Method and apparatus for performing sidelink retransmission

Abstract

According to an embodiment of the present disclosure, a method for performing sidelink communication is provided. The method may include: performing an initial transmission to a second device; performing at least one first retransmission to the second device; receiving a hybrid automatic repeat request negative acknowledgement (HARQ NACK) related to the initial transmission and the at least one first retransmission from the second device; and performing at least one second retransmission to the second device.

Description

Technical Field

[0001] The present disclosure relates to wireless communication systems. Background Art

[0002] Sidelink (SL) communication is a communication scheme in which a direct link is established between user equipments (UEs) and the UEs directly exchange voice and data with each other without intervention of an evolved Node B (eNB). SL communication is being considered as a solution to eNB overhead caused by the rapid growth of data traffic.

[0003] V2X (Vehicle to Everything) refers to the communication technology used by vehicles to exchange information with other vehicles, pedestrians, objects equipped with infrastructure, etc. V2X can be divided into four types such as V2V (Vehicle to Vehicle), V2I (Vehicle to Infrastructure), V2N (Vehicle to Network), and V2P (Vehicle to Pedestrian). V2X communication can be provided through the PC5 interface and / or the Uu interface.

[0004] In addition, as more and more communication devices require larger communication capacity, mobile broadband communication enhanced relative to traditional radio access technology (RAT) is required. Therefore, the design of communication systems taking into account UEs or services that are sensitive to reliability and latency has also been discussed, and the next generation radio access technology taking into account enhanced mobile broadband communication, massive MTC, and ultra-reliable low-latency communication (URLLC) can be referred to as a new RAT (radio access technology) or NR (new radio).

[0005] Figure 1 is a diagram for describing NR-based V2X communication compared with V2X communication based on a RAT used before NR. Figure 1 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0006] Regarding V2X communication, when discussing the RAT used before NR, the focus is on the scheme of providing safety services based on V2X messages such as BSM (Basic Safety Message), CAM (Cooperative Awareness Message) and DENM (Decentralized Environment Notification Message). V2X messages may include location information, dynamic information, attribute information, etc. For example, a UE may send a periodic message type CAM and / or an event-triggered message type DENM to another UE.

[0007] For example, CAM may include dynamic state information of the vehicle such as direction and speed, static data of the vehicle such as size, and basic vehicle information such as external lighting status, route details, etc. For example, UE may broadcast CAM, and the latency of CAM may be less than 100ms. For example, UE may generate DENM and send it to another UE in an unexpected situation such as vehicle failure, accident, etc. For example, all vehicles within the transmission range of UE can receive CAM and / or DENM. In this case, DENM may have a higher priority than CAM.

[0008] Since then, various V2X scenarios have been proposed in NR regarding V2X communication. For example, these various V2X scenarios may include vehicle platooning, advanced driving, extended sensors, remote driving, etc.

[0009] For example, based on vehicle platooning, vehicles can move together by dynamically forming groups. For example, in order to perform platooning operations based on vehicle formation, vehicles belonging to the group can receive periodic data from the leading vehicle. For example, vehicles belonging to the group can reduce or increase the interval between vehicles by using the periodic data.

[0010] For example, based on advanced driving, the vehicles can be semi-autonomous or fully autonomous. For example, each vehicle can adjust trajectory or maneuver based on data obtained from local sensors of nearby vehicles and / or nearby logical entities. In addition, for example, each vehicle can share driving intentions with nearby vehicles.

[0011] For example, based on the extended sensors, raw data, processed data or real-time video data obtained by local sensors can be exchanged between the vehicle, the logical entity, the pedestrian UE and / or the V2X application server, so that, for example, the vehicle can recognize a further improved environment compared to the environment detected using its own sensors.

[0012] For example, based on the extended sensors, raw data, processed data or real-time video data obtained by local sensors can be exchanged between the vehicle, the logical entity, the pedestrian UE and / or the V2X application server, so that, for example, the vehicle can recognize a further improved environment compared to the environment detected using its own sensors.

[0013] In addition, schemes for specifying service requirements for various V2X scenarios such as vehicle platooning, advanced driving, extended sensors, remote driving, etc. are discussed in NR-based V2X communications. Summary of the invention

[0014] Technical issues

[0015] The technical problem of the present disclosure is to provide a side link communication method between devices (or terminals) and a device (or terminal) for executing the method.

[0016] Technical Solution

[0017] According to an embodiment of the present disclosure, a method for performing sidelink communication by a first device is provided. The method includes: performing an initial transmission to a second device based on the transmission of a first physical sidelink control channel (PSCCH) and a first physical sidelink shared channel (PSSCH) related to the PSCCH; performing at least one first retransmission to the second device based on at least one second PSCCH and at least one second PSSCH related to the at least one second PSCCH; receiving a hybrid automatic repeat request negative acknowledgment (HARQ NACK) related to the initial transmission and at least one first retransmission from the second device based on a physical sidelink feedback channel (PSFCH); and performing at least one second retransmission to the second device based on the reception of the HARQ NACK.

[0018] According to an embodiment of the present disclosure, a first device for performing sidelink communication is provided. The first device may include at least one memory storing instructions, at least one transceiver, and at least one processor connecting the at least one memory and the at least one transceiver, wherein the at least one processor may control the at least one transceiver to perform an initial transmission to a second device based on the transmission of a first physical sidelink control channel (PSCCH) and a first physical sidelink shared channel (PSSCH) associated with the PSCCH, control the at least one transceiver to perform at least one first retransmission to the second device based on at least one second PSCCH and at least one second PSSCH associated with the at least one second PSCCH, control the at least one transceiver to receive a hybrid automatic repeat request negative acknowledgment (HARQ NACK) associated with the initial transmission and at least one first retransmission from the second device based on a physical sidelink feedback channel (PSFCH), and control the at least one transceiver to perform at least one second retransmission to the second device based on the reception of the HARQ NACK.

[0019] According to an embodiment of the present disclosure, a device (or chip) configured to control a first UE is provided. The device may include at least one processor and at least one computer memory, the at least one computer memory being connected to be executable by the at least one processor and storing instructions, wherein the at least one processor executes the instructions to enable the first UE to: perform an initial transmission to a second device based on the transmission of a first physical sidelink control channel (PSCCH) and a first physical sidelink shared channel (PSSCH) related to the PSCCH, perform at least one first retransmission to the second device based on at least one second PSCCH and at least one second PSSCH related to the at least one second PSCCH, receive a hybrid automatic repeat request negative acknowledgment (HARQ NACK) related to the initial transmission and at least one first retransmission from the second device based on a physical sidelink feedback channel (PSFCH), and perform at least one second retransmission to the second device based on the reception of the HARQ NACK.

[0020] According to an embodiment of the present disclosure, a non-transitory computer-readable storage medium storing instructions (or indications) is provided. When the instructions are executed, the instructions cause a first device to: perform an initial transmission to a second device based on the transmission of a first physical sidelink control channel (PSCCH) and a first physical sidelink shared channel (PSSCH) related to the PSCCH, perform at least one first retransmission to the second device based on at least one second PSCCH and at least one second PSSCH related to the at least one second PSCCH, receive a hybrid automatic repeat request negative acknowledgment (HARQ NACK) related to the initial transmission and at least one first retransmission from the second device based on a physical sidelink feedback channel (PSFCH), and perform at least one second retransmission to the second device based on the reception of the HARQ NACK.

[0021] According to an embodiment of the present disclosure, a method for performing sidelink communication by a second device is provided. The method includes: receiving an initial transmission from a first device based on a first physical sidelink control channel (PSCCH) and a first physical sidelink shared channel (PSSCH) related to the PSCCH; receiving at least one first retransmission from the first device based on at least one second PSCCH and at least one second PSSCH related to the at least one second PSCCH; sending a hybrid automatic repeat request negative acknowledgment (HARQ NACK) related to the initial transmission and at least one first retransmission to the first device based on a physical sidelink feedback channel (PSFCH); and receiving at least one second retransmission from the first device based on the sent HARQ NACK.

[0022] According to an embodiment of the present disclosure, a second device for performing sidelink communication is provided. The second device may include at least one memory storing instructions, at least one transceiver, and at least one processor connected to the at least one memory and the at least one transceiver, wherein the at least one processor is configured to: control at least one transceiver to receive an initial transmission from a first device based on a first physical sidelink control channel (PSCCH) and a first physical sidelink shared channel (PSSCH) related to the PSCCH, control at least one transceiver to receive at least one first retransmission from the first device based on at least one second PSCCH and at least one second PSSCH related to the at least one second PSCCH, control at least one transceiver to send a hybrid automatic repeat request negative acknowledgment (HARQ NACK) related to the initial transmission and at least one first retransmission to the first device based on a physical sidelink feedback channel (PSFCH); and control at least one transceiver to receive at least one second retransmission from the first device based on the sent HARQ NACK.

[0023] Technical Effects

[0024] According to the present disclosure, a UE (or device) can efficiently perform SL communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a diagram for describing NR-based V2X communication compared with V2X communication based on a RAT used before NR.

[0026] Figure 2 The structure of the NR system according to an embodiment of the present disclosure is shown.

[0027] Figure 3 The functional division between NG-RAN and 5GC according to an embodiment of the present disclosure is shown.

[0028] Figure 4A and Figure 4B A radio protocol architecture according to an embodiment of the present disclosure is shown.

[0029] Figure 5 The structure of the NR system according to an embodiment of the present disclosure is shown.

[0030] Figure 6 The structure of the time slot of the NR frame according to an embodiment of the present disclosure is shown.

[0031] Figure 7 An example of a BWP according to an embodiment of the present disclosure is shown.

[0032] Fig. 8A and Figure 8BA radio protocol architecture for SL communication according to an embodiment of the present disclosure is shown.

[0033] Fig. 9 A UE performing V2X or SL communication according to an embodiment of the present disclosure is shown.

[0034] Fig. 10A and Fig. 10B A process of performing V2X or SL communication by a UE based on a transmission mode according to an embodiment of the present disclosure is shown.

[0035] FIG. 11A to FIG. 11C Three playback types according to an embodiment of the present disclosure are shown.

[0036] Fig.12 An example of adaptive blind retransmission when HARQ is enabled is shown.

[0037] Fig.13 An example of adaptive blind retransmission when HARQ is disabled is shown.

[0038] Fig.14 is a flowchart illustrating the operation of the first device according to an embodiment of the present disclosure.

[0039] Fig.15 is a flowchart illustrating the operation of the second device according to an embodiment of the present disclosure.

[0040] Fig.16 A communication system according to an embodiment of the present disclosure is shown.

[0041] Fig.17 A wireless device according to an embodiment of the present disclosure is shown.

[0042] Fig.18 A signal processing circuit for transmitting a signal according to an embodiment of the present disclosure is shown.

[0043] Fig.19 A wireless device according to an embodiment of the present disclosure is shown.

[0044] Fig. 20 A handheld device according to an embodiment of the present disclosure is shown.

[0045] Fig.21 An automobile or autonomous vehicle is shown according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0046] In this specification, "A or B" may mean "only A", "only B", or "both A and B". In other words, in this specification, "A or B" may be interpreted as "A and / or B". For example, in this specification, "A, B or C" may mean "only A", "only B", "only C", or "any combination of A, B, C".

[0047] A slash ( / ) or a comma used in this specification may mean "and / or". For example, "A / B" may mean "A and / or B". Thus, "A / B" may mean "only A", "only B", or "both A and B". For example, "A, B, C" may mean "A, B, or C".

[0048] In the present specification, "at least one of A and B" may mean "only A", "only B", or "both A and B". In addition, in the present specification, the expression "at least one of A or B" or "at least one of A and / or B" may be interpreted as "at least one of A and B".

[0049] In addition, in the present specification, "at least one of A, B, and C" may mean "only A", "only B", "only C", or "any combination of A, B, and C". In addition, "at least one of A, B, or C" or "at least one of A, B and / or C" may mean "at least one of A, B, and C".

[0050] In addition, brackets used in this specification may mean "for example". Specifically, when indicated as "control information (PDCCH)", this may mean that "PDCCH" is proposed as an example of "control information". In other words, the "control information" of this specification is not limited to "PDCCH", and "PDDCH" may be proposed as an example of "control information". Specifically, when indicated as "control information (ie, PDCCH)", this may also mean that "PDCCH" is proposed as an example of "control information".

[0051] The technical features described in each of the drawings in this specification may be implemented separately or simultaneously.

[0052] The techniques described below can be used in various wireless communication systems such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), etc. CDMA can be implemented using radio technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA-2000. TDMA can be implemented using radio technologies such as Global System for Mobile Communications (GSM) / General Packet Radio Service (GPRS) / Enhanced Data Rates for GSM Evolution (EDGE). OFDMA can be implemented using radio technologies such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Evolved UTRA (E-UTRA), etc. IEEE 802.16m is an evolved version of IEEE 802.16e and provides backward compatibility for systems based on IEEE 802.16e. UTRA is part of Universal Mobile Telecommunications System (UMTS). 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is a part of Evolved UMTS (E-UMTS) using E-UTRA. 3GPP LTE uses OFDMA in the downlink and SC-FDMA in the uplink. LTE-Advanced (LTE-A) is an evolution of LTE.

[0053] 5G NR is a subsequent technology of LTE-A corresponding to a new mobile communication system with high performance, low latency, high availability, etc. 5G NR can use all available spectrum resources including low frequency bands less than 1 GHz, intermediate frequency bands from 1 GHz to 10 GHz, and high frequency (millimeter wave) above 24 GHz.

[0054] For the sake of clarity, the following description will mainly focus on LTE-A or 5G NR. However, the technical features of the embodiments of the present disclosure will not be limited thereto.

[0055] Figure 2 The structure of the NR system based on the embodiment of the present disclosure is shown. Figure 2 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0056] Reference Figure 2, the next generation radio access network (NG-RAN) may include a BS 20 that provides user plane and control plane protocol terminations to the UE 10. For example, the BS 20 may include a next generation Node B (gNB) and / or an evolved Node B (eNB). For example, the UE 10 may be fixed or mobile and may be referred to as other terms such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a mobile terminal (MT), a wireless device, etc. For example, the BS may be referred to as a fixed station that communicates with the UE 10 and may be referred to as other terms such as a base transceiver system (BTS), an access point (AP), etc.

[0057] Figure 2 The embodiment of the present invention illustrates a case where only gNB is included. BS20 may be connected to each other via an Xn interface. BS20 may be connected to each other via a fifth generation (5G) core network (5GC) and an NG interface. More specifically, BS20 may be connected to an access and mobility management function (AMF) 30 via an NG-C interface, and may be connected to a user plane function (UPF) 30 via an NG-U interface.

[0058] Figure 3 The functional division between NG-RAN and 5GC based on an embodiment of the present disclosure is shown.

[0059] Reference Figure 3 , gNB can provide functions such as inter-cell radio resource management (inter-cell RRM), radio bearer (RB) control, connection mobility control, radio admission control, measurement configuration and provision, dynamic resource allocation, etc. AMF can provide functions such as non-access stratum (NAS) security, idle state mobility processing, etc. UPF can provide functions such as mobility anchoring, protocol data unit (PDU) processing, etc. Session management function (SMF) can provide functions such as user equipment (UE) Internet protocol (IP) address allocation, PDU session control, etc.

[0060] The radio interface protocol layer between the UE and the network can be classified into the first layer (L1), the second layer (L2), and the third layer (L3) based on the lower three layers of the open system interconnection (OSI) model known in the communication system. Here, the physical (PHY) layer belonging to the first layer provides an information transmission service using a physical channel, and the radio resource control (RRC) layer located at the third layer controls radio resources between the UE and the network. To this end, the RRC layer exchanges RRC messages between the UE and the BS layer.

[0061] Figure 4A and Figure 4B A radio protocol architecture according to an embodiment of the present disclosure is shown.

[0062] Figure 4A and Figure 4B The embodiments of can be combined with various embodiments of the present disclosure. Specifically, Figure 4A shows the radio protocol architecture for the user plane, and Figure 4B The radio protocol architecture for the control plane is shown. The user plane corresponds to the protocol stack for user data transmission and the control plane corresponds to the protocol stack for control signal transmission.

[0063] Reference Figure 4A and Figure 4B , the physical layer provides information transfer services to the upper layer through the physical channel. The physical layer is connected to the medium access control (MAC) layer, which is the upper layer of the physical layer, through the transport channel. Data is transferred between the MAC layer and the physical layer through the transport channel. The transport channel is classified according to how the data is transmitted through the radio interface and what characteristics of the data it transmits.

[0064] Data is transmitted through a physical channel between different PHY layers (ie, a PHY layer of a transmitter and a PHY layer of a receiver). The physical channel may be modulated using an Orthogonal Frequency Division Multiplexing (OFDM) scheme, and uses time and frequency as radio resources.

[0065] The MAC layer provides services to the Radio Link Control (RLC) layer via logical channels, and the RLC layer is a higher layer of the MAC layer. The MAC layer provides a function of mapping multiple logical channels to multiple transport channels. The MAC layer also provides a function of logical channel multiplexing by mapping multiple logical channels to a single transport channel. The MAC layer provides data transmission services through logical channels.

[0066] The RLC layer performs concatenation, segmentation, and reassembly of Radio Link Control Service Data Units (RLC SDUs). In order to ensure different Quality of Service (QoS) required by Radio Bearers (RBs), the RLC layer provides three types of operation modes, namely, Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). AM RLC provides error correction through Automatic Repeat Request (ARQ).

[0067] The Radio Resource Control (RRC) layer is defined only in the control plane. And, the RRC layer performs the function of controlling the physical channel, transport channel, and logical channel associated with the configuration, reconfiguration, and release of the radio bearer. RB refers to a logical path provided by the first layer (i.e., the PHY layer) and the second layer (i.e., the MAC layer, the RLC layer, and the PDCP layer) to transmit data between the UE and the network.

[0068] The functions of the Packet Data Convergence Protocol (PDCP) in the user plane include transmission, header compression and encryption of user data. The functions of the Packet Data Convergence Protocol (PDCP) in the control plane include transmission and encryption / integrity protection of control plane data.

[0069] The Service Data Adaptation Protocol (SDAP) layer is defined only in the user plane. The SDAP layer performs mapping between Quality of Service (QoS) flows and Data Radio Bearers (DRBs) and QoS Flow ID (QFI) marking in both DL and UL packets.

[0070] Configuration of RB refers to the process for specifying radio protocol layers and channel attributes to provide a specific service and for determining corresponding detailed parameters and operation methods. RB can then be classified into two types, namely, signaling radio bearer (SRB) and data radio bearer (DRB). SRB is used as a path for sending RRC messages in the control plane, and DRB is used as a path for sending user data in the user plane.

[0071] When the RRC connection is established between the RRC layer of the UE and the RRC layer of the E-UTRAN, the UE is in the RRC connected (RRC_CONNECTED) state, otherwise the UE can be in the RRC idle (RRC_IDLE) state. In the case of NR, the RRC inactive (RRC_INACTIVE) state is additionally defined, and the UE in the RRC_INACTIVE state can maintain the connection with the core network and release its connection with the BS.

[0072] The downlink transmission channels for sending (or transmitting) data from the network to the UE include a broadcast channel (BCH) for sending system information and a downlink shared channel (SCH) for sending other user services or control messages. The services or control messages of downlink multicast or broadcast services can be sent via the downlink SCH or can be sent via a separate downlink multicast channel (MCH). In addition, the uplink transmission channels for sending (or transmitting) data from the UE to the network include a random access channel (RACH) for sending initial control messages and an uplink shared channel (SCH) for sending other user services or control messages.

[0073] Logical channels existing in a higher layer than the transport channel and mapped to the transport channel may include a broadcast control channel (BCCH), a paging control channel (PCCH), a common control channel (CCCH), a multicast control channel (MCCH), a multicast traffic channel (MTCH), and the like.

[0074] The physical channel is configured by multiple OFDM symbols in the time domain and multiple subcarriers in the frequency domain. A subframe is configured by multiple OFDM symbols in the time domain. A resource block is configured by multiple subcarriers and multiple OFDM symbols in a resource allocation unit. In addition, each subframe can use a specific subcarrier of a specific OFDM symbol (e.g., the first OFDM symbol) of the corresponding subframe of the physical downlink control channel (PDCCH), i.e., the L1 / L2 control channel. The transmission time interval (TTI) refers to the unit time of subframe transmission.

[0075] Figure 5 The structure of the NR system based on the embodiment of the present disclosure is shown. Figure 5 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0076] Reference Figure 5 In NR, a radio frame can be used to perform uplink and downlink transmissions. The length of a radio frame is 10ms and can be defined as consisting of two half frames (HF). A half frame can include five 1ms subframes (SF). A subframe (SF) can be divided into one or more time slots, and the number of time slots within a subframe can be determined based on a subcarrier spacing (SCS). Each time slot can include 12 or 14 OFDM (A) symbols depending on the cyclic prefix (CP).

[0077] When a normal CP is used, each time slot may include 14 symbols. When an extended CP is used, each time slot may include 12 symbols. Herein, a symbol may include an OFDM symbol (or a CP-OFDM symbol) and a single carrier-FDMA (SC-FDMA) symbol (or a discrete Fourier transform spread OFDM (DFT-s-OFDM) symbol).

[0078] Table 1 below shows the number of time slots (N) of each symbol based on SCS setting (μ) when a normal CP is used. slot symb ), the number of time slots per frame (N frame,μ slot ) and the number of time slots per subframe (N subframe,μ slot ).

[0079] [Table 1]

[0080]

[0081]

[0082] Table 2 shows an example of the number of symbols per slot, the number of slots per frame, and the number of slots per subframe based on the SCS in case of using the extended CP.

[0083] [Table 2]

[0084] <![CDATA[SCS(15*2 μ )]]> <![CDATA[N slot symb ]]> <![CDATA[N frame,μ slot ]]> <![CDATA[N subframe,μ slot ]]> 60KHz(μ=2) 12 40 4

[0085] In the NR system, OFDM (A) parameter sets (e.g., SCS, CP length, etc.) between multiple cells integrated into one UE may be configured differently. Therefore, the (absolute time) duration (or interval) of a time resource (e.g., a subframe, a time slot, or a TTI) (collectively referred to as a time unit (TU) for simplicity) consisting of the same number of symbols may be configured differently in the integrated cells.

[0086] In NR, multiple parameter sets or SCSs can be supported to support various 5G services. For example, with an SCS of 15kHz, a wide range of traditional cellular bands can be supported, and with an SCS of 30kHz / 60kHz, dense cities, lower latency, and wider carrier bandwidths can be supported. With an SCS of 60kHz or higher, bandwidths greater than 24.25GHz can be used to overcome phase noise.

[0087] The NR frequency band may be defined as two different types of frequency ranges. The two different types of frequency ranges may be FR1 and FR2. The values ​​of the frequency ranges may be changed (or varied), for example, the two different types of frequency ranges may be as shown in Table 3 below. Among the frequency ranges used in the NR system, FR1 may mean "a range below 6 GHz", and FR2 may mean "a range above 6 GHz", and may also be referred to as millimeter wave (mmW).

[0088] [Table 3]

[0089] Frequency range specification Corresponding frequency range Subcarrier Spacing (SCS) FR1 450MHz-6000MHz 15, 30, 60kHz FR2 24250MHz-52600MHz 60, 120, 240kHz

[0090] As described above, the value of the frequency range in the NR system may be changed (or varied). For example, as shown in Table 4 below, FR1 may include a bandwidth in the range of 410 MHz to 7125 MHz. More specifically, FR1 may include frequency bands of 6 GHz (or 5850, 5900, 5925 MHz, etc.) and higher. For example, the frequency bands of 6 GHz (or 5850, 5900, 5925 MHz, etc.) and higher included in FR1 may include unlicensed frequency bands. Unlicensed frequency bands may be used for various purposes, for example, unlicensed frequency bands are used for vehicle-specific communications (e.g., autonomous driving).

[0091] [Table 4]

[0092] Frequency range specification Corresponding frequency range Subcarrier Spacing (SCS) FR1 410MHz-7125MHz 15, 30, 60kHz FR2 24250MHz-52600MHz 60, 120, 240kHz

[0093] Figure 6The structure of the time slot of the NR frame based on the embodiment of the present disclosure is shown.

[0094] Reference Figure 6 , a time slot includes multiple symbols in the time domain. For example, in the case of normal CP, one time slot may include 14 symbols. For example, in the case of extended CP, one time slot may include 12 symbols. Alternatively, in the case of normal CP, one time slot may include 7 symbols. However, in the case of extended CP, one time slot may include 6 symbols.

[0095] A carrier includes multiple subcarriers in the frequency domain. A resource block (RB) can be defined as multiple consecutive subcarriers in the frequency domain (e.g., 12 subcarriers). A bandwidth part (BWP) can be defined as multiple consecutive (physical) resource blocks ((P)RBs) in the frequency domain, and a BWP can correspond to a parameter set (e.g., SCS, CP length, etc.). A carrier can include up to N BWPs (e.g., 5 BWPs). Data communication can be performed via an activated BWP. Each element can be referred to as a resource element (RE) in a resource grid, and a complex symbol can be mapped to each element.

[0096] In addition, the radio interface between a UE and another UE or the radio interface between a UE and a network may include an L1 layer, an L2 layer, and an L3 layer. In various embodiments of the present disclosure, the L1 layer may refer to a physical layer. In addition, for example, the L2 layer may refer to at least one of a MAC layer, an RLC layer, a PDCP layer, and an SDAP layer. In addition, for example, the L3 layer may refer to an RRC layer.

[0097] Hereinafter, the bandwidth part (BWP) and the carrier will be described in detail.

[0098] A BWP may be a contiguous set of physical resource blocks (PRBs) within a given parameter set. A PRB may be selected from a contiguous set of common resource blocks (CRBs) for a given parameter set on a given carrier.

[0099] When bandwidth adaptation (BA) is used, the reception bandwidth and transmission bandwidth of the user equipment (UE) are not required to be as wide (or large) as the bandwidth of the cell, and the reception bandwidth and transmission bandwidth of the UE can be controlled (or adjusted). For example, the UE can receive information / configuration for bandwidth control (or adjustment) from the network / base station. In this case, bandwidth control (or adjustment) can be performed based on the received information / configuration. For example, bandwidth control (or adjustment) can include a reduction / expansion of bandwidth, a change in the position of bandwidth, or a change in the subcarrier spacing of bandwidth.

[0100] For example, the bandwidth can be reduced during a duration with little activity in order to save power. For example, the location of the bandwidth can be relocated (or moved) from the frequency domain. For example, the location of the bandwidth can be relocated (or moved) from the frequency domain to enhance scheduling flexibility. For example, the subcarrier spacing of the bandwidth can be changed. For example, the subcarrier spacing of the bandwidth can be changed to authorize different services. A subset of the total cell bandwidth of a cell can be referred to as a bandwidth part (BWP). BA can be performed when the base station / network configures a BWP for the UE and when the base station / network notifies the UE of the BWP that is currently activated among the BWPs.

[0101] For example, the BWP may be one of an activated BWP, an initial BWP, and / or a default BWP. For example, the UE cannot monitor the downlink radio link quality in a DL BWP other than an activated DL BWP within a primary cell (PCell). For example, the UE cannot receive PDCCH, a physical downlink shared channel (PDSCH), or a channel state information-reference signal (CSI-RS) (except RRM) from outside an activated DL BWP. For example, the UE cannot trigger a channel state information (CSI) report for an unactivated DL BWP. For example, the UE cannot send a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH) from outside an unactivated DL BWP. For example, in the case of a downlink, the initial BWP may be given as a continuous RB set for a remaining minimum system information (RMSI) control resource set (CORESET) (configured by a physical broadcast channel (PBCH)). For example, in the case of an uplink, the initial BWP may be given by a system information block (SIB) for a random access procedure. For example, a default BWP may be configured by a higher layer. For example, the initial value of the default BWP may be an initial DL BWP. To save energy, if the UE cannot detect downlink control information (DCI) within a predetermined period of time, the UE may switch the active BWP of the UE to the default BWP.

[0102] In addition, a BWP can be defined for SL. The same SL BWP can be used for transmission and reception. For example, a transmitting UE can send a SL channel or a SL signal within a specific BWP, and a receiving UE can receive a SL channel or a SL signal within the same specific BWP. In a licensed carrier, the SL BWP can be defined separately from the Uu BWP, and the SL BWP can have configuration signaling separate from the Uu BWP. For example, the UE can receive a configuration for the SL BWP from the base station / network. The SL BWP can be configured (in advance) for NR V2X UEs and RRC_IDLE UEs out of coverage. For UEs operating in RRC_CONNECTED mode, at least one SL BWP can be activated within the carrier.

[0103] Figure 7 An example of a BWP based on an embodiment of the present disclosure is shown. Figure 7 The embodiments of can be combined with various embodiments of the present disclosure. Figure 7 In an implementation manner, the number of BWPs is 3.

[0104] Reference Figure 7 , a common resource block (CRB) may be a carrier resource block numbered from one end of a carrier frequency band to the other end thereof. Additionally, a PRB may be a resource block numbered within each BWP. Point A may indicate a common reference point of a resource block grid.

[0105] It can be obtained by point A, the offset relative to point A (N start BWP ) and bandwidth (N size BWP ) to configure the BWP. For example, point A may be an external reference point of the PRBs of the carrier, and subcarrier 0 of all parameter sets (e.g., all parameter sets supported by the network on the corresponding carrier) are aligned in point A. For example, the offset may be the PRB distance between the lowest subcarrier within a given parameter set and point A. For example, the bandwidth may be the number of PRBs within a given parameter set.

[0106] Hereinafter, V2X or SL communication will be described.

[0107] Fig. 8A and Figure 8B A radio protocol architecture for SL communication according to an embodiment of the present disclosure is shown.

[0108] Fig. 8A and Figure 8B The embodiments of can be combined with various embodiments of the present disclosure. More specifically, Fig. 8A shows the user plane protocol stack, and Figure 8B The control plane protocol stack is shown.

[0109] Hereinafter, a side link synchronization signal (SLSS) and synchronization information will be described in detail.

[0110] The SLSS may include a primary sidelink synchronization signal (PSSS) and a secondary sidelink synchronization signal (SSSS) as SL specific sequences. The PSSS may be referred to as a sidelink primary synchronization signal (S-PSS), and the SSSS may be referred to as a sidelink secondary synchronization signal (S-SSS). For example, an M sequence of length 127 may be used for the S-PSS, and a gold sequence of length 127 may be used for the S-SSS. For example, the UE may use the S-PSS for initial signal detection and synchronization acquisition. For example, the UE may use the S-PSS and the S-SSS for acquiring detailed synchronization and for detecting a synchronization signal ID.

[0111] The physical sidelink broadcast channel (PSBCH) can be a (broadcast) channel for sending default (system) information, which must be known by the UE first before SL signal transmission / reception. For example, the default information can be information related to SLSS, duplex mode (DM), time division duplex (TDD) uplink / downlink (UL / DL) configuration, information related to resource pool, type of application related to SLSS, subframe offset, broadcast information, etc. For example, in order to evaluate PSBCH performance, in NR V2X, the payload size of PSBCH can be 56 bits, including 24-bit CRC.

[0112] S-PSS, S-SSS, and PSBCH may be included in a block format that supports periodic transmission (e.g., SL synchronization signal (SS) / PSBCH block, hereinafter, sidelink synchronization signal block (S-SSB)). The S-SSB may have the same parameter set (i.e., SCS and CP length) as the physical sidelink control channel (PSCCH) / physical sidelink shared channel (PSSCH) in the carrier, and the transmission bandwidth may exist within a (pre-) configured sidelink (SL) BWP. For example, the S-SSB may have a bandwidth of 11 resource blocks (SBs). For example, the PSBCH may exist across 11 RBs. In addition, the frequency position of the S-SSB may be (pre-) configured. Therefore, the UE does not have to perform hypothesis detection at the frequency to discover the S-SSB in the carrier.

[0113] Fig. 9 A UE performing V2X or SL communication according to an embodiment of the present disclosure is shown. Fig. 9 The embodiments of the present disclosure may be combined with various embodiments of the present disclosure.

[0114] Reference Fig. 9In V2X or SL communication, the term "UE" may generally refer to a user's UE. However, if a network device such as a BS transmits / receives signals according to a communication scheme between UEs, the BS may also be regarded as a type of UE. For example, UE 1 may be a first device 100, and UE 2 may be a second device 200.

[0115] For example, UE 1 may select a resource unit corresponding to a specific resource in a resource pool meaning a set of resource series. In addition, UE 1 may send an SL signal by using the resource unit. For example, a resource pool in which UE 1 can send a signal may be configured to UE 2 as a receiving UE, and a signal of UE 1 may be detected in the resource pool.

[0116] Herein, if UE 1 is within the connection range of the BS, the BS may inform the resource pool to UE 1. Otherwise, if UE 1 is out of the connection range of the BS, another UE may inform UE 1 of the resource pool, or UE 1 may use a pre-configured resource pool.

[0117] Generally, a resource pool may be configured in units of multiple resources, and each UE may select one or more units of resources to use in its SL signaling.

[0118] Hereinafter, resource allocation in SL will be described.

[0119] Fig. 10A and Fig. 10B A process of performing V2X or SL communication by a UE based on a transmission mode according to an embodiment of the present disclosure is shown.

[0120] Fig. 10A and Fig. 10B The embodiments of the present disclosure may be combined with various embodiments of the present disclosure. In various embodiments of the present disclosure, the transmission mode may be referred to as a mode or a resource allocation mode. Hereinafter, for ease of explanation, in LTE, the transmission mode may be referred to as an LTE transmission mode. In NR, the transmission mode may be referred to as an NR resource allocation mode.

[0121] For example, Fig. 10A UE operations related to LTE transmission mode 1 or LTE transmission mode 3 are shown. Alternatively, for example, Fig. 10B UE operations related to NR resource allocation mode 1 are shown. For example, LTE transmission mode 1 can be applied to conventional SL communication, and LTE transmission mode 3 can be applied to V2X communication.

[0122] For example, Fig. 10B UE operations related to LTE transmission mode 2 or LTE transmission mode 4 are shown. Alternatively, for example, Fig. 10BUE operations associated with NR resource allocation mode 2 are shown.

[0123] Reference Fig. 10A , in LTE transmission mode 1, LTE transmission mode 3, or NR resource allocation mode 1, the BS may schedule SL resources to be used by the UE for SL transmission. For example, the BS may perform resource scheduling to UE 1 through PDCCH (more specifically, downlink control information (DCI)), and UE 1 may perform V2X or SL communication with respect to UE 2 according to the resource scheduling. For example, UE1 may transmit sidelink control information (SCI) to UE 2 through a physical sidelink control channel (PSCCH), and thereafter transmit data based on the SCI to UE 2 through a physical sidelink shared channel (PSSCH).

[0124] Reference Fig. 10B , in LTE transmission mode 2, LTE transmission mode 4, or NR resource allocation mode 2, the UE can determine the SL transmission resources within the SL resources configured by the BS / network or the pre-configured SL resources. For example, the configured SL resources or the pre-configured SL resources may be a resource pool. For example, the UE may autonomously select or schedule resources for SL transmission. For example, the UE may perform SL communication by autonomously selecting resources within the configured resource pool. For example, the UE may autonomously select resources within a selective window by performing a sensing and resource (re)selection process. For example, sensing may be performed in units of subchannels. In addition, UE 1, which has autonomously selected resources within the resource pool, may send SCI to UE 2 via PSCCH, and thereafter may send data based on the SCI to UE 2 via PSSCH.

[0125] FIG. 11A to FIG. 11C Three playback types based on embodiments of the present disclosure are shown.

[0126] FIG. 11A to FIG. 11C The embodiments of can be combined with various embodiments of the present disclosure. Specifically, Fig.11A shows a broadcast type SL communication, Fig. 11B shows unicast type SL communication, and Fig. 11C Multicast type SL communication is shown. In the case of unicast type SL communication, the UE can perform one-to-one communication with respect to another UE. In the case of multicast type SL transmission, the UE can perform SL communication with respect to one or more UEs in the group to which the UE belongs. In various embodiments of the present disclosure, SL groupcast communication may be replaced by SL multicast communication, SL one-to-many communication, etc.

[0127] In addition, in sidelink communication, the UE may need to effectively select resources for sidelink transmission. Hereinafter, a method for the UE to effectively select resources for sidelink transmission and a device supporting the method will be described according to various embodiments of the present disclosure. In various embodiments of the present disclosure, the sidelink communication may include V2X communication.

[0128] At least one solution proposed according to various embodiments of the present disclosure may be applied to at least any one of unicast communication, multicast communication and / or broadcast communication.

[0129] At least one method proposed in various embodiments of the present embodiment can be applied not only to side link communication or V2X communication based on PC5 interface or SL interface (for example, PSCCH, PSSCH, PSBCH, PSSS / SSSS, etc.) or V2X communication, but also to side link communication or V2X communication based on Uu interface (for example, PUSCH, PDSCH, PDCCH, PUCCH, etc.).

[0130] In various embodiments of the present disclosure, the receiving operation of the UE may include a decoding operation and / or a receiving operation of a sidelink channel and / or a sidelink signal (e.g., PSCCH, PSSCH, PSFCH, PSBCH, PSSS / SSSS, etc.). The receiving operation of the UE may include a decoding operation and / or a receiving operation of a WAN DL channel and / or a WAN DL signal (e.g., PDCCH, PDSCH, PSS / SSS, etc.). The receiving operation of the UE may include a sensing operation and / or a CBR measurement operation. In various embodiments of the present disclosure, the sensing operation of the UE may include a PSSCH-RSRP measurement operation based on a PSSCH DM-RS sequence, a PSSCH-RSRP measurement operation based on a PSSCH DM-RS sequence successfully scheduled by a PSCCH successfully decoded by the UE, a sidelink RSSU (S-RSSI) measurement operation, and an S-RSSI measurement operation based on a V2X resource pool-related subchannel. In various embodiments of the present disclosure, the transmission operation of the UE may include the transmission operation of the sidelink channel and / or the sidelink signal (e.g., PSCCH, PSSCH, PSFCH, PSBCH, PSSS / SSSS, etc.). The transmission operation of the UE may include the transmission operation of the WAN UL channel and / or the WAN UL signal (e.g., PUSCH, PUCCH, SRS, etc.). In various embodiments of the present disclosure, the synchronization signal may include SLSS and / or PSBCH.

[0131] In various embodiments of the present disclosure, configuration may include signaling, signaling from the network, configuration from the network, and / or pre-configuration from the network. In various embodiments of the present disclosure, definition may include signaling, signaling from the network, configuration from the network, and / or pre-configuration from the network. In various embodiments of the present disclosure, designation may include signaling, signaling from the network, configuration from the network, and / or pre-configuration from the network.

[0132] In various embodiments of the present disclosure, ProSe per-packet reliability (PPPR) may be used instead of ProSe per-packet priority (PPPP), and PPPR may be used instead of PPPP. For example, this may mean that: the smaller the PPPP value, the higher the priority; and the larger the PPPP value, the lower the priority. For example, this may mean that: the smaller the PPPR value, the higher the reliability, and the larger the PPPR value, the lower the reliability. For example, the PPPP value associated with a service, packet, or message associated with a high priority may be smaller than the PPPP value associated with a service, packet, or message associated with a low priority. For example, the PPPR value associated with a service, packet, or message associated with a high reliability may be smaller than the PPPR value associated with a service, packet, or message associated with a low reliability.

[0133] In various embodiments of the present disclosure, a session may include at least any one of a unicast session (e.g., a unicast session for a side link), a groupcast / multicast session (e.g., a multicast / multicast session for a side link), and / or a broadcast session (e.g., a broadcast session for a side link).

[0134] In various embodiments of the present disclosure, a carrier may be interpreted as at least any one of a BWP and / or a resource pool. For example, a carrier may include at least any one of a BWP and / or a resource pool. For example, a carrier may include one or more BWPs. For example, a BWP may include one or more resource pools.

[0135] In an embodiment, according to TR 38.885, the minimum required range is a physical layer parameter in meters (defined by upper layers) useful for QoS management.

[0136] RAN1#96bis has discussed this issue in the context of sidelink HARQ feedback. The so-called "distance-based HARQ feedback" was discussed and the following working assumptions described in Table 5 below were made in a recent RAN1#96bis meeting:

[0137] [Table 5]

[0138]

[0139] The main idea is that if the RX UE is outside the minimum communication range, it does not need to send HARQ feedback because reliable packet delivery to that specific RX UE is not required (which may cause unnecessary interference). Examples of protocols related to SL HARQ feedback for multicast are disclosed in Table 6 below.

[0140] [Table 6]

[0141]

[0142]

[0143] Examples of SA2 proposals are as follows. This range also determines whether specific QoS parameters can be applied; otherwise, SL communication is best effort [R2-1905536]. For example, when the target (receiver) UE is <X meters, QoS parameter 1 is applicable, when the target (receiver) UE is <Y meters, QoS parameter 2 is applicable, and so on. Currently, no mechanism is specified for location-based blind retransmission.

[0144] Due to the short-range communication characteristics of PC5 (sidelink, SL) communication, a change in the geographical distance between the source (transmitting) UE and the destination (receiving) UE can affect the performance of SL communication. Such high mobility changes of in-vehicle UEs (e.g., traveling in the same or opposite directions at different speeds) can result in frequent changes in geographical distance, which can affect reliability and thus the quality of a specific V2X service.

[0145] The present disclosure provides details regarding enabling and adapting the number of blind retransmissions based on location information provided by nodes.

[0146] Embodiments of the following disclosure are as follows:

[0147] In one embodiment, a method for performing retransmission in a UE is provided. The method includes: determining the distance between the UE and a node; where the distance is determined based on location information received from the node, where the node is another UE or a base station, performing a new transmission of a data unit to the node; determining retransmission of the data unit based on the distance; where the maximum number of retransmissions is determined based on the distance.

[0148] In one embodiment, a method for performing retransmission in a UE is provided. The method includes: determining a CSI-RSRP / SSB-RSRP / other RSRP between the UE and a node; wherein the CSI-RSRP / SSB-RSRP / other RSRP value is measured based on a report received from the node, wherein the node is another UE or a base station, and a new transmission of a data unit to the node is performed; determining retransmission of the data unit based on the CSI-RSRP / SSB-RSRP / other RSRP; wherein a maximum number of retransmissions is determined based on the CSI-RSRP / SSB-RSRP / other RSRP value.

[0149] In one embodiment, a method according to the above embodiment is provided, wherein the following physical layer parameters can be adapted: UE transmit power (maximum or minimum), MCS (Modulation Coding Scheme) level, MIMO transmission mode and number of layers.

[0150] One of the main applications of the proposed embodiment is to enhance the reliability of UEs involved in sidelink communications. The process of the method for performing retransmission in this embodiment can be described as follows: Determine parameters such as distance estimation / CSI-RSRP / SSB-RSRP / other RSRP between the UE and the node.

[0151] The transmitting UE may receive distance information relative to another node, which may be: a base station, a UE, or a road side unit (RSU).

[0152] The distance estimate is calculated using a positioning technique that is either associated with or independent of the Radio Access Terminal (RAT). Additional assistance data may be used to calculate the distance estimate, and this may include the location and time related information of the node.

[0153] Layer 1 measurements are typically used to determine CSI-RSRP / SSB-RSRP / other RSRP values.

[0154] Fig.12 An example of adaptive blind retransmission when HARQ is enabled is shown.

[0155] In an embodiment, a method for performing a new transmission is provided. The method can be used in conjunction with HARQ to reduce overhead signaling from HARQ feedback. Consider the following case:

[0156] Case 1: When HARQ is enabled

[0157] Describe the following steps:

[0158] Step 1): UE initially performs the K 1 Blind retransmission of a retransmission.

[0159] In an embodiment, blind retransmission may mean that the transmitter performs a certain number of retransmissions of a packet without receiving HARQ feedback from the receiver.

[0160] Step 2): The receiving node provides the following feedback

[0161] 2.1) If an ACK is sent, a successful transmission has been performed.

[0162] 2.2) If a NACK is sent, the transmitting UE may use adaptive blind retransmission based on distance, CSI-RSRP / SSB-RSRP / other RSRP.

[0163] Step 3): The transmitting UE sends a configurable K based on distance, CSI-RSRP / SSB-RSRP / other RSRP 2 Blind retransmission.

[0164] Note: In step 1), the transmitting UE may also configure a K based on distance, CSI-RSRP / SSB-RSRP / other RSRP measurements. 1 initial transmission of one retransmission.

[0165] The distance estimate between the UE and the node and other parameters such as channel state information (CSI) reference signal received power (RSRP), synchronization signal block (SSB) RSRP or any other RSRP measurement can also help the transmitting UE determine whether retransmission is needed. This can be determined before a new data unit / packet is ready to be sent.

[0166] In the following Fig.13 In the description of , case 2 regarding when to disable HARQ is as follows.

[0167] Fig.13 An example of adaptive blind retransmission when HARQ is disabled is shown.

[0168] Case 2: When HARQ is disabled

[0169] This mechanism can be applied directly using a single step and application of Table 7 as shown below.

[0170] In one embodiment, a method for performing K 2 Once blind retransmission is enabled, distance estimation, CSI-RSRP / SSB-RSRP / other RSRP can also assist the UE in selecting the required number of retransmissions. For example, if the distance estimation falls within a specified distance interval, the UE can determine the appropriate number of retransmissions. Table 7 shows the possible link parameters to the number of retransmissions (K 2). In one embodiment, the mapping information of Table 7 can be applied to both Case 1 and Case 2 above.

[0171] [Table 7]

[0172] Distance estimate (r) (meters) <![CDATA[Number of retransmissions (K 2 or K 1 )]]> Unavailable <![CDATA[0 (Default HARQ / Default K 2 or K 1 )]]> 0<r≤100 <![CDATA[K 2 or K 1 ={0,1}]]> 100<r≤200 <![CDATA[K 2 or K 1 ={2,3}]]> 200<r≤300 <![CDATA[K 2 or K 1 ={4,5}]]> ... ... <![CDATA[r>r Max ]]> <![CDATA[K 2 or K 1 =K Max ]]> CSI-RS <![CDATA[Retransmission count (K 2 or K 1 )]]> Unavailable <![CDATA[0 (Default HARQ / Default K 2 or K 1 )]]> <![CDATA[x 1 <CSI-RSRP≤x 2 (High)]]> <![CDATA[K 2 or K 1 ={0,1}]]> <![CDATA[x 2 <CSI-RSRP ≤ x 3 (Chinese)]]> <![CDATA[K 2 or K 1 ={2,3}]]> <![CDATA[x 3 <CSI-RSRP≤x 4 (Low)]]> <![CDATA[K 2 or K 1 ={4,5}]]> ... ... <![CDATA[CSI-RSRP>CSI-RSRP Max ]]> <![CDATA[K 2 or K 1 =K Max <!-- 14 --> ]]> SSB-RSRP <![CDATA[Number of retransmissions (K 2 or K 1 )]]> Unavailable <![CDATA[0 (Default HARQ / Default K 2 or K 1 )]]> <![CDATA[y 1 <SSB-RSRP≤y 2 (High)]]> <![CDATA[K 2 or K 1 ={0,1}]]> <![CDATA[y 2 <SSB - RSRP ≤ y 3 (Chinese)]]> <![CDATA[K 2 or K 1 ={2,3}]]> <![CDATA[y 3 <SSB-RSRP≤y 4 (Low)]]> <![CDATA[K 2 or K 1 ={4,5}]]> ... ... <![CDATA[SSB-RSRP>SSB-RSRP Max ]]> <![CDATA[K 2 or K 1 =K Max ]]>

[0173] If any of the above link parameters are not available, the UE may fall back to the normal HARQ feedback process or the default K 2 (or K 1 ) blind retransmissions. In addition, the example shows the basic categories of CSI-RS and SSB RSRP measurement intervals (low, medium and high) mapped to the required number of retransmissions. The parameters rMax, CSI-RSRP Max and SSB-RSRP Max are upper limits, if exceeded, the maximum number of retransmissions (K) is selected. Max ). In order to cater to the flexibility of UE, the number of retransmissions (K 2 or K 1 ) can be selected from a set of predefined sizes (e.g., Table 7 shows K 2 (or K 1 ) values, where size 2 is set corresponding to each interval).

[0174] The above proposals can be combined. The proposed method can be implemented by various devices described below.

[0175] Based on resource allocation (e.g., UL grant, DL assignment), the data units in the present disclosure (e.g., PDCP SDU, PDCP PDU, RLC SDU, RLC PDU, RLC SDU, MAC SDU, MAC CE, MAC PDU) are sent / received on a physical channel (e.g., PDSCH, PUSCH). In the present disclosure, uplink resource allocation is also referred to as uplink grant, and downlink resource allocation is also referred to as downlink assignment. Resource allocation includes time domain resource allocation and frequency domain resource allocation. In the present disclosure, the uplink grant is either dynamically received by the UE on the PDCCH, in a random access response, or semi-persistently configured to the UE by the RRC. In the present disclosure, the downlink assignment is either dynamically received by the UE on the PDCCH, or semi-persistently configured to the UE by RRC signaling from the BS.

[0176] In one embodiment, location information is utilized to enable and adapt the number of retransmissions to achieve efficient and reliable transmission.

[0177] In one embodiment, a UE with a higher reporting range may dynamically increase the number of blind retransmissions to enhance the reliability of transmission.

[0178] In one embodiment, excessive HARQ feedback signaling overhead can be avoided by switching to distance-based blind retransmission.

[0179] Fig.14 is a flowchart illustrating the operation of the first device according to an embodiment of the present disclosure.

[0180] Fig.14 The operations disclosed in the flowchart can be performed in combination with various embodiments of the present disclosure. In one example, based on Figures 16 to 21 At least one of the devices shown is used to perform Fig.14 In another example, Fig.14 The operations disclosed in the flowchart can be combined in various ways Fig.12 and Fig.13 The various operations of the embodiments disclosed in the present invention are performed.

[0181] In one example, Fig.14 The first device and / or the second device may correspond to the following description Fig.17 In another example, Fig.14 The first device and / or the second device may correspond to the following description Fig.17 The second wireless device 200.

[0182] In operation S1410, the first device according to the embodiment may perform initial transmission to the second device based on transmission of a first physical sidelink control channel (PSCCH) and a first physical sidelink shared channel (PSSCH) related to the PSCCH.

[0183] In operation S1420, the first device according to the embodiment may perform at least one first retransmission to the second device based on at least one second PSCCH and at least one second PSSCH related to the at least one second PSCCH.

[0184] In operation S1430, the first device according to the embodiment may receive a hybrid automatic repeat request negative acknowledgement (HARQ NACK) related to initial transmission and at least one first retransmission from the second device based on a physical sidelink feedback channel (PSFCH).

[0185] In operation S1440, the first device according to the embodiment may perform at least one second retransmission to the second device based on the reception of the HARQ NACK.

[0186] In one embodiment, the first device may receive information about a distance estimate between the first device and the second device from the second device. The first device may determine the distance between the first device and the second device based on the information about the distance estimate.

[0187] In one embodiment, the number of the at least one second retransmission is determined based on a distance between the first device and the second device.

[0188] In an example, the number of at least one second retransmission may correspond to Fig.12 and Fig.13 K 2 .

[0189] In one embodiment, the maximum number of the at least one second retransmission is determined based on a distance between the first device and the second device.

[0190] In one embodiment, the range of times in the at least one second retransmission is determined based on a distance between the first device and the second device.

[0191] In one embodiment, the first device may receive at least one of information about reference signal received power (RSRP) of a channel state information-reference signal (CSI-RS) or information about RSRP of a synchronization signal block (SSB) from the second device. In addition, the first device may determine at least one of the RSRP of the CSI-RS or the RSRP of the SSB based on at least one of the information about the RSRP of the CSI-RS or the information about the RSRP of the SSB.

[0192] In one embodiment, the number of the at least one second retransmission is determined based on at least one of the RSRP of the CSI-RS or the RSRP of the SSB.

[0193] In one embodiment, the maximum number of the at least one second retransmission is determined based on at least one of the RSRP of the CSI-RS or the RSRP of the SSB.

[0194] In one embodiment, the range of the number of at least one second retransmission is determined based on at least one of the RSRP of the CSI-RS or the RSRP of the SSB.

[0195] In one embodiment, the second device is one of a user equipment (UE), a node or a base station.

[0196] In one embodiment, the number of the at least one first retransmission is determined based on a distance between the first device and the second device.

[0197] In an example, the number of at least one first retransmission may correspond to Fig.12 and Fig.13 K 1 .

[0198] In one embodiment, the number of at least one first retransmission is determined based on at least one of the RSRP of the CSI-RS or the RSRP of the SSB.

[0199] In one embodiment, the number of at least one first retransmission is determined based on a configuration from the base station.

[0200] According to an embodiment of the present disclosure, a first device for performing sidelink communication is provided. The first device may include at least one memory storing instructions, at least one transceiver, and at least one processor connecting the at least one memory and the at least one transceiver, wherein the at least one processor may control the at least one transceiver to perform an initial transmission to a second device based on a first physical sidelink control channel (PSCCH) and a first physical sidelink shared channel (PSSCH) associated with the PSCCH, control the at least one transceiver to perform at least one first retransmission to the second device based on at least one second PSCCH and at least one second PSSCH associated with the at least one second PSCCH, control the at least one transceiver to receive a hybrid automatic repeat request negative acknowledgment (HARQ NACK) associated with the initial transmission and at least one first retransmission from the second device based on a physical sidelink feedback channel (PSFCH), and control the at least one transceiver to perform at least one second retransmission to the second device based on the reception of the HARQ NACK.

[0201] According to an embodiment of the present disclosure, a device (or chip) configured to control a first UE is provided. The device may include at least one processor and at least one computer memory, the at least one computer memory being connected to be executable by the at least one processor and storing instructions, wherein the at least one processor executes the instructions to enable the first UE to: perform an initial transmission to a second device based on the transmission of a first physical sidelink control channel (PSCCH) and a first physical sidelink shared channel (PSSCH) related to the PSCCH, perform at least one first retransmission to the second device based on at least one second PSCCH and at least one second PSSCH related to the at least one second PSCCH, receive a hybrid automatic repeat request negative acknowledgment (HARQ NACK) related to the initial transmission and at least one first retransmission from the second device based on a physical sidelink feedback channel (PSFCH), and perform at least one second retransmission to the second device based on the reception of the HARQ NACK.

[0202] In one example, the first UE of an embodiment may indicate the first device throughout the present disclosure. In one example, each of at least one processor, at least one memory, etc. in a device for controlling the first UE may be configured as a separate sub-chip, or at least two of them may be configured by a single sub-chip.

[0203] According to an embodiment of the present disclosure, a non-transitory computer-readable storage medium storing instructions (or indications) is provided. When the instructions are executed, the instructions cause a first device to: perform an initial transmission to a second device based on the transmission of a first physical sidelink control channel (PSCCH) and a first physical sidelink shared channel (PSSCH) related to the PSCCH, perform at least one first retransmission to the second device based on at least one second PSCCH and at least one second PSSCH related to the at least one second PSCCH, receive a hybrid automatic repeat request negative acknowledgment (HARQ NACK) related to the initial transmission and at least one first retransmission from the second device based on a physical sidelink feedback channel (PSFCH), and perform at least one second retransmission to the second device based on the reception of the HARQ NACK.

[0204] Fig.15 is a flowchart illustrating the operation of the second device according to an embodiment of the present disclosure.

[0205] Fig.15 The operations disclosed in the flowchart can be performed in combination with various embodiments of the present disclosure. In one example, based on Figures 16 to 21 At least one of the devices shown is used to perform Fig.15 In another example, Fig.15 The operations disclosed in the flowcharts can be combined in various ways Fig.12 and Fig.13 The various operations of the embodiments disclosed in the present invention are performed.

[0206] In one example, Fig.15 The first device and / or the second device may correspond to the following description Fig.17 The second wireless device 200. In another example, Fig.14 The first device and / or the second device may correspond to the following description Fig.17 A first wireless device 100 is provided.

[0207] In operation S1510, the second device may receive an initial transmission from the first device based on a first physical sidelink control channel (PSCCH) and a first physical sidelink shared channel (PSSCH) related to the PSCCH.

[0208] In operation S1520, the second device may receive at least one first retransmission from the first device based on at least one second PSCCH and at least one second PSSCH related to the at least one second PSCCH.

[0209] In operation S1530, the second device may transmit a hybrid automatic repeat request negative acknowledgement (HARQ NACK) related to the initial transmission and at least one first retransmission to the first device based on a physical sidelink feedback channel (PSFCH).

[0210] In operation S1540, the second device may receive at least one second retransmission from the first device based on the transmitted HARQ NACK.

[0211] In one embodiment, the first device may receive information about a distance estimate between the first device and the second device from the second device. The first device may determine the distance between the first device and the second device based on the information about the distance estimate.

[0212] In one embodiment, the number of the at least one second retransmission is determined based on a distance between the first device and the second device.

[0213] In an example, the number of at least one second retransmission may correspond to Fig.12 and Fig.13 K 2 .

[0214] In one embodiment, the maximum number of the at least one second retransmission is determined based on a distance between the first device and the second device.

[0215] In one embodiment, a range of the number of at least one second retransmission is determined based on a distance between the first device and the second device.

[0216] In one embodiment, the first device may receive at least one of information about reference signal received power (RSRP) of a channel state information-reference signal (CSI-RS) or information about RSRP of a synchronization signal block (SSB) from the second device. In addition, the first device may determine at least one of the RSRP of the CSI-RS or the RSRP of the SSB based on at least one of the information about the RSRP of the CSI-RS or the information about the RSRP of the SSB.

[0217] In one embodiment, the number of the at least one second retransmission is determined based on at least one of the RSRP of the CSI-RS or the RSRP of the SSB.

[0218] In one embodiment, the maximum number of the at least one second retransmission is determined based on at least one of the RSRP of the CSI-RS or the RSRP of the SSB.

[0219] In one embodiment, the range of the number of at least one second retransmission is determined based on at least one of the RSRP of the CSI-RS or the RSRP of the SSB.

[0220] In one embodiment, the second device is one of a user equipment (UE), a node or a base station.

[0221] In one embodiment, the number of the at least one first retransmission is determined based on a distance between the first device and the second device.

[0222] In an example, the number of at least one first retransmission may correspond to Fig.12 and Fig.13 K 1 .

[0223] In one embodiment, the number of at least one first retransmission is determined based on at least one of the RSRP of the CSI-RS or the RSRP of the SSB.

[0224] In one embodiment, the number of at least one first retransmission is determined based on a configuration from the base station.

[0225] According to an embodiment of the present disclosure, a second device for performing sidelink communication is provided. The second device may include at least one memory storing instructions, at least one transceiver, and at least one processor connected to the at least one memory and the at least one transceiver, wherein the at least one processor is configured to: control at least one transceiver to receive an initial transmission from a first device based on a first physical sidelink control channel (PSCCH) and a first physical sidelink shared channel (PSSCH) associated with the PSCCH, control at least one transceiver to receive at least one first retransmission from a first device based on at least one second PSCCH and at least one second PSSCH associated with at least one second PSCCH, control at least one transceiver to send a hybrid automatic repeat request negative acknowledgment (HARQ NACK) associated with the initial transmission and at least one first retransmission to the first device based on a physical sidelink feedback channel (PSFCH); and control at least one transceiver to receive at least one second retransmission from the first device based on the sent HARQ NACK.

[0226] Various embodiments of the present disclosure may be implemented independently. Alternatively, various embodiments of the present disclosure may be implemented by combination or merging. For example, although various embodiments of the present disclosure have been described based on the 3GPP LTE system for ease of explanation, various embodiments of the present disclosure may also be applied extensively to another system other than the 3GPP LTE system. For example, various embodiments of the present disclosure may also be used in uplink or downlink situations, rather than being limited to direct communication between terminals. In this case, base stations, relay nodes, etc. may use methods proposed according to various embodiments of the present disclosure. For example, it may be defined that information about whether the method according to various embodiments of the present disclosure is applied is reported by a base station to a terminal or by a transmitting terminal to a receiving terminal through predefined signaling (e.g., physical layer signaling or high-level signaling). For example, it may be defined that information about rules according to various embodiments of the present disclosure is reported by a base station to a terminal or by a transmitting terminal to a receiving terminal through predefined signaling (e.g., physical layer signaling or high-level signaling). For example, some of the various embodiments of the present disclosure may be limited to be applied only to resource allocation mode 1. For example, some of the various embodiments of the present disclosure may be limited to be applied only to resource allocation mode 2.

[0227] Hereinafter, devices to which various embodiments of the present disclosure can be applied will be described.

[0228] The various descriptions, functions, processes, proposals, methods and / or operational flows of the present disclosure described in this document may be applied to, but not limited to, various fields requiring wireless communication / connection between devices (e.g., 5G).

[0229] Hereinafter, a description will be given in more detail with reference to the accompanying drawings. In the following drawings / descriptions, unless otherwise described, the same reference numerals may represent the same or corresponding hardware blocks, software blocks or functional blocks.

[0230] Fig.16 A communication system (1) according to an embodiment of the present disclosure is shown.

[0231] Reference Fig.16, a communication system (1) to which various embodiments of the present disclosure are applied includes a wireless device, a base station (BS), and a network. Herein, a wireless device refers to a device that performs communication using a radio access technology (RAT) (e.g., 5G new RAT (NR) or long term evolution (LTE)), and may be referred to as a communication / radio / 5G device. The wireless device may include, but is not limited to, a robot (100a), a vehicle (100b-1 and 100b-2), an extended reality (XR) device (100c), a handheld device (100d), a home appliance (100e), an Internet of Things (IoT) device (100f), and an artificial intelligence (AI) device / server (400). For example, a vehicle may include a vehicle with a wireless communication function, an autonomous vehicle, and a vehicle capable of performing inter-vehicle communication. Herein, a vehicle may include an unmanned aerial vehicle (UAV) (e.g., a drone). XR devices may include augmented reality (AR) / virtual reality (VR) / mixed reality (MR) devices and may be implemented in the form of head mounted devices (HMD), head up displays (HUD) installed in vehicles, televisions, smart phones, computers, wearable devices, home appliance devices, digital signage, vehicles, robots, etc. Handheld devices may include smart phones, smart boards, wearable devices (e.g., smart watches or smart glasses), and computers (e.g., notebooks). Home appliances may include TVs, refrigerators, and washing machines. IoT devices may include sensors and smart meters. For example, a BS and a network may be implemented as wireless devices, and a specific wireless device (200a) may operate as a BS / network node relative to other wireless devices.

[0232] The wireless devices 100a to 100f may be connected to the network 300 via the BS 200. The AI ​​technology may be applied to the wireless devices 100a to 100f, and the wireless devices 100a to 100f may be connected to the AI ​​server 400 via the network 300. The network 300 may be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. Although the wireless devices 100a to 100f may communicate with each other via the BS 200 / network 300, the wireless devices 100a to 100f may perform direct communication (e.g., side link communication) with each other without passing through the BS / network. For example, the vehicles 100b-1 and 100b-2 may perform direct communication (e.g., vehicle-to-vehicle (V2V) / vehicle-to-everything (V2X) communication). An IoT device (e.g., a sensor) may perform direct communication with other IoT devices (e.g., a sensor) or other wireless devices 100a to 100f.

[0233] Wireless communication / connection 150a, 150b or 150c can be established between wireless devices 100a to 100f / BS200 or BS200 / BS200. Here, the wireless communication / connection can be established through various RATs (e.g., 5G NR) such as uplink / downlink communication 150a, sidelink communication 150b (or D2D communication) or inter-BS communication (e.g., relay, integrated access backhaul (IAB)). The wireless device and the BS / wireless device can send / receive radio signals to / from each other through wireless communication / connection 150a and 150b. For example, wireless communication / connection 150a and 150b can send / receive signals through various physical channels. To this end, various configuration information configuration processes for sending / receiving radio signals, various signal processing processes (e.g., channel coding / decoding, modulation / demodulation and resource mapping / demapping) and at least a portion of the resource allocation process can be performed based on various proposals of the present disclosure.

[0234] Fig.17 A wireless device according to an embodiment of the present disclosure is shown.

[0235] Reference Fig.17 , the first wireless device (100) and the second wireless device (200) may transmit radio signals via various RATs (e.g., LTE and NR). Herein, {the first wireless device (100) and the second wireless device (200)} may correspond to Fig.16 {wireless device (100x) and BS (200)} and / or {wireless device (100x) and wireless device (100x)}.

[0236] The first wireless device 100 may include one or more processors 102 and one or more memories 104, and may additionally further include one or more transceivers (transceivers) 106 and / or one or more antennas (antenna units) 108. The (one or more) processors 102 may control the (one or more) memories 104 and / or the (one or more) transceivers 106, and may be configured to implement the descriptions, functions, processes, proposals, methods and / or operation flows disclosed in this document. For example, the (one or more) processors 102 may process the information in the (one or more) memories 104 to generate first information / signals, and then send a radio signal including the first information / signals through the (one or more) transceivers 106. The (one or more) processors 102 may receive a radio signal including a second information / signal through the transceiver 106, and then store the information obtained by processing the second information / signals in the (one or more) memories 104. The (one or more) memories 104 may be connected to the (one or more) processors 102, and may store various information related to the operation of the (one or more) processors 102. For example, (one or more) memories 104 may store software code including commands for executing part or all of the processing controlled by (one or more) processors 102 or for executing the descriptions, functions, processes, proposals, methods and / or operational flows disclosed in this document. Here, (one or more) processors 102 and (one or more) memories 104 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). (One or more) transceivers 106 may be connected to (one or more) processors 102 and send and / or receive radio signals through (one or more) antennas 108. Each transceiver 106 may include a transmitter and / or a receiver. (One or more) transceivers 106 may be used interchangeably with (one or more) radio frequency (RF) units. In the present disclosure, a wireless device may represent a communication modem / circuit / chip.

[0237] The second wireless device 200 may include one or more processors 202 and one or more memories 204, and may additionally further include one or more transceivers (transceivers) 206 and / or one or more antennas 208. The (one or more) processors 202 may control the (one or more) memories 204 and / or the (one or more) transceivers 206, and may be configured to implement the descriptions, functions, processes, proposals, methods and / or operation flows disclosed in this document. For example, the (one or more) processors 202 may process the information in the (one or more) memories 204 to generate third information / signals, and then transmit a radio signal including the third information / signals through the (one or more) transceivers 206. The (one or more) processors 202 may receive a radio signal including a fourth information / signal through the (one or more) transceivers 106, and then store the information obtained by processing the fourth information / signals in the (one or more) memories 204. The (one or more) memories 204 may be connected to the (one or more) processors 202, and may store various information related to the operation of the (one or more) processors 202. For example, (one or more) memories 204 may store software code including commands for executing part or all of the processing controlled by (one or more) processors 202 or for executing the descriptions, functions, processes, proposals, methods and / or operational flows disclosed in this document. Here, (one or more) processors 202 and (one or more) memories 204 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). (One or more) transceivers 206 may be connected to (one or more) processors 202 and transmit and / or receive radio signals through (one or more) antennas 208. Each transceiver 206 may include a transmitter and / or a receiver. (One or more) transceivers 206 may be used interchangeably with (one or more) RF units. In the present disclosure, a wireless device may represent a communication modem / circuit / chip.

[0238] Below, the hardware elements of the wireless devices 100 and 200 will be described in more detail. One or more protocol layers may be implemented by, but are not limited to, one or more processors 102 and 202. For example, one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, and SDAP). One or more processors 102 and 202 may generate one or more protocol data units (PDUs) and / or one or more service data units (SDUs) according to the description, function, process, proposal, method, and / or operation flow disclosed in this document. One or more processors 102 and 202 may generate messages, control information, data, or information according to the description, function, process, proposal, method, and / or operation flow disclosed in this document. One or more processors 102 and 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the description, function, process, proposal, method, and / or operation flow disclosed in this document, and provide the generated signals to one or more transceivers 106 and 206. One or more processors 102 and 202 can receive signals (e.g., baseband signals) from one or more transceivers 106 and 206 and obtain PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, processes, proposals, methods, and / or operating procedures disclosed in this document.

[0239] One or more processors 102 and 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more application specific integrated circuits (ASICs), one or more digital signal processors (DSPs), one or more digital signal processing devices (DSPDs), one or more programmable logic devices (PLDs), or one or more field programmable gate arrays (FPGAs) may be included in one or more processors 102 and 202. The descriptions, functions, processes, proposals, methods, and / or operational flows disclosed in this document may be implemented using firmware or software, and the firmware or software may be configured to include modules, processes, or functions. Firmware or software configured to execute the descriptions, functions, processes, proposals, methods, and / or operational flows disclosed in this document may be included in one or more processors 102 and 202 or stored in one or more memories 104 and 204, thereby being driven by one or more processors 102 and 202. The descriptions, functions, processes, proposals, methods, and / or operational flows disclosed in this document may be implemented using software or firmware in the form of code, commands, and / or command sets.

[0240] One or more memories 104 and 204 may be connected to one or more processors 102 and 202 and may store various types of data, signals, messages, information, programs, codes, instructions, and / or commands. One or more memories 104 and 204 may be composed of read-only memory (ROM), random access memory (RAM), electrically erasable programmable read-only memory (EPROM), flash memory, hard drive, registers, cash memory, computer-readable storage media, and / or combinations thereof. One or more memories 104 and 204 may be located inside and / or outside one or more processors 102 and 202. One or more memories 104 and 204 may be connected to one or more processors 102 and 202 via various technologies such as wired or wireless connections.

[0241] One or more transceivers 106 and 206 may send user data, control information, and / or radio signals / channels mentioned in the method and / or operation flow of this document to one or more other devices. One or more transceivers 106 and 206 may receive user data, control information, and / or radio signals / channels mentioned in the description, function, process, proposal, method, and / or operation flow disclosed in this document from one or more other devices. For example, one or more transceivers 106 and 206 may be connected to one or more processors 102 and 202, and may send and receive radio signals. For example, one or more processors 102 and 202 may perform control so that one or more transceivers 106 and 206 may send user data, control information, or radio signals to one or more other devices. One or more processors 102 and 202 may perform control so that one or more transceivers 106 and 206 may receive user data, control information, or radio signals from one or more other devices. One or more transceivers 106 and 206 may be connected to one or more antennas 108 and 208, and one or more transceivers 106 and 206 may be configured to send and receive user data, control information and / or radio signals / channels mentioned in the description, functions, processes, proposals, methods and / or operation flows disclosed in this document through one or more antennas 108 and 208. In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers 106 and 206 may convert received radio signals / channels, etc. from RF band signals to baseband signals to process received user data, control information, radio signals / channels, etc. using one or more processors 102 and 202. One or more transceivers 106 and 206 may convert user data, control information, radio signals / channels, etc. processed using one or more processors 102 and 202 from baseband signals to RF band signals. To this end, one or more transceivers 106 and 206 may include (analog) oscillators and / or filters.

[0242] Fig.18 A signal processing circuit for transmitting a signal according to an embodiment of the present disclosure is shown.

[0243] Reference Fig.18 The signal processing circuit (1000) may include a scrambler (1010), a modulator (1020), a layer mapper (1030), a precoder (1040), a resource mapper (1050), and a signal generator (1060). Fig.18 Operation / function, not limited to Fig.17 The processor (102, 202) and / or transceiver (106, 206) of Fig.17The processor (102, 202) and / or the transceiver (106, 206) are implemented Fig.18 For example, you can Fig.17 The processor (102, 202) implements blocks 1010 to 1060. Alternatively, Fig.17 The processor (102, 202) implements blocks 1010 to 1050 and can be implemented by Fig.17 The transceiver (106, 206) is used to implement box 1060.

[0244] Can be through Fig.18 The signal processing circuit (1000) converts the codeword into a radio signal. Herein, the codeword is a coded bit sequence of an information block. The information block may include a transport block (e.g., UL-SCH transport block, DL-SCH transport block). The radio signal may be transmitted through various physical channels (e.g., PUSCH and PDSCH).

[0245] Specifically, the codeword can be converted into a scrambled bit sequence by the scrambler 1010. The scrambling sequence for scrambling can be generated based on an initial value, and the initial value can include the ID information of the wireless device. The scrambled bit sequence can be modulated into a modulation symbol sequence by the modulator 1020. The modulation scheme may include pi / 2-binary phase shift keying (pi / 2-BPSK), m-phase shift keying (m-PSK) and m-quadrature amplitude modulation (m-QAM). The complex modulation symbol sequence can be mapped to one or more transmission layers by the layer mapper 1030. The modulation symbol of each transmission layer can be mapped (precoded) to (one or more) corresponding antenna ports by the precoder 1040. The output z of the precoder 1040 can be obtained by multiplying the output y of the layer mapper 1030 with the N*M precoding matrix W. Here, N is the number of antenna ports and M is the number of transmission layers. The precoder 1040 can perform precoding after performing transform precoding (e.g., DFT) for the complex modulation symbol. Alternatively, the precoder 1040 may perform precoding without performing transform precoding.

[0246] The resource mapper 1050 may map the modulation symbols of each antenna port to time-frequency resources. The time-frequency resources may include multiple symbols in the time domain (e.g., CP-OFDMA symbols and DFT-s-OFDMA symbols) and multiple subcarriers in the frequency domain. The signal generator 1060 may generate a radio signal from the mapped modulation symbols, and the generated radio signal may be sent to other devices through each antenna. To this end, the signal generator 1060 may include an inverse fast Fourier transform (IFFT) module, a cyclic prefix (CP) inserter, a digital-to-analog converter (DAC), and an up-converter.

[0247] Can be used with Fig.18 The signal processing process for a signal received in the wireless device is configured in a manner opposite to the signal processing process (1010 to 1060) of the wireless device. Fig.17 100 and 200) can receive a radio signal from the outside through an antenna port / transceiver. The received radio signal can be converted into a baseband signal by a signal restorer. To this end, the signal restorer may include a frequency downlink converter, an analog-to-digital converter (ADC), a CP remover, and a fast Fourier transform (FFT) module. Next, the baseband signal can be restored to a codeword through a resource demapping process, a post-coding process, a demodulation processor, and a descrambling process. The codeword can be restored to the original information block by decoding. Therefore, a signal processing circuit (not illustrated) for receiving a signal may include a signal restorer, a resource demapper, a post-encoder, a demodulator, a descrambler, and a decoder.

[0248] Fig.19 Another example of a wireless device according to an embodiment of the present disclosure is shown. The wireless device can be implemented in various forms according to use cases / services (see Fig.16 ).

[0249] Reference Fig.19 , the wireless device (100 and 00) may correspond to Fig.17 The wireless devices (100 and 200) may be configured by various elements, components, units / portions and / or modules. For example, each of the wireless devices (100 and 200) may include a communication unit (110), a control unit (120), a storage unit (130) and additional components (140). The communication unit may include a communication circuit (112) and (one or more) transceivers (114). For example, the communication circuit (112) may include Fig.17 One or more processors (102 and 202) and / or one or more memories (104 and 204) of the present invention. For example, the transceiver (114) may include Fig.17The control unit (120) is electrically connected to the communication unit (110), the memory / storage unit (130), and the additional components (140), and controls the overall operation of the wireless device. For example, the control unit (120) can control the electrical / mechanical operation of the wireless device based on the program / code / command / information stored in the storage unit (130). The control unit (120) can send the information stored in the storage unit (130) to the outside (e.g., other communication devices) via the communication unit (110) through the wireless / wired interface, or store the information received from the outside (e.g., other communication devices) via the communication unit (110) through the wireless / wired interface in the storage unit (130).

[0250] The additional component (140) may be configured in various ways depending on the type of the wireless device. For example, the additional component (140) may include at least one of a power supply unit / battery, an input / output (I / O) unit, a drive unit, and a computing unit. The wireless device may be implemented in the following forms without limitation: a robot ( Fig.16 100a), vehicles ( Fig.16 100b-1 and 100b-2), XR devices ( Fig.16 100c), handheld device ( Fig.16 100d), household appliances ( Fig.16 100e), IoT devices ( Fig.16 100f), digital broadcast terminal, hologram device, public safety device, MTC device, medical device, fintech device (or financial device), security device, climate / environmental device, AI server / device ( Fig.16 400), BS( Fig.16 200), network nodes, etc. Depending on the use case / service, the wireless device can be used in a mobile or fixed place.

[0251] exist Fig.19In the wireless device (100 and 200), various elements, components, units / parts and / or modules in the wireless device (100 and 200) can all be connected to each other through a wired interface, or at least part of them can be wirelessly connected through the communication unit (110). For example, in each of the wireless devices (100 and 200), the control unit (120) and the communication unit (110) can be connected by wire, and the control unit (120) and the first unit (e.g., 130 and 140) can be wirelessly connected through the communication unit (110). Each element, component, unit / part and / or module in the wireless device (100 and 200) can also include one or more elements. For example, the control unit (120) can be constructed by a collection of one or more processors. As an example, the control unit (120) can be constructed by a collection of a communication control processor, an application processor, an electronic control unit (ECU), a graphics processing unit and a memory control processor. As another example, the memory ( 130 ) may be constructed by random access memory (RAM), dynamic RAM (DRAM), read only memory (ROM), flash memory, volatile memory, nonvolatile memory, and / or combinations thereof.

[0252] Hereinafter, the implementation will be described in detail with reference to the accompanying drawings. Fig.19 .

[0253] Fig. 20 A handheld device based on an embodiment of the present disclosure is shown. The handheld device may include a smart phone, a smart board, a wearable device (e.g., a smart watch or smart glasses), or a portable computer (e.g., a notebook). The handheld device may be referred to as a mobile station (MS), a user terminal (UT), a mobile subscriber station (MSS), a subscriber station (SS), an advanced mobile station (AMS), or a wireless terminal (WT).

[0254] Reference Fig. 20 The handheld device (100) may include an antenna unit (108), a communication unit (110), a control unit (120), a storage unit (130), a power supply unit (140a), an interface unit (140b) and an I / O unit (140c). The antenna unit (108) may be configured as a part of the communication unit (110). Blocks 110 to 130 / 140a to 140c correspond to Fig.19 Frame 110 to 130 / 140.

[0255] The communication unit 110 may send and receive signals (e.g., data signals and control signals) to and from other wireless devices or BSs. The control unit 120 may perform various operations by controlling the constituent elements of the handheld device 100. The control unit 120 may include an application processor (AP). The storage unit 130 may store data / parameters / programs / codes / commands required to drive the handheld device 100. The storage unit 130 may store input / output data / information. The power supply unit 140a may supply power to the handheld device 100 and include a wired / wireless charging circuit, a battery, etc. The interface unit 140b may support the connection of the handheld device 100 to other external devices. The interface unit 140b may include various ports (e.g., audio I / O ports and video I / O ports) for connecting to external devices. The I / O unit 140c may input or output video information / signals, audio information / signals, data and / or information input by a user. The I / O unit 140c may include a camera, a microphone, a user input unit, a display unit 140d, a speaker and / or a tactile module.

[0256] For example, in the case of data communication, the I / O unit 140c can obtain information / signals (e.g., touch, text, voice, image, or video) input by the user, and the obtained information / signals can be stored in the storage unit 130. The communication unit 110 can convert the information / signals stored in the memory into radio signals, and directly send the converted radio signals to other wireless devices or to the BS. The communication unit 110 can receive radio signals from other wireless devices or BSs, and then restore the received radio signals to the original information / signals. The restored information / signals can be stored in the storage unit 130, and can be output as various types (e.g., text, voice, image, video, or tactile) through the I / O unit 140.

[0257] Fig.21 A vehicle or autonomous vehicle based on an embodiment of the present disclosure is shown. The vehicle or autonomous vehicle can be implemented by a mobile robot, a car, a train, a manned / unmanned aerial vehicle (AV), a ship, etc.

[0258] Reference Fig.21 The vehicle or autonomous vehicle (100) may include an antenna unit (108), a communication unit (110), a control unit (120), a drive unit (140a), a power supply unit (140b), a sensor unit (140c) and an autonomous driving unit (140d). The antenna unit (108) may be configured as a part of the communication unit (110). Blocks 110 / 130 / 140a to 140d correspond to Fig.19 Frame 110 / 130 / 140.

[0259] The communication unit 110 may send and receive signals (e.g., data signals and control signals) to and from external devices such as other vehicles, BSs (e.g., gNBs and roadside units), and servers. The control unit 120 may perform various operations by controlling elements of the vehicle or autonomous vehicle 100. The control unit 120 may include an electronic control unit (ECU). The drive unit 140a may cause the vehicle or autonomous vehicle 100 to travel on the road. The drive unit 140a may include an engine, a motor, a transmission system, wheels, brakes, a steering device, etc. The power supply unit 140b may supply power to the vehicle or autonomous vehicle 100, and may include a wired / wireless charging circuit, a battery, etc. The sensor unit 140c may acquire vehicle status, external environment information, user information, etc. The sensor unit 140c may include an inertial measurement unit (IMU) sensor, a collision sensor, a wheel sensor, a speed sensor, a slope sensor, a weight sensor, a heading sensor, a position module, a vehicle forward / reverse sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, a lighting sensor, a pedal position sensor, etc. The autonomous driving unit 140d may implement a technology for maintaining a lane in which the vehicle is traveling, a technology for automatically adjusting a speed (e.g., adaptive cruise control), a technology for autonomously driving along a determined path, a technology for driving by automatically setting a path when a destination is set, and the like.

[0260] For example, the communication unit 110 may receive map data, traffic information data, etc. from an external server. The autonomous driving unit 140d may generate an autonomous driving path and a driving plan from the acquired data. The control unit 120 may control the drive unit 140a so that the vehicle or the autonomous driving vehicle 100 may move along the autonomous driving path according to the driving plan (e.g., speed / direction control). In the middle of autonomous driving, the communication unit 110 may aperiodically / periodically acquire the most recent traffic information data from an external server and acquire surrounding traffic information data from adjacent vehicles. In the middle of autonomous driving, the sensor unit 140c may acquire vehicle status and / or surrounding environment information. The autonomous driving unit 140d may update the autonomous driving path and driving plan based on the newly acquired data / information. The communication unit 110 may transmit information about the vehicle position, autonomous driving path, and / or driving plan to an external server. The external server may predict traffic information data using AI technology, etc. based on information collected from the vehicle or autonomous driving vehicle, and provide the predicted traffic information data to the vehicle or autonomous driving vehicle.

[0261] The scope of the present disclosure may be expressed by the accompanying claims, and it should be understood that all changes or modifications derived from the meaning and scope of the claims and their equivalents may be included in the scope of the present disclosure.

[0262] The claims in this specification may be combined in various ways. For example, the technical features in the method claims of this specification may be combined to be implemented or performed in a device, and the technical features in the device claims may be combined to be implemented or performed in a method. In addition, the technical features in (one or more) method claims and (one or more) device claims may be combined to be implemented or performed in a device. In addition, the technical features in (one or more) method claims and (one or more) device claims may be combined to be implemented or performed in a method.

Claims

1. A method for performing sidelink communication by a first device, the method comprising the following steps: determining a distance between the first device and the second device; performing an initial transmission to the second device based on the transmission of a first physical sidelink control channel, PSCCH, and a first physical sidelink shared channel, PSSCH, associated with the first PSCCH; performing at least one first retransmission to the second device based on at least one second PSCCH and at least one second PSSCH related to the at least one second PSCCH; receiving, from the second device based on a physical sidelink feedback channel PSFCH, a hybrid automatic repeat request negative acknowledgement HARQ NACK related to the initial transmission or the at least one first retransmission; as well as performing at least one second retransmission to the second device based on receipt of the HARQ NACK, wherein (i) the number of the at least one first retransmission performed before receiving the HARQ NACK and (ii) the number of the at least one second retransmission performed after receiving the HARQ NACK are respectively determined based on the mapping information between the distance and the number of retransmissions, and The mapping information includes information related to the number of retransmissions mapped for each distance interval that is less than or equal to the minimum communication range.

2. The method according to claim 1, wherein: The maximum number of the at least one first retransmission and the maximum number of the at least one second retransmission are determined based on the distance exceeding the minimum communication range.

3. The method according to claim 1, wherein: The number of retransmissions for each distance interval mapping is preconfigured in the first device.

4. The method according to claim 1, wherein: Based on the information related to the distance determined to be available, it is determined whether to perform the at least one first retransmission and the at least one second retransmission, respectively.

5. The method according to claim 1, wherein: Based on the distance being included in a first distance interval and two or more retransmissions being mapped to the first distance interval, the number of the at least one first retransmission and the number of the at least one second retransmission are randomly determined from among the two or more retransmissions, respectively.

6. The method according to claim 1, wherein: Based on the distance being unavailable, the number of the at least one first retransmission and the number of the at least one second retransmission are determined as the number of default retransmissions.

7. The method according to claim 1, wherein: Based on determining the number of the at least one first retransmission according to the mapping information, the number of the at least one second retransmission is determined differently from the number of the at least one first retransmission.

8. The method according to claim 1, wherein: Powers for performing the at least one first retransmission and the at least one second retransmission are determined based on the distances, respectively.

9. A first device adapted to perform sidelink communication, the first device comprising: at least one transceiver; at least one processor; as well as At least one memory, the at least one memory is connected to the at least one processor and stores instructions, the instructions being executed to cause the at least one processor to perform operations, the operations comprising: determining a distance between the first device and the second device; performing an initial transmission to the second device based on the transmission of a first physical sidelink control channel, PSCCH, and a first physical sidelink shared channel, PSSCH, associated with the first PSCCH; performing at least one first retransmission to the second device based on at least one second PSCCH and at least one second PSSCH related to the at least one second PSCCH; receiving a hybrid automatic repeat request negative acknowledgement HARQ NACK related to the initial transmission or the at least one first retransmission from the second device based on a physical sidelink feedback channel PSFCH; and performing at least one second retransmission to the second device based on receipt of the HARQ NACK, wherein i) the number of the at least one first retransmission performed before receiving the HARQ NACK and (ii) the number of the at least one second retransmission performed after receiving the HARQ NACK are respectively determined based on the mapping information between the distance and the number of retransmissions, and The mapping information includes information related to the number of retransmissions mapped for each distance interval that is less than or equal to the minimum communication range.

10. A processing device adapted to control a first device to perform wireless communication, the processing device comprising: at least one processor; as well as At least one memory, the at least one memory is connected to the at least one processor and stores instructions, the instructions being executed to cause the at least one processor to perform operations, the operations comprising: determining a distance between the first device and the second device; performing an initial transmission to the second device based on the transmission of a first physical sidelink control channel, PSCCH, and a first physical sidelink shared channel, PSSCH, associated with the first PSCCH; performing at least one first retransmission to the second device based on at least one second PSCCH and at least one second PSSCH related to the at least one second PSCCH; receiving a hybrid automatic repeat request negative acknowledgement HARQ NACK related to the initial transmission or the at least one first retransmission from the second device based on a physical sidelink feedback channel PSFCH; and performing at least one second retransmission to the second device based on receipt of the HARQ NACK, wherein i) the number of the at least one first retransmission performed before receiving the HARQ NACK and ii) the number of the at least one second retransmission performed after receiving the HARQ NACK are respectively determined based on the mapping information between the distance and the number of retransmissions, and The mapping information includes information related to the number of retransmissions mapped for each distance interval that is less than or equal to the minimum communication range.

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