WO2025089902A1 - Resource selection method for sidelink communication in wireless communication system, and device therefor - Google Patents

Abstract

A method according to an embodiment of the present specification comprises the steps of: receiving configuration information related to resource selection; measuring RSRP; determining resources on the basis of the RSRP and an RSRP threshold value; and selecting resources for PSCCH transmission and/or PSSCH transmission on the basis of the resources. The resources are related to sidelink resource allocation mode 2. The selected resources include a resource selected on the basis of a reuse distance, and the reuse distance is related to a minimum distance between different terminals capable of using the same resource.

Description

Method for selecting resources for sidelink communication in a wireless communication system and device therefor

The present specification relates to a method for selecting resources for sidelink communication in a wireless communication system and a device therefor.

In order to meet the increasing demand for wireless data traffic since the commercialization of the 4G (4th generation) communication system, efforts are being made to develop an improved 5G (5th generation) communication system or pre-5G communication system. For this reason, the 5G communication system or pre-5G communication system is also called a communication system after the 4G network (Beyond 4G Network) or a system after the LTE (Long-Term Evolution) system (Post LTE). In order to achieve a high data transmission rate, the 5G communication system is being considered for implementation in an ultra-high frequency (mmWave) band (for example, a 60 gigabit (70 GHz) band). To mitigate radio path loss and increase the transmission range of radio waves in ultra-high frequency bands, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antenna, analog beam-forming, and large scale antenna technologies are being discussed in 5G communication systems. In addition, to improve the network of the system, technologies such as evolved small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network, device to device communication (D2D), wireless backhaul, moving network, cooperative communication, CoMP (Coordinated Multi-Points), and interference cancellation are being developed in 5G communication systems. In addition, advanced coding modulation (ACM) methods such as Hybrid FSK and QAM Modulation (FQAM) and Sliding Window Superposition Coding (SWSC), as well as advanced access technologies such as Filter Bank Multi Carrier (FBMC), Non-Orthogonal Multiple Access (NOMA), and Sparse Code Multiple Access (SCMA) are being developed in 5G systems.

Sidelink (SL) refers to a communication method that establishes a direct link between user equipment (UE) to directly exchange voice or data between terminals without going through a base station (BS). SL is being considered as a solution to solve the burden on base stations due to rapidly increasing data traffic.

V2X (vehicle-to-everything) refers to a communication technology that exchanges information with other vehicles, pedestrians, and objects with built-in infrastructure through wired/wireless communication. V2X can be divided into four types: 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.

Meanwhile, as more and more communication devices require greater communication capacity, there is a growing need for improved mobile broadband communication over existing Radio Access Technology (RAT). Accordingly, communication systems that consider services or terminals sensitive to reliability and latency are being discussed, and the next-generation radio access technology that considers improved mobile broadband communication, massive MTC (Machine Type Communication), URLLC (Ultra-Reliable and Low Latency Communication), etc. can be called new RAT (new radio access technology) or NR (new radio). V2X (vehicle-to-everything) communication can also be supported in NR.

Meanwhile, according to the Sensing-Based Semi-Persistent Scheduling (SB-SPS) method for sidelink resource selection, resources for PSCCH/PSSCH are randomly selected from the resources determined based on the RSRP threshold, and the same resources are reused multiple times in succession. According to the above-described operation, adjacent terminals (e.g., terminals neighboring to terminal #1 that has selected resources) can determine resources based on similar conditions. Thereafter, the adjacent terminals can select resources that have a large overlap with resources of other terminals (e.g., terminal #1) or resources that are identical to resources of other terminals among the determined resources.

Therefore, the existing method does not guarantee the selection of resources with low interference. In addition, since the existing method allows the same resources to be reused without limitation, resource competition due to resource conflicts intensifies.

This specification proposes a method for solving problems occurring in existing sidelink resource selection methods as described above.

The technical problems to be achieved in this specification are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention belongs from the description below.

A method performed by a first terminal in a wireless communication system according to one embodiment of the present specification includes the steps of receiving configuration information related to resource selection, measuring Received Signal Received Power (RSRP), determining resources based on the RSRP and an RSRP threshold, and selecting resources for PSCCH transmission and/or PSSCH transmission based on the resources.

The above configuration information includes configurations related to a resource selection mechanism. Based on the configurations related to the resource selection mechanism, at least one of full sensing, partial sensing, and/or random selection is allowed.

The above RSRP is Physical Sidelink Shared Channel (PSSCH) RSRP or Physical Sidelink Control Channel (PSCCH) RSRP.

The above resources are related to sidelink resource allocation mode 2.

The above-described selected resources include resources selected based on a reuse distance, and the reuse distance is characterized in that it is related to a minimum distance between different terminals that can use the same resource.

The distance between the first terminal and another terminal using the resource selected based on the above reuse distance may be greater than the above reuse distance.

The above reuse distance can be based on a fixed positive integer value.

The above reuse distance can be determined based on a coefficient based on a ratio related to a resource competition situation.

The above ratio may be based on a ratio of the number of terminals to the number of resources, and the coefficient may be determined based on a Gaussian function to which the above ratio is applied.

The above reuse distance can be determined as the smaller value among i) a value calculated based on the above coefficient and ii) a maximum value of the above reuse distance.

The above resources can be sorted in ascending order of the RSRP, and the selected resources can be determined based on a reuse distance judgment performed from the first resource among the sorted resources.

Based on the distance between the terminal using the resource based on the current order among the above-mentioned sorted resources and the first terminal being greater than the reuse distance, the resource based on the current order can be selected for the PSCCH transmission and/or the PSSCH transmission.

Based on the distance between the terminal using the resource based on the current order and the first terminal being less than or equal to the reuse distance, the reuse distance determination can be performed for the resource based on the next order among the sorted resources.

A first terminal operating in a wireless communication system according to another embodiment of the present disclosure includes one or more transceivers, one or more processors, and one or more memories storing instructions for operations executed by the one or more processors and connected to the one or more processors.

The above operations include a step of receiving configuration information related to resource selection, a step of measuring Received Signal Received Power (RSRP), a step of determining resources based on the RSRP and an RSRP threshold, and a step of selecting resources for PSCCH transmission and/or PSSCH transmission based on the resources.

The above configuration information includes configurations related to a resource selection mechanism. Based on the configurations related to the resource selection mechanism, at least one of full sensing, partial sensing, and/or random selection is allowed.

The above RSRP is Physical Sidelink Shared Channel (PSSCH) RSRP or Physical Sidelink Control Channel (PSCCH) RSRP.

The above resources are related to sidelink resource allocation mode 2.

The above-described selected resources include resources selected based on a reuse distance, and the reuse distance is characterized in that it is related to a minimum distance between different terminals that can use the same resource.

A device according to another embodiment of the present disclosure comprises one or more memories and one or more processors coupled to the one or more memories.

The one or more memories store instructions that cause the one or more processors to perform operations based on what is executed by the one or more processors.

The above operations include a step of receiving configuration information related to resource selection, a step of measuring Received Signal Received Power (RSRP), a step of determining resources based on the RSRP and an RSRP threshold, and a step of selecting resources for PSCCH transmission and/or PSSCH transmission based on the resources.

The above configuration information includes configurations related to a resource selection mechanism. Based on the configurations related to the resource selection mechanism, at least one of full sensing, partial sensing, and/or random selection is allowed.

The above RSRP is Physical Sidelink Shared Channel (PSSCH) RSRP or Physical Sidelink Control Channel (PSCCH) RSRP.

The above resources are related to sidelink resource allocation mode 2.

The above-described selected resources include resources selected based on a reuse distance, and the reuse distance is characterized in that it is related to a minimum distance between different terminals that can use the same resource.

In another embodiment of the present disclosure, one or more non-transitory computer-readable media store instructions, the instructions being executable by one or more processors, that cause the one or more processors to perform operations.

The above operations include a step of receiving configuration information related to resource selection, a step of measuring Received Signal Received Power (RSRP), a step of determining resources based on the RSRP and an RSRP threshold, and a step of selecting resources for PSCCH transmission and/or PSSCH transmission based on the resources.

The above configuration information includes configurations related to a resource selection mechanism. Based on the configurations related to the resource selection mechanism, at least one of full sensing, partial sensing, and/or random selection is allowed.

The above RSRP is Physical Sidelink Shared Channel (PSSCH) RSRP or Physical Sidelink Control Channel (PSCCH) RSRP.

The above resources are related to sidelink resource allocation mode 2.

The above-described selected resources include resources selected based on a reuse distance, and the reuse distance is characterized in that it is related to a minimum distance between different terminals that can use the same resource.

According to an embodiment of the present specification, resources selected from among resources determined based on RSRP include resources selected based on a reuse distance.

Therefore, compared to the existing method in which resources are randomly selected from among the above-determined resources, resources with a low probability of collision with resources of other terminals can be selected. Since the possibility of selecting resources with less interference increases, packet reception speed can be improved and waiting time can be shortened.

The effects obtainable from the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art to which the present invention belongs from the description below.

The accompanying drawings, which are incorporated in and are intended to aid in the understanding of the present invention and are intended to be a part of the detailed description, provide embodiments of the present invention and, together with the detailed description, serve to explain the technical features of the present invention.

FIG. 1 illustrates an example of a wireless network according to embodiments of the present specification.

FIG. 2 illustrates an example of a base station according to embodiments of the present specification.

FIG. 3 illustrates an example of a terminal according to embodiments of the present specification.

FIG. 4 is a diagram showing the basic structure of a time-frequency domain, which is a radio resource domain in which data or control channels are transmitted, in an NR system according to one embodiment of the present specification.

Figures 5 and 6 schematically illustrate the structure of a wireless frame applied to this specification.

Figure 7 is a diagram illustrating sidelink communication performance.

Figure 8 is a diagram for explaining the concept of cellular network-based D2D communication applied to this specification.

FIG. 9 is a diagram illustrating a system according to one embodiment of the present specification.

FIG. 10 is a diagram for explaining a resource pool defined as a set of time and frequency resources used for transmission and reception of a side link according to one embodiment of the present specification.

FIG. 11 is a flowchart illustrating a method for scheduled resource allocation (mode 1) in a side link according to one embodiment of the present specification.

FIG. 12 is a flowchart illustrating a UE autonomous resource allocation (mode 2) method in a sidelink according to one embodiment of the present specification.

Figure 13 is an example of a flowchart explaining the existing SB-SPS method.

Figure 14 illustrates a resource structure related to the existing SB-SPS method.

Figure 15 illustrates a resource selection procedure based on the existing SB-SPS method.

FIG. 16 illustrates a flowchart for explaining an improved SB-SPS scheme (always-best scheme) according to one embodiment of the present specification.

Figure 17 illustrates a procedure of an improved SB-SPS scheme according to one embodiment of the present specification.

Figure 18 is a graph showing the packet reception ratio (PRR) of the existing SB-SPS method and the always-best method.

Figure 19 is a graph showing the error block rate of the existing SB-SPS method and the always-best method.

Figure 20 shows a flowchart for explaining an improved SB-SPS method applying reuse distance judgment.

Figure 21 illustrates resource selection according to the conventional SB-SPS method and resource selection according to the improved SB-SPS method based on reuse distance judgment.

FIG. 22 illustrates a procedure of an improved SB-SPS applying reuse distance determination according to one embodiment of the present specification.

FIG. 23 is a flowchart illustrating an improved SB-SPS method applying fixed reuse distance determination according to one embodiment of the present specification.

Figure 24 is a graph showing the packet reception ratio (PRR) of the conventional SB-SPS method and the improved SB-SPS method with a fixed reuse distance value.

FIG. 25 is a flowchart of an improved SB-SPS applying adaptive reuse distance determination according to one embodiment of the present specification.

FIG. 26 is a graph showing coefficients related to determining resource reuse distance values according to one embodiment of the present specification.

Figure 27 is a graph showing the packet reception ratio (PRR) of the existing SB-SPS, Always-Best method, and improved SB-SPS method with fixed/adaptive reuse distance values.

Figure 28 is a graph showing the error block rates of the conventional SB-SPS method, the Always-Best method, and the improved SB-SPS method with fixed/adaptive reuse distance values.

Figure 29 is a graph showing the range of the conventional SB-SPS method, the Always-Best method, and the improved SB-SPS method with fixed/adaptive reuse distance values.

Figure 30 is a graph showing the packet reception ratio (PRR) at 100 m for the existing SB-SPS method, the Always-Best method, and the improved SB-SPS method with fixed/adaptive reuse distance values.

Figure 31 is a diagram showing the complementary cumulative distribution function (CCDF) of the Inter-Packet Gap (IPG) at rho=100.

Figure 32 is a diagram showing the complementary cumulative distribution function (CCDF) of the Inter-Packet Gap (IPG) at rho=200.

FIG. 33 is a flowchart for explaining a method performed by a first terminal in a wireless communication system according to one embodiment of the present specification.

In various embodiments of the present specification, "/" and "," should be interpreted as representing "and/or". For example, "A/B" can mean "A and/or B". Furthermore, "A, B" can mean "A and/or B". Furthermore, "A/B/C" can mean "at least one of A, B, and/or C". Furthermore, "A, B, C" can mean "at least one of A, B, and/or C".

In various embodiments of this specification, "or" should be interpreted as meaning "and/or." For example, "A or B" can include "only A," "only B," and/or "both A and B." In other words, "or" should be interpreted as meaning "additionally or alternatively."

The following technology can be used in various wireless communication systems, such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented with wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented with wireless technologies such as GSM (global system for mobile communications)/GPRS (general packet radio service)/EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented with wireless technologies such as IEEE (institute of electrical and electronics engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (evolved UTRA). IEEE 802.16m is an evolution of IEEE 802.16e, providing backward compatibility with systems based on IEEE 802.16e. UTRA is part of UMTS (universal mobile telecommunications system). 3GPP (3rd generation partnership project) LTE (long term evolution) is a part of E-UMTS (evolved UMTS) that uses E-UTRA (evolved-UMTS terrestrial radio access), employing OFDMA in the downlink and SC-FDMA in the uplink. LTE-A (advanced) is an evolution of 3GPP LTE.

5G NR is a new clean-slate type mobile communication system that is the successor technology to LTE-A and has the characteristics of high performance, low latency, and high availability. 5G NR can utilize all available spectrum resources, from low frequency bands below 1 GHz to intermediate frequency bands between 1 GHz and 10 GHz, and high frequency (millimeter wave) bands above 24 GHz.

For clarity of explanation, the description will focus on LTE-A or 5G NR, but the technical ideas according to an embodiment of the present specification are not limited thereto.

In order to meet the increasing demand for wireless data traffic since the commercialization of 4G communication systems, efforts are being made to develop improved 5G communication systems or pre-5G communication systems. For this reason, 5G communication systems or pre-5G communication systems are also called Beyond 4G Network communication systems or Post LTE systems. The 5G communication system specified by 3GPP is called the New Radio (NR) system. In order to achieve high data transmission rates, 5G communication systems are being considered for implementation in ultra-high frequency (mmWave) bands (e.g., 60 gigahertz (60 GHz) bands). To mitigate radio path loss and increase the transmission range of radio waves in ultra-high frequency bands, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antenna, analog beam-forming, and large scale antenna technologies have been discussed and applied to NR systems in 5G communication systems. In addition, to improve the network of the system, technologies such as evolved small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network, device to device communication (D2D), wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation are being developed in 5G communication systems. In addition, advanced coding modulation (ACM) methods such as Hybrid FSK and QAM Modulation (FQAM) and Sliding Window Superposition Coding (SWSC), as well as advanced access technologies such as Filter Bank Multi Carrier (FBMC), Non-Orthogonal Multiple Access (NOMA), and Sparse Code Multiple Access (SCMA) are being developed in 5G systems.

Meanwhile, the Internet is evolving from a human-centered network where humans create and consume information to an Internet of Things (IoT) network where information is exchanged and processed between distributed components such as objects. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technology through connection to cloud servers, is also emerging. In order to implement IoT, technological elements such as sensing technology, wireless communication and network infrastructure, service interface technology, and security technology are required, and recently, technologies such as sensor networks for connection between objects, machine-to-machine (M2M), and machine type communication (MTC) are being studied. In the IoT environment, intelligent IT (Internet Technology) services can be provided that collect and analyze data generated from connected objects to create new values for human life. IoT can be applied to fields such as smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart home appliances, and advanced medical services through convergence and combination between existing IT (information technology) technologies and various industries.

Accordingly, various attempts are being made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine-to-machine (M2M), and machine-type communication (MTC) are being implemented by 5G communication technologies such as beam forming, MIMO, and array antennas. The application of cloud radio access networks (cloud RAN) as a big data processing technology described above can also be said to be an example of the convergence of 5G and IoT technologies.

Meanwhile, the new 5G communication, NR (New Radio access technology), is designed to allow various services to be freely multiplexed in time and frequency resources, and accordingly, waveform/numerology, etc. and reference signals can be dynamically or freely allocated according to the needs of the corresponding service. In order to provide the optimal service to the terminal in wireless communication, optimized data transmission through measurement of channel quality and interference amount is important, and therefore accurate channel status measurement is essential. However, unlike 4G communication where channel and interference characteristics do not change significantly depending on frequency resources, in the case of 5G channels, channel and interference characteristics change significantly depending on the service, so support for subsets at the FRG (Frequency Resource Group) level is required to allow for dividing and measuring them. Meanwhile, the types of services supported in the NR system can be divided into categories such as eMBB (Enhanced mobile broadband), mMTC (massive Machine Type Communications) (mMTC), and URLLC (Ultra-Reliable and low-latency Communications). eMBB can be seen as a service that aims for high-speed transmission of large-capacity data, mMTC as a service that aims for minimizing terminal power and connecting multiple terminals, and URLLC as a service that aims for high reliability and low delay. Different requirements may be applied depending on the type of service applied to the terminal.

In this way, multiple services can be provided to users in a communication system, and in order to provide such multiple services to users, a method and a device using the same are required that can provide each service within the same time period according to its characteristics.

Hereinafter, embodiments of the present specification will be described in detail with reference to the attached drawings.

In describing the embodiments, descriptions of technical contents that are well known in the technical field to which this specification belongs and are not directly related to this specification are omitted. This is to convey the gist of this specification more clearly without obscuring it by omitting unnecessary explanations.

For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically illustrated. In addition, the size of each component does not entirely reflect the actual size. The same or corresponding components in each drawing are given the same reference numbers.

The advantages and features of the present specification, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present specification is not limited to the embodiments disclosed below and may be implemented in various different forms, and the present embodiments are provided only to make the disclosure of the present specification complete and to fully inform those skilled in the art of the scope of the disclosure, and the present specification is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the disclosure.

At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagrams can be performed by computer program instructions. These computer program instructions can be loaded onto a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flow diagram block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can be directed to a computer or other programmable data processing equipment to implement the function in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured article including an instruction means for performing the functions described in the flow diagram block(s). Since the computer program instructions may be installed on a computer or other programmable data processing apparatus, a series of operational steps may be performed on the computer or other programmable data processing apparatus to produce a computer-executable process, so that the instructions executing the computer or other programmable data processing apparatus may also provide steps for executing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a particular logical function(s). It should also be noted that in some alternative implementation examples, the functions mentioned in the blocks may occur out of order. For example, two blocks shown in succession may in fact be performed substantially concurrently, or the blocks may sometimes be performed in reverse order, depending on the functionality they perform.

Here, the term '~ part' used in the present embodiment means a software or hardware component such as an FPGA or ASIC, and the '~ part' performs certain roles. However, the '~ part' is not limited to software or hardware. The '~ part' may be configured to be in an addressable storage medium and may be configured to reproduce one or more processors. Thus, as an example, the '~ part' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and '~ parts' may be combined into a smaller number of components and '~ parts' or further separated into additional components and '~ parts'. In addition, the components and '~ parts' may be implemented to reproduce one or more CPUs in a device or a secure multimedia card. Additionally, in the embodiment, '~bu' may include one or more processors.

Wireless communication systems are evolving from the initial voice-oriented services to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as 3GPP's HSPA (high speed Packet Access), LTE (long term evolution or E-UTRA (evolved universal terrestrial radio access)), LTE-Advanced (LTE-A), 3GPP2's HRPD (high rate packet data), UMB (ultra mobile broadband), and IEEE's 802.16e. In addition, communication standards for 5G or NR (new radio) are being created as the 5th generation wireless communication system.

As a representative example of a wideband wireless communication system, the NR system adopts the OFDM (orthogonal frequency division multiplexing) method in the downlink (DL) and uplink. More specifically, the CP-OFDM (cyclic-prefix OFDM) method is adopted in the downlink, and both the CP-OFDM and the DFT-S-OFDM (discrete Fourier transform spreading OFDM) method are adopted in the uplink. The uplink refers to a wireless link in which a user equipment (UE) or mobile station (MS) transmits data or a control signal to a base station (gNode B or base station (BS)), and the downlink refers to a wireless link in which a base station transmits data or a control signal to a user equipment (UE). The above multiple access method typically allocates and operates the time-frequency resources to be used to transmit data or control information to each user so that they do not overlap with each other, that is, so as to achieve orthogonality, thereby distinguishing the data or control information of each user.

Wireless Network General

FIGS. 1 to 3 illustrate various embodiments implemented in the wireless communication system disclosed below and utilizing orthogonal frequency division multiplexing (OFDM) or orthogonal frequency division multiple access.

FIGS. 1-3 are not intended to imply physical or structural limitations on the manner in which other embodiments may be implemented. Other embodiments of the present disclosure may be implemented in any suitably arranged communication system.

FIG. 1 illustrates an example of a wireless network according to embodiments of the present disclosure. The embodiment of the wireless network illustrated in FIG. 1 is for illustrative purposes only. Other embodiments of the wireless network 100 may be used without departing from the scope of the present disclosure.

As illustrated in FIG. 1, the wireless network may include gNB 101, gNB 102, and gNB 103. Additionally, gNB 101 may communicate with at least one network 103, for example, the Internet, a proprietary Internet protocol (IP) network, or another data network.

A gNB 102 may provide wireless broadband access to a network 130 for a first plurality of user equipment (UE) within a coverage area 120 of the gNB 102. The first plurality of user equipment may include a user device 111 that may be located in a small business (SB), a user device 112 that may be located in an enterprise (E), a user device 113 that may be located in a WIFI hotspot (HS), a UE 114 that may be located in a first residence (R), a UE 115 that may be located in a second residence (R), a UE 115 that may be located in a mobile device (M), for example, a cell phone, a wireless laptop, a wireless PDF, or the like.

The gNB 103 may provide wireless broadband access to the network 130 for a second plurality of UEs within a coverage area 125 of the gNB 103. The second plurality of UEs may include UE 115, UE 116. In one embodiment, at least one of the gNBs 101-103 may communicate with each other or with the UEs 111-116 using 5G, LTE, LTE-A, WiMAX, WIFI, or other wireless communication technologies.

Depending on the network type, the term "base station" or "BS" may refer to any component (or collection of components) configured to provide wireless access to the network, such as a transmit point (TP), a transmit-receive point (TRP), an enhanced base station (eNodeB or eNB), a 5G base station (gNB), a macro cell, a femtocell, a WiFi access point (AP), or other radio-enabled device.

A base station may provide wireless access according to one or more wireless communication protocols, e.g., 5G 3GPP New Radio Interface/Access (NR), Long Term Evolution (LTE), LTE Advanced (LTE-A), High-Speed Packet Access (HSPA)), Wi-Fi 802.11a/b/g/n/ac, etc. For convenience, the terms "BS" and "TRP" are used interchangeably in this patent document to refer to a network infrastructure component that provides wireless access to a remote terminal. Additionally, depending on the network type, the term "user equipment" or "UE" may refer to any component, such as a "mobile station", "subscriber", "remote terminal", "wireless terminal", "receiving point" or "user device".

For convenience, the terms “user equipment” and “UE” are used in this patent document to refer to remote wireless equipment that wirelessly accesses a BS, wherein the UE may be a mobile device (e.g., a mobile phone or a smart phone) or generally considered a stationary device (e.g., a desktop computer or a vending machine).

The dotted lines represent approximate extents of coverage areas 120 and 125, which are depicted as roughly circular for illustration and illustrative purposes only. Coverage areas 120 and 125 associated with a gNB may have other shapes, including irregular shapes, depending on variations in the radio environment associated with the configuration of the gNB, natural and human-made obstacles, etc.

As described in more detail below, at least one of the UEs 111-116 may include circuitry, programming or a combination thereof for reception reliability for data and control information in an advanced wireless communication system. In certain embodiments, at least one of the gNBs 101-103 may include circuitry, programming or a combination thereof for efficient network control resource allocation in New Radio (NR) vehicle-to-everything (V2X).

While FIG. 1 illustrates an example of a wireless network, various modifications may be made to FIG. 1 . For example, the wireless network may include any number of gNBs and any number of UEs in any suitable arrangement. In addition, gNB 101 may communicate directly with any number of UEs and provide those UEs with wireless broadband access to the network 130. Similarly, each of gNBs 102-103 may communicate directly with the network 130 and provide the UEs with direct wireless broadband access to the network 130. In addition, gNBs 101, 102, and/or 103 may provide access to other or additional external networks, such as an external telephone network or other type of data network.

FIG. 2 illustrates an example of a gNB 102 according to embodiments of the present disclosure. The embodiment of the gNB 102 illustrated in FIG. 1 is for illustration only, and gNB 101 and gNB 103 of FIG. 1 may have the same or similar configurations. However, the gNB may be provided in various configurations, and FIG. 2 does not limit the scope of the disclosure to any particular implementation of a gNB.

As illustrated in FIG. 2, the gNB 102 may include multiple antennas 205a-205n, multiple radio frequency (RF) transceivers 210a-210n, transmit (TX) processing circuitry 215, and receive (RX) processing circuitry 220. The gNB 102 may also include a controller/processor 225, memory 230, and a backhaul or network interface (network IF) 235.

The RF transceivers 210a-210n can receive incoming RF signals, such as signals transmitted by UEs in the network 100, from the antennas 205a-205n. The RF transceivers 210a-210n can down-convert the incoming RF signals to generate intermediate frequency (IF) or baseband signals. The IF or baseband signals are transmitted to RX processing circuitry 220, which can generate baseband signals that are processed by filtering, decoding, and/or digitizing. The RX processing circuitry 220 can transmit the processed baseband signals to a controller/processor 225 for further processing.

The TX processing circuitry 215 may receive analog or digital data (e.g., voice data, web data, e-mail, interactive video game data) from the controller/processor 225. The TX processing circuitry 215 may encode, multiplex, and/or digitize the outgoing baseband data to generate processed baseband or IF signals.

The controller/processor 225 may include at least one processor or other processing device that controls the overall operation of the gNB 102. For example, the controller/processor 225 may control the reception of forward channel signals and the transmission of reverse channel signals by the RF transceivers 210a-210n, the RX processing circuitry 220, and the TX processing circuitry 215 according to well-known principles. The controller/processor 225 may also support additional functions, such as more advanced wireless communication capabilities. For example, the controller/processor 225 may support beamforming or directional routing operations in which signals from the multiple antennas 205a-205n are weighted differently to effectively steer them in a desired direction. Any of a variety of other functions may be supported in the gNB 102 by the controller/processor 225.

The controller/processor 225 may also execute programs and other processes residing in the memory 230, such as an operating system (OS). The controller/processor 225 may move data in and out of the memory 230 as required by the executing processes.

Additionally, the controller/processor 225 may be connected to a backhaul or network interface 235. The backhaul or network interface 235 enables the gNB 102 to communicate with other devices or systems over a backhaul connection or a network. The interface 235 may support communication over any suitable wired or wireless connection(s). For example, when the gNB 102 is implemented as part of a cellular communication system (e.g., supporting 5G, LTE, or LTE-A), the interface 235 may allow the gNB 102 to communicate with other gNBs over a wired or wireless backhaul connection. When the gNB 102 is implemented as an access point, the interface 235 may enable the gNB 102 to communicate over a wired or wireless local area network, or over a wired or wireless connection to a larger network (e.g., the Internet). Interface 235 may include any suitable structure that supports communications over wired or wireless connections, such as Ethernet or an RF transceiver.

Memory 230 may be coupled to controller/processor 225. Part of memory 230 may include RAM, and another part of memory 230 may include flash memory or other ROM.

While FIG. 2 illustrates an example of a gNB 102, various changes may be made to FIG. 2 . For example, the gNB 102 may include any number of each of the components illustrated in FIG. 2 . As a specific example, the access point may include multiple interfaces 235 , and the controller/processor 225 may support routing functions for routing data between different network addresses. As another specific example, while illustrated as including a single instance of TX processing circuitry (215) and a single instance of RX processing circuitry (220), the gNB (102) may include multiple instances of each (e.g., one per RF transceiver).

Additionally, the various components of FIG. 2 may be combined, further subdivided, or omitted, and additional components may be added as required.

FIG. 3 illustrates an exemplary UE 116, according to embodiments of the present disclosure. The embodiment of UE 116 illustrated in FIG. 3 is for illustrative purposes only and may have a configuration similar to or similar to UEs 111-115 of FIG. 1. However, UEs are provided in a variety of configurations, and FIG. 3 does not limit the scope of the present disclosure to any particular implementation of a UE.

As illustrated in FIG. 3, the UE 116 may include an antenna 305, a radio frequency (RF) transceiver 310, transmit (TX) processing circuitry 315, a microphone 320, and receive (RX) processing circuitry 325. Additionally, the UE 116 may include a speaker 330, a processor 340, an input/output (I/O) interface (IF) 345, a touch screen 350, a display 355, and a memory 360. The memory 360 may include an operating system (OS) 361 and one or more applications 362.

The RF transceiver 310 can receive an incoming RF signal transmitted by a gNB of the network 100 from the antenna 305. The RF transceiver 310 can down-convert the incoming RF signal to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signals are transmitted to the RX processing circuitry 325, which can generate a processed baseband signal by filtering, decoding, and/or digitizing. The RX processing circuitry 325 can transmit the processed baseband signal to a speaker 330 (e.g., voice data) or a processor 340 for further processing (e.g., web browsing data).

The TX processing circuitry 315 may receive analog or digital voice data from the microphone 320 or other outgoing baseband data (such as web data, e-mail, or interactive video game data) from the processor 340. The TX processing circuitry 315 may encode, multiplex, and/or digitize the transmitting baseband data to generate processed baseband or IF signals.

The RF transceiver 310 can receive a baseband or IF signal from the TX processing circuit 315 that has been transmitted and up-convert the baseband or IF signal to an RF signal transmitted through the antenna 305.

The processor 340 may include one or more processors or other processing devices and may execute an OS 361 stored in the memory 360 to control the overall operation of the UE 116. For example, the controller/processor 225 may control the reception of forward channel signals and transmission of reverse channel signals by the RF transceivers 210a-210n, the RX processing circuitry 220 and the TX processing circuitry 215 according to well-known principles. In some embodiments, the processor 340 may include one or more microprocessors or microcontrollers.

Additionally, the processor 340 may execute other processes and programs residing in the memory 360, such as processes for beam management. The processor 340 may move data into and out of the memory 360 as required by the executing processes. In one embodiment, the processor 340 may be configured to execute an application 362 based on the OS 361 or in response to signals received from the gNB or an operator.

Additionally, the processor 340 is connected to an I/O interface 345, which may provide the UE 116 with the ability to connect to other devices, such as laptop computers and handheld computers.

Additionally, the processor 340 may be coupled to a touch screen 350 and a display 355. An operator of the UE 116 may use the touch screen 350 to enter data into the UE 116. The display 355 may be a liquid crystal display, a light emitting diode display, or other display capable of rendering text and/or at least limited graphics, such as a website.

Memory 360 may be coupled to processor 340. Part of memory 360 may include random access memory (RAM), and another part of memory 360 may include flash memory or other read-only memory (ROM).

FIG. 3 illustrates an example of a UE 116, and FIG. 3 may be modified in various ways. For example, various components of FIG. 3 may be combined, further subdivided, or omitted, and additional components may be added as needed. As a specific example, the processor 340 may be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). FIG. 3 also illustrates a UE 116 configured as a mobile phone or smart phone, and the UE may be configured to operate as other types of mobile or stationary devices.

This specification relates generally to wireless communication systems, and more specifically to vehicular communication network protocols including vehicle-to-device, vehicle-to-vehicle, and vehicle-to-network communication resource allocation and synchronization schemes.

A communication system may include a downlink (DL) that transmits signals from a transmission point, such as a base station (BS) or NodeB, to user equipment (UE), and an uplink (UL) that transmits signals from the UE to a receiving point, such as a NodeB.

Additionally, sidelink (SL) can carry signals from UEs to other UEs or to other non-infrastructure-based nodes. A UE, also commonly referred to as a terminal or mobile station, can be fixed or mobile and can be a cellular phone, a personal computing device, etc. A NodeB, which is usually a fixed station, may also be referred to as an access point or other equivalent terms, such as an eNodeB. An access network that includes a NodeB associated with 3GPP LTE is called an Evolved Universal Terrestrial Access Network (E-UTRAN).

NR System Related

FIG. 4 is a diagram showing the basic structure of a time-frequency domain, which is a radio resource domain in which data or control channels are transmitted, in an NR system according to one embodiment of the present specification.

Specifically, FIG. 4 shows the basic structure of the time-frequency domain, which is a radio resource domain in which data or control channels are transmitted in the downlink or uplink in an NR system.

Referring to Fig. 4, the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain is an OFDM symbol, and Nsymb OFDM symbols (1-02) can be gathered to form one slot (1-06). The length of a subframe is defined as 1.0 ms, and a radio frame (1-14) is defined as 10 ms. The minimum transmission unit in the frequency domain is a subcarrier, and the bandwidth of the entire system transmission bandwidth can be composed of a total of NBW subcarriers (1-04).

In the time-frequency domain, the basic unit of resources is the resource element (RE) (1-12), which can be represented by an OFDM symbol index and a subcarrier index. A resource block (RB) (1-08) can be defined as Nsymb consecutive OFDM symbols (1-02) in the time domain and NRB consecutive subcarriers (1-10) in the frequency domain. Accordingly, one RB (1-08) can be composed of Nsymb x NRB REs (1-12). In general, the minimum transmission unit of data is an RB unit. In an NR system, Nsymb = 14, NRB = 12, and NBW and NRB can be proportional to the bandwidth of the system transmission band. In addition, the data rate can be increased in proportion to the number of RBs scheduled to the terminal.

In the NR system, in the case of an FDD system that operates the downlink and uplink by distinguishing them by frequency, the downlink transmission bandwidth and the uplink transmission bandwidth may be different from each other. The channel bandwidth may represent an RF bandwidth corresponding to the system transmission bandwidth. [Table 1] and [Table 2] represent part of the correspondence between the system transmission bandwidth, subcarrier spacing, and channel bandwidth defined in the NR system in a frequency band lower than 6 GHz and a frequency band higher than 6 GHz, respectively. For example, an NR system having a channel bandwidth of 100 MHz with a subcarrier spacing of 30 kHz has a transmission bandwidth composed of 273 RBs. In the following, N/A may be a bandwidth-subcarrier combination not supported by the NR system.

In the NR system, the frequency range can be divided into FR1 and FR2 and defined as shown in Table 3 below.

The ranges of FR1 and FR2 may be changed and applied differently. For example, the frequency range of FR1 may be changed and applied from 450 MHz to 6000 MHz.

In the NR system, scheduling information for downlink data or uplink data is transmitted from the base station to the terminal via downlink control information (DCI). DCI can be defined according to various formats, and DCI can indicate, depending on each format, whether it is scheduling information for uplink data (UL grant) or scheduling information for downlink data (DL grant), whether it is compact DCI having a control information size smaller than a predetermined size, whether it applies spatial multiplexing using multiple antennas, and whether it is DCI for power control. For example, DCI format 1-1, which is scheduling control information (DL grant) for downlink data, can include at least one of the following control information.

- Carrier indicator: Indicates on which frequency carrier the transmission is being made.

- DCI format indicator: This is an indicator that distinguishes whether the DCI is for downlink or uplink.

- Bandwidth part (BWP) indicator: Indicates which BWP is being transmitted.

- Frequency domain resource allocation: Indicates the RB of the frequency domain allocated for data transmission. The resource to be expressed is determined based on the system bandwidth and resource allocation method.

- Time domain resource allocation: Indicates in which OFDM symbol of which slot the data-related channel will be transmitted.

- VRB-to-PRB mapping: Indicates how to map the virtual RB (VRB) index and the physical RB (PRB) index.

- Modulation and coding scheme (MCS): Indicates the modulation method used for data transmission and the size of the transport block, which is the data to be transmitted.

- HARQ process number: Indicates the HARQ process number.

- New data indicator: Indicates whether it is a HARQ initial transmission or a retransmission.

- Redundancy version: Indicates the redundancy version of HARQ.

- Transmit power control (TPC) command for PUCCH (physical uplink control channel): Indicates a transmit power control command for PUCCH, which is an uplink control channel.

For data transmission via PDSCH or PUSCH, time domain resource assignment can be determined by information about a slot in which the PDSCH/PUSCH is transmitted, a start symbol position S in the slot, and the number of symbols L to which the PDSCH/PUSCH is mapped. S can be a relative position from the start of the slot, L can be a number of consecutive symbols, and S and L can be determined from a start and length indicator value (SLIV) defined as follows.

In the NR system, a terminal can receive information about a SLIV value, a PDSCH/PUSCH mapping type, and a slot in which PDSCH/PUSCH is transmitted through RRC configuration in one row (for example, the information can be set in the form of a table). In the subsequent time domain resource allocation of DCI, the base station can transmit information about the SLIV value, the PDSCH/PUSCH mapping type, and the slot in which PDSCH/PUSCH is transmitted to the terminal by indicating an index value in the set table.

In the NR system, PDSCH mapping types can be defined as type A and type B. According to PDSCH mapping type A, the first symbol of DMRS symbols can be located in the second or third OFDM symbol of a slot. According to PDSCH mapping type B, the first symbol of DMRS symbols can be located in the first OFDM symbol of the time-domain resource allocated for PUSCH transmission.

DCI can be transmitted on a downlink physical control channel (PDCCH) through channel coding and modulation processes. In this specification, when control information is transmitted through a PDCCH or a PUCCH, it can be expressed as PDCCH or PUCCH transmission. Similarly, in this specification, when data is transmitted through a PUSCH or a PDSCH, it can be expressed as PUSCH or PDSCH transmission.

In general, DCI can be scrambled with a specific RNTI (radio network temporary identifier) (or terminal identifier) for each terminal independently, a CRC (cyclic redundancy check) is added, channel coded, and then configured as an independent PDCCH for transmission. The PDCCH can be mapped and transmitted in a control resource set (CORESET) set for the terminal.

Downlink data can be transmitted on the physical downlink shared channel (PDSCH), which is a physical channel for downlink data transmission. The PDSCH can be transmitted after the control channel transmission period, and scheduling information such as specific mapping locations and modulation methods in the frequency domain can be determined based on the DCI transmitted through the PDCCH.

Among the control information constituting the DCI, the base station can notify the terminal of the modulation method applied to the PDSCH to be transmitted and the size of the data to be transmitted (transport block size; TBS) through the MCS (Modulation Coding Scheme). According to an embodiment of the present specification, the MCS can be composed of 5 bits or more or less bits. The TBS (Transport Block Size) can correspond to the size of the data (transport block, TB) to be transmitted by the base station before channel coding for error correction is applied.

In this specification, a transport block (TB) may include a MAC (medium access control) header, a MAC control element (CE), one or more MAC SDUs (service data units), and padding bits. Alternatively, a TB may represent a unit of data delivered from a MAC layer to a physical layer, or a MAC PDU (protocol data unit).

The modulation methods supported in the NR system are QPSK (quadrature phase shift keying), 16QAM (quadrature amplitude modulation), 64QAM, and 256QAM, and the modulation orders (Qm) correspond to 2, 4, 6, and 8, respectively. That is, in the case of QPSK modulation, 2 bits per symbol can be transmitted, in the case of 16QAM modulation, 4 bits per symbol, in the case of 64QAM modulation, 6 bits per symbol, and in the case of 256QAM modulation, 8 bits per symbol can be transmitted.

LTE system related

Figures 5 and 6 schematically illustrate the structure of a wireless frame applied to this specification.

Referring to FIGS. 5 and 6, one radio frame includes 10 subframes, and one subframe includes two consecutive slots. The basic time (length) unit for transmission control in a radio frame is called a transmission time interval (TTI). The TTI can be 1 ms. The length of one subframe can be 1 ms, and the length of one slot can be 0.5 ms.

A slot may include multiple symbols in the time domain. For example, in the case of a wireless system using OFDMA (Orthogonal Frequency Division Multiple Access) in the downlink (DL), the symbol may be an OFDM (Orthogonal Frequency Division Multiplexing) symbol, and in the case of a wireless system using SC-FDMA (Single Carrier-Frequency Division Multiple Access) in the uplink (UL), the symbol may be an SC-FDMA (Single Carrier-Frequency Division Multiple Access) symbol. Meanwhile, the expression of a symbol period in the time domain is not limited by a multiple access method or name.

The number of symbols included in one slot may vary depending on the length of the CP (Cyclic Prefix). For example, in the case of a normal CP, one slot may include 7 symbols, and in the case of an extended CP, one slot may include 6 symbols.

A resource element (RE) represents the smallest time-frequency unit to which a modulation symbol of a data channel or a modulation symbol of a control channel is mapped. A resource block (RB) is a resource allocation unit and includes time-frequency resources corresponding to 180 kHz in the frequency axis and 1 slot in the time axis. Meanwhile, a resource block pair (PBR) means a resource unit that includes two consecutive slots in the time axis.

In the physical layer, several physical channels can be used, and the physical channels can be mapped to the radio frame and transmitted. As a downlink physical channel, the Physical Downlink Control Channel (PDCCH)/Enhanced PDCCH (EPDCCH) informs the UE of resource allocation of the PCH (Paging Channel) and the DL-SCH (Downlink Shared Channel) and HARQ (Hybrid Automatic Repeat Request) information related to the DL-SCH. The PDCCH/EPDCCH can carry an uplink grant that informs the UE of resource allocation of uplink transmission. The PDCCH and EPDCCH have differences in the resource areas to which they are mapped. The DL-SCH is mapped to the PDSCH (Physical Downlink Shared Channel). The Physical Control Format Indicator Channel (PCFICH) informs the UE of the number of OFDM symbols used for the PDCCH, and is transmitted in every subframe. PHICH (Physical Hybrid ARQ Indicator Channel) is a downlink channel that carries HARQ (Hybrid Automatic Repeat reQuest) ACK (Acknowledgement)/NACK (Non-acknowledgement) signals, which are responses to uplink transmissions. HARQ ACK/NACK signals can be called HARQ-ACK signals.

As an uplink physical channel, the Physical Random Access Channel (PRACH) carries a random access preamble. The Physical Upnlink Control Channel (PUCCH) carries uplink control information such as HARQ-ACK, which is a response to downlink transmission, and channel status information (CSI) indicating the downlink channel status, such as the Channel Quality Indicator (CQI), precoding matrix index (PMI), precoding type indicator (PTI), and rank indicator (RI). The Physical Uplink Shared Channel (PUSCH) carries the Uplink Shared Channel (UL-SCH).

Uplink data may be transmitted on a PUSCH, and the uplink data may be a transport block (TB), which is a data block for an UL-SCH transmitted during a transmission time interval (TTI). The transport block may include user data. Alternatively, the uplink data may be multiplexed data. The multiplexed data may be a transport block for an UL-SCH and uplink control information multiplexed. That is, when there is user data to be transmitted on an uplink, the uplink control information may be multiplexed with the user data and transmitted through a PUSCH.

Sidelink (SL) General

Hereinafter, sidelink (SL) refers to a signal transmission/reception path between terminals, and it can be used interchangeably with the PC5 interface. Hereinafter, the base station is an entity that performs resource allocation of the terminal, and can be a base station that supports both V2X communication and general cellular communication, or a base station that supports only V2X communication. In other words, the base station can mean an NR base station (gNB), an LTE base station (eNB), or an RSU (road site unit) (or fixed station). The terminal may include not only general user equipment, a mobile station, but also a vehicle supporting vehicular-to-vehicular (V2V) communication, a vehicle or pedestrian's handset (e.g., a smartphone) supporting vehicular-to-pedestrian (V2P) communication, a vehicle supporting vehicular-to-network (V2N) communication, or a vehicle supporting vehicular-to-infrastructure (V2I) communication, and an RSU equipped with a terminal function, an RSU equipped with a base station function, or an RSU equipped with a part of a base station function and a part of a terminal function. In this specification, a downlink (DL) refers to a wireless transmission path of a signal that a base station transmits to a terminal, and an uplink (UL) refers to a wireless transmission path of a signal that a terminal transmits to a base station. In addition, although an embodiment of the present specification is described below based on an NR system, an embodiment of the present specification may also be applied to a wireless communication system having a similar technical background or channel type. In addition, the embodiment of the present specification may be applied to other communication systems through some modifications without significantly departing from the scope of the present specification at the discretion of a person having skilled technical knowledge.

In this specification, the conventional terms physical channel and signal may be used interchangeably with data or control signals. For example, PDSCH is a physical channel through which data is transmitted, but PDSCH may also mean the data being transmitted.

Hereinafter, in this specification, upper signaling refers to a signal transmission method in which a base station transmits a signal to a terminal using a downlink data channel of a physical layer, or a terminal transmits a signal to a base station using an uplink data channel of a physical layer, and may also be referred to as RRC signaling or a MAC control element (CE).

Figure 7 is a diagram illustrating sidelink communication performance.

Referring to FIG. 7, in order to transmit a packet, a UE (10) on the transmitting side requires resources (e.g., time and frequency) for transmitting sidelink control data and sidelink data. In order to obtain the resources, a UE (10) interested in sidelink communication can transmit a sidelink UE information (SidelinkUEInformation) message including a destination info list (destinationInfoList), i.e., a destination list, to a base station, i.e., an eNB (20) (S305).

The eNB (20) can allocate a sidelink resource pool (SC Pool) and sidelink Radio Network Temporary Identities (SL-RNTI) for transmitting sidelink control data through a Radio Resource Control (RRC) connection reconfiguration message (S310). The sidelink resource pool represents time and frequency resources, i.e., at least one subframe and PRB (Physical Resource Block) of each subframe, on which sidelink control (scheduling control) data can be transmitted. The time and frequency can be allocated periodically by a sidelink control period.

Thereafter, the UE (10) can request dedicated resources for sidelink control data and sidelink data transmission by transmitting a sidelink buffer status report (BSR) (S315).

The eNB (20) can allocate dedicated resources and transmit a grant (201) for sidelink communication, i.e., information about the dedicated resources (S320). The received single grant (201) may be for the first available sidelink control period starting after specific subframes from the subframe at the end point of the grant allocation period N (220-N) in which the single grant (201) was received. The UE (10) can transmit in the first available sidelink control period (210) using only one single grant (201) (S325).

Figure 8 is a diagram for explaining the concept of cellular network-based D2D communication applied to this specification.

Referring to FIG. 8, a cellular communication network is configured including a first base station (410), a second base station (420), and a first cluster (430). A first terminal (411) and a second terminal (412) belonging to a cell provided by the first base station (410) perform communication through a normal access link (cellular link) via the first base station (410). This is an in-coverage-single-cell terminal-to-terminal communication scenario. Meanwhile, a first terminal (411) belonging to the first base station (410) can perform terminal-to-terminal communication with a fourth terminal (421) belonging to the second base station (420). This is an in-coverage-multi-cell terminal-to-terminal communication scenario. In addition, the fifth terminal (431) that is out of network coverage may create a cluster (430) with the sixth terminal (432) and the seventh terminal (433) and perform terminal-to-terminal communication with them. This is an out-of-coverage terminal-to-terminal communication scenario. In addition, the third terminal (413) may perform terminal-to-terminal communication with the sixth terminal (432), which is a partial-coverage terminal-to-terminal communication scenario. In this way, terminal-to-terminal communication links are possible between devices that have the same cell as their serving cell, between devices that have different cells as their serving cells, and between devices connected to a serving cell and devices not connected to a serving cell, or between devices not connected to a serving cell. In particular, D2D communication may be required between devices that are out of network coverage for purposes such as public safety.

In order to perform D2D data transmission and reception through D2D communication, related control information must be transmitted and received between terminals. The related control information may be called Scheduling Assignment (SA). The Rx terminal may perform configuration for D2D data reception based on the SA. The SA may include, for example, at least one of a New Data indicator (NDI), a Transmit UE Identification (Tx terminal ID), a Redundancy Version indicator (RV indicator), a Modulation and Coding Scheme Indication (MCS indication), a Resource Allocation (RA) indication, and a power control indication.

Here, NDI indicates whether the current transmission is a repetition of data, i.e., a retransmission, or a new transmission. The receiver can combine the same data based on the NDI. The Tx terminal ID indicates the ID of the transmitting terminal. The RV indicator indicates a redundancy version by specifying different starting points in a circular buffer for reading the encoded buffer. Based on the RV indicator, the transmitting terminal can choose different redundancy versions for repetition of the same packet. The MCS indicator indicates an MCS level for D2D communication. The resource allocation indicator indicates to which time/frequency physical resource the corresponding D2D data is allocated and transmitted. The power control indicator will be a command for the terminal receiving the corresponding information to control an appropriate power size for the corresponding D2D transmission.

For a terminal supporting D2D communication, a radio resource for D2D communication may use an uplink channel of the (cellular) wireless communication system. In this case, SA and data for the D2D communication may be transmitted based on a structure of a PUSCH among uplink physical channels of the wireless communication system. That is, a PUSCH structure may be reused for a physical channel for D2D communication. For example, a 24-bit CRC (Cyclic Redundancy Check) may be inserted into the physical channel for D2D communication, and turbo coding may be used. In addition, rate matching may be used for bit size matching and generating multiple transmissions. Scrambling may be used for interference randomization. A PUSCH DMRS (Demodulation Reference Signal) may be used. The DMRS is used for channel estimation for coherent demodulation of an uplink received signal.

FIG. 9 is a diagram illustrating a system according to one embodiment of the present specification.

Referring to (a) of FIG. 9, it shows a case where all V2X terminals (UE-1, UE-2) are located within the coverage of the base station (gNB/eNB/RSU) (In-coverage scenario). All V2X terminals (UE-1, UE-2) can receive data and control information from the base station (gNB/eNB/RSU) through the downlink (DL) or transmit data and control information to the base station through the uplink (UL). At this time, the data and control information may be data and control information for V2X communication or data and control information for general cellular communication, not V2X communication. In addition, in (a) of FIG. 9, V2X terminals (UE-1, UE-2) can transmit and receive data and control information for V2X communication through the sidelink (SL).

Referring to (b) of FIG. 9, it shows a case where UE-1 among V2X terminals is located within the coverage of the base station (gNB/eNB/RSU) and UE-2 is located outside the coverage of the base station (gNB/eNB/RSU) (partial coverage scenario). Referring to (b) of FIG. 9, the terminal (UE-1) located within the coverage of the base station can receive data and control information from the base station through downlink (DL) or transmit data and control information to the base station through uplink (UL). Referring to (b) of FIG. 9, the terminal (UE-2) located outside the coverage of the base station cannot receive data and control information from the base station through downlink and cannot transmit data and control information to the base station through uplink. The terminal (UE-2) can transmit and receive data and control information for V2X communication with the terminal (UE-1) through sidelink (SL).

Fig. 9 (c) shows a case where all V2X terminals (UE-1, UE-2) are located outside the coverage of the base station (gNB/eNB/RSU). Referring to Fig. 9 (c), the terminals (UE-1, UE-2) cannot receive data and control information from the base station through the downlink (DL), and cannot transmit data and control information to the base station through the uplink (UL). Meanwhile, the terminals (UE-1) and (UE-2) can transmit/receive data and control information for V2X communication through the sidelink (SL).

FIG. 9 (d) shows a case where a V2X transmitting terminal and a V2X receiving terminal are connected to different base stations (gNB/eNB/RSU) (RRC connected state) or are camping on them (RRC disconnected state, i.e., RRC idle state) (inter-cell V2X communication). At this time, the terminal (UE-1) may be a V2X transmitting terminal and the terminal (UE-2) may be a V2X receiving terminal. Alternatively, the terminal (UE-1) may be a V2X receiving terminal and the terminal (UE-2) may be a V2X transmitting terminal. The terminal (UE-1) can receive a V2X-dedicated SIB (System Information Block) from the base station to which the terminal (UE-1) is connected (or is camping on), and the terminal (UE-2) can receive a V2X-dedicated SIB from another base station to which the terminal (UE-2) is connected (or is camping on). At this time, the information of the V2X-only SIB received by the terminal (UE-1) and the information of the V2X-only SIB received by the terminal (UE-2) may be different from each other. Therefore, in order to perform V2X communication between terminals located in different cells, it is necessary to unify the received SIB information.

In Fig. 9, a V2X system composed of two terminals (UE-1, UE-2) is described as an example for convenience of explanation, but the present invention is not limited thereto, and a variety of terminals may participate in the V2X system. In addition, the uplink (UL) and downlink (DL) between the base station (eNB/gNB/RSU) and the V2X terminals (UE-1, UE-2) may be named as Uu interface, and the sidelink (SL) between the V2X terminals (UE-1, UE-2) may be named as PC5 interface. Therefore, these may be used interchangeably in this specification.

Meanwhile, in this specification, a terminal may mean a vehicle supporting vehicular-to-vehicular (V2V) communication, a vehicle or a pedestrian's handset (e.g., a smartphone) supporting vehicular-to-pedestrian (V2P) communication, a vehicle supporting vehicular-to-network (V2N) communication, or a vehicle supporting vehicular-to-infrastructure (V2I) communication. In addition, in this specification, a terminal may mean an RSU (Road Side Unit) equipped with a terminal function, an RSU equipped with a base station function, or an RSU equipped with a part of a base station function and a part of a terminal function.

In this specification, a sidelink control channel may be called a physical sidelink control channel (PSCCH), and a sidelink shared channel or data channel may be called a physical sidelink shared channel (PSSCH). In addition, a broadcast channel broadcasted with a synchronization signal may be called a physical sidelink broadcast channel (PSBCH), and a channel for feedback transmission may be called a physical sidelink feedback channel (PSFCH). However, PSCCH or PSSCH may be used for feedback transmission. Depending on the communication system, it may be referred to as LTE-PSCCH, LTE-PSSCH, NR-PSCCH, NR-PSSCH, etc. In this specification, a sidelink may mean a link between terminals, and a Uu link may mean a link between a base station and a terminal.

FIG. 10 is a diagram for explaining a resource pool defined as a set of time and frequency resources used for transmission and reception of a side link according to one embodiment of the present specification.

Referring to 1110 of FIG. 10, a case is illustrated where a resource pool is allocated non-contiguously in time and frequency. Although this specification focuses on the case where a resource pool is allocated non-contiguously in frequency, it is of course possible for a resource pool to be allocated continuously in frequency.

Referring to 1120 of FIG. 10, non-contiguous resource allocation can be made on a frequency basis. The granularity of resource allocation on a frequency basis can be a PRB (Physical Resource Block).

Also, referring to 1121 of FIG. 10, resource allocation on the frequency may be performed based on a sub-channel. A sub-channel may be defined as a resource allocation unit on the frequency composed of a plurality of RBs. Specifically, a sub-channel may be defined as an integer multiple of an RB. Referring to 1121 of FIG. 10, a case in which a size of a sub-channel is composed of four consecutive PRBs is illustrated. The size of a sub-channel may be set differently, and although one sub-channel is generally composed of consecutive PRBs, it does not necessarily have to be composed of consecutive PRBs. A sub-channel may be a basic unit of resource allocation for a PSSCH (Physical Sidelink Shared Channel) or a PSCCH (Physical Sidelink Control Channel), and the size of a sub-channel may be set differently depending on whether the corresponding channel is a PSSCH or a PSCCH. It should also be noted that a sub-channel may be referred to as an RBG (Resource Block Group). Below, we describe methods for allocating non-contiguous resource pools on a frequency basis and dividing the allocated resource pools into multiple subchannels.

Referring to 1122 of FIG. 10, startRBSubchanel can indicate the starting position of a subchannel on a frequency in a resource pool.

Resource blocks, which are frequency resources belonging to the resource pool for PSSCH in the LTE V2X system, can be determined in the same manner as in Table 5 below.

1130 of Fig. 10 represents a case where resource allocation is discontinuous in time. The granularity of resource allocation in time can be a slot. This specification focuses on the case where a resource pool is discontinuously allocated in time, but it is of course also possible for a resource pool to be allocated continuously in time.

Referring to 1131 of FIG. 10, startSlot can indicate the starting position of a slot in time in a resource pool.

Subframes, which are time resources belonging to the resource pool for PSSCH in the LTE V2X system, can be determined in the same manner as in Table 6 below.

[Correction under Rule 91 12.12.2024]
[Table 6]

FIG. 11 is a flowchart illustrating a method for scheduled resource allocation (mode 1) in a side link according to one embodiment of the present specification.

Scheduled resource allocation (mode 1) is a method in which a base station allocates resources used for sidelink transmission to RRC-connected terminals using a dedicated scheduling method. Scheduled resource allocation (mode 1) is effective for interference management and resource pool management because the base station can manage sidelink resources.

Referring to FIG. 11, a terminal (1201) that is camping on (1205) can receive (1210) an SL SIB (Sidelink System Information Bit) from a base station (1203). The system information may include resource pool information for transmission and reception, setting information for sensing operation, information for setting synchronization, information for inter-frequency transmission and reception, etc. When data traffic for V2X is generated in the terminal (1201), an RRC connection with the base station can be performed (1220). Here, the RRC connection between the terminal and the base station can be referred to as Uu-RRC (1220). The Uu-RRC connection can be performed before data traffic for V2X is generated. The terminal (1201) can request transmission resources for V2X communication with other terminals (1202) from the base station (1203) (1230). At this time, the terminal (1201) can request transmission resources for V2X communication from the base station (1203) using an RRC message or MAC CE (1230). Here, SidelinkUEInformation and UEAssistanceInformation messages can be used as RRC messages. Meanwhile, the MAC CE can be a buffer status report MAC CE of a new format (including at least an indicator indicating that it is a buffer status report for V2X communication and information on the size of data buffered for D2D communication). For detailed format and content of buffer status report used in 3GPP, refer to 3GPP standard TS36.321 E-UTRA MAC Protocol Specification". The base station (1203) can allocate V2X transmission resources to the terminal (1201) through a dedicated Uu-RRC message. The dedicated Uu-RRC message can be included in the RRCConnectionReconfiguration message. The allocated resources can be V2X resources through Uu or resources for PC5 depending on the type of traffic requested by the terminal (1201) or congestion of the corresponding link. To determine resource allocation, the terminal can send PPPP (ProSe Per Packet Priority) or LCID (Logical Channel ID) information of V2X traffic additionally through UEAssistanceInformation or MAC CE. Since the base station (1203) also knows information about resources used by other terminals (1202), it can allocate the remaining resource pool among the resources requested by the terminal (1201) (12-35). The base station (1203) can instruct the terminal (1201) to perform final scheduling by transmitting DCI through PDCCH (1240).

In the case of broadcast transmission, the terminal (1201) can broadcast SCI (Sidelink Control Information) to other terminals (1202) via PSCCH without additional RRC configuration of sidelink (1270). In addition, data can be broadcast to other terminals (12-02) via PSSCH (1270).

In contrast, in the case of unicast and groupcast transmission, the terminal (1201) can perform RRC connection one-to-one with other terminals (1202). Here, the RRC connection between terminals can be named PC5-RRC to distinguish it from Uu-RRC. Even in the case of groupcast, PC5-RRC (1215) can be individually connected between terminals in the group. In Fig. 11, the connection of PC5-RRC (1215) is depicted as an operation after transmission of SL SIB (1210), but it can be performed at any time before transmission of SL SIB (1210) or before transmission of SCI (1260). If RRC connection is required between terminals, PC5-RRC (1215) connection of sidelink can be performed and SCI (Sidelink Control Information) can be transmitted to other terminals (1202) through PSCCH as unicast or groupcast (1260). At this time, groupcast transmission of SCI can be interpreted as group SCI. In addition, data can be transmitted to other terminals (1202) through PSSCH as unicast or groupcast (1270).

FIG. 12 is a flowchart illustrating a UE autonomous resource allocation (mode 2) method in a sidelink according to one embodiment of the present specification.

In the UE autonomous resource allocation (mode 2) method, the base station (1303) provides a sidelink transmission/reception resource pool for V2X as system information, and the terminal (1301) can select a transmission resource according to a set rule. Resource selection methods may include zone mapping, sensing-based resource selection, and random selection. Unlike the scheduled resource allocation (mode 1) method in which the base station (1303) directly participates in resource allocation, FIG. 12 is different from the scheduled resource allocation (mode 1) method in that the terminal (1301) autonomously selects a resource pool and transmits data based on the resource pool received in advance through system information. In V2X communication, the base station (1303) can allocate various types of resource pools (V2V resource pool, V2P resource pool) for the terminal (1301). The allocatable resource pool may be composed of a resource pool from which a terminal can autonomously select an available resource pool after sensing resources used by other surrounding terminals (1302), and a resource pool from which a terminal randomly selects a resource from a preset resource pool.

The terminal (1301) that is camping on (1305) can receive (1310) SL SIB (Sidelink System Information Bit) from the base station (1303). The system information can include resource pool information for transmission and reception, setting information for sensing operation, information for setting synchronization, information for inter-frequency transmission and reception, etc. The difference in the operation of FIG. 11 and FIG. 12 is that in the case of FIG. 11, the base station (1203) and the terminal (1201) operate in an RRC-connected state, whereas in FIG. 12, they can also operate in an idle mode (1320) that is not RRC-connected. In addition, in the idle mode (1320) that is not RRC-connected, the base station (1303) does not directly participate in resource allocation and can operate so that the terminal (1301) autonomously selects transmission resources. When data traffic for V2X is generated in the terminal (1301), the terminal (1301) can select (1330) a resource pool in the time/frequency domain according to a set transmission operation among the resource pools received through system information from the base station (1303).

Next, in the case of broadcast transmission, the terminal (1301) can broadcast SCI (Sidelink Control Information) to other terminals (1302) via PSCCH without additional RRC configuration of sidelink (1350). In addition, the terminal (1301) can broadcast data to other terminals (1302) via PSSCH (1360).

In contrast, in the case of unicast and groupcast transmission, the terminal (1301) can perform one-to-one RRC connection with other terminals (1302). Here, the RRC connection between terminals can be referred to as PC5-RRC to distinguish it from Uu-RRC. Even in the case of groupcast, PC5-RRC can be individually connected between terminals in the group. This may be similar to the connection of the RRC layer in the connection between the base station and the terminal in NR uplink and downlink, and the connection of the RRC layer stage in the sidelink can be referred to as PC5-RRC. Through the PC5-RRC connection, terminal-to-terminal capability (UE capability) information for the sidelink can be exchanged, or configuration information required for signal transmission and reception can be exchanged. In FIG. 12, the connection of PC5-RRC (1315) is illustrated as an operation after SL SIB transmission (13-10), but it can be performed at any time before SL SIB transmission (13-10) or before SCI transmission (13-50). If an RRC connection is required between terminals, a PC5-RRC connection of the sidelink is performed (1315) and SCI (Sidelink Control Information) can be transmitted to other terminals (1302) as unicast or groupcast through PSCCH (1350). At this time, groupcast transmission of SCI can be interpreted as group SCI. In addition, data can be transmitted to other terminals (1302) as unicast and groupcast through PSSCH (1360).

Hereinafter, in the present specification, a transmitting terminal (TX UE) may be a terminal that transmits data to a (target) receiving terminal (RX UE). For example, the TX UE may be a terminal that performs PSCCH and/or PSSCH transmission. And/or, the TX UE may be a terminal that transmits an SL CSI-RS and/or an SL CSI report request indicator to the (target) RX UE. And/or, the TX UE may be a terminal that transmits a (control) channel (e.g., PSCCH, PSSCH, etc.) and/or a reference signal (e.g., DM-RS, CSI-RS, etc.) on the (control) channel to be used for SL RLM and/or SL RLF operation of the (target) RX UE.

Also, in the present specification, a receiving terminal (RX UE) may be a terminal that transmits SL HARQ feedback to a transmitting terminal (TX UE) based on (i) whether decoding of data received from a TX UE is successful and/or (ii) whether detection/decoding of PSCCH (related to PSSCH scheduling) transmitted by the TX UE is successful. And/or, the RX UE may be a terminal that performs SL CSI transmission to the TX UE based on SL CSI-RS and/or SL CSI report request indicator received from the TX UE. And/or, the RX UE may be a terminal that transmits an SL (L1) RSRP measurement value measured based on a (predefined) reference signal and/or SL (L1) RSRP report request indicator received from the TX UE to the TX UE. And/or, the RX UE may be a terminal that transmits its own data to the TX UE. And/or, the RX UE may be a terminal performing SL RLM and/or SL RLF operation based on a (pre-configured) (control) channel received from a TX UE and/or a reference signal on the (control) channel.

Meanwhile, in the present specification, for example, when the RX UE transmits SL HARQ feedback information for the PSSCH and/or PSCCH received from the TX UE, the following schemes or some of the following schemes may be considered. Here, for example, the following schemes or some of the following schemes may be applied only when the RX UE successfully decodes/detects the PSCCH scheduling the PSSCH.

Option 1) NACK information can be transmitted to the TX UE only when the RX UE fails to decode/receive the PSSCH received from the TX UE.

Method (Option) 2) If the RX UE succeeds in decoding/receiving the PSSCH received from the TX UE, it can transmit ACK information to the TX UE, and if the PSSCH decoding/reception fails, it can transmit NACK information to the TX UE.

Meanwhile, in this specification, for example, the TX UE may transmit the following information or some of the following information to the RX UE via the SCI. Here, for example, the TX UE may transmit some or all of the following information to the RX UE via the first SCI (FIRST SCI) and/or the second SCI (SECOND SCI).

- PSSCH (and/or PSCCH) related resource allocation information (e.g., time/frequency resource location/number, resource reservation information (e.g., period))

- SL CSI Report Request Indicator or SL (L1) RSRP (and/or SL (L1) RSRQ and/or SL (L1) RSSI) Report Request Indicator

- SL CSI Transmission Indicator (or SL (L1) RSRP (and/or SL (L1) RSRQ and/or SL (L1) RSSI) Information Transmission Indicator) (on PSSCH)

- MCS Information

- TX POWER information

- L1 DESTINATION ID information and/or L1 SOURCE ID information

- SL HARQ PROCESS ID information

- NDI Information

- RV Information

- (Transmission TRAFFIC/PACKET related) QoS information (e.g. PRIORITY information)

- SL CSI-RS transmission indicator or information on the number of SL CSI-RS antenna ports (to be transmitted)

- TX UE location information or location (or range area) information of the target RX UE (for which SL HARQ feedback is requested).

- Reference signal (e.g., DM-RS, etc.) information related to decoding (and/or channel estimation) of data transmitted via PSSCH. For example, it may be information related to the pattern of (time-frequency) mapping resources of DM-RS, RANK information, antenna port index information, etc.

Meanwhile, in the present specification, since the TX UE can transmit SCI, the first SCI (FIRST SCI) and/or the second SCI (SECOND SCI) to the RX UE via the PSCCH, the PSCCH can be replaced/substituted with (i) SCI and/or (ii) FIRST SCI and/or (iii) SECOND SCI. And/or, the SCI can be replaced/substituted with the PSCCH and/or the FIRST SCI and/or the SECOND SCI. And/or, since the TX UE can transmit SECOND SCI to the RX UE via the PSSCH, the PSSCH can be replaced/substituted with the SECOND SCI.

Meanwhile, in this specification, for example, when SCI configuration fields are divided into two groups in consideration of (relatively) high SCI payload size, the first SCI including the first SCI configuration field group may be referred to as FIRST SCI, and the second SCI including the second SCI configuration field group may be referred to as SECOND SCI. In addition, for example, the FIRST SCI may be transmitted to the receiving terminal via the PSCCH. In addition, for example, the SECOND SCI may be transmitted to the receiving terminal via the (independent) PSCCH, or may be transmitted piggybacked with data via the PSSCH.

Meanwhile, in this specification, for example, “configuration” or “definition” may mean (PRE)CONFIGURATION (resource pool specific) from a base station or network (via predefined signaling (e.g., SIB, MAC, RRC, etc.)).

Meanwhile, in this specification, for example, RLF can be determined based on the OUT-OF-SYNCH (OOS) indicator or the IN-SYNCH (IS) indicator, and thus can be replaced/substituted with OUT-OF-SYNCH (OOS) or IN-SYNCH (IS).

Meanwhile, in this specification, for example, RB may be replaced/substituted with SUBCARRIER. Also, as an example, in this specification, PACKET or TRAFFIC may be replaced/substituted with TB or MAC PDU depending on the layer being transmitted.

Meanwhile, in this specification, CBG or CG may be replaced/substituted with TB.

Meanwhile, in this specification, for example, SOURCE ID may be replaced/substituted with DESTINATION ID.

Meanwhile, in this specification, for example, L1 ID may be replaced/substituted with L2 ID. For example, L1 ID may be L1 SOURCE ID or L1 DESTINATION ID. For example, L2 ID may be L2 SOURCE ID or L2 DESTINATION ID.

Hereinafter, a method for a resource selection algorithm for NR-V2X mode 2 side link communication through resource status judgment including interference value and reuse distance is described. More specifically, a method is examined in which a terminal (e.g., a vehicle) selects a resource with less interference by utilizing Sending Based Semi-Persistent Scheduling (SB-SPS) based on reuse distance judgment. In this specification, 'resource reuse distance' means 'reuse distance' and can be interchanged/replaced.

C-V2X (Cellular-V2X) supports direct communication between vehicles and other user equipment through side links to improve the efficiency of vehicle Internet communication. C-V2X can support the establishment of communication links between vehicles and other entities, including vehicle-to-vehicle (V2V), vehicle-to-pedestrian (V2P), vehicle-to-infrastructure (V2I), and vehicle-to-network (V2N) communications.

And by defining LTE-V2X in Release 14, the initial standard to support V2X services was completed. In addition, the 5G version of NR-V2X was defined in Release 16. In addition, the biggest difference between LTE-V2X and NR-V2X is as follows. NR-V2X allows more subcarrier spacing for the side link, and provides multicast and unicast in addition to the broadcast transmission mode supported by LTE-V2X.

Additionally, C-V2X has two resource allocation methods: centralized mode and distributed mode. The centralized mode may be referred to as Mode 3 in LTE-V2X and Mode 1 in NR-V2X. The distributed mode may be referred to as Mode 4 in LTE-V2X and Mode 2 in NR-V2X.

In the centralized mode, the base station (BS) manages and allocates resources, and the UE can communicate in the uplink (UL) and downlink (DL) through the Uu interface. In the distributed mode, the UE outside the BS coverage area can independently select resources and communicate in the sidelink (SL) through the PC5 interface. In addition, since the distributed resource selection is based on sensing information without going through the base station, it supports service requirements such as low latency and high reliability. In addition, SB-SPS is adopted in NR-V2X mode 2 to support user resource selection, as in LTE-V2X mode 4. According to SB-SPS, the UE can randomly select a resource from available resources generated after the sensing process, and the UE can reserve the same resource for multiple periods.

In this specification, a vehicle may be replaced with a terminal (UE), and a terminal (UE) may be replaced with a vehicle.

First, the operation and problems based on the existing SB-SPS method are examined with reference to FIGS. 13 to 15.

Figure 13 is an example of a flowchart explaining the existing SB-SPS method.

)은 S1320 내지 S1360을 수행한다.Referring to Figure 13, a terminal (or vehicle) that must select a new resource in S1310

) performs S1320 to S1360.

In S1320, the terminal performs channel sensing. For example, the terminal continuously measures the Reference Signal Received Power (RSRP) of each resource as an interference value (Step 1 of FIG. 15).

를 얻는다. In S1330, the terminal has a list of available resources.

Get .

보다 높은 경우, 해당 자원은 가용 자원들에서 제외된다.For example, a resource that satisfies at least one of the following two conditions is excluded from the available resources. First, resources related to half-duplex (HD) are excluded. Specifically, since a terminal cannot receive when transmitting, the corresponding resource (e.g., a resource for reception of the terminal) must be excluded from the resources for transmission of the terminal. Second, the RSRP value of the resource is a pre-set RSRP threshold.

If it is higher, the resource is excluded from the available resources.

이하의 RSRP를 갖는 자원들(상기 가용 자원들)을 포함하는 리스트

를 얻는다(도 15의 Step 2).Based on the resource detection results obtained by the terminal (e.g. RSRP for PSSCH or PSCCH), the terminal

A list containing resources (the available resources above) with the following RSRPs:

(Step 2 of Figure 15).

내의 자원들의 수가 전체 자원들의 수의 X%보다 작으면 단말은

를 3dB씩 증가시킨 후, 가용 자원들의 수가 전체 자원들 수의 X%를 초과할 때까지 S1330을 반복한다. In S1340, list

If the number of resources in my terminal is less than X% of the total number of resources, the terminal

After increasing by 3 dB, repeat S1330 until the number of available resources exceeds X% of the total number of resources.

에서 자원을 임의로 선택한다(Random selection)(도 15의 Step 3). 이 단계는 선택 윈도우(selection window)(도 14 참조)로 지칭될 수 있다. 또한, SB-SPS 방식에 기초하여, 자원을 선택한 단말은 사이드링크 제어 정보(Sidelink Control Information, SCI)를 통해 인접 단말(들)에 예약 정보를 알려준 다음 N회 연속 전송 기간 동안 동일한 자원을 유지/사용할 수 있다. N은 재선택 카운터(RC)라고도 한다. RC는 전송할 때마다 1씩 감소한다. In S1350, the terminal is listed

Randomly select a resource (Random selection) (Step 3 of Fig. 15). This step may be referred to as a selection window (see Fig. 14). In addition, based on the SB-SPS method, a terminal that has selected a resource may inform its neighboring terminal(s) of reservation information through Sidelink Control Information (SCI) and then maintain/use the same resource for N consecutive transmission periods. N is also called a reselection counter (RC). RC decreases by 1 for each transmission.

)로 새로운 자원을 선택하거나 확률(

)로 이전 자원을 유지한다.In S1360, when RC becomes 0, the terminal has a probability (1-

) to select a new resource or a probability (

) to maintain previous resources.

Figure 14 illustrates a resource structure related to the existing SB-SPS method.

내의 자원들) 중에서 PSCCH/PSSCH 전송을 위한 자원을 선택할 수 있다.Referring to Fig. 14, the sensing operation (S1320) of the terminal (i.e., RSRP measurement) can be performed in a sensing window. The resource selection operation (S1330) of the terminal based on a list of available resources (available resources) can be performed in a selection window (or resource selection window). The terminal selects available resources (Available Resources) (the list described above).

A resource for PSCCH/PSSCH transmission can be selected from among the resources within the UE.

Based on the resource reservation interval, the resource(s) selected in the selection window and the resource(s) within a certain interval are reserved. In other words, the reserved resource may be a resource after a certain time interval (or a certain period) from the resource selected in the resource selection window.

Figure 15 illustrates a resource selection procedure based on the existing SB-SPS method.

Referring to FIG. 15, Step 1 (Channel sensing) corresponds to S1320 of FIG. 13, Step 2 (Available resources) corresponds to S1330 of FIG. 13, and Step 3 corresponds to S1350 of FIG. 13, so redundant description is omitted.

In Step 1, the terminal performs sensing operations for resources #1 to #100. Specifically, the terminal measures RSRP of resources #1 to #100. X1 to X100 may represent RSRP of resources #1 to #100.

In Step 2, based on the above X1 to X100, the terminal can determine available resources (resource #2, resource #3, resource #4, resource #6, ..., resource #98, resource #100).

In Step 3, the terminal randomly selects a resource (e.g., resource #100) for PSCCH/PSSCH transmission among the available resources.

에서 최종 자원을 무작위로 선택하며, 단말은 동일한 자원을 여러 번 연속으로 사용한다. 그러나 이러한 설정에 의하면, 이웃 단말들이 비슷한 조건의 가용 자원들의 리스트를 생성한 후 상기 단말이 선택한 자원과 중복이 큰 자원을 선택한 후 동일 자원을 반복하여 사용할 수 있다. 따라서, 상술한 기존 SB-SPS 알고리즘은 상기 단말에 의해 선택된 자원이 사이드링크 통신에 적합하고 간섭이 적다는 것을 보장해주지 못한다.As described above, the existing SB-SPS algorithm provides a list of available resources.

In this case, the final resource is randomly selected, and the terminal uses the same resource multiple times in succession. However, according to this setting, neighboring terminals may generate a list of available resources with similar conditions, select a resource with a large overlap with the resource selected by the terminal, and then repeatedly use the same resource. Therefore, the existing SB-SPS algorithm described above cannot guarantee that the resource selected by the terminal is suitable for sidelink communication and has little interference.

In addition, interference terminals using the same resources also affect the SINR value when determining whether to receive a packet. Resource conflicts are more serious in high-density scenarios, because resource competition inevitably intensifies as the number of users increases for limited resources. However, the existing SB-SPS mechanism does not specify the conditions that terminals must meet when selecting reusable resources.

To solve the above-mentioned problem, it is possible to consider improving the resource selection algorithm to limit the resource reuse situation. For example, the reuse distance judgment can be utilized before selecting the resource. Specifically, by limiting the reuse distance, the possibility of adjacent terminals selecting the same resource can be reduced.

In the existing SB-SPS method, random selection inevitably causes resource conflict, which causes adjacent terminals to select and use the same resource for multiple periods of time, which increases interference between terminals and reduces the possibility of successful data reception. It is necessary to improve the existing method so that terminals can select resources with less interference and receive data packets accurately and with short delay times. The overall flowchart and procedure of the improved SB-SPS with the reuse distance determination method described below applied are shown in FIG. 20 and FIG. 22 described below. And a comparison of resource selection through existing SB-SPS random selection or reuse distance determination is shown in FIG. 21.

Below, we will examine specific examples for solving problems in the existing SB-SPS method.

Method 1

The method according to the present embodiment aims to improve the packet reception success rate and minimize resource conflicts due to random resource selection. To this end, the first solution considers the optimal resource with the lowest RSRP value, which means the resource with the least interference. For convenience of explanation, the present embodiment is referred to as 'always-best selection', 'always-best method' or 'always-best' in the following.

The overall algorithm structure according to the present embodiment is described below with reference to FIG. 16.

FIG. 16 illustrates a flowchart for explaining an improved SB-SPS scheme (always-best scheme) according to one embodiment of the present specification.

In Fig. 16, Step 1 (S1620), Step 2 (S1630), and Step 4 (S1670) are identical to Step 1 (S1320), Step 2 (S1330), and Step 4 (S1360) of the existing SB-SPS method (Fig. 13) described above, and thus, redundant descriptions are omitted.

)은 가용 자원들의 리스트

를 생성한다. 구체적으로, 단말은 센싱 윈도우에서 자원 센싱을 수행한다. 단말은 다른 단말에 의해 점유된 자원 또는 RSRP 임계값을 초과하는 자원은 상기 가용 자원들에서 제외한다(S1610 내지 S1640).When resource selection is required, the terminal (or vehicle)

) is a list of available resources.

Specifically, the terminal performs resource sensing in the sensing window. The terminal excludes resources occupied by other terminals or resources exceeding the RSRP threshold from the available resources (S1610 to S1640).

를 생성/획득한다(Step3.1). 일 예로, 상기 리스트

는 리스트

내의 자원들을 각 자원의 RSRP 값에 따라 오름차순으로 순위를 매김으로써 생성/획득될 수 있다. 일 예로, 상기 리스트

의 첫번째 자원은 RSRP 값이 가장 낮은 자원일 수 있다.In S1650, the terminal has an ascending RSRP resource list.

Create/obtain (Step 3.1). For example, the above list

is a list

The resources in my list can be created/obtained by ranking them in ascending order according to the RSRP value of each resource. For example, the list above

The first resource may be the one with the lowest RSRP value.

에서 첫 번째 자원을 선택한다(Step 3.2). 상기 리스트

내의 첫 번째 자원의 선택은 단말이 전송을 위해 가장 낮은 RSRP 값을 가진 최상의 자원을 선택한다는 것을 의미한다. 이하 도 17을 참조하여 본 실시예에 따른 Step1 내지 Step4를 설명한다.In S1660, the terminal is listed

Select the first resource from the list above (Step 3.2).

The selection of the first resource within means that the terminal selects the best resource with the lowest RSRP value for transmission. Steps 1 to 4 according to the present embodiment are described below with reference to FIG. 17.

Fig. 17 illustrates a procedure of an improved SB-SPS method according to one embodiment of the present specification. In Fig. 17, Step 1 and Step 2 are identical to Step 1 and Step 2 of Fig. 15, and thus, redundant descriptions are omitted. The description focuses on operations that are distinct from the existing SB-SPS method (Step 3 of Fig. 15).

)를 결정한다. 구체적으로, 단말은 Step 2에서 결정된 가용 자원들(자원 #2, 자원 #3, 자원 #4, 자원 #6, 자원 #98, ... 자원 #100)(즉, 상술한

내의 자원들)을 RSRP 값의 오름차순에 따라 정렬함으로써 리스트

(자원 #6, 자원 #2, 자원#4, 자원 #100, ..., 자원 #3, 자원 #98)을 생성/획득한다. 본 명세서에서 단말에 의한 리스트

의 생성/획득은 가용 자원들(available resoures)의 결정으로 표현될 수 있다. 본 명세서에서 단말에 의한 리스트

의 생성/획득은 RSRP 오름차순으로 정렬된 가용 자원들(available resoures)의 결정으로 표현될 수 있다.In Step 3, the terminal retrieves the ascending RSRP resource list (

) is determined. Specifically, the terminal determines the available resources (resource #2, resource #3, resource #4, resource #6, resource #98, ... resource #100) determined in Step 2 (i.e., the above

The list is sorted by ascending order of RSRP values (resources within)

(Resource #6, Resource #2, Resource #4, Resource #100, ..., Resource #3, Resource #98) is created/obtained. List by terminal in this specification

The creation/acquisition of can be expressed as a determination of available resources. In this specification, a list by a terminal

The creation/acquisition of can be expressed as a determination of available resources sorted in ascending RSRP order.

In Step 4, the terminal selects the first resource (resource #6) from among the available resources (resource #6, resource #2, resource #4, resource #100, ..., resource #3, resource #98) sorted in ascending RSRP order. Referring to FIGS. 18 and 19 below, the packet reception ratio (PRR) and error block rate of the present embodiment (always-best) and the existing SB-SPS method are compared and explained.

Figure 18 is a graph showing the packet reception ratio (PRR) of the existing SB-SPS method and the always-best method. Figure 19 is a graph showing the error block rate of the existing SB-SPS method and the always-best method.

Referring to FIGS. 18 and 19, as the rho value increases, the performance related to PRR and Error block rate decreases compared to the existing SB-SPS method. Specifically, as the rho value increases, the PRR based on the always-best method decreases compared to the PRR based on the existing SB-SPS method (FIG. 18), and the Error block rate based on the always-best method increases compared to the Error block rate based on the existing SB-SPS method (FIG. 19). Here, rho represents the number of terminals (or vehicles) per km. That is, rho can be interpreted/replaced with a density related to a resource competition situation.

The random selection of the existing SB-SPS has the risk that neighboring terminals will select the same resource. In addition, since Mode 2 SB-SPS lists all available resources as candidate resources, the terminal has a high probability of selecting a resource with a high interference value. This probability increases even more in high density. According to the Always-best method, the terminal always selects the resource with the least interference. The Always-best method ensures that data transmission is received accurately.

However, as the density (rho value in Figs. 18 and 19) increases, resource conflicts may become more serious as the number of adjacent terminals generating similar candidate resource lists based on the Always-best method increases.

In order to improve the above-described always-best method, the use of reuse distance can be considered. The reuse distance can mean the minimum distance at which different terminals are allowed to use the same resource. This will be described in detail with reference to FIGS. 20 to 22 below.

Fig. 20 is a flowchart for explaining an improved SB-SPS method applying reuse distance judgment. In Fig. 20, S2010 to S2030, S2060, and S2070 are identical to S1620 to S1640, S1660, and S1670 of Fig. 16, and therefore, redundant descriptions are omitted.

Reuse distance judgement can be performed based on S2040 to S2050.

)은 리스트

(또는 리스트

)의 각 자원(current resource)을 점유하는 다른 단말(예: vehicle

)과 단말 자신(예: vehicle

)과의 거리(

)가 자원 재사용 거리(

)보다 큰 지 여부를 결정한다(S2050).The terminal determines the reuse distance of available resources. Specifically, the terminal (e.g., vehicle)

) is a list

(or list

) other terminals (e.g., vehicle) occupying each resource (current resource)

) and the terminal itself (e.g. vehicle

) and distance from (

) is the resource reuse distance (

) is greater than (S2050).

가

보다 크지 않은 경우, 단말은 리스트

내의 다음 자원(next resource)에 대해서 상술한 자원 재사용 거리 판단을 수행한다.The above related to the current resource

go

If not larger than , the terminal is listed

The resource reuse distance determination described above is performed for the next resource within the system.

가

보다 큰 경우, 단말은 해당 자원을 선택하고, 이후 N 번의 전송 주기 동안 해당 자원을 사용한다(S2060). 자원 재선택 카운터(N)가 0이 되면 현재 자원을 유지하거나 새로운 자원을 재선택한다(S2070).The above related to the current resource

go

If it is greater than that, the terminal selects the corresponding resource and uses the corresponding resource for N transmission cycles thereafter (S2060). When the resource reselection counter (N) becomes 0, the current resource is maintained or a new resource is reselected (S2070).

Figure 21 illustrates resource selection according to the conventional SB-SPS method and resource selection according to the improved SB-SPS method based on reuse distance judgment.

Referring to (a) of Fig. 21, n terminals (n vehicles) perform resource selection randomly.

)가 자원 재사용 거리보다 큰 바, 단말(V2 또는 V7)은 다른 단말(V7 또는 V2)이 사용하는/점유하는 자원(R5)과 동일한 자원을 선택할 수 있다.Referring to (b) of Fig. 21, n terminals (n vehicles) perform resource selection based on reuse distance judgment. Specifically, terminals (V2, V7) select the same resource (R5) based on resource reuse distance judgment. That is, the distance between terminals (V2, V7) for the same resource (R5) (above)

) is greater than the resource reuse distance, the terminal (V2 or V7) can select the same resource (R5) used/occupied by another terminal (V7 or V2).

Fig. 22 illustrates a procedure of an improved SB-SPS applying reuse distance judgment according to one embodiment of the present specification. Steps 1 to 3 in Fig. 22 are identical to Steps 1 to 3 in Fig. 17, and thus redundant descriptions are omitted.

)은 재사용 거리 판단(reuse distance judgement)을 수행한다. 구체적으로, 단말은 RSRP 오름차순으로 정렬된 가용 자원들(예: 자원#6, 자원#2, 자원#4..) 중 단말간 거리(

)가 자원 재사용 거리(

)보다 큰 자원을 결정한다. 이하 보다 상세하게 설명한다.In Step 4, the terminal (

) performs reuse distance judgment. Specifically, the terminal selects the terminal-to-terminal distance ( ) among the available resources sorted in ascending RSRP order (e.g., resource #6, resource #2, resource #4, etc.).

) is the resource reuse distance (

) determines a resource larger than the number of users. This is explained in more detail below.

)이 사용하고 있다. 이 경우, 단말(

)은 해당 단말(

)과의 거리(

)가 자원 재사용 거리(

)보다 큰 지 여부를 결정한다. 상기 자원 #6과 관련된 단말과의 거리(

)가 자원 재사용 거리(

)보다 작으므로 단말은 그 다음 자원(두번째 자원)에 대해 자원 재사용 거리 판단을 수행한다.The first resource #6 among the available resources sorted in ascending RSRP order is another terminal (

) is being used. In this case, the terminal (

) is the corresponding terminal (

) and distance from (

) is the resource reuse distance (

) is greater than the distance from the terminal associated with the above resource #6 (

) is the resource reuse distance (

) is smaller than the resource reuse distance, the terminal performs resource reuse distance judgment for the next resource (the second resource).

)과의 거리(

)가 자원 재사용 거리(

)보다 작다. 따라서, 단말은 다음 자원(세번재 자원)에 대해 자원 재사용 거리 판단을 수행한다.Even for the second resource #2 among the available resources sorted in RSRP ascending order, the terminal associated with resource #2 (

) and distance from (

) is the resource reuse distance (

) is smaller than the resource reuse distance. Therefore, the terminal performs resource reuse distance judgment for the next resource (the third resource).

)과의 거리(

)가 자원 재사용 거리(

)보다 크다.For the third resource #4 among the available resources sorted in ascending order of RSRP, the terminal associated with resource #4 (

) and distance from (

) is the resource reuse distance (

) is larger than.

In Step 5, the terminal selects a resource based on the reuse distance judgment described above. Specifically, the terminal selects the third resource #4 among the available resources sorted in ascending RSRP order.

Hereinafter, an improved SB-SPS method (method 2 and method 3) to which the above-described resource reuse distance judgment is applied is described with reference to FIGS. 23 to 26.

Method 2

The method according to the present embodiment aims to improve the packet reception success rate and minimize resource conflicts caused by random resource selection. The present embodiment introduces resource reuse distance judgment into the SB-SPS algorithm. Specifically, whether a current terminal selects a resource may vary depending on its proximity to an adjacent terminal using the same resource.

This embodiment utilizes a fixed reuse distance. For convenience of explanation in this specification, this embodiment is referred to as an improved SB-SPS method applying a fixed reuse distance determination.

The overall algorithm structure according to the present embodiment is described below with reference to FIG. 23.

Fig. 23 is a flowchart for explaining an improved SB-SPS method applying fixed reuse distance determination according to one embodiment of the present specification. In Fig. 23, S2310 to S2330, S2360, and S2370 are identical to S2010 to S2030, S2060, and S2070 of Fig. 20, and therefore, redundant descriptions are omitted.

를 생성/획득한다(Step3.1). S2340은 도 16의 S1650과 동일한바 중복된 설명을 생략한다.In S2340, the terminal has an ascending RSRP resource list.

Create/obtain (Step 3.1). S2340 is identical to S1650 of Fig. 16, so duplicate description is omitted.

에서 자원

을 획득/결정한다. 구체적으로, 단말은

의 자원을 순서대로 선택하여 다음 동작을 수행한다. 단말(

)은 현재 자원

과 동일한 자원을 사용하는 다른 이웃 단말(

)에 대한 정보와 해당 단말과의 거리를 획득한다. 이러한 이웃 단말(

)을 점유자로 설정하고 리스트

에 포함시킨다(Step3.2).

내 단말이 존재하지 않거나 한 번에 두 개 이상의 단말들이 있을 수 있다.In S2341, the terminal is listed

Resources in

acquires/determines. Specifically, the terminal

Selects the resources in order and performs the following actions: Terminal (

) is the current resource

Other neighboring terminals using the same resources (

) obtains information about the neighboring terminals and the distance to the terminal. These neighboring terminals (

) as the occupant and list

Include it in (Step 3.2).

My terminal may not exist or there may be more than one terminal at a time.

에 단말이 없는 경우 단말(

)은 추가적인 동작 없이 현재 자원

를 PSCCH/PSSCH 전송을 위한 자원

로 결정할 수 있다. 이 경우, 단말(

)은 S2360 및 S2370을 수행한다.

에 단말이 있는 경우 단말은 S2351을 수행한다.In S2350,

If there is no terminal in the terminal (

) is the current resource without any additional action.

Resources for PSCCH/PSSCH transmission

can be determined. In this case, the terminal (

) performs S2360 and S2370.

If there is a terminal in , the terminal performs S2351.

)은 재사용 거리(

) 값을 결정한다(Step3.3).

값은 고정된 값(fixed value)일 수 있다. 일 예로,

값은 모든 양의 정수 값(positive integer value)일 수 있다. Terminal in S2351 (

) is the reuse distance (

) determines the value (Step 3.3).

The value can be a fixed value. For example,

The value can be any positive integer value.

)은 현재 자원(

)을 사용/점유하는 단말(

)과 단말 자신간의 거리(

)가 자원 재사용 거리(

)보다 큰지 확인한다.

에 복수의 단말들이 포함된 경우에, 단말(

)은 각 단말(예:

, j=1, 2, ..)과의 거리가 자원 재사용 거리(

)보다 큰지 확인한다In S2352, the terminal performs reuse distance judgment (Step 3.4). Specifically, the terminal (

) is the current resource (

) that uses/occupies the terminal (

) and the distance between the terminal itself (

) is the resource reuse distance (

) is greater than that.

In case multiple terminals are included, the terminal (

) is for each terminal (e.g.

, j=1, 2, ..) is the resource reuse distance (

) is greater than

)과

내의 모든 단말(

) 사이의 거리가 자원 재사용 거리보다 큰 경우에만(

>

), 단말(

)는 현재 자원(

)를 선택할 수 있다. 그렇지 않은 경우(

<=

), 단말(

)은

에서 다음 자원

에 대해 상술한 자원 재사용 거리 판단을 계속 수행한다.Terminal(

)class

All terminals within (

) only if the distance between them is greater than the resource reuse distance.

>

), terminal(

) is the current resource (

) can be selected. Otherwise (

<=

), terminal(

)silver

Next resource in

Continue to perform the resource reuse distance judgment described above.

의 모든 자원들을 순환시킨다. 여기서, 순환시킨다는 것은 자원 재사용 거리 판단의 대상이 되는 자원을 그 다음 자원으로 변경한다는 것을 의미한다.

내의 모든 자원들이 순환되지 않은 경우(S2354), 단말은

내의 다음 자원(next resource)에 대해 상술한 재사용 거리 판단(S2341 내지 S2352)을 수행한다. In S2353 and S2354, the terminal changes the target resource to the following resource:

Circulates all resources. Here, circulating means changing the resource that is the target of resource reuse distance judgment to the next resource.

If all my resources are not circulated (S2354), the terminal

The reuse distance judgment (S2341 to S2352) described above is performed for the next resource within the device.

If the terminal acquires a resource satisfying the condition related to the reuse distance in the previous step (S2352), S2353 and S2354 may be omitted. In other words, S2353 and S2354 may be performed when selection of resources for PSCCH/PSSCH is not completed (i.e., only some of the resources required for PSCCH/PSSCH are selected or no resources are selected). If all of the resources required for PSCCH/PSSCH are selected, S2353 and S2354 may be omitted.

If the terminal fails to acquire a resource satisfying the condition related to the reuse distance in the previous step (S2352), the terminal performs reuse distance judgment (S2341 to S2352) based on S2353 and S2354.

의 모든 자원이 순환되어 단말간 거리(

)가 재사용 거리(

)보다 큰 자원이 없을 때까지 위의 단계들이 반복된 경우, 단말은

의 모든 후보 자원들이 적합하지 않은 것으로 결정한다. 단말(

)은 다음 간격을 기다려야 하고 현재 데이터 패킷이 차단된다(S2355).

All resources are circulated and the distance between terminals (

) is the reuse distance (

) If the above steps are repeated until there are no more resources than

All candidate resources are determined to be unsuitable. Terminal(

) must wait for the next interval and the current data packet is blocked (S2355).

)의 값이 클수록 향상된 SB-SPS 방식의 PRR이 크다. 또한, 향상된 SB-SPS 방식의 PRR이 기존 SB-SPS 방식의 PRR보다 크다. Figure 24 is a graph showing the packet reception ratio (PRR) of the conventional SB-SPS method and the improved SB-SPS method with a fixed reuse distance value. Referring to Figure 24, when the density (rho) is up to 100, the reuse distance (

) is larger, the PRR of the improved SB-SPS method is larger. In addition, the PRR of the improved SB-SPS method is larger than that of the existing SB-SPS method.

)(100m, 150m)에 기반하는 PRR만 기존 SB-SPS 방식의 PRR보다 크다. 나머지 재사용 거리(

)에 기반하는 PRR은 기존 SB-SPS 방식의 PRR보다 작다.On the other hand, as the density (rho) increases, the specific reuse distance (

)(100m, 150m) is greater than the PRR of the existing SB-SPS method. The remaining reuse distance (

) is smaller than the PRR of the existing SB-SPS method.

Method 3

값으로 패킷 수신 성공률을 향상시키고, 랜덤 자원 선택으로 인한 자원 충돌을 최소화하는 것을 목표로 한다. 본 실시예는 자원 재사용 거리 판단을 SB-SPS 알고리즘에 도입한다. 구체적으로, 현재 단말이 자원을 선택할지 여부는 동일한 자원을 사용하는 인접 단말과의 근접성에 따라 달라질 수 있다.The method according to this embodiment is optimal in any scenario.

The goal is to improve packet reception success rate by value and minimize resource conflicts due to random resource selection. This embodiment introduces resource reuse distance judgment into the SB-SPS algorithm. Specifically, whether the current terminal selects a resource may vary depending on the proximity to the adjacent terminal using the same resource.

This embodiment utilizes adaptive reuse distance. For the convenience of explanation in this specification, this embodiment is referred to as an improved SB-SPS method applying adaptive reuse distance judgment. This embodiment is not only effective in various scenarios, but also does not require additional technical support, so that packet loss, error reception, and data delay time due to resource conflict can be reduced.

The overall algorithm structure according to the present embodiment is described below with reference to FIG. 25.

Fig. 25 is a flowchart of an improved SB-SPS applying adaptive reuse distance determination according to one embodiment of the present specification. In Fig. 25, S2510 to S2550, S2552 to S2555, S2560, and S2570 are identical to S2310 to S2350, S2352 to S2355, S2360, and S2370 of Fig. 23, and thus redundant descriptions are omitted. Hereinafter, the operation (S2551) related to determination of an adaptive reuse distance will be described in comparison with Fig. 23 (fixed reuse distance).

값을 구하고 자원 선택이 보다 효율적으로 수행된다.Unlike the embodiments that use a fixed reuse distance, this embodiment adaptively changes the reuse distance value according to the scenario and other parameter settings.

Values are obtained and resource selection is performed more efficiently.

)은 재사용 거리(

) 값을 결정한다(Step3.3). 여기서

값은 단말 밀도(rho)에 따라 구한 계수 Co에 기초하여 결정되는 적응적인 값(adaptive value)이다. 계수 Co는 아래 수학식 1에 따라 계산/결정될 수 있고, 재사용 거리(

) 값은 아래 수학식 2에 따라 계산/결정될 수 있다.In S2551, the terminal (

) is the reuse distance (

) determines the value (Step 3.3). Here,

The value is an adaptive value determined based on the coefficient Co obtained according to the terminal density (rho). The coefficient Co can be calculated/determined according to the mathematical expression 1 below, and the reuse distance (

) value can be calculated/determined according to the mathematical formula 2 below.

The specific contents of mathematical expressions 1 and 2 are described later with reference to FIG. 26.

Based on the above steps, appropriate resources can be selected, and the possibility of resource conflicts between neighbors is reduced, resulting in a higher rate of successful packet reception.

FIG. 26 is a graph showing coefficients related to determining resource reuse distance values according to one embodiment of the present specification.

는 시나리오 설정에 따라 적응적으로 조정된다. 차량 수(

)는 밀도(rho) * 차선 폭(lane width)이다. 즉, 한 시나리오에서 밀도 rho(예: 단말 수/km)가 높을수록

가 높아지는 것은 명백하다. 자원의 개수는

이다.

이 고정되어 있다고 가정할 때 기준선은 rho가 높을수록 PRR(패킷 수신 비율)이 낮아진다. 그 이유는

은 고정되어 있고

가 증가하면 의심할 여지 없이 자원 경쟁이 증가하여 간섭 및 패킷 오류율이 커지므로 PRR이 감소하기 때문이다.For an embodiment applying adaptive reuse distance judgment

is adaptively adjusted according to the scenario settings. Number of vehicles (

) is density (rho) * lane width. That is, the higher the density rho (e.g. number of terminals/km) in a scenario,

It is clear that the number of resources is increasing.

am.

Assuming this is fixed, the baseline is that the higher the rho, the lower the PRR (packet reception ratio). This is because

is fixed

As increases, resource competition undoubtedly increases, which leads to higher interference and packet error rates, thus decreasing PRR.

가 작을수록 혼잡한 시나리오(예: 밀도(rho)가 높은 환경)에서는 더 높은 PRR을 달성하는 데 도움이 된다. 또한, 혼잡하지 않은 시나리오(예: 밀도(rho)가 낮은 환경)에서는

가 클수록 더 높은 성능을 나타낸다. 이러한 경향은 고정된

가 사용되는 경우에도 관찰된다(도 24 참조). 따라서 본 실시예는 어떤 시나리오에서도 최적의

값으로 더 높은 PRR 성능을 달성하는 것이 목표이다.Also, when considering the resource selection method that includes the reuse distance judgment,

A smaller rho helps achieve higher PRR in crowded scenarios (e.g. high density (rho) environments). Also, in non-crowded scenarios (e.g. low density (rho) environments),

The larger the value, the higher the performance. This trend is fixed.

is observed even when used (see Fig. 24). Therefore, this embodiment is optimal in any scenario.

The goal is to achieve higher PRR performance at a lower cost.

=

가 정의/활용될 수 있다. 그리고 가우스 함수(Gaussian function)를 이용하여

를 연결하면

의 값을 결정하는 계수 Co를 얻을 수 있다. 다시 말하면, 계수 Co는

를 적용한 가우스 함수에 기반하여 계산/결정될 수 있다.To this end, we present the resource competition situation within the scenario.

=

can be defined/utilized. And using the Gaussian function,

If you connect

We can obtain the coefficient Co that determines the value of . In other words, the coefficient Co is

can be calculated/determined based on the Gaussian function applied.

가

로 표현되었다. σ와 μ는 가우스 함수의 매개변수이고 값은 각각 0.4와 0일 수 있다. Co는 계수로서

값이 밀도 rho가 증가함에 따라 정규성(Gaussianity)의 감소 추세를 나타내는 것을 보장할 수 있다. 또한, rho

이기 때문에 rho가 클수록

도 커지게 되어 자원 경쟁이 더욱 심각해지며, 결과적으로 rho가 증가하면 획득된 계수 Co는 감소하게 된다.Mathematical expression 3 is identical to mathematical expression 1,

go

is expressed as . σ and μ are parameters of the Gaussian function and their values can be 0.4 and 0, respectively. Co is a coefficient.

It can be ensured that the values show a decreasing trend of normality (Gaussianity) as the density rho increases. Also, rho

Therefore, the larger rho is,

As rho increases, competition for resources becomes more severe, and as a result, the coefficient Co obtained decreases as rho increases.

를 얻기 위해 Co를 아래 수학식(수학식 2와 동일)에 대입한다.In certain scenarios, the final

To obtain , substitute Co into the following mathematical formula (same as mathematical formula 2).

과

는

에 허용되는 최소값과 최대값이다.

과

는

의 범위를 제한한다. 수학식 2에 따르면. 다음이 보장된다. Min is the minimum function,

class

Is

are the minimum and maximum values allowed.

class

Is

limits the scope of. According to mathematical expression 2, the following is guaranteed.

값은 항상 [

,

]의 허용 간격 내에 있다. ②

값은 rho가 증가함에 따라 감소하며, 이는 각 시나리오에 대한 최적의 값을 얻는 데 도움이 될 수 있다.①

The value is always [

,

] is within the allowable interval. ②

The values decrease as rho increases, which can help in obtaining the optimal values for each scenario.

과

값은 Raw,

로 설정된다. Raw는 인식 범위이며 단말(차량)이 이 범위 내의 모든 이웃 단말(차량)에게 주소를 지정하기 위해 비콘 정보를 주기적으로 방송(broadcast)하는 데 사용된다.

는 패킷이 전송될 수 있는 최대 거리로서 많은 매개변수의 영향을 받으며, Raw는

보다 작아야 한다. 이 설정의 이유는 재사용 거리의 범위가 이 두 매개변수 내에서 유지되도록 하기 위한 것이다. Raw 값 미만으로 인해 자원 선택이 더 심각해지거나

값을 초과하여 알고리즘이 무효화되지 않도록 하기 위함이다. 그리고 Raw 값은 시뮬레이션에서 미리 결정된 고정 매개변수이고

는 다음 수학식에서 도출된다.also

class

The value is Raw,

is set to . Raw is the recognition range and is used by the terminal (vehicle) to periodically broadcast beacon information to address all neighboring terminals (vehicles) within this range.

is the maximum distance over which a packet can be transmitted and is affected by many parameters, and Raw is

The reason for this setting is to ensure that the range of reuse distances remains within these two parameters. Anything less than the Raw value will result in more severe resource selection or

This is to prevent the algorithm from being invalidated by exceeding the value. And the Raw value is a fixed parameter that is predetermined in the simulation.

is derived from the following mathematical formula.

는 전송 전력이고,

와

은 각각 송신기와 수신기의 안테나 이득이다.

는 RB의 대역폭이다.

는 데이터 패킷의 수신 성공 여부를 판단하기 위한 SINR의 임계값이며 다음 수학식 4에 기초하여 계산된다.

은 경로 손실 기능에 대한 파라미터이다.

은 잡음 전력이다. β는 채널 모델의 경로 손실 지수이고 SDshadowLOS는 LOS(Line of Sight)에서 섀도잉의 표준 편차(standard deviation of shadowing)이다.Here,

is the transmitted power,

and

are the antenna gains of the transmitter and receiver, respectively.

is the bandwidth of RB.

is the threshold value of SINR for determining whether reception of a data packet is successful and is calculated based on the following mathematical expression 4.

is a parameter for the path loss function.

is the noise power, β is the path loss exponent of the channel model, and SDshadowLOS is the standard deviation of shadowing at the Line of Sight (LOS).

와

은 각각 RB의 부반송파(subcarrier)와 심볼(symbol)의 개수이다.

은 변조 차수(modulation order), CR은 유효 코딩율(effective coding rate)이다.

및 CR의 값은 MCS(Modulation and Coding Scheme)에 따라 달라진다.

은 하나의 슬롯의 지속 시간(duration)이다. α는 손실 계수(loss factor)이며 0.4로 설정된다.Here,

and

are the number of subcarriers and symbols of RB, respectively.

is the modulation order, and CR is the effective coding rate.

and the values of CR vary depending on the Modulation and Coding Scheme (MCS).

is the duration of one slot. α is a loss factor and is set to 0.4.

In addition, if the transmitting terminal (transmitting vehicle) is denoted as i and the receiving terminal (receiving vehicle) is denoted as j, the SINR at the receiving terminal is calculated as shown in the following mathematical expression 6.

는 송신기와 수신기 사이의 거리이고,

은 잡음 전력이다.The numerator of mathematical expression 6 represents the useful received power and can be expressed as mathematical expression 7. In mathematical expression 7,

is the distance between the transmitter and the receiver,

is the noise power.

는 간섭의 누적이며 수학식 8과 같이 계산된다. 수학식 8에서,

은 동일한 RB(Resource Block)를 사용하는 모든 단말들(송신 단말 i 제외)을 포함하는 집합이고, k는

에 속하는 단말을 의미한다.In mathematical expression 6

is the accumulation of interference and is calculated as in Equation 8. In Equation 8,

is a set that includes all terminals (excluding transmitting terminal i) that use the same RB (Resource Block), and k is

It refers to a terminal belonging to .

의 값은 밀도, 자원 수, Raw, MCS, 전송 전력 등과 같은 매개변수에 따라 달라진다. 이는

가 시나리오 설정에 따라 적응적으로 조정되어 자원 재사용을 위한 요구 사항을 충족하고 더 높은 성능을 달성하는 것을 보장한다.Through the above steps

The value of depends on parameters such as density, number of resources, Raw, MCS, transmission power, etc.

It adaptively adjusts according to the scenario settings to ensure that it meets the requirements for resource reuse and achieves higher performance.

According to the embodiments described above, the following effects are achieved.

Based on the existing SB-SPS, resource reuse distance judgment is added so that the terminal can make a judgment based on the relationship between the distance between occupied terminals and the reuse distance value before selecting a resource. Therefore, this enables efficient resource selection and avoids collisions with neighboring terminals, and increases the possibility that the terminal will select a resource with less interference, thereby improving packet reception speed and reducing waiting time.

The problems of the above-mentioned prior art and the embodiments of the present specification for solving them are summarized as follows.

To improve the efficiency of vehicular Internet communication, C-V2X supports direct communication between vehicles and other user equipment via sidelink. In addition, NR-V2X mode 2 can automatically select resources for users by using the existing sensing-based semi-persistent scheduling (SB-SPS) resource selection algorithm. Through this mechanism, users can obtain a list of available resources after a sensing window, and users can randomly select resources and keep the same resources for several periods before selecting them again. However, during the sensing window, neighboring terminals may generate similar lists of available resources, and random resource selection may cause resource conflicts. This not only degrades communication performance, but also increases update delay time due to incorrect message reception.

In this specification, we propose an improved SB-SPS with a reuse distance determination method that takes into account reuse distance determination and reduces resource conflicts and interference due to random resource selection in association with SB-SPS.

In addition, the reuse distance judgment is performed before the final resource selection, and whether a terminal will select the current resource depends on the reuse distance between the terminal and the occupied terminal. In addition, this work can also provide performance analysis of the existing SB-SPS and the proposed method using various scenarios and measurement criteria.

Figures 27 to 32 show simulation results based on the improved SB-SPS method with adaptive reuse distance determination and other methods.

Figure 27 is a graph showing the packet reception ratio (PRR) of the existing SB-SPS, Always-Best method, and the improved SB-SPS method with fixed/adaptive reuse distance values. Referring to Figure 27, the PRR based on the adaptive reuse distance (RD-RS) is the highest even as the density (rho) increases.

Fig. 28 is a graph showing the error block rate of the conventional SB-SPS method, the Always-Best method, and the improved SB-SPS method with fixed/adaptive reuse distance values. Referring to Fig. 28, the error block rate based on the adaptive reuse distance (RD-RS) is the lowest even as the density (rho) increases.

Fig. 29 is a graph showing the range of the existing SB-SPS method, the Always-Best method, and the improved SB-SPS method with fixed/adaptive reuse distance values. Referring to Fig. 29, the range for each rho is the largest for the adaptive reuse distance (RD-RS). Here, the range can mean the communication distance.

Figure 30 is a graph showing the packet reception ratio (PRR) at 100 m for the existing SB-SPS method, the Always-Best method, and the improved SB-SPS method with fixed/adaptive reuse distance values.

Figure 31 is a diagram showing the complementary cumulative distribution function (CCDF) of the Inter-Packet Gap (IPG) at rho=100.

Figure 32 is a diagram showing the complementary cumulative distribution function (CCDF) of the Inter-Packet Gap (IPG) at rho=200.

The simulation results according to Figs. 30 to 32 show that the proposed method not only provides a higher data packet reception rate than the existing resource selection method, but also effectively reduces the inter-packet gap. In addition, in certain scenarios, the method utilizing the adaptive reuse distance can outperform the existing method (SB-SPS) by 9% and 70% in terms of PRR and range, respectively.

The various embodiments of this specification may be combined with each other.

In terms of implementation, the operations of the base station/terminal according to the embodiments described above (e.g., resource selection operations for sidelink communication) can be processed by the devices of FIGS. 1 to 3 (e.g., processor (225) of FIG. 2, processor (340) of FIG. 3).

In addition, the operations of the base station/terminal according to the above-described embodiment (e.g., resource selection operation for sidelink communication) may be stored in a memory (e.g., 230 of FIG. 2, 360 of FIG. 3) in the form of a command/program (e.g., instruction, executable code) for driving at least one processor (e.g., processor (225) of FIG. 2/processor (340) of FIG. 3).

The embodiments described below are specifically described with reference to Fig. 33 in terms of terminal operation. The methods described below are distinguished only for convenience of explanation, and it goes without saying that some components of one method may be substituted for some components of another method or may be applied in combination with each other.

FIG. 33 is a flowchart for explaining a method performed by a first terminal in a wireless communication system according to one embodiment of the present specification.

Referring to FIG. 33, a method performed by a first terminal in a wireless communication system according to one embodiment of the present specification includes a step of receiving configuration information related to resource selection (S3310), a step of measuring RSRP (S3320), a step of determining resources based on RSRP (S3330), and a step of selecting resources for PSCCH/PSSCH based on the resources (S3340).

)과의 관계에서 재사용 거리 판단을 수행하는 단말(

)을 의미할 수 있다.Hereinafter, the first terminal may mean a terminal that selects resource(s) for PSCCH/PSSCH transmission in mode 2 related to resource allocation. The second terminal may mean a terminal that receives PSCCH/PSSCH from the first terminal based on the selected resource(s). In addition, the first terminal may mean a neighboring terminal (

) that performs reuse distance judgment in relation to the terminal (

) can mean.

In S3310, the first terminal receives configuration information related to resource selection from the base station. The configuration information includes configuration information related to a resource selection mechanism.

Based on the settings related to the above resource selection mechanism, at least one of full sensing, partial sensing and/or random selection may be allowed.

For example, the configuration information related to the resource selection may be based on SL-PBPS-CPS-Config, and the configuration related to the resource selection mechanism may be based on sl-AllowedResourceSlectionConfig. For example, the resource selection mechanism may be set to one of the following c1 to c7.

c1: only full sensing allowed

c2: only partial sensing allowed

c3: only random selection allowed

c4: full sensing+random selection allowed

c5: full sensing+ partial sensing allowed

c6: partial sensing + random selection allowed

c7: full sensing + partial sensing + random selection allowed

Here, the random selection, which is a setting related to the resource selection mechanism, does not mean a random selection related to the problem of the above-described conventional technology, but means a setting in which a terminal randomly selects a resource without a sensing operation (RSRP measurement). The problem of the above-described conventional technology occurs when at least one of full sensing and/or partial sensing is allowed, and then resources are determined based on the measured RSRP, and then resource(s) for PSCCH/PSSCH are randomly selected from among the determined resources.

In S3320, the first terminal measures a reference signal received power (RSRP). The RSRP may be based on RSRP for resource selection. The RSRP may be a Physical Sidelink Shared Channel (PSSCH) RSRP or a Physical Sidelink Control Channel (PSCCH) RSRP.

This step may be performed when at least one of full sensing and/or partial sensing is allowed (e.g., when set to one of c1 to c2, c4 to c7). An operation based on this step may correspond to the channel sensing operation of FIGS. 16, 20, 23 to 25.

For example, when a Demodulation Reference Signal (DMRS) of PSCCH is used for RSRP measurement, the RSRP may be PSCCH RSRP. For example, when a Demodulation Reference Signal (DMRS) of PSSCH is used for RSRP measurement, the RSRP may be PSCCH RSRP.

In S3330, the first terminal determines resources based on the RSRP and RSRP thresholds.

The above resources are related to sidelink resource allocation mode 2.

)에 기반할 수 있다. 일 예로, 상기 자원들은 RSRP 오름차순으로 정렬된 자원들의 리스트(

)에 기반할 수 있다.The above resources may be based on available resources determined based on a threshold value (Pth) in FIG. 16, FIG. 20, FIG. 23 to FIG. 25. For example, the resources may be a list of available resources (

) can be based on. For example, the resources may be a list of resources sorted in RSRP ascending order (

) can be based on.

In S3340, the first terminal selects resources for PSCCH transmission and/or PSSCH transmission based on the resources.

의 자원들)중에서 PSCCH/PSSCH를 위한 자원들(시간/주파수 자원들)이 랜덤하게 선택된다. 이러한 경우 다른 단말과의 간섭이 큰 자원이 선택됨에 따라 자원 경쟁이 심화되어 사이드링크 통신의 신뢰성(reliability)이 저하될 수 있다. 이하에서는 상술한 문제점을 해결하기 위한 실시예들(방법 2 및/또는 방법 3)을 구체적으로 설명한다.According to the existing method, resources with RSRP less than the RSRP threshold (e.g., as described above)

Among the resources of the UE, resources (time/frequency resources) for PSCCH/PSSCH are randomly selected. In this case, if resources with high interference with other terminals are selected, resource competition may intensify, which may deteriorate the reliability of sidelink communication. Hereinafter, embodiments (Method 2 and/or Method 3) for solving the above-described problem will be specifically described.

에 기반할 수 있다. 상기 재사용 거리(

)는 동일한 자원을 사용할 수 있는 서로 다른 단말들간의 최소 거리(minimum distance)와 관련될 수 있다.The above selected resources may include resources selected based on a reuse distance. The reuse distance may be one of method 2 and/or method 3.

can be based on the above reuse distance (

) may be related to the minimum distance between different terminals that can use the same resource.

)과 상기 제1 단말(예:

)간의 거리(예:

)는 상기 재사용 거리(

)보다 클 수 있다.For example, another terminal (e.g.,

) and the first terminal (e.g.

) distance (eg:

) is the reuse distance (

) can be greater than.

The above reuse distance can be a fixed reuse distance (method 2) or an adaptive reuse distance (method 3). This is described in detail below.

In one embodiment, the reuse distance may be based on a fixed positive integer value. The present embodiment may be based on Method 2. Information about the fixed positive integer value may be set in advance. For example, the first terminal may receive a setting related to the reuse distance from the base station. For example, the fixed positive integer value may be a value defined in advance between the first terminal and the base station (between the first terminal and other terminals).

In one embodiment, the reuse distance can be determined based on a coefficient based on a ratio related to a resource contention situation. Information related to determining the reuse distance (e.g., parameter(s) for determining the coefficient Co, parameter(s) related to a maximum value of the reuse distance) can be set in advance. For example, the first terminal can receive information related to determining the reuse distance from the base station. For example, the information related to determining the reuse distance can be based on information defined in advance between the first terminal and the base station (between the first terminal and other terminals). The present embodiment can be based on Method 3.

를 의미할 수 있다. 구체적으로, 상기 비율은 자원들의 수(예:

)에 대한 단말들의 수(예:

)의 비율(예:

)에 기반할 수 있다.The above ratio is described in Method 3.

can mean. Specifically, the ratio refers to the number of resources (e.g.,

) for the number of terminals (e.g.

) ratio (eg:

) can be based on.

The above coefficient can be determined based on a Gaussian function to which the above ratio is applied. For example, the coefficient can be Co based on mathematical expression 3.

) 중에서 작은 값으로 결정될 수 있다. 예를 들어, 상기 재사용 거리는 수학식 2에 기초하여 결정될 수 있다. The above reuse distance is i) a value calculated based on the above coefficient and ii) a maximum value of the above reuse distance (e.g.

) can be determined as a smaller value. For example, the reuse distance can be determined based on mathematical expression 2.

)에 상기 계수를 곱한 값일 수 있다. 상기 제2 값은 상기 재사용 거리의 최소 값(예:

)일 수 있다. 상기 최대값(

)은 수학식 4에 기반할 수 있다.Specifically, the value calculated based on the coefficient may be based on the sum of the first value and the second value. The first value may be the maximum value (

) may be a value obtained by multiplying the coefficient. The second value may be a minimum value of the reuse distance (e.g.,

) can be. The above maximum value (

) can be based on mathematical expression 4.

)에 기반할 수 있다. 이하 정렬된 자원들에 기초한 재사용 거리 판단 동작에 대하여 구체적으로 설명한다.As described above, the resources (i.e., candidate resources for PSCCH/PSSCH) determined based on the RSRP threshold are listed in the order of RSRP ascending.

) can be based on. The following describes in detail the reuse distance determination operation based on the sorted resources.

In one embodiment, the resources (i.e., candidate resources for PSCCH/PSSCH) can be sorted in ascending order of the RSRP (i.e., RSRP of each resource). The selected resources can be determined based on a reuse distance determination performed from a first resource among the sorted resources. The present embodiment can be based on Method 2 or Method 3. The resource selection/resource circulation operation based on the reuse distance determination can be performed based on S2340 to S2354 of FIG. 23 or S2540 to S2554 of FIG. 25.

)과 상기 제1 단말(예:

)간의 거리(예:

)가 상기 재사용 거리(예:

)보다 큰 것에 기초하여, 상기 현재 순서에 기초한 자원은 상기 PSCCH 전송 및/또는 PSSCH 전송을 위해 선택될 수 있다.A terminal (e.g., a terminal using a resource based on the current order among the above-mentioned sorted resources (e.g., resource #6, which is the first resource among the sorted resources in Fig. 22)

) and the first terminal (e.g.

) distance (eg:

) is the reuse distance (e.g.

), the resources based on the current order can be selected for the PSCCH transmission and/or the PSSCH transmission.

)과 상기 제1 단말(예:

)간의 거리(예:

)가 상기 재사용 거리(예:

)보다 작거나 같은 것에 기초하여, 상기 정렬된 자원들 중 다음 순서에 기초한 자원(예: 도 22에서 정렬된 자원들 중 두번째 자원인 자원 #2)에 대해 상기 재사용 거리 판단이 수행될 수 있다.A terminal (e.g., resource #6, which is the first resource among the resources sorted in Fig. 22) using a resource based on the current order above (e.g.,

) and the first terminal (e.g.

) distance (eg:

) is the reuse distance (e.g.

), the reuse distance determination can be performed on a resource (e.g., resource #2, which is the second resource among the sorted resources in FIG. 22) based on the next order among the sorted resources.

The above-described reuse distance determination operation can be performed repeatedly until the selection of resources for PSCCH/PSSCH is completed. For example, if there are two resources required for PSCCH/PSSCH but only one resource has been selected so far, the reuse distance determination for the sorted resources can be performed until one additional resource is selected.

에 하나 이상의 단말들이 존재하는 경우(즉, 현재 자원을 점유/사용하는 다른 단말들이 존재하는 경우), 상술한 재사용 거리 판단(예: 도 23의 S2350 내지 S2354)이 수행될 수 있다.In one embodiment, the operation for determining the resource reuse distance described above may be performed on the premise that there are one or more terminals that currently occupy/use the resource among the sorted resources. For example, a list of neighboring terminals for the current resource among the sorted resources

If there are one or more terminals (i.e., if there are other terminals currently occupying/using the resource), the reuse distance determination described above (e.g., S2350 to S2354 of FIG. 23) can be performed.

The operations based on S3310 to S3340 described above can be implemented by the device of FIG. 3. For example, one or more processors (340) can control one or more transceivers (310) and/or one or more memories (360) to perform the operations based on S3310 to S3340.

Although not limited thereto, the various descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts disclosed in this document may be applied to various fields requiring wireless communication/connectivity (e.g., 5G) between devices.

The operations described above can be realized by providing a memory device storing the corresponding program code in any component within the UE or eNB. That is, the control unit of the UE or eNB can execute the operations described above by reading and executing the program code stored in the memory device by a processor or a CPU (Central Processing Unit).

Various components and modules of the UE or eNB described in this specification may be operated using hardware circuits, for example, logic circuits based on complementary metal oxide semiconductors, firmware, software, and/or a combination of hardware and firmware and/or software embedded in a machine-readable medium. For example, various electrical structures and methods may be implemented using electrical circuits such as transistors, logic gates, and application-specific semiconductors.

Meanwhile, although the detailed description of this specification has described specific embodiments, it is obvious that various modifications are possible within the scope of this specification. Therefore, the scope of this specification should not be limited to the described embodiments, but should be determined not only by the scope of the claims described below, but also by the equivalents of the scope of these claims.

Claims (12)

In a method performed by a first terminal in a wireless communication system, A step of receiving configuration information related to resource selection, wherein the configuration information includes configuration information related to a resource selection mechanism, Based on the settings related to the above resource selection mechanism, at least one of full sensing, partial sensing and/or random selection is allowed; A step of measuring a Received Signal Received Power (RSRP), wherein the RSRP is a Physical Sidelink Shared Channel (PSSCH) RSRP or a Physical Sidelink Control Channel (PSCCH) RSRP; A step of determining resources based on the RSRP and RSRP thresholds, wherein the resources are related to a sidelink resource allocation mode (sidelink resource allocation mode 2); and A step of selecting resources for PSCCH transmission and/or PSSCH transmission based on the above resources; Including, The above selected resources include resources selected based on reuse distance, A method characterized in that the above reuse distance is related to the minimum distance between different terminals that can use the same resource. In the first paragraph, A method characterized in that the distance between the first terminal and another terminal using the resource selected based on the reuse distance is greater than the reuse distance. In the first paragraph, A method characterized in that the above reuse distance is based on a fixed positive integer value. In the first paragraph, A method characterized in that the above reuse distance is determined based on a coefficient based on a ratio related to a resource competition situation. In the fourth paragraph, The above ratio is based on the ratio of the number of terminals to the number of resources. A method characterized in that the above coefficients are determined based on a Gaussian function to which the above ratio is applied. In clause 5, A method characterized in that the reuse distance is determined as a smaller value among i) a value calculated based on the coefficient and ii) a maximum value of the reuse distance. In the first paragraph, The above resources are sorted in ascending order of the RSRP, A method characterized in that the above-mentioned selected resources are determined based on a reuse distance judgment performed from the first resource among the above-mentioned sorted resources. In Article 7, A method characterized in that the resource based on the current order is selected for the PSCCH transmission and/or the PSSCH transmission based on the distance between the terminal using the resource based on the current order among the sorted resources and the first terminal being greater than the reuse distance. In Article 8, A method characterized in that the reuse distance determination is performed for a resource based on the next order among the sorted resources based on the distance between the terminal using the resource based on the current order and the first terminal being less than or equal to the reuse distance. In a first terminal operating in a wireless communication system, One or more transmitters and receivers; one or more processors; and storing instructions for operations to be executed by said one or more processors, and including one or more memories connected to said one or more processors; The above actions are, A step of receiving configuration information related to resource selection, wherein the configuration information includes configuration information related to a resource selection mechanism, Based on the settings related to the above resource selection mechanism, at least one of full sensing, partial sensing and/or random selection is allowed; A step of measuring a Received Signal Received Power (RSRP), wherein the RSRP is a Physical Sidelink Shared Channel (PSSCH) RSRP or a Physical Sidelink Control Channel (PSCCH) RSRP; A step of determining resources based on the RSRP and RSRP thresholds, wherein the resources are related to a sidelink resource allocation mode (sidelink resource allocation mode 2); and A step of selecting resources for PSCCH transmission and/or PSSCH transmission based on the above resources; Including, The above selected resources include resources selected based on reuse distance, A first terminal, characterized in that the above reuse distance is related to the minimum distance between different terminals that can use the same resource. In a device comprising one or more memories and one or more processors connected to the one or more memories, The one or more memories store instructions that cause the one or more processors to perform operations based on what is executed by the one or more processors, The above actions are, A step of receiving configuration information related to resource selection, wherein the configuration information includes configuration information related to a resource selection mechanism, Based on the settings related to the above resource selection mechanism, at least one of full sensing, partial sensing and/or random selection is allowed; A step of measuring a Received Signal Received Power (RSRP), wherein the RSRP is a Physical Sidelink Shared Channel (PSSCH) RSRP or a Physical Sidelink Control Channel (PSCCH) RSRP; A step of determining resources based on the RSRP and RSRP thresholds, wherein the resources are related to a sidelink resource allocation mode (sidelink resource allocation mode 2); and A step of selecting resources for PSCCH transmission and/or PSSCH transmission based on the above resources; Including, The above selected resources include resources selected based on reuse distance, A device characterized in that the above reuse distance is related to the minimum distance between different terminals that can use the same resource. In one or more non-transitory computer-readable media storing instructions, The instructions executable by one or more processors cause the one or more processors to perform operations, The above actions are, A step of receiving configuration information related to resource selection, wherein the configuration information includes configuration information related to a resource selection mechanism, Based on the settings related to the above resource selection mechanism, at least one of full sensing, partial sensing and/or random selection is allowed; A step of measuring a Received Signal Received Power (RSRP), wherein the RSRP is a Physical Sidelink Shared Channel (PSSCH) RSRP or a Physical Sidelink Control Channel (PSCCH) RSRP; A step of determining resources based on the RSRP and RSRP thresholds, wherein the resources are related to a sidelink resource allocation mode (sidelink resource allocation mode 2); and A step of selecting resources for PSCCH transmission and/or PSSCH transmission based on the above resources; Including, The above selected resources include resources selected based on reuse distance, One or more non-transitory computer-readable media characterized in that the reuse distance relates to the minimum distance between different terminals that can use the same resource.

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