Beam reporting method and apparatus for initial beam pairing in sidelink communication

Abstract

Provided are a method and an apparatus for beam reporting in sidelink communication. A reception terminal according to one disclosure of the present specification receives, from a transmission terminal, at least one of a reference signal (RS) and a direct link establishment request (DCR) message. Thereafter, the reception terminal determines a transmission beam of the transmission terminal and a reception beam of the reception terminal on the basis of the received reference signal or direct link establishment request message, and transmits beam reporting including information on at least one of the transmission beam of the transmission terminal and the reception beam of the reception terminal, wherein a resource through which the beam reporting is transmitted is associated with at least one of the reception beam and the transmission beam of the transmission terminal.

Description

Beam reporting method and device for initial beam pairing in sidelink communication

[0001] This specification relates to 3GPP 5G sidelink communications.

[0002] As more and more communication devices demand ever-increasing communication traffic, the need for next-generation 5G systems, which offer enhanced wireless broadband communication capabilities over existing LTE systems, is growing. This next-generation 5G system, known as NewRAT, differentiates communication scenarios into Enhanced Mobile BroadBand (eMBB), Ultra-reliability and low-latency communication (URLLC), and Massive Machine-Type Communications (mMTC).

[0003] Here, eMBB is a next-generation mobile communication scenario with characteristics such as High Spectrum Efficiency, High User Experienced Data Rate, and High Peak Data Rate; URLLC is a next-generation mobile communication scenario with characteristics such as Ultra Reliable, Ultra Low Latency, and Ultra High Availability (e.g., V2X, Emergency Service, and Remote Control); and mMTC is a next-generation mobile communication scenario with characteristics such as Low Cost, Low Energy, Short Packet, and Massive Connectivity (e.g., IoT).

[0004] The disclosure of the present specification seeks to provide a beam reporting method and device for initial beam pairing in sidelink communication.

[0005] One embodiment of the present specification provides a method in which, in sidelink (SL) communication, a receiving terminal receives at least one of a reference signal (RS) and a direct link establishment request (DCR) message from a transmitting terminal. Thereafter, the receiving terminal determines a transmission beam of the transmitting terminal and a reception beam of the receiving terminal based on the received reference signal or direct link establishment request message, and transmits beam reporting including information about at least one of the transmission beam of the transmitting terminal and the reception beam of the receiving terminal, wherein a resource to which the beam reporting is transmitted is associated with at least one of the transmission beam and the reception beam of the transmitting terminal.

[0006] In addition, one embodiment of the present specification provides a method in which, in sidelink (SL) communication, a transmitting terminal transmits at least one of a reference signal (RS) and a direct link establishment request (DCR) message to a receiving terminal. Thereafter, the transmitting terminal receives beam reporting including information about at least one of a transmission beam of the transmitting terminal and a reception beam of the receiving terminal, which are determined based on the transmitted reference signal or direct link establishment request message, and a resource for receiving beam reporting is associated with at least one of the transmission beam and the reception beam of the transmitting terminal.

[0007] In addition, one embodiment of the present specification includes, in a sidelink (SL) communication, a control unit and a memory unit storing instructions and being operably electrically connectable to the control unit, wherein, based on the instructions being executed by the control unit, an operation is performed: receiving at least one of a reference signal (RS) and a direct link establishment request (DCR) message from a transmitting terminal. Then, based on the received reference signal or direct link establishment request message, a transmission beam of the transmitting terminal and a reception beam of the receiving terminal are determined, and beam reporting including information about at least one of the transmission beam of the transmitting terminal and the reception beam of the receiving terminal is transmitted, wherein a resource to which the beam reporting is transmitted provides a receiving terminal that is associated with at least one of the transmission beam and the reception beam of the transmitting terminal.

[0008] In addition, one embodiment of the present specification includes, in a sidelink (SL) communication, a control unit and a memory unit storing instructions and being operably electrically connectable to the control unit, wherein, based on the instructions being executed by the control unit, an operation performed is: transmitting at least one of a reference signal (RS) and a direct link establishment request (DCR) message to a receiving terminal. Thereafter, beam reporting including information about at least one of a transmission beam of a transmitting terminal and a reception beam of a receiving terminal determined based on the transmitted reference signal or the direct link establishment request message is received, wherein a resource for receiving beam reporting provides a transmitting terminal associated with at least one of the transmission beam and the reception beam of the transmitting terminal.

[0009] The resource to which beam reporting is transmitted may be resource pool specific or terminal specific.

[0010] Meanwhile, beam reporting can be repeatedly transmitted from a receiving terminal and received by a transmitting terminal. That is, beam reporting can be repeatedly transmitted through the resource through which beam reporting is transmitted.

[0011] Alternatively, beam reporting may be transmitted and received via a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), or a physical sidelink feedback channel (PSFCH). Here, beam reporting transmitted via the PSCCH or PSSCH may be in message form, while beam reporting transmitted via the PSFCH may be in sequence form.

[0012] According to the disclosure of this specification, beam reporting for initial beam pairing for sidelink communication in the 3GPP 5G FR2 (frequency range 2) band can be efficiently performed.

[0013] Figure 1 is a diagram illustrating an NR wireless communication system.

[0014] Figure 2 illustrates the structure of a radio frame used in NR.

[0015] Figure 3 illustrates the slot structure of an NR frame.

[0016] Figure 4 is an example showing an NG-RAN architecture supporting the PC5 interface.

[0017] Figures 5a and 5b illustrate a procedure for performing sidelink communication according to a sidelink resource allocation mode.

[0018] FIGS. 6A and 6B are examples showing resource allocation for beam reporting according to one embodiment of the present specification.

[0019] FIG. 7 is an example of beam reporting signaling for initial beam pairing according to one embodiment of the present specification.

[0020] FIG. 8 illustrates a wireless communication device according to one embodiment of the present specification.

[0021] Although this specification describes embodiments using LTE systems, LTE-A systems, and NR systems, these embodiments may be applied to any communication system falling within the above definitions.

[0022] Additionally, the name of the base station in this specification may be used as a comprehensive term including RRH (remote radio head), eNB, TP (transmission point), RP (reception point), relay, etc.

[0023] 3GPP-based communication standards define downlink physical channels corresponding to resource elements that carry information originating from higher layers, and downlink physical signals corresponding to resource elements that are used by the physical layer but do not carry information originating from higher layers. For example, the physical downlink shared channel (PDSCH), physical broadcast channel (PBCH), physical multicast channel (PMCH), physical control format indicator channel (PCFICH), physical downlink control channel (PDCCH), and physical hybrid ARQ indicator channel (PHICH) are defined as downlink physical channels, and reference signals and synchronization signals are defined as downlink physical signals. A reference signal (RS), also referred to as a pilot, is a signal with a predefined special waveform known to the gNB and the UE. For example, cell specific RS, UE-specific RS (UE-RS), positioning RS (PRS), and channel state information RS (CSI-RS) are defined as downlink reference signals. The 3GPP LTE / LTE-A standard defines uplink physical channels corresponding to resource elements carrying information originating from higher layers, and uplink physical signals corresponding to resource elements used by the physical layer but not carrying information originating from higher layers.For example, a physical uplink shared channel (PUSCH), a physical uplink control channel (PUCCH), and a physical random access channel (PRACH) are defined as uplink physical channels, and a demodulation reference signal (DMRS) for uplink control / data signals and a sounding reference signal (SRS) used for uplink channel measurement are defined.

[0024] In this specification, PDCCH (Physical Downlink Control CHannel) / PCFICH (Physical Control Format Indicator CHannel) / PHICH ((Physical Hybrid automatic retransmit request Indicator CHannel) / PDSCH (Physical Downlink Shared CHannel) mean a set of time-frequency resources or a set of resource elements that carry DCI (Downlink Control Information) / CFI (Control Format Indicator) / downlink ACK / NACK (ACKnowlegement / Negative ACK) / downlink data, respectively. In addition, PUCCH (Physical Uplink Control CHannel) / PUSCH (Physical Uplink Shared CHannel) / PRACH (Physical Random Access CHannel) mean a set of time-frequency resources or a set of resource elements that carry UCI (Uplink Control Information) / uplink data / random access signals, respectively.

[0025] Meanwhile, the NR frequency band can be defined by two types of frequency ranges (FR1, FR2). The numerical values ​​of the frequency ranges can be changed, and for example, the two types of frequency ranges (FR1, FR2) can be as shown in Table 1 below. For convenience of explanation, among the frequency ranges used in the NR system, FR1 can mean the “sub 6 GHz range”, and FR2 can mean the “above 6 GHz range” and can be called millimeter wave (mmW).

[0026] Frequency Range designationCorresponding frequency rangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0027] The numerical value of the frequency range of the NR system can be changed. For example, FR1 can include a band from 410 MHz to 7125 MHz, as shown in Table 1. That is, FR1 can include frequency bands above 6 GHz (or 5850, 5900, 5925 MHz, etc.). For example, the frequency bands above 6 GHz (or 5850, 5900, 5925 MHz, etc.) included within FR1 can include unlicensed bands. Unlicensed bands can be used for various purposes, such as for vehicle communications (e.g., autonomous driving).

[0028] Figure 1 is a diagram illustrating an NR wireless communication system.

[0029] Referring to FIG. 1, the NR wireless communication system can be divided into a 5G core network (5GC) and a next generation-radio access network (NG-RAN), and the NG-RAN can include a base station (gNB and / or ng-eNB) that provides user plane and control plane protocol termination to user equipment (UE). The gNB (next generation-Node B) provides NR user plane and control plane protocol termination to the UE, and the ng-eNB (next generation-evolved Node B) provides evolved-universal terrestrial radio access (E-UTRA) user plane and control plane protocol termination to the UE. The UE can be fixed or mobile, and may be referred to by other terms such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a mobile terminal (MT), or a wireless device. A base station (gNB and / or ng-eNB) may be a fixed station that communicates with a terminal (UE) and may be called by other terms such as base transceiver system (BTS), access point, etc.

[0030] Base stations (gNB and / or ng-eNB) can be connected to each other via Xn interfaces and can be connected to 5GC (5G core network) via NG interfaces. Specifically, base stations (gNB and / or ng-eNB) can be connected to AMF (access and mobility management function) via NG-C interfaces and can be connected to UPF (user plane function) via NG-U interfaces.

[0031] Figure 2 illustrates the structure of a radio frame used in NR.

[0032] In NR, uplink and downlink transmissions are structured as frames. A radio frame is 10ms long and is defined by two 5ms half-frames (HF). Each half-frame is defined by five 1ms subframes (SF). A subframe is divided into one or more slots, and the number of slots in a subframe depends on the subcarrier spacing (SCS). Each slot contains 12 or 14 OFDM(A) symbols, depending on the cyclic prefix (CP). When a regular CP is used, each slot contains 14 symbols. When an extended CP is used, each slot contains 12 symbols. Here, the symbols can include OFDM symbols (or CP-OFDM symbols), SC-FDMA symbols (or DFT-s-OFDM symbols).

[0033] Table 2 illustrates that when CP is normally used, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary depending on the SCS.

[0034] SCS(15*2 u )N slot symb N frame,u slot N subframe,u slot 15 KHz(u =0)1410130 KHz(u=1)1420260 KHz(u=2)14404120 KHz(u=3)14808240 KHz(u=4)1416016

[0035] N slot symb : Number of symbols in the slot

[0036] N frame,u slot : Number of slots in the frame

[0037] ​​N subframe,u slot : Number of slots in a subframe

[0038] Table 3 illustrates that when extended CP is used, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary depending on the SCS.

[0039] SCS (15*2 u )N slot symb N frame,u slot N subframe,u slot 60KHz (u=2)12404

[0040] In an NR system, OFDM(A) numerology (e.g., SCS, CP length, etc.) may be set differently between multiple cells that are merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., SF, slot, or TTI) (conveniently referred to as TU (Time Unit)) consisting of the same number of symbols may be set differently between the merged cells.

[0041] Figure 3 illustrates the slot structure of an NR frame.

[0042] ​​A slot contains multiple symbols in the time domain. For example, a slot contains 14 symbols for a regular CP, but 12 symbols for an extended CP. A carrier contains multiple subcarriers in the frequency domain. A resource block (RB) is defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A bandwidth part (BWP) is defined as multiple consecutive (P)RBs in the frequency domain, and can correspond to a single numerology (e.g., SCS, CP length, etc.). A carrier can contain up to N (e.g., 4) BWPs. Data communication is performed through activated BWPs, and only one BWP can be activated for a single terminal. Each element in the resource grid is referred to as a resource element (RE), to which one complex symbol can be mapped.

[0043] Figure 4 is an example showing an NG-RAN architecture supporting the PC5 interface.

[0044] Referring to Figure 4, the NG-RAN (next generation-radio access network) architecture supports the PC5 interface. Sidelink transmission and reception via the PC5 interface are supported when the UE is inside NG-RAN coverage and when the UE is outside NG-RAN coverage, regardless of the RRC (radio resource control) state the UE is in.

[0045] Support for V2X (Vehicle-to-Everything) services via the PC5 interface can be provided by NR sidelink communications and / or V2X sidelink communications. NR sidelink communications can also be used to support services other than V2X services.

[0046] NR sidelink communication can support one of the following transmission modes: unicast, groupcast, and broadcast. In the case of unicast sidelink communication, a terminal can perform one-to-one communication with another terminal, and in the case of groupcast sidelink communication, a terminal can perform sidelink communication with one or more terminals within the group to which it belongs.

[0047] Figures 5a and 5b illustrate a procedure for performing sidelink communication according to a sidelink resource allocation mode.

[0048] Figure 5a shows terminal operation related to NR resource allocation mode 1, and Figure 5b shows terminal operation related to NR resource allocation mode 2.

[0049] Referring to FIG. 5A, in NR resource allocation mode 1, a base station can schedule sidelink (SL) resources to be used by a terminal (UE) for sidelink (SL) transmission. For example, the base station can perform resource scheduling using downlink control information (DCI) transmitted to terminal 1 (UE1) via a physical downlink control channel (PDCCH), and UE1 can perform V2X or SL communication with terminal 2 (UE2) according to the resource scheduling. For example, UE1 can transmit sidelink control information (SCI) to UE2 via a physical sidelink control channel (PSCCH), and then transmit SL data based on the SCI to UE2 via a physical sidelink shared channel (PSSCH).

[0050] Referring to FIG. 5b, in NR resource allocation mode 2, a terminal can determine an SL transmission resource within the SL resources configured by the base station or within preset SL resources. For example, the configured SL resources or preset SL resources may be an SL resource pool (sidelink resource pool). For example, the terminal can autonomously select or schedule resources for SL transmission. That is, the terminal can perform SL communication by selecting resources within the configured resource pool. In addition, the terminal can perform sensing and resource (re)selection procedures to select resources within a selection window. For example, the sensing can be performed on a sub-channel basis. As illustrated in FIG. 5b, UE1, which has selected a resource within the resource pool, can transmit SCI to UE2 via PSCCH and then transmit data based on the SCI to UE2 via PSSCH.

[0051] The beam reporting method may vary depending on beam correspondence during initial beam pairing. Furthermore, beam reporting resource allocation and operation may vary depending on whether beam reporting is transmitted in message or sequence format. The above matters are currently under discussion in the standardization meeting and have not yet been decided. Therefore, this specification aims to develop the above-mentioned issues and propose related solutions.

[0052] In this specification, for the convenience of explanation, UE1 is used as a terminal transmitting data / signal in sidelink (SL) communication, and UE2 is used as a target terminal receiving data / signal from UE1. In addition, a transmission beam used for data / signal transmission is referred to as TX beam, and a reception beam used for data / signal reception is referred to as RX beam. In this specification, a transmission and operation method for reporting beam information for UE1 measured by UE2 when performing initial beam pairing and unicast link establishment operations for sidelink (SL) communication in a frequency range 2 (FR2) band is proposed.

[0053] To perform initial beam pairing and unicast link establishment operations, UE1 may transmit a reference signal (RS) and / or a direct link establishment request message in the form of beam sweeping. Thereafter, UE2 may select one or more TX beams of UE1 and one or more RX beams of UE2 that can be used for SL communication among the Tx beams used by UE1 by receiving the RS or direct link establishment request message. That is, UE2 may acquire a pair of a TX beam of UE1 and a corresponding RX beam of UE2. After performing the above operations, UE2 must transmit to UE1 the acquired TX beam information of UE1 and information associated with the beam pair, such as beam quality information such as L1-RSRP (layer 1-reference signal received power), and a process of transmitting the information, i.e., beam reporting, is required.

[0054] This specification proposes an operational method in which UE2 reports beam information acquired by UE1 to UE2 through two operation processes, regardless of the order in which UE1 and UE2 perform the initial beam pairing operation and the unicast link establish operation.

[0055] In this specification, when performing beam reporting for initial beam pairing, the signal transmitted by UE2 is described in the form of a message transmitted through a physical sidelink control channel (PSCCH) and a physical sidelink shared channel (PSSCH), and in the form of a sequence. When performing beam reporting in the form of a sequence, this includes the case where the sequence is transmitted through a physical sidelink feedback channel (PSFCH).

[0056] 1st disclosure: When beam reporting, beam-related information is transmitted in the form of a message.

[0057] At the initial beam pairing stage, the beam reporting point is a situation where UE1 does not know the information related to the beam to be transmitted and received with UE2. Depending on the presence or absence of beam correspondence between the sidelink transmitted from UE1 to UE2 and the sidelink transmitted from UE2 to UE1, the following two methods can be applied to transmit and receive beam reporting in message form. For convenience of explanation, the sidelink transmitted from UE1 to UE2 is referred to as SL1, and the sidelink transmitted from UE2 to UE1 is referred to as SL2.

[0058] 1) Beam reporting method when there is no beam correspondence between SL1 and SL2

[0059] For initial beam pairing, the information about the beam measured and acquired by UE2 from the signal and / or message transmitted via SL1 may be the Tx beam information of UE1 and the Rx beam information of UE2. Information about the TX beam of UE2 for transmitting beam reporting of UE2 and the Rx beam for receiving beam reporting of UE1 are not available for both UE2 and UE1. Therefore, beam reporting can be performed in the following manner.

[0060] For beam reporting transmitted by UE2, a specific resource area can be configured, and within the specific resource area, UE2 can repeatedly transmit a beam reporting message in a beam sweeping format. At this time, if UE1 successfully receives the beam reporting message in the beam sweeping format, it can obtain information about the Rx beam of UE1. In addition, it can obtain information about the Tx beam of UE1 by performing decoding of the beam reporting message. The Tx beam information of UE1 included in the beam reporting message may be information about the resource area in which the signal and / or message transmitted by UE1 via SL1 is transmitted when UE2 attempts to receive the signal and / or message transmitted by UE1 in the beam sweeping format and successfully receives the signal and / or message. Alternatively, it may be the Tx beam index of UE1 associated to the resource area.

[0061] In the above process, each beam reporting transmission resource within the resource area set for beam reporting transmitted by UE2 can be operated in association with the Tx beam of UE1. In this case, when UE1 receives a beam reporting message, it can be operated so that it can obtain Tx beam information of UE1 corresponding to the specific resource area where the message was transmitted.

[0062] Thereafter, the signal and / or message transmitted by UE1 through SL1 may be transmitted including Tx beam information of UE2, and UE2, which receives the signal and / or message, may obtain Tx beam information of UE2. At this time, the Tx beam information of UE2 may be information on a resource area in which UE1 successfully received a beam reporting message or a Tx beam index of UE2 associated to the resource area.

[0063] 2) Beam reporting method when there is beam correspondence between SL1 and SL2

[0064] For initial beam pairing, the beam information measured and acquired by UE2 from the signal and / or message transmitted via SL1 may be UE1's Tx beam information and UE2's Rx beam information. If there is beam correspondence, the previously acquired UE2 Rx beam may be applied as the UE2's Tx beam used when transmitting the beam reporting message via SL2. Alternatively, the UE2's Tx beam may be set based on the corresponding UE2's Rx beam information.

[0065] A specific resource area is configured for beam reporting transmitted by UE2, and within the specific resource area, UE2 can repeatedly transmit a beam reporting message one or more times using the Tx beam acquired in the above process.

[0066] At this time, resources for beam reporting transmission may be associated with UE1's Tx beam and / or Rx beam for each resource area. In this case, when UE1 receives a beam reporting message, it may attempt to receive it using the Rx beam corresponding to the specific resource area where the message was transmitted. Alternatively, UE1 may attempt to receive it in the form of beam sweeping in a resource area where the beam reporting message is repeatedly transmitted.

[0067] If the beam reporting message is successfully received, UE1 can obtain information about UE1's Rx beam. The Rx beam information can be applied and used as UE1's Tx beam. Alternatively, UE1's Tx beam can be set based on the Rx beam information.

[0068] Additionally, information about the Tx beam(s) of UE1 can be additionally obtained or confirmed by performing beam reporting message decoding.

[0069] The Tx beam information of UE1 included in the beam reporting message may be information on the resource area where the signal and / or message was transmitted when UE2 attempted to receive the signal and / or message transmitted by UE1 via SL1 in the form of beam sweeping and succeeded in receiving the signal and / or message. Alternatively, it may be the Tx beam index of UE1 associated with the resource area.

[0070] 3) Beam reporting resource area setting method and beam information mapping method with the resource area

[0071] In the first disclosure method 1) and method 2) described above, the information about the Tx beam transmitted by UE2 during beam reporting may be information about one Tx beam or two or more Tx beams.

[0072] The resource configuration for beam reporting in methods 1) and 2) of the first disclosure described above is configured for each resource pool (RP) and can be shared and used among UEs using the corresponding RP. In other words, beam reporting resources can be operated in an RP-specific manner. The configuration information can be indicated through radio resource control (RRC), medium access control-control element (MAC-CE), downlink control information (DCI), or system information block (SIB). Alternatively, it can be indicated by a combination of the corresponding signals.

[0073] Resource configuration for beam reporting in methods 1) and 2) of the first disclosure described above can be configured and operated on a per-UE basis. That is, beam reporting resources can be operated UE-specifically. This configuration information can be indicated via RRC, MAC-CE, or DCI. Alternatively, it can be indicated by a combination of these signals.

[0074] In setting up a resource area for beam reporting in the first disclosure method 1) and method 2) described above, if the resource area is associated with a specific Tx beam and / or Rx beam of UE1, the mapping between each orthogonal time / frequency resource area and beam may correspond 1:1, or the mapping between some or overlapping combinations of time / frequency resources and beams may correspond 1:1.

[0075] FIGS. 6A and 6B are examples showing resource allocation for beam reporting according to one embodiment of the present specification.

[0076] In FIGS. 6A and 6B, R1, R2, R3, etc. are resource units composed of specific time-frequency resources, and are defined for convenience of explanation. For example, one resource unit may be composed of one or more time resources such as symbols, mini-slots, slots, etc., and in the case of frequency, it may be composed of one or more frequency resources such as sub-carriers, resource blocks, sub-channels, etc. It is assumed that two resource units are required for one beam reporting transmission. FIG. 6A is an example of allocating six resource units, and if resources capable of beam reporting are allocated orthogonally to each other, three opportunities can be configured as shown in Table 5.

[0077] Occasion #1R1, R4Occasion #2R2, R5Occasion #3R3, R6

[0078] UE2 can transmit beam reporting messages repeatedly up to three times using Occasion #1, Occasion #2, and Occasion #3. The configuration in Table 5 is an example of allocating occasions with orthogonal resources having different time domains when configuring occasions, assuming that a specific beam is applied and transmitted and received in each time unit when transmitting and receiving beam reporting in the form of beam sweeping. In the absence of beam correspondence, resource allocation as shown in Fig. 6a and Table 5 can be operated to enable repeated transmission of beam reporting messages using different beams for each occasion. Meanwhile, Fig. 6b is a resource area where six resource units R1 to R6 are set for beam reporting, similar to Fig. 6a. In a case where beam reporting message transmission is possible using two resource units, if the resources are allocated orthogonally to each other, two occasions can be allocated as in the example in Table 6. In this case, the entire resource units cannot be used efficiently.

[0079] Occasion #1R1, R3Occasion #2R2, R4

[0080] However, if occasions are operated in a non-orthogonal and nested form, up to 4 occasions can be allocated as shown in Table 7.

[0081] Occasion #1R1, R3Occasion #2R2, R4Occasion #3R3, R5Occasion #4R4, R6

[0082] In Table 7, Occasion #1 and Occasion #3 overlap each other, and Occasion #2 and Occasion #4 overlap each other. If there is beam correspondence, UE2 can be operated in a manner of transmitting a beam reporting message once in an occasion associated with specific Rx beam information of UE1. In this case, resources can be allocated as shown in Fig. 6b and Table 7, and many occasions can be allocated by a combination of time and frequency resources.

[0083] Increasing the number of occasions used in SL communications allows UEs to utilize more beams, thus narrowing the beam size, thereby improving performance. Conversely, operating a fixed number of beams can minimize the resources allocated for beam reporting message transmission. For example, minimizing UE-specific beam reporting resource allocation and operation can improve resource efficiency.

[0084] 4) Beam correspondence indication method in V2X (vehicle-to-everything) SL communication

[0085] In V2X SL communication, UE2 can provide an indication to UE1 regarding beam correspondence. The beam correspondence indication can be transmitted during the unicast link establishment process or the initial beam pairing process. For example, the beam correspondence indication can be included in the direct link establishment accept message that UE2 transmits to UE1 during the unicast link establishment process. Alternatively, the beam correspondence indication can be included in the beam reporting message that UE2 transmits to UE1 during the initial beam pairing process.

[0086] 2nd Disclosure: When beam-related information is transmitted in sequence format during beam reporting

[0087] All of the suggestions made in this specification for cases where beam-related information is transmitted in the form of a message during beam reporting can be applied in a simple, extended, modified or combined form when beam reporting information is transmitted in the form of a sequence rather than a message.

[0088] When beam reporting is transmitted in sequence form, the cases in which it is applied in a modified form compared to message form transmission are described as follows.

[0089] Since a sequence is not a message, no information can be obtained through decoding. Instead, beam information can be obtained through sequence detection. That is, beam information can be transmitted by combining information from the resource area where the sequence is transmitted with the sequence detected in that resource area. Therefore, occasions for beam reporting can be set using this combination.

[0090] For example, if there are two sequences that UE2 can use and the sequences are orthogonal or semi-orthogonal to each other, the occasions based on FIGS. 6a and 6b can be combined and operated with the sequences as shown in Tables 8 and 9. At this time, the sequence includes an orthogonal sequence form in the form of a sequence having different cyclic shifts based on the same sequence, such as a Zadoff-Chu sequence.

[0091] Occasion #1R1, R4, sequence #1Occasion #2R2, R5, sequence #1Occasion #3R3, R6, sequence #1Occasion #4R1, R4, sequence #2Occasion #5R2, R5, sequence #2Occasion #6R3, R6, sequence #2

[0092] In the case of FIG. 6a and Table 8, if there is no beam correspondence, up to two UEs can be supported for transmitting beam reporting messages three times. That is, in Table 5, since message transmissions by different users in the same resource area in message form cause interference, beam reporting message transmission for one UE is possible for stable beam reporting message transmission and reception.

[0093] If there are two UEs, UE2 and UE3, that want to transmit beam reporting messages based on the method in Table 8, Occasions #1, #2, and #3 can be assigned to UE2, and Occasions #4, #5, and #6 can be assigned to UE3. In this case, stable detection is possible due to the orthogonality of the sequences even in occasions with overlapping resource areas, such as Occasion #1 and Occasion #4. Therefore, operation is possible so that up to two UEs can use it. When the resource area operated for beam reporting is operated RP-specifically, in order to allow as many users as possible to use the common resource area, beam reporting in the form of sequence can be performed and occasions can be combined and operated in the manner as in Table 8.

[0094] When the method of FIG. 6a and Table 4 is applied and operated in the case where beam correspondence exists, UE2 can be operated in a form in which the beam reporting message is transmitted once at an occasion associated with specific Rx beam information of UE1. In this case, if the operation of resources for beam reporting transmission is UE-specific, UE2 can perform beam reporting through one of the six occasions. In other words, increasing the number of occasions used in SL communication allows UEs to use more beams during SL communication, that is, to use narrower beams, which can improve performance. Conversely, when operating a fixed number of beams, the allocated resources for beam reporting message transmission can be minimized. For example, when allocating and operating beam reporting resources in a UE-specific form, resource efficiency can be improved by minimizing the corresponding resources.

[0095] In the above case, if the operation of the resource for beam reporting transmission is RP specific, that is, if there is UE3 that wants to transmit beam reporting sequence using the resource in addition to UE2, each UE can be allocated three occasions in the following form. UE2 can be allocated Occasion #1, Occasion #2, and Occasion #3, and UE3 can be allocated Occasion #4, Occasion #5, and Occasion #6. In other words, even if UE2 and UE3 transmit sequences for beam reporting in the same resource area, they can be allocated and operated so that they can be detected without mutual interference due to orthogonality between the sequences by assigning different sequences.

[0096] Occasion #1R1, R3, sequence #1Occasion #2R2, R4, sequence #1Occasion #3R3, R5, sequence #1Occasion #4R4, R6, sequence #1Occasion #5R1, R3, sequence #2Occasion #6R2, R4, sequence #2Occasion #7R3, R5, sequence #2Occasion #8R4, R6, sequence #2

[0097] In the case of Fig. 6b and Table 9, up to 8 occasions can be allocated and operated compared to Table 7. If there is beam correspondence, UE2 can be operated in a form of transmitting a beam reporting message once in an occasion associated with specific Rx beam information of UE1, and in this case, resources can be allocated as shown in Fig. 6b and Table 9, and many occasions can be allocated by a combination of time / frequency resources and sequences.

[0098] Increasing the number of occasions used in SL communications allows UEs to utilize more beams, thus narrowing the beam size, thereby improving performance. Conversely, operating a fixed number of beams can minimize the resources allocated for beam reporting message transmission. For example, minimizing UE-specific beam reporting resource allocation and operation can improve resource efficiency.

[0099] Although arbitrary time / frequency resources and sequence resources are set for convenience of explanation in FIGS. 6a to 6b and Tables 5 to 9, all contents proposed in this specification can be applied and operated in a simple, modified or extended form in an SL communication environment.

[0100] In addition, although this specification is described based on a 5G NR system, all cases to which the concepts disclosed in this specification are applied can be included in the scope of this specification regardless of the specific wireless communication technology.

[0101] FIG. 7 is an example of beam reporting signaling for initial beam pairing according to one embodiment of the present specification.

[0102] Referring to FIG. 7, a receiving terminal (UE2) receives at least one of a reference signal (RS) and a direct link establishment request (DCR) message from a transmitting terminal (UE1) (S701, S702).

[0103] Thereafter, the receiving terminal (UE2) determines the transmission beam of the transmitting terminal and the reception beam of the receiving terminal based on the received reference signal or direct link establishment request message, and transmits beam reporting including information on at least one of the transmission beam of the transmitting terminal and the reception beam of the receiving terminal to the transmitting terminal (UE1) (S703). Here, the resource to which the beam reporting is transmitted is associated with at least one of the transmission beam and the reception beam of the transmitting terminal.

[0104] The resource to which beam reporting is transmitted may be resource pool specific or terminal specific.

[0105] Meanwhile, beam reporting can be repeatedly transmitted from a receiving terminal and received by a transmitting terminal. That is, beam reporting can be repeatedly transmitted through the resource through which beam reporting is transmitted.

[0106] Alternatively, beam reporting may be transmitted and received via a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), or a physical sidelink feedback channel (PSFCH). Here, beam reporting transmitted via the PSCCH or PSSCH may be in message form, while beam reporting transmitted via the PSFCH may be in sequence form.

[0107] Below, a description is given of a device to which this specification can be applied.

[0108] FIG. 8 illustrates a wireless communication device according to one embodiment of the present specification.

[0109] Referring to FIG. 8, the wireless communication system may include a first device (100) and a second device (200).

[0110] The first device (100) may be a base station, a network node, a transmitting terminal, a receiving terminal, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, a connected car, a drone (Unmanned Aerial Vehicle, UAV), an AI (Artificial Intelligence) module, a robot, an AR (Augmented Reality) device, a VR (Virtual Reality) device, an MR (Mixed Reality) device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, a device related to 5G services, or any other device related to the 4th industrial revolution field.

[0111] The second device (200) may be a base station, a network node, a transmitting terminal, a receiving terminal, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, a connected car, a drone (Unmanned Aerial Vehicle, UAV), an AI (Artificial Intelligence) module, a robot, an AR (Augmented Reality) device, a VR (Virtual Reality) device, an MR (Mixed Reality) device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, a device related to 5G services, or a device related to other fields of the 4th industrial revolution.

[0112] The first device (100) may include at least one processor, such as a control unit (1020), at least one memory, such as a memory unit (1030), and at least one transceiver, such as a transceiver unit (1010). In addition, the first device (100) may further include a power supply unit (1040) that supplies and controls power to the control unit (1020), the memory unit (1030), and / or the transceiver unit (1010). The control unit (1020) may perform the functions, procedures, and / or methods described above. The control unit (1020) may perform one or more protocols. For example, the control unit (1020) may perform one or more layers of a wireless interface protocol. The memory unit (1030) may be connected to the control unit (1020) and may store various types of information and / or commands. The above transmitting and receiving unit (1010) is connected to the control unit (1020) and can be controlled to transmit and receive wireless signals.

[0113] The second device (200) may include at least one processor, such as a control unit (2020), at least one memory, such as a memory unit (2030), and at least one transceiver, such as a transceiver unit (2010). In addition, the second device (200) may further include a power supply unit (2040) that supplies and controls power to the control unit (2020), the memory unit (2030), and / or the transceiver unit (2010). The control unit (2020) may perform the functions, procedures, and / or methods described above. The control unit (2020) may perform one or more protocols. For example, the control unit (2020) may perform one or more layers of a wireless interface protocol. The memory unit (2030) may be connected to the control unit (2020) and may store various types of information and / or commands. The above transmitting and receiving unit (2010) is connected to the control unit (2020) and can be controlled to transmit and receive wireless signals.

[0114] The memory unit (1030) and / or the memory unit (2030) may be connected to the control unit (1020) and / or the control unit (2020) either internally or externally, respectively, and may be connected to other control units via various technologies such as wired or wireless connections.

[0115] The first device (100) and / or the second device (200) may have one or more antennas. For example, the antenna (1050) and / or the antenna (2050) may be configured to transmit and receive wireless signals.

[0116] Although the preferred embodiments have been described above by way of example, the disclosure of this specification is not limited to these specific embodiments, and may be modified, changed, or improved in various forms within the scope described in the spirit and claims of this specification.

Claims

1. In a method for a receiving terminal to perform sidelink communication, A step of receiving at least one of a reference signal (RS) and a direct link establishment request (DCR) message; A step of determining a transmission beam of a transmitting terminal and a reception beam of a receiving terminal based on the reference signal or the direct link establishment request message; and A step of transmitting beam reporting including information on at least one of a transmission beam of the transmitting terminal and a reception beam of the receiving terminal, A method in which the resource through which the beam reporting is transmitted is associated with at least one of the transmission beam and the reception beam of the transmitting terminal.

2. In paragraph 1 A method in which the resource to which the above beam reporting is transmitted is resource pool specific or terminal specific.

3. In paragraph 1, A method wherein the above beam reporting is repeatedly transmitted through a resource through which the above beam reporting is transmitted.

4. In paragraph 1, The above beam reporting is transmitted through a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), or a physical sidelink feedback channel (PSFCH).

5. In paragraph 4, A method wherein the beam reporting transmitted through the PSCCH or the PSSCH is in message form, and the beam reporting transmitted through the PSFCH is in sequence form.

6. In a method for a transmitting terminal to perform sidelink communication, a step of transmitting at least one of a reference signal (RS) and a direct link establishment request (DCR) message; and A step of receiving beam reporting including information on at least one of a transmission beam of the transmitting terminal and a reception beam of the receiving terminal, determined based on the reference signal or the direct link setup request message, A method in which a resource from which the beam reporting is received is associated with at least one of a transmission beam and a reception beam of the transmitting terminal.

7. In paragraph 6 A method in which the resource from which the above beam reporting is received is resource pool specific or terminal specific.

8. In paragraph 6, The above beam reporting is repeatedly transmitted and received from a receiving terminal, 9. In paragraph 6, The above beam reporting is received via a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), or a physical sidelink feedback channel (PSFCH).

10. In paragraph 9, A method wherein the beam reporting received through the PSCCH or the PSSCH is in message form, and the beam reporting received through the PSFCH is in sequence form.

11. As a receiving terminal performing sidelink communication, control unit; and A memory unit storing instructions and being operably electrically connectable to the control unit, wherein the operations performed based on the instructions being executed by the control unit are: A step of receiving at least one of a reference signal (RS) and a direct link establishment request (DCR) message, A step of determining a transmission beam of a transmitting terminal and a reception beam of a receiving terminal based on the reference signal or the direct link setup request message, and A step of transmitting beam reporting including information on at least one of a transmission beam of the transmitting terminal and a reception beam of the receiving terminal, A receiving terminal, wherein the resource to which the beam reporting is transmitted is associated with at least one of the transmission beam and the reception beam of the transmitting terminal.

12. In Article 11 The resource to which the above beam reporting is transmitted is a receiving terminal, which is resource pool specific or terminal specific.

13. In paragraph 11, The above beam reporting is repeatedly transmitted through the resource through which the above beam reporting is transmitted, the receiving terminal.

14. In paragraph 11, The above beam reporting is transmitted to a receiving terminal via a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), or a physical sidelink feedback channel (PSFCH).

15. In paragraph 14, A receiving terminal, wherein the beam reporting transmitted through the PSCCH or the PSSCH is in message form, and the beam reporting transmitted through the PSFCH is in sequence form.

16. As a transmitting terminal performing sidelink communication, control unit; and A memory unit storing instructions and being operably electrically connectable to the control unit, wherein the operations performed based on the instructions being executed by the control unit are: A step of transmitting at least one of a reference signal (RS) and a direct link establishment request (DCR) message, A step of receiving beam reporting including information on at least one of a transmission beam of the transmitting terminal and a reception beam of the receiving terminal, determined based on the reference signal or the direct link setup request message, and A transmitting terminal, wherein the resource from which the beam reporting is received is associated with at least one of a transmission beam and a reception beam of the transmitting terminal.

17. In Article 16 The resource from which the above beam reporting is received is a transmitting terminal, which is resource pool specific or terminal specific.

18. In paragraph 16, The above beam reporting is transmitted repeatedly from the receiving terminal and received by the transmitting terminal.

19. In paragraph 16, The above beam reporting is received by a transmitting terminal via a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), or a physical sidelink feedback channel (PSFCH).

20. In paragraph 19, A transmitting terminal, wherein the beam reporting received through the PSCCH or the PSSCH is in message form, and the beam reporting received through the PSFCH is in sequence form.

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