG-U interface. The NG-RAN architecture is shown in Figure 18 (see, for example, 3GPP TS 38.300 v15.6.0, section 4).

[0236] The NR user plane protocol stack (see, for example, 3GPP TS 38.300, section 4.4.1) includes a PDCP (Packet Data Convergence Protocol (see, for example, TS 38.300, section 6.4)) sublayer, a RLC (Radio Link Control (see, for example, TS 38.300, section 6.3)) sublayer, and a MAC (Medium Access Control (see, for example, TS 38.300, section 6.2)) sublayer, which are terminated on the network side in the gNB. A new access stratum (AS) sublayer (SDAP: Service Data Adaptation Protocol) has also been introduced above PDCP (see, for example, 3GPP TS 38.300, section 6.5). A control plane protocol stack has also been defined for NR (see, for example, TS 38.300, section 4.4.2). An overview of Layer 2 functions is described in Section 6 of TS 38.300. The functions of the PDCP sublayer, RLC sublayer, and MAC sublayer are listed in clauses 6.4, 6.3, and 6.2 of TS 38.300, respectively. The functions of the RRC layer are listed in clause 7 of TS 38.300.

[0237] For example, the Medium-Access-Control layer handles logical channel multiplexing and scheduling and scheduling-related functions, including handling various numerologies.

[0238] For example, the physical layer (PHY) is responsible for coding, PHY HARQ processing, modulation, multi-antenna processing, and mapping of signals to appropriate physical time-frequency resources. The physical layer also handles 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 for transmitting a specific transport channel, and each transport channel is mapped to a corresponding physical channel. For example, physical channels include the Physical Random Access Channel (PRACH), the Physical Uplink Shared Channel (PUSCH), and the Physical Uplink Control Channel (PUCCH) as uplink physical channels, and the Physical Downlink Shared Channel (PDSCH), the Physical Downlink Control Channel (PDCCH), and the Physical Broadcast Channel (PBCH) as downlink physical channels.

[0239] NR use cases / deployment scenarios may include enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communication (mMTC), which have diverse 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 approximately three times higher than those offered by IMT-Advanced. On the other hand, URLLC imposes stricter requirements on ultra-low latency (0.5 ms for user plane latency in both UL and DL) and high reliability (1-10-5 within 1 ms). Finally, mMTC preferably requires high connection density (1,000,000 devices / km in urban environments).２ ), wide coverage in adverse environments, and extremely long battery life (15 years) for a low-cost device may be desired.

[0240] Therefore, OFDM numerology (e.g., subcarrier spacing, OFDM symbol length, cyclic prefix (CP) length, number of symbols per scheduling interval) suitable for one use case may not be effective for another use case. For example, low-latency services may preferably require a shorter symbol length (and therefore a larger subcarrier spacing) and / or fewer symbols per scheduling interval (also referred to as TTI) than mMTC services. Furthermore, deployment scenarios with large channel delay spreads may preferably require a longer CP length than scenarios with short delay spreads. The subcarrier spacing may be optimized accordingly to maintain similar CP overhead. NR may support one or more subcarrier spacing values. Correspondingly, subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, etc. are currently considered. The symbol length Tu and subcarrier spacing Δf are directly related by the formula Δf = 1 / Tu. Similar to LTE systems, the term "resource element" can be used to mean the smallest resource unit consisting of one subcarrier for the length of one OFDM / SC-FDMA symbol.

[0241] In the new radio system 5G-NR, for each numerology and each carrier, a resource grid of subcarriers and OFDM symbols is defined for each uplink and downlink. Each element of the resource grid is called a resource element and is specified based on a frequency index in the frequency domain and a symbol position in the time domain (see 3GPP TS 38.211 v15.6.0).

[0242] <Functional separation between NG-RAN and 5GC in 5G NR> Figure 19 shows 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.

[0243] For example, gNB and ng-eNB host the following main functions: - Radio Resource Management functions such as Radio Bearer Control, Radio Admission Control, Connection Mobility Control, dynamic allocation (scheduling) of resources to UEs in both uplink and downlink; - IP header compression, ciphering and integrity protection of data; - AMF selection at UE attach time if routing to the AMF cannot be determined from the information provided by the UE; - Routing of user plane data towards the UPF; - Routing of control plane information towards the AMF; - Connection setup and release; - Scheduling and transmission of paging messages; - Scheduling and transmission of system broadcast information (sourced from the AMF or Operation, Admission, Maintenance (OAM)); - Configuration of measurements and measurement reports for mobility and scheduling; - Transport level packet marking in the uplink; - Session management; Support for network slicing; - QoS flow management and mapping to data radio bearers; - Support for UEs in RRC_INACTIVE state; - NAS message delivery function; - Radio access network sharing; - Dual connectivity; - Close coordination between NR and E-UTRA.

[0244] The Access and Mobility Management Function (AMF) hosts the following main functions: - Termination of Non-Access Stratum (NAS) signalling; - Security of NAS signalling; - Security control of Access Stratum (AS); - Signalling between Core Network (CN) nodes for mobility between 3GPP access networks; - Reachability to idle mode UEs (including control and execution of paging retransmissions); - Registration area management; - Support for intra-system and inter-system mobility; - Access authentication; - Access authorization including checking of roaming rights; - Mobility management control (subscription and policy); - Support for network slicing; - Selection of Session Management Function (SMF).

[0245] Furthermore, the User Plane Function (UPF) hosts the following main functions: - anchor point for intra-RAT mobility / inter-RAT mobility (if applicable); - external PDU (Protocol Data Unit) session point for interconnection with data networks; - packet routing and forwarding; - packet inspection and policy rule enforcement for the user plane part; - traffic usage reporting; - uplink classifier to support routing of traffic flows to the data network; - branching point to support multi-homed PDU sessions; - QoS processing for the user plane (e.g. packet filtering, gating, UL / DL rate enforcement); - uplink traffic validation (mapping of SDF to QoS flows); - downlink packet buffering and triggering of downlink data notifications.

[0246] Finally, the Session Management Function (SMF) hosts the following main functions: session management; allocation and management of IP addresses for UEs; selection and control of UPF; configuration of traffic steering in the User Plane Function (UPF) to route traffic to the appropriate destination; policy enforcement and QoS of the control part; downlink data notification.

[0247] <RRC connection setup and reconfiguration procedure> Figure 20 shows some of the interactions between the UE, gNB, and AMF (5GC entities) when the UE transitions from RRC_IDLE to RRC_CONNECTED in the NAS part (see TS 38.300 v15.6.0).

[0248] RRC is a higher layer signaling (protocol) used to configure the UE and gNB. With this transition, the AMF prepares UE context data (including, for example, PDU session context, security keys, UE radio capabilities, UE security capabilities, etc.) and sends it to the gNB along with an INITIAL CONTEXT SETUP REQUEST. The gNB then activates AS security together with the UE. This is done by the gNB sending a SecurityModeCommand message to the UE, and the UE responding with a SecurityModeComplete message to the gNB. The gNB then sends an RRCReconfiguration message to the UE, and upon receiving an RRCReconfigurationComplete from the UE, the gNB performs reconfiguration to set up a Signaling Radio Bearer 2 (SRB2) and a Data Radio Bearer (DRB). For signaling-only connections, the steps related to RRCReconfiguration are omitted because SRB2 and DRB are not set up. Finally, the gNB notifies the AMF that the setup procedure is complete with an INITIAL CONTEXT SETUP RESPONSE.

[0249] Accordingly, the present disclosure provides a 5th Generation Core (5GC) entity (e.g., AMF, SMF, etc.) that includes: a control circuit that, upon operation, establishes a Next Generation (NG) connection with a gNodeB; and a transmitter that, upon operation, transmits an initial context setup message to the gNodeB via the NG connection so that a signaling radio bearer between the gNodeB and a user equipment (UE) is set up. Specifically, the gNodeB transmits Radio Resource Control (RRC) signaling, including a resource allocation configuration information element (IE), to the UE via the signaling radio bearer. The UE then transmits in uplink or receives in downlink based on the resource allocation configuration.

[0250] <IMT Usage Scenarios Beyond 2020> Figure 21 shows some use cases for 5G NR. The 3rd Generation Partnership Project New Radio (3GPP NR) is considering three use cases envisioned by IMT-2020 to support a wide variety of services and applications. The first phase of specifications for enhanced mobile broadband (eMBB) has been completed. Current and future work includes standardization for ultra-reliable and low-latency communications (URLLC) and massive machine-type communications (mMTC), in addition to expanding support for eMBB. Figure 21 shows some examples of envisioned usage scenarios for IMT beyond 2020 (see, for example, ITU-R M.2083 Figure 2).

[0251] The URLLC use case has stringent performance requirements, such as throughput, latency, and availability. It is envisioned as one of the enabling technologies for future applications, such as wireless control of industrial or manufacturing processes, remote medical surgery, automated power transmission and distribution in smart grids, and road safety. URLLC's ultra-high reliability is supported by identifying technologies that meet the requirements set by TR 38.913. Key requirements for NR URLLC in Release 15 include a target user plane latency of 0.5 ms on the uplink (UL) and 0.5 ms on the downlink (DL). The overall URLLC requirement for a single packet transmission is a block error rate (BLER) of 1E-5 for a 32-byte packet size with a user plane latency of 1 ms.

[0252] From a physical layer perspective, reliability can be improved in many possible ways. Current room for reliability improvement includes defining a separate CQI table for URLLC, more compact DCI formats, PDCCH repetition, etc. However, this room can be expanded to achieve ultra-high reliability as NR (with respect to the key requirements of NR URLLC) becomes more stable and developed. Specific use cases for NR URLLC in Release 15 include Augmented Reality / Virtual Reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0253] Additionally, the technology enhancements targeted by NR URLLC aim to improve latency and reliability. Technology enhancements for latency improvement include configurable numerology, non-slot-based scheduling with flexible mapping, grant-free (configured grant) uplink, slot-level repetition in the data channel, and preemption in the downlink. Preemption means that a transmission with already allocated resources is stopped and the already allocated resources are used for another transmission with a later requested lower latency / higher priority. Therefore, a previously allowed transmission is preempted by a later transmission. Preemption is applicable regardless of the specific service type. For example, a transmission of service type A (URLLC) may be preempted by a transmission of service type B (eMBB, etc.). Technology enhancements for reliability improvement include a dedicated CQI / MCS table for a target BLER of 1E-5.

[0254] The use case of mMTC (massive machine type communication) is characterized by a very large number of connected devices that typically transmit relatively small amounts of data that are not sensitive to delays. These devices are required to be low-cost and have very long battery life. From the NR perspective, utilizing very narrow bandwidth portions is one solution that saves power from the UE's perspective and enables long battery life.

[0255] As mentioned above, the scope of reliability improvement in NR is expected to be broader. One of the key requirements for all cases, for example, URLLC and mMTC, is high or ultra-high reliability. Several mechanisms can improve reliability from a radio perspective and a network perspective. Generally, there are two to three key areas that can help improve reliability. These areas include compact control channel information, repetition of data channels / control channels, and diversity in the frequency, time, and / or spatial domains. These areas are generally applicable to reliability improvement regardless of the specific communication scenario.

[0256] For NR URLLC, further use cases with more stringent requirements are envisaged, such as factory automation, transportation, and power distribution, such as high reliability (up to 10-6 level), high availability, packet size up to 256 bytes, time synchronization down to a few μs (depending on the use case, the value can be 1 μs or a few μs depending on the frequency range and low latency in the order of 0.5 ms to 1 ms (e.g., 0.5 ms latency on the targeted user plane)).

[0257] Furthermore, for NR URLLC, there may be several technical enhancements from the physical layer perspective. These technical enhancements include PDCCH (Physical Downlink Control Channel) enhancements for compact DCI, PDCCH repetition, and increased PDCCH monitoring. Also, UCI (Uplink Control Information) enhancements relate to enhanced Hybrid Automatic Repeat Request (HARQ) and CSI feedback enhancements. There may also be PUSCH enhancements related to minislot-level hopping and retransmission / repetition enhancements. The term "minislot" refers to a Transmission Time Interval (TTI) that contains fewer symbols than a slot (a slot comprises 14 symbols).

[0258] <QoS Control> The 5G Quality of Service (QoS) model is based on QoS flows and supports both QoS flows that require a guaranteed flow bit rate (Guaranteed Bit Rate QoS flows (GBR)) and QoS flows that do not require a guaranteed flow bit rate (non-GBR QoS flows). Thus, at the NAS level, a QoS flow is the finest granularity of QoS classification in a PDU session. A QoS flow is identified within a PDU session by a QoS Flow ID (QFI) carried in an encapsulation header over the NG-U interface.

[0259] For each UE, 5GC establishes one or more PDU sessions. For each UE, the NG-RAN establishes at least one Data Radio Bearer (DRB) for each PDU session, e.g., as shown above with reference to Figure 20. Additional DRBs for the QoS flows of that PDU session can be configured later (when this is up to the NG-RAN). The NG-RAN maps packets belonging to different PDU sessions to different DRBs. NAS-level packet filters in the UE and 5GC associate UL and DL packets with QoS flows, while AS-level mapping rules in the UE and NG-RAN associate UL and DL QoS flows with DRBs.

[0260] Figure 22 shows the non-roaming reference architecture for 5G NR (see TS 23.501 v16.1.0, section 4.23). An Application Function (AF) (e.g., an external application server hosting 5G services, as illustrated in Figure 21) interacts with the 3GPP core network to provide services. For example, it may access a Network Exposure Function (NEF) to support applications that affect traffic routing, or interact with a policy framework for policy control (e.g., QoS control) (see Policy Control Function (PCF)). Based on operator deployment, Application Functions considered trusted by the operator can interact directly with associated Network Functions. Application Functions not permitted by the operator to directly access Network Functions interact with associated Network Functions using an external exposure framework via the NEF.

[0261] Figure 22 further illustrates 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, e.g., operator-provided services, Internet access, or third-party services). All or part of the core network functions and application services may be deployed and run in a cloud computing environment.

[0262] Therefore, the present disclosure provides an application server (e.g., an AF in a 5G architecture) comprising: a transmitter that, in operation, sends a request including QoS requirements for at least one of a URLLC service, an eMMB service, and an mMTC service to at least one of 5GC functions (e.g., an NEF, an AMF, an SMF, a PCF, an UPF, etc.) to establish a PDU session including a radio bearer between a gNodeB and a UE according to the QoS requirements; and a control circuit that, in operation, performs a service using the established PDU session.

[0263] The present disclosure can be realized by software, hardware, or software in conjunction with hardware. Each functional block used in the description of the above embodiments may be partially or entirely realized as an LSI, which is an integrated circuit, and each process described in the above embodiments may be partially or entirely controlled by a single LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of a single chip that includes some or all of the functional blocks. The LSI may have data input and output. Depending on the degree of integration, the LSI may also be called an IC, system LSI, super LSI, or ultra LSI.

[0264] The integrated circuit method is not limited to LSI, and may be realized by a dedicated circuit, a general-purpose processor, or a dedicated processor. Also, a field programmable gate array (FPGA) that can be programmed after LSI manufacturing, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells within the LSI, may be used. The present disclosure may be realized as digital processing or analog processing.

[0265] Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derivative technologies, it is natural that such technology may be used to integrate functional blocks. The application of biotechnology, etc. is also a possibility.

[0266] The present disclosure may be implemented in any type of apparatus, device, or system (collectively referred to as a communications apparatus) that has a communications function. The communications apparatus may include a radio transceiver and processing / control circuitry. The radio transceiver may include a receiver and a transmitter, or both functions. The radio transceiver (transmitter and receiver) may include a radio frequency (RF) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or the like. Non-limiting examples of communication devices include telephones (e.g., cell phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, notebooks), cameras (e.g., digital still / video cameras), digital players (e.g., digital audio / video players), wearable devices (e.g., wearable cameras, smartwatches, tracking devices), game consoles, digital book readers, telehealth / telemedicine devices, communication-enabled vehicles or mobile transportation (e.g., cars, airplanes, ships), and combinations of the above devices.

[0267] The communication devices are not limited to portable or mobile devices, but also include any kind of non-portable or fixed equipment, devices, and systems, such as smart home devices (such as home appliances, lighting equipment, smart meters or measuring devices, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0268] Communications include data communications via cellular systems, wireless LAN systems, communication satellite systems, and the like, as well as data communications via combinations of these.

[0269] A communications apparatus also includes devices such as controllers and sensors connected or coupled to a communications device that performs the communications functions described in this disclosure, such as controllers and sensors that generate control and data signals used by the communications device to perform the communications functions of the communications apparatus.

[0270] The communication apparatus also includes infrastructure facilities, such as base stations, access points, and any other apparatus, device, or system that communicates with or controls the various apparatuses listed above, but are not limited to these.

[0271] A communication device according to one embodiment of the present disclosure includes a control circuit that allocates signals to resource allocation units consisting of consecutively numbered interlaces in terminal-to-terminal communication in an unlicensed band, and a transmission circuit that transmits the signals.

[0272] In one embodiment of the present disclosure, the resource allocation unit is a subchannel, and the number of interlaces constituting each of the plurality of subchannels is different.

[0273] In one embodiment of the present disclosure, the signal includes a control signal and a data signal for which resource allocation is indicated by the control signal, and when the control signal is allocated to some of the multiple resource blocks constituting the resource allocation unit to which the data signal is allocated, the control circuit allocates the data signal to a resource block of the multiple resource blocks in the same symbol that is different from the resource block to which the control signal is allocated, and sets the transmission power per resource block to be the same for the control signal and the data signal in the multiple resource blocks.

[0274] In one embodiment of the present disclosure, the control circuit allocates the control signal included in the signal to a resource block with a lower number among a plurality of resource blocks that constitute the resource allocation unit.

[0275] In one embodiment of the present disclosure, the resource allocation unit is a subchannel, and when the signal is allocated to multiple subchannels, the control circuit places the control signal in a subchannel with a lower number among the multiple subchannels.

[0276] In one embodiment of the present disclosure, the control circuit places the control signal included in the signal in a lower-numbered resource block included in a lower-numbered interlace among the multiple resource blocks that make up the resource allocation unit.

[0277] In one embodiment of the present disclosure, the control circuit places the control signal included in the signal in a lower-numbered resource block in a specified number of lower-numbered interlaces among the multiple interlaces included in the resource allocation unit.

[0278] In one embodiment of the present disclosure, the resource allocation unit is a subchannel, and if the number of subchannels that can be set when there is one time resource candidate for arranging a control signal included in the signal within a slot is C, and if there are K time resource candidates within the slot, the number of subchannels that can be set is set to C / K.

[0279] A communication device according to one embodiment of the present disclosure includes a receiving circuit for receiving a signal allocated in a resource allocation unit consisting of consecutively numbered interlaces in terminal-to-terminal communication in an unlicensed band, and a control circuit for demodulating the signal.

[0280] In a communication method according to one embodiment of the present disclosure, a communication device allocates a signal to a resource allocation unit consisting of consecutively numbered interlaces in terminal-to-terminal communication in an unlicensed band, and transmits the signal.

[0281] In a communication method according to one embodiment of the present disclosure, a communication device receives a signal allocated in a resource allocation unit consisting of consecutively numbered interlaces in terminal-to-terminal communication in an unlicensed band, and demodulates the signal.

[0282] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2022-128348, filed on August 10, 2022, are incorporated herein by reference in their entirety.

[0283] One aspect of the present disclosure is useful in wireless communication systems.

[0284] 100 Base station 200 Terminal 201 Receiving unit 202 LBT carrier sense unit 203 Signal separation unit 204 Demodulation unit 205 Error correction decoding unit 206 Control signal receiving unit 207 Error correction coding unit 208 Modulation unit 209 Control signal generating unit 210 Signal allocation unit 211 Transmission unit

Claims

1. In terminal-to-terminal communication in an unlicensed band, a control circuit that assigns signals to resource allocation units consisting of interlaced consecutive numbers, A transmitting circuit that transmits the aforementioned signal, A communication device equipped with the following.

2. The aforementioned resource allocation unit is a subchannel, The number of interlaces constituting the subchannel is different. The communication device according to claim 1.

3. The signal includes a control signal and a data signal instructing resource allocation by the control signal. The communication device according to claim 1.

4. The number of interlaces constituting the subchannel is notified by the upper layer, The communication device according to claim 2.

5. The aforementioned resource allocation unit is a subchannel, When the signal is assigned to a plurality of subchannels, the control circuit places the control signal included in the signal in the subchannel with the lowest number among the plurality of subchannels. The communication device according to claim 1.

6. The resource allocation unit is a subchannel, The maximum number of interlaces constituting the subchannel varies depending on the value of Subcarrier Spacing (SCS). The communication device according to claim 1.

7. The aforementioned resource allocation unit is a subchannel, If the number of interlaces in a resource block set is M, and the number of subchannels in the resource block set is C, then the number of interlaces per subchannel is set to M / C. The communication device according to claim 1.

8. The signal is a Physical Sidelink Shared Channel (PSSCH), When the control circuit places the signal in two adjacent resource block sets including the resource allocation unit, it allows transmission in the intra-cell guard band between the two resource block sets. The communication device according to claim 1.

9. When the signal is placed in two adjacent resource block sets including the resource allocation unit, if the signal is a Physical Sidelink Shared Channel (PSSCH), the control circuit allows transmission in the intra-cell guard band between the two resource block sets. If the signal is a Physical Sidelink Control Channel (PSCCH), the control circuit does not allow transmission in the intra-cell guard band. The communication device according to claim 1.

10. The signal is a Physical Sidelink Control Channel (PSCCH), The control circuit sets a first start position and a second start position that is later than the first start position as the start position for transmitting the PSCCH. The communication device according to claim 1.

11. When the PSCCH transmission is started from the second starting position in the slot, the PSCCH transmission is limited to the section from the second starting position to the end of the slot. The communication device according to claim 10.

12. In terminal-to-terminal communication in an unlicensed band, a receiving circuit receives signals allocated in resource allocation units consisting of interlaced consecutive numbers, A control circuit for demodulating the aforementioned signal, A communication device equipped with the following.

13. Communication equipment, In inter-terminal communication in an unlicensed band, signals are assigned to resource allocation units consisting of interlaced consecutive numbers. The signal is transmitted, Communication method.

14. Communication equipment, In inter-terminal communication in an unlicensed band, a signal is received that is allocated in a resource allocation unit consisting of interlaced consecutive numbers. Demodulate the aforementioned signal. Communication method.

15. A control circuit that, in terminal-to-terminal communication in an unlicensed band, allocates signals to resource allocation units consisting of interlaced consecutive numbers, A transmitting circuit that transmits the aforementioned signal, An integrated circuit comprising the following:

16. In terminal-to-terminal communication in an unlicensed band, a receiving circuit that receives signals allocated in resource allocation units consisting of interlaced consecutive numbers, A control circuit for demodulating the aforementioned signal, An integrated circuit comprising the following: