KR20240077194A - Method and System for Resource Management for Collaborative 5G-NR-V2X RSUs to enhance V2I/N Link Reliability - Google Patents

Abstract

A resource management method and system in cooperative 5G-NR-V2X RSU to improve V2I/N link reliability is presented. The resource management method in cooperative 5G-NR-V2X RSU for improving V2I/N link reliability proposed in the present invention applies BS-type and UE-type together to wrap around method in network layout (RSU) Steps of deploying a Road Side Unit and generating a network layout, antenna model, channel model, and physical layer for placing VUEs (Vehicle Users) on the road according to a spatial location process (Spatial Poisson Process), and creating the above It includes the step of allocating a V2X message through a hybrid RSU that selectively uses BS-type and UE-type to secure efficient user service using the network layout, antenna model, channel model, and physical layer.

Description

Resource management method and system in collaborative 5G-NR-V2X RSUs to improve V2I/N link reliability {Method and System for Resource Management for Collaborative 5G-NR-V2X RSUs to enhance V2I/N Link Reliability}

The present invention relates to a resource management method and system in cooperative 5G-NR-V2X RSU for improving V2I/N link reliability.

As interest in autonomous driving has recently increased, V2X technology maximizes traffic safety and road efficiency by comprehensively utilizing not only the status of your vehicle, but also the operation status and flow of other vehicles on the road, pedestrian status, and signal status, etc. Research is in progress. To support V2X services, the telecommunications and automotive industries are requesting the transmission of larger messages as V2X applications develop, and requirements such as data rate, reliability, latency, communication range, and movement speed are required to meet the requirements. Must be able to meet the required KPI (Key Performance Indicator). To meet the required KPIs, 5G-NR (New Radio) technology provides flexible design and higher energy efficiency to support lower latency, higher throughput, wider coverage, and more reliable services. In particular, the International Telecommunication Union - Radio (ITU-R) introduces three groups of improved usage scenarios covering 5G-NR characteristics, which should be able to provide more flexible, reliable and secure services than before when providing various services. In three scenarios consisting of eMBB (enhanced Mobile Broadband), URLLC (Ultra-Reliable & Low-Latency Communications), and mMTC (Machine-Type Communications), eMBB has a larger capacity to handle services that require high-capacity transmission in places where users are concentrated. It aims to provide faster data transmission speeds by using frequency bandwidth and using more antennas. In particular, it aims to provide high speeds not only in areas with strong signals near base stations, but also in cell edge areas where signals are weak. URLLC enables services that require real-time response speed for autonomous vehicles that communicate and share surrounding traffic conditions while meeting stringent requirements for features such as throughput, latency, and availability. mMTC enables large-scale communication services suitable for low data rates and low-cost devices for a large number of devices based on high reliability and low latency. To address these diverse and demanding requirements, 3GPP NR V2X supports and is being studied for more advanced use cases such as platooning, extended sensors, advanced driving, and remote driving, as classified according to the prior art. As mentioned earlier, the high reliability requirements of V2X communication require great technical challenges, and having a vehicle terminal communicate with a single BS/UE-type RSU is not sufficient to support V2X services. Therefore, in this study, we propose a cooperative utilization method between BS/UE-type RSUs to improve system performance, and utilize the transmission and reception of vehicle information through RSU interconnection to ensure that messages received when providing services are fast and reliable. The goal is to reduce the size of reception interference and maximize the average throughput of vehicle terminals. Separately, resource cooperation management technology, CRE (Cell Range Expansion) technology, and 3D beamforming are used to contribute to higher system capacity or better power use in direct communication between vehicle terminals and RSU. Dynamic ICIC (Inter-Cell Interference Coordination) and CS-CoMP (Coordinated Scheduling Coordinated Multi-Point) technologies used as resource cooperative management technologies are used to address major problems occurring in cellular V2I networks in dense urban environments. It is an effective method to improve the channel situation of cell edge users by alleviating Channel Interference, and this method can be used to satisfy the safety, reliability, and high-quality driving required in the V2X environment. In addition, in the antenna model, antenna arrays and frequencies are attracting attention as candidates that can meet the high requirements of 5G mobile networks. Considering the large path loss attenuation in these bands, in order to perform transmission, it is necessary to generate a beam in the direction of the user equipment. 3D beamforming technology is essential. We aim to apply 3D beamforming by characterizing realistic antenna radiation patterns to address the need to understand achievable performance in 5G cellular scenarios. In particular, we check how performance changes depending on the antenna pattern used, and determine the impact of using an appropriate antenna model through performance evaluation.

[1] 3GPP TR 22.885 (V14.0.0). ;Study on LTE support for Vehicle to Everything (V2X) services; Release 14 December 2015. [2] “Study on LTE-based V2X Services,” 3GPP TR 36.885, V14.0.0, Jun. 2016. [3] 3GPP TR 37.885 (V15.3.0). ; Study on evaluation methodology of new Vehicle-to-Everything (V2X) use cases for LTE and NR; Released 15 June 2015. [4] “Study on NR Vehicle-to-Everything (V2X),” 3GPP TR 38.885, V16.0.0, Mar. 2019.

The technical problem to be achieved by the present invention is to propose vehicle communication using an RSU consisting of BS-type and UE-type, and to develop a resource management method and system in cooperative 5G-NR-V2X RSU to improve V2I/N link reliability. It is provided. In addition, system performance when providing services from different and heterogeneous RSUs is confirmed, and the shadow area of the 5G-NR-V2X environment is minimized through a cooperative approach between the proposed BS/UE-type RSUs. We want to maximize the average throughput of vehicle terminals.

In one aspect, the resource management method in the cooperative 5G-NR-V2X RSU for improving V2I/N link reliability proposed in the present invention applies a wrap around method in the network layout by applying BS-type and UE-type together. method) to place RSUs (Road Side Units) and create a network layout, antenna model, channel model, and physical layer that places VUEs (Vehicle Users) on the road according to a spatial location process (Spatial Poisson Process). A step of allocating a V2X message through a hybrid RSU that selectively uses BS-type and UE-type to secure efficient user service using the generated network layout, antenna model, channel model, and physical layer, and It includes applying resource cooperation management technology, CRE (Cell Range Expansion) technology, and 3D beamforming method to contribute to higher system capacity or better power use in communication between vehicle terminals and RSU.

The step of generating the network layout, antenna model, channel model, and physical layer configures the antenna model differently according to the BS-type and UE-type RSU, and configures the antenna model differently according to the RSU of the BS-type and UE-type. By configuring a channel model using propagation loss according to RSU and calculating user throughput using specific modulation and coding levels, the PER (Packet Error Rate) for each packet in the channel is obtained to configure the physical layer.

The step of allocating a V2X message through a hybrid RSU that selectively uses BS-type and UE-type to secure efficient user service using the generated network layout, antenna model, channel model, and physical layer involves different transmission The BS-type and UE-type of the hybrid RSU with power and parameters are used to identify the RSU with the highest received SINR and select the RSU to provide service to the VUE.

The BS-type applies resource cooperation management to satisfy the Quality of Service (QoS) required in vehicle communication, and the UE-type is a HetNet (Heterogeneous) consisting of a macro cell and a small cell. Networks) applies cell expansion techniques (Cell Range Expansion) to support spectral efficiency and energy efficiency.

In another aspect, the resource management system in the cooperative 5G-NR-V2X RSU for improving V2I/N link reliability proposed in the present invention applies BS-type and UE-type together to use a circular method in the network layout ( Network layout, antenna model, channel model, and physical layer that deploy Road Side Units (RSUs) using a wrap around method and place Vehicle Users (VUEs) on the road according to a spatial location process (Spatial Poisson Process) A V2X message is sent through a hybrid RSU that selectively uses BS-type and UE-type to secure efficient user service using a model generator that generates and the generated network layout, antenna model, channel model, and physical layer. Includes a resource allocation unit that allocates.

According to embodiments of the present invention, vehicle communication using an RSU consisting of BS-type and UE-type is proposed, and a resource management method in a cooperative 5G-NR-V2X RSU to improve the proposed V2I/N link reliability and Through the system, you can check system performance when providing services from different and heterogeneous RSUs. In addition, through the proposed approach of cooperatively utilizing BS/UE-type RSUs, the shadow area of the 5G-NR-V2X environment can be minimized and the average throughput of vehicle terminals can be maximized.

Figure 1 is a diagram showing the configuration of a resource management system in a cooperative 5G-NR-V2X RSU for improving V2I/N link reliability according to an embodiment of the present invention.
Figure 2 is a diagram showing an example of a road and circulation model configuration according to an embodiment of the present invention.
Figure 3 is a diagram showing the network layout and vehicle distribution in a 5G-NR-V2X environment according to an embodiment of the present invention.
Figure 4 is a flowchart illustrating a resource management method in a cooperative 5G-NR-V2X RSU for improving V2I/N link reliability according to an embodiment of the present invention.
Figure 5 shows SNR vs. LLS results when using turbo coding in an LTE environment and LLS results when using LDPC coding in a 5G-NR environment according to an embodiment of the present invention. This is the PER curve.
Figure 6 is a diagram showing a SINR color map according to an embodiment of the present invention.
Figure 7 is a graph showing the probability of 5G-NR V2X BS/UE/hybrid RSU interruption according to an embodiment of the present invention.
Figure 8 is a graph showing 5G-NR V2X BS/UE/hybrid RSU interference according to an embodiment of the present invention.
Figure 9 is a graph showing 5G-NR V2X BS/UE/hybrid RSU throughput according to an embodiment of the present invention.
Figure 10 is a graph showing a 3D beamforming antenna pattern according to an embodiment of the present invention.
Figure 11 is a graph showing VUE throughput applying dynamic ICIC and CS CoMP according to an embodiment of the present invention.
Figure 12 is a graph showing VUE throughput applying cell range expansion according to an embodiment of the present invention.
Figure 13 is a graph showing VUE throughput applying 3D beamforming according to an embodiment of the present invention.

In the development of autonomous driving technology, C-ITS (Cooperative-Intelligent Transport System) technology and 5G-NR-V2X (Vehicle-to-Everything) technology are key technologies that enhance safety and effectively manage traffic information. In this technology, RSU (Road Side Unit), a communication device for vehicle networks that provides V2I (Vehicle-to-Infrastructure) connectivity to nearby vehicles, exchanges traffic and safety information of future autonomous vehicles and based on this, traffic safety and traffic Not only does it improve efficiency, but it also enables supporting and enhancing vehicle-to-vehicle (V2V) communications.

The present invention deals with vehicle communication using RSUs composed of BS-type and UE-type, and checks system performance when providing services from different and heterogeneous RSUs. In addition, the focus is on minimizing the shadow area of the 5G-NR-V2X environment through a cooperative approach between BS/UE-type RSUs and maximizing the average throughput of vehicle terminals. In order to achieve high reliability requirements, each RSU is equipped with resource cooperation management technologies such as Dynamic ICIC (Dynamic Inter-Cell Interference Coordination), CS-CoMP (Coordinated Scheduling Coordinated Multi-Point) technology, CRE (Cell Range Expansion), and 3D beamforming. By applying Beamforming technology, we provide insight into how different technologies will perform when applied to each RSU, and verify the increase in average throughput through simulation to confirm that performance is maximized when working together. The simulation results confirm that the outage probability performance of vehicle terminals is improved through SINR (Signal-to-Interference-plus-Noise Ratio) measurement after applying the proposed method and the shadow area is reduced accordingly. We confirm that vehicle terminal reliability is improved due to a reduction in the size of reception interference and an increase in average throughput, and we confirm that cooperation between BS-type RSU and UE-type RSU contributes to improving the overall reliability of the V2X communication link. Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

First, we explain the mutual cooperation method and various technologies to maximize RSU performance designed in V2V communication and V2I communication-based systems using RSU consisting of UE-type and BS-type.

Current 3GPP and 5GAA standards define communication based on the air interface Uu interface and communication based on the PC5 interface for sending and receiving V2X messages. Uu interface-based communication is a cellular network-supported V2I that performs communication between BS-type RSU and vehicle users (VUE), and provides high reliability and information transfer rate. PC5 interface-based communication performs communication with different VUEs and UE-type RSUs, reduces latency, and provides high-speed data transmission in areas not belonging to the network area. In particular, in a method that uses a mixture of the Uu interface and the PC5 interface simultaneously, the VUE communicates with the UE-type RSU and other nearby VUEs through the PC5 interface for sending and receiving V2X messages, and the UE-type RSU directly communicates with the PC5 communication range as needed. It communicates with V2X application servers in the mobile network through the Uu interface to manage communication of V2X messages beyond. This hybrid use of V2X communication based on the PC5 interface and Uu interface eliminates the need for MBMS (Multimedia Broadcast or Multicast Service) broadcast in the downlink, thereby reducing latency with the RSU for communicating with the local V2X server. . Additionally, a technology was proposed to maximize capacity through utilization of V2I links while ensuring the reliability of all V2V links, including low latency between vehicles and RSUs. Considering the case where V2I links share spectrum with multiple V2V links, CSI Based on fading statistics of (Channel State Information), an algorithm was proposed to efficiently allocate power by studying the resource allocation problem of D2D (Device-to-Device) vehicle communication. In another prior art, research has been conducted on spectrum sharing and power allocation for V2X to provide efficient and reliable vehicular communication in cellular networks supporting D2D communication, ensuring reliability for all V2V links and V2I links. An algorithm was proposed to maximize the sum and minimum ergodic capacities, respectively. In addition, research has been conducted to optimally select RSUs in small-scale areas to achieve maximum performance in limited RSU deployment in VANETs (Vehicular Ad-hoc NETworks), and V2X requirements and limited RSU deployments have been conducted. To reduce the gap between available resources, we formulate a utility maximization problem involving coverage constraints through hybrid RSU placement and management, which facilitates RSU management. In this way, through research on RSU, research has been conducted on improving communication reliability, reducing delay time, and efficient power allocation. In the present invention, the characteristics of each RSU type are analyzed along with parameter analysis, and the interaction between BS/UE-type RSUs is conducted. We analyze the efficiency of the proposed algorithm when using a collaborative utilization method. In addition, various technologies and settings are applied to improve V2I/N link reliability, and the reduction of shadow areas in the system and improvement of communication reliability are verified.

Figure 1 is a diagram showing the configuration of a resource management system in a cooperative 5G-NR-V2X RSU for improving V2I/N link reliability according to an embodiment of the present invention.

The resource management system 100 according to this embodiment may include a processor 110, a bus 120, a network interface 130, a memory 140, and a database 150. The memory 140 may include an operating system 141 and a resource management routine 142 in a cooperative 5G-NR-V2X RSU for improving V2I/N link reliability.

The resource management routine 142 in the cooperative 5G-NR-V2X RSU for improving V2I/N link reliability according to this embodiment is BS-type and UE-type as there is data to be transmitted to the vehicle user terminal when using the hybrid RSU method. The best channel can be assigned to the vehicle user terminal based on the received SINR in the type RSU (142a).

The resource management routine 142 in the cooperative 5G-NR-V2X RSU for improving V2I/N link reliability according to this embodiment is a resource cooperative management technology, CRE, to satisfy the QoS required in vehicle communication when using the hybrid RSU method. technology and 3D beamforming technology can be applied.

The processor 110 may include a model creation unit 111 and a resource allocation unit 112. In other embodiments, resource management system 100 may include more components than those of FIG. 1 . However, there is no need to clearly show most prior art components. For example, the resource management system 100 may include other components such as a display or transceiver.

The memory 140 is a computer-readable recording medium and may include a non-permanent mass storage device such as random access memory (RAM), read only memory (ROM), and a disk drive. Additionally, the memory 140 may store program codes for the operating system 141 and the resource management routine 142 in the cooperative 5G-NR-V2X RSU for improving V2I/N link reliability. These software components may be loaded from a computer-readable recording medium separate from the memory 140 using a drive mechanism (not shown). Such separate computer-readable recording media may include computer-readable recording media (not shown) such as floppy drives, disks, tapes, DVD/CD-ROM drives, and memory cards. In another embodiment, software components may be loaded into the memory 140 through the network interface 130 rather than a computer-readable recording medium.

The bus 120 may enable communication and data transmission between components of the resource management system 100. Bus 120 may be configured using a high-speed serial bus, parallel bus, storage area network (SAN), and/or other suitable communication technology.

The network interface 130 may be a computer hardware component for connecting the resource management system 100 to a computer network. The network interface 130 can connect the resource management system 100 to a computer network through a wireless or wired connection.

The database 150 may serve to store and maintain all information necessary for resource management in a cooperative 5G-NR-V2X RSU to improve V2I/N link reliability. In Figure 1, it is shown that the database 150 is built and included inside the resource management system 100, but it is not limited to this and may be omitted depending on the system implementation method or environment, or all or part of the database may be installed separately. It is also possible to exist as an external database built on another system.

The processor 110 may be configured to process instructions of a computer program by performing basic arithmetic, logic, and input/output operations of the resource management system 100. Commands may be provided to processor 110 by memory 140 or network interface 130 and via bus 120. The processor 110 may be configured to execute program codes for the model creation unit 111 and the resource allocation unit 112. These program codes may be stored in a recording device such as memory 140.

The model creation unit 111 and the resource allocation unit 112 may be configured to perform steps 410 to 420 of FIG. 4.

The resource management system 100 may include a model creation unit 111 and a resource allocation unit 112.

The model generator 111 applies the BS-type and UE-type together to place the RSU (Road Side Unit) in a wrap around method in the network layout, and places the VUE according to the spatial location process (Spatial Poisson Process). Create a network layout, antenna model, channel model, and physical layer that places (Vehicle User) on the road.

The model generator 111 configures the antenna models differently according to the BS-type and UE-type RSUs, and configures a channel model using propagation loss according to the BS-type and UE-type RSUs, By calculating user throughput using specific modulation and coding levels, the PER (Packet Error Rate) for each packet in the channel is obtained to form the physical layer.

The resource allocation unit 112 uses the generated network layout, antenna model, channel model, and physical layer to send a V2X message through a hybrid RSU that selectively uses BS-type and UE-type to secure efficient user service. Allocate.

The resource allocation unit 112 identifies the RSU with the highest received SINR using the BS-type and UE-type of the hybrid RSU with different transmission powers and parameters and selects the RSU to provide service to the VUE. .

The resource allocation unit 112 applies resource cooperation management to satisfy the Quality of Service (QoS) required in vehicle communication for the BS-type.

The resource allocation unit 112 uses a cell range expansion technique (Cell Range Expansion) to support spectral efficiency and energy efficiency in HetNet (Heterogeneous Networks) composed of macro cells and small cells for the UE-type. ) is applied.

In the present invention, a network is implemented using a general deployment scenario provided by 3GPP. In 3GPP, definitions of services including V2V, V2I/N, and V2P are presented in [1], and in [2], a methodology for evaluating new functions required for LTE-based V2X service operation is presented, and various technologies are used using this. Compare performance when applied. Additionally, in [3], a study is conducted on the evaluation methodology of new V2X use cases for LTE and NR, comparing the performance of various technology options for new 5G V2X use cases. In [4], research on NR-V2X is conducted and covers improvements to the Uu interface to support improved V2X use in NR-V2X, and allocation/configuration of SL (Sidelink) resources based on the Uu interface by LTE and NR. . Below, we describe the system settings including network layout, antenna model, channel model, and physical layer to achieve the requirements in the 5G NR environment by applying the simulation methodology of the 3GPP document described above.

Figure 2 is a diagram showing an example of a road and circulation model configuration according to an embodiment of the present invention.

The cellular network considered for evaluation in the present invention is evaluated using SLS of 5G-NR-V2X in the Manhattan urban environment of the previously mentioned 3GPP [2], [3], [4]. The simulation area of the Manhattan urban environment is a 1-tier network, as shown in Figure 2(a), where the distance between road grids between intersections is 250 m horizontally and 433 m vertically, and the minimum size in the simulation is 750 m. It consists of 1299m. At this time, each road with a width of 3.5m consists of two in each direction and a total of four on each street. In the 3GPP standard, a fixed infrastructure entity that supports V2X applications that can exchange messages with other entities is defined as RSU [1], and RSU is divided into BS-type RSU and UE-type RSU as shown in Figure 2 (b) in the network layout. ) is placed by applying a wrap around method. For BS-type RSU, hexagonal grid, 7 macro sites, 7 satisfying 3 sectors per site It consists of a total of 7 BS-type RSUs in the simulation, which consists of 3 cells and satisfies the ISD (Inter-Site Distance) of 500m between BS-type RSUs. In the case of UE-type RSU, the RSU is placed in the center of the intersection in an urban environment, and within the presented simulation, a total of 16 UE-type RSUs are composed.

Figure 3 is a diagram showing the network layout and vehicle distribution in a 5G-NR-V2X environment according to an embodiment of the present invention.

VUE in the simulation is distributed on the road according to a spatial Poisson Process, and the vehicle density distributed on each road is determined according to assumptions about vehicle speed. In an urban environment, the absolute vehicle speed of VUE is 60km/h, and the average distance between vehicles in the same lane is 2.5sec. It is set to absolute vehicle speed and defined as vehicle density. Additionally, VUEs on all roads in the simulator have the same density and speed. Also, assuming that all vehicles only move straight without changing direction at an intersection, a network configuration is used in which BS-type RSU and UE-type RSU are applied together to the SLS designed as shown in Figure 3. In Figure 3, the red circle-shaped dot means BS-type RSU, and the blue circle-shaped dot means UE-type RSU. The red square represents the distribution of each VUE.

The antenna model according to an embodiment of the present invention is a factor that has the greatest influence on performance evaluation, and within the system model, the antenna models of BS-type RSU and UE-type RSU are configured differently. The antenna parameters of each RSU are defined according to the 3GPP technical document that presents a methodology for evaluating V2X user cases in NR. In the case of the BS-type RSU antenna, the antenna configuration satisfies 3 sectors in the hexagonal grid and has a height of 25m. The number of antenna elements in every panel of the BS-type RSU antenna consists of a maximum of 256 TX/RX antenna elements, and the array model has M (number of antenna elements configured in each column), N (number of antenna elements configured in each row) per panel. ), P (polarized type of antenna panel, single polarized (P = 1) or dual polarized (P = 2)), M _g (number of panels configured in each row) , N _g (number of panels comprised in each row) is modeled as a uniform rectangular panel array represented by antenna elements. In 3GPP, the antenna array of BS-type RSU is configured as (M, N, P, M _g , N _g ) = (8, 8, 2, 1, 1), and the spacing of the antenna panels is [d _H (horizontal array distance between them), d _V (distance between vertical arrays)] = (0.5, 0.8) It is composed of uniform intervals that satisfy. In addition, the UE-type RSU has a different antenna configuration from the BS-type RSU. The antenna height of the UE-type RSU is 5m, and the number of antenna elements in all panels is up to 8 TX/RX antenna elements with an antenna array of (1, 2). , 2, 1, 1), and the spacing between antenna arrays is (d _H , d _V ) = (0.5, 0.8) It has a uniform spacing that satisfies . A larger number of antenna elements in the antenna configuration increases the power received at the VUE, enabling narrower beams and higher accuracy.

We consider the 3D beamforming proposed by 3GPP in BS-type RSU and identify some limitations related to the steering range caused by the vertical cell geometry. In addition, 3D beamforming that combines horizontal beam pattern adaptation, vertical antenna pattern adaptation, and vertical pattern is introduced to maximize VUE throughput performance as the received SINR of the vehicle terminal increases.

In the channel model according to an embodiment of the present invention, the propagation loss for the transmission link in each RSU considers all path loss, shadowing, and fast fading. The main propagation loss models for the two proposed RSU types are implemented and used according to Equation (1).

(One)

Assumptions for the channel model between VUE and RSU are applied according to [Table 1], and the corresponding parameters are considered by applying the 3GPP TR SLS methodology.

<Table 1>

For BS-type RSU, a shadowing correlation coefficient of 0.5 is used for shading between RSU sites to form shadowing correlation between RSUs in the urban case, and a shading correlation coefficient of 1.0 is used between sectors of the same RSU site. Shadowing is applied using the shadow correlation coefficient. In the case of UE-type RSU, the same parameters related to PC5 interface-based V2V evaluation are used with the antenna height changed to 5m. For the WINNER + B1 Manhattan grid layout Urban micro-cell scenario used in the pathloss model, the antenna heights of the VUE and RSU are assumed to be lower than the tops of surrounding buildings, from all locations to the RSU in both LOS and NLOS cases. It is calculated by defining . Also, in the case of fading, in the case of NLOS of ITU-R Urban Micro Clustered Delay Line models (CDL) in 3GPP TR, simulation with fixed large scale parameters is required, but the same fading as BS-type RSU is required. Since applying parameters does not have a significant impact on the propagation loss model value when conducting a simulation, the 3GPP Spatial Channel Model (SCM) NLOS is applied to simplify the simulation.

For adaptation (abstraction) in the physical layer (PHY) according to an embodiment of the present invention, the UE throughput is calculated using a specific modulation and coding level to obtain the Packet Error Rate (PER) for each packet. 5G-NR uses LDPC coding rather than turbo coding used in LTE, and is expressed as 15 CQI (Channel Quality Indicator) indices using MCS (Modulation Coding Scheme) that provides up to 256QAM, allowing Allows different spectral efficiencies to be achieved. In these PHY calculations, perfect time and frequency synchronization of urban environment VUE received signals must be assumed, and performing measurements by obtaining PER over SLS and considering all transmit and receive architectures for signal processing is expensive and time-consuming, making it difficult to perform specific Difficult to adapt to communication scenarios. For simulation analysis, it is required to simplify and apply limiting assumptions and systems, and link-level simulation (LLS) is used to evaluate the analysis results under realistic conditions. To utilize LLS, the LLS curve of the AWGN (Additive White Gaussian Noise) channel using the Vienna 5G Link Level Simulator is implemented and applied.

Figure 4 is a flowchart illustrating a resource management method in a cooperative 5G-NR-V2X RSU for improving V2I/N link reliability according to an embodiment of the present invention.

The resource management method in the proposed cooperative 5G-NR-V2X RSU to improve V2I/N link reliability is to apply BS-type and UE-type together to implement RSU (Road Side Unit) in a wrap around method in the network layout. ) and generating a network layout, antenna model, channel model, and physical layer for placing VUEs (Vehicle Users) on the road according to a spatial location process (Spatial Poisson Process) (410), the generation Step 420 of allocating a V2X message through a hybrid RSU that selectively uses BS-type and UE-type to secure efficient user service using the network layout, antenna model, channel model, and physical layer and vehicle terminal It includes a step 430 of applying resource cooperation management technology, CRE (Cell Range Expansion) technology, and 3D beamforming method to contribute to higher system capacity or better power use in communication between and RSU.

In step 410, the BS-type and the UE-type are applied together to place the Road Side Unit (RSU) in a wrap around method in the network layout, and the VUE ( Create a network layout, antenna model, channel model, and physical layer that places vehicle users on the road.

In step 410, the antenna models are configured differently according to the BS-type and UE-type RSUs, a channel model is configured using propagation loss according to the BS-type and UE-type RSUs, and a specific By calculating user throughput using modulation and coding levels, the PER (Packet Error Rate) for each packet in the channel is obtained to form the physical layer.

In step 420, a V2X message is allocated through a hybrid RSU that selectively uses BS-type and UE-type to secure efficient user service using the generated network layout, antenna model, channel model, and physical layer. do.

In step 420, the RSU with the highest received SINR is identified using the BS-type and UE-type of the hybrid RSU with different transmission powers and parameters, and the RSU that will serve the VUE is selected.

The BS-type applies resource cooperation management to satisfy the Quality of Service (QoS) required in vehicle communication, and the UE-type is a HetNet (Heterogeneous) consisting of a macro cell and a small cell. Networks) applies cell expansion techniques (Cell Range Expansion) to support spectral efficiency and energy efficiency.

In step 430, resource cooperation management technology, CRE (Cell Range Expansion) technology, and 3D beamforming method are applied to contribute to higher system capacity or better power use in communication between vehicle terminals and RSUs.

In step 430, co-channel interference (CCI) control that occurs targeting user terminals located in overlapping areas is performed (431), and the desired user signal is maximized by combining horizontal beam pattern adaptation with vertical antenna pattern application to reach the receiver. Improve the SINR of (432).

In step 431 of performing co-channel interference (CCI) control, co-channel interference control is performed based on dynamic ICIC (431a), co-channel interference control is performed based on CS-CoMP (431b), and CRE is performed. Based on this, co-channel interference control can be performed (431c).

In the step of improving the SINR of the receiver (432), the received SINR may be improved based on 3D beamforming (432a).

Figure 5 shows SNR vs. LLS results when using turbo coding in an LTE environment and LLS results when using LDPC coding in a 5G-NR environment according to an embodiment of the present invention. This is the PER curve.

The simulation results shown in Figure 5 are a comparison of the simulation results in LTE and 5G NR, and are the results performed in the AWGN channel with CQI values 1 to 15. In addition to comparing LLS performance, the simulation results provide correction values for effective SINR mapping when calculating feedback. In the present invention, L2S (Link-to-System) mapping using MIESM (Mutual Information Effective SNR Mapping) is performed based on the results. The ESM (Effective SNR Mapping) algorithm provides important link layer adaptation to SLS, and in the case of MIESM applied in the paper, Equation (2) and (3) are utilized to provide higher accuracy than other ESM methods, and effective SINR To calculate , the calculation is based on the non-linear mapping relationship from SINR to mutual information.

(2)

(3)

here, is a correction factor chosen to minimize the root mean square (rms) error between the effective SNR derived from the Rayleigh channel and the fixed SNR value.

According to an embodiment of the present invention, mutual cooperation method of BS / UE-type RSU for V2X communication when UE-type RSU is deployed in the coverage area of urban terrain macro BS-type RSU in 5G-NR-V2X network We propose a Hybrid RSU method. The proposed Hybrid RSU method is a method of efficiently allocating V2X messages by selectively using BS/UE-type RSU to secure efficient user services, and the Hybrid RSU method is a method to efficiently allocate V2X messages in the 5G-NR-V2X environment. By minimizing the area, data can be used more efficiently and reliably for road and traffic environments that change in real time.

Figure 6 is a diagram showing a SINR color map according to an embodiment of the present invention.

Each RSU type configured in the Cellular Multi-tier Network consists of different parameters, including different transmission power, and VUE selects the RSU with the highest received SINR from the V2X Application Server. Confirm and select the RSU that will provide services to VUE. Based on the cellular V2X network presented earlier, the shadow area for each RSU type is identified, and the simulation results show that the shadow area is minimized through mutual cooperation between each RSU. The simulation is conducted through SLS analysis implemented in the 5G-NR-V2X environment, and after configuring the V2X environment considering network layout (Urban Case), VUE distribution and mobility model, RSU distribution, channel model, and traffic model, vehicle terminal is stopped. Evaluated through probability, reception interference, average throughput, etc. The shaded area within the simulation environment is expressed by the reception SINR value of each vehicle according to the RSU type, and the SINR value for general reception is calculated by equation (4).

(4)

here is calculated as the size of the signal supported by n, where VUE m is a BS-type RSU, as the product of the channel gain and the transmission power from the BS, represents the total interference received from BS-type RSU k of all neighboring cells excluding the supported RSU. Additionally, the received SINR value generated by the UE-type RSU is calculated by equation (5).

(5)

The VUE received SINR values obtained by applying the SINR values calculated through each equation to SLS are shown in Figure 6. In the case of Figure 6(a), the SINR value received when the VUE receives a service from a BS-type RSU, and in the case of Figure 6(b), the SINR value received when the VUE receives a service from a UE-type RSU Each result is expressed as a SINR map. In order to minimize the shadow area, a formula such as Equation (6) is applied to select a supported RSU according to the SINR value received from the RSU.

(6)

Figure 6(c) shows the results shown through the SINR map when using the proposed hybrid RSU method. Simulation results confirm that the proposed hybrid RSU method reduces co-channel interference and reduces shadow areas.

In order to confirm the reduction of shadow areas through the hybrid RSU installation method, performance evaluation is conducted on the following three indicators. The vehicle terminal outage probability (Outage Probability) refers to the probability that the VUE will be interrupted because the received SINR value of the VUE is less than the SINR threshold. If the VUE outage probability value is 5% by measuring the VUE received SINR value, the SINR threshold is determined. Set it as a value (Threshold). Additionally, the interruption probability value in each case is evaluated, and the interruption probability is calculated using equation (7).

(7)

Figure 7 is a graph showing the probability of 5G-NR V2X BS/UE/hybrid RSU interruption according to an embodiment of the present invention.

In the case of Figure 7, in the case of UE-type RSU, BS-type RSU, and hybrid RSU, 5% of all users was set as the SINR threshold, and the values at this time were -4.8 dB, -2.64 dB, and -0.84, respectively. It has a value of dB. It is confirmed that the UE-type RSU has a lower SINR threshold than the BS-type RSU, and that the overall received SINR value improves when the two RSUs cooperate. When calculating the interruption probability value for each type using the SINR threshold value of -0.84dB when using the hybrid RSU method, it can be confirmed that 16% of VUEs experience interruption in the case of BS-type RSU and UE-type RSU, and BS When /UE-type RSU cooperates, the probability of interruption is 5%, so it can be seen that the probability of interruption is reduced by about 11%. Reducing the probability of interruption within the simulation means reducing the shadow area, and reducing the shadow area allows for more efficient use in resource allocation. Vehicle terminal interference refers to all interference received from adjacent cells other than the cell providing services to the VUE, and interference is calculated using the formula below.

(8)

In the case of interference, it can be seen that the interference value of UE type RSU is greater than that of BS type RSU, which is in the form of a denser distribution of the number of deployments of UE type RSU than that of BS type. As a result, interference from other UE-type RSUs increases, and VUE receives signals from nearby UE-type RSUs, and different parameters from BS-type RSUs are applied, confirming that VUE interference appears large.

Figure 8 is a graph showing 5G-NR V2X BS/UE/hybrid RSU interference according to an embodiment of the present invention.

In the case of Figure 8, the interference value is confirmed by performing evaluation in the CDF (Cumulative Distribution Function) 50% section, -77.37dB for BS-type RSU, -50.71dB for UE-type RSU, and BS/UE-type RSU mutually In cooperation, it is -62.26dB, which is a lower value than the interference when only UE-type RSU is applied. In the case of vehicle terminal average throughput, evaluation is performed at 50% CDF, and throughput is calculated by the equation below.

(9)

Throughput refers to the size of the TB (Transport Block) received per unit time, the TB value represents the total number of bits received in the VUE, and Accounted _TTIs is the maximum transmission time interval (TTI) of the RB allocated to the UE receiver.

Figure 9 is a graph showing 5G-NR V2X BS/UE/hybrid RSU throughput according to an embodiment of the present invention.

Figure 9 shows the VUE average throughput results, and it can be seen that the average throughput value is 1.528Mbp/s when the vehicle only receives data from the BS-type RSU, and 2.5Mbp/s when the vehicle receives data from the UE-type RSU. It has a throughput value of s. The average throughput value when using the hybrid RSU method, which is the proposed BS/UE-type RSU mutual cooperation method, is 3.06Mbp/s, which shows a 100% performance improvement compared to 1.532Mbp/s when receiving data from a BS-type RSU. . In addition, it can be seen that the average throughput increases by 0.56Mbp/s compared to when data is transmitted from a UE-type RSU, improving performance by about 22%. As a result, it can be confirmed that the proposed hybrid RSU method improves the reliability of vehicle users by alleviating co-channel interference and improving the quality of the communication system.

Each RSU type according to an embodiment of the present invention has a configuration in which various technologies can be applied by applying different and heterogeneous parameters, and throughput performance can be maximized when mutual cooperation between RSUs is applied by applying the presented technologies. Each applied technology applies dynamic ICIC (Dynamic Inter-Cell Interference Coordination), CS-CoMP (Coordinated Scheduling Coordinated Multi-Point), and 3D beamforming technology to cell edge users in the BS-type RSU, and UE-type RSU. By applying CRE (Cell Range Expansion) technology, performance improvement is confirmed and the characteristics of each technology are analyzed.

According to an embodiment of the present invention, resource cooperation management is applied to satisfy QoS (Quality of Service) required in vehicle communication. Resource cooperation management technology improves the reliability of the entire communication system by mitigating CCI in the cellular V2I network where BS-type RSU and vehicle users communicate in a 5G-NR-V2X environment, and dynamic ICIC and CS-CoMP technologies, which are interference mitigation methods. Coordinated interference management is possible. In the case of dynamic ICIC, resources are reallocated by redistributing frequencies using the FFR (Fractional Frequency Reuse) method, which uses a frequency reuse coefficient for cell edge users. At a fixed overall frequency, frequencies are allocated to users at the center of a cell where a large number of vehicles are located using the FR (Full Reuse) spectrum, and to users located at the edge of the cell, frequencies are allocated to the PR (Partial Reuse) spectrum. The proposed dynamic ICIC is allocated to vehicles. Additional BBW (Bonus Bandwidth) is allocated to vehicles located at the edges of the cell, including these multiple intersections, allowing more resources to be used. At this time, the standard for dividing the PR band and FR band to allocate frequencies by distinguishing between cell center users and edge users is defined as 5% of the total users to set the SINR threshold, and this is used to determine whether or not to allocate BBW. Decide. Apply dynamic ICIC technology by using Equation (10) to determine the users assigned to the PR band and FR band.

(10)

In addition, CS-CoMP, which is applied to resource cooperative management, is a method to enhance the spectral efficiency of cell edge users from signals received from other cell sites, and improves the quality of the received signal through coordination between signals transmitted from the site. . A blocking-based scheduling process is applied to reduce unwanted CCI between BS-type RSUs, and each BS-type RSU receives feedback from VUE through the central scheduler and decides whether to apply CS-CoMP. In addition, VUE applies CS-CoMP by blocking interference signals from adjacent BSs with the same PRB and implementing inter-sector muting.

According to an embodiment of the present invention, Cell Range Expansion is used to support higher spectral efficiency and energy efficiency in HetNet (Heterogeneous Networks) composed of existing macro cells and small cells. The method used is to adjust the range of the small cell RSU by adding a bias to the measured received signal when connecting a cell that supports VUE in HetNet, where macro cell RSU and small cell RSU exist simultaneously, and adjust the range of small cell RSU between macro cell RSU and small cell RSU. This is a proposed method to balance. In this way, a cell expansion technique is proposed to efficiently use UE-type RSU, which has higher throughput performance in the urban environment of the 5G-NR-V2X network, and terminals adjacent to the UE-type RSU border can access the BS-type RSU. To prevent connectivity, the area of the UE-type RSU is expanded using cell expansion techniques. A given received signal bias is used to expand the cell area. When , CRE is applied using equation (11).

Equation (11)

Here, the bias applied to the received signal The value is calculated as in equation (12).

Equation (12)

here, Each item in Equation (13) is calculated by considering each case of the SINR value. In other words, when applying the cell expansion technique, interference from the BS-type RSU is excluded from the UE-type RSU. Calculate the value.

Here, the received signal power of VUE is and represents the total interference size received from BS/UE-type RSU. Model the SINR value of VUE by calculating .

Figure 10 is a graph showing a 3D beamforming antenna pattern according to an embodiment of the present invention.

In the case of 3D beamforming, the applied horizontal beam pattern adaptation is combined with vertical antenna pattern adaptation to maximize the desired user signal, thereby improving the receiver's SINR. 3D beamforming provides improved transmission power, improving spectral efficiency and cell edge throughput performance, and for VUEs located at cell boundaries and connected to different BS-type RSUs, it allocates orthogonal resources to avoid interference. The antenna for 3D beamforming is constructed using the method described previously, and the 3D antenna pattern has vertical and horizontal angles. Defined by pairs. The setting of vertical and horizontal angles is an important parameter that enables communication between distant nodes by determining the power transmission and reception position of the antenna in a scenario where directional transmission is used, and the method of combining vertical and horizontal patterns follows equation (14). .

(14)

The antenna element gain pattern is a vertical pattern. and horizontal pattern It shows maximum gain and high directivity in the main lobe direction of 8dBi of the single element radiation pattern. Here, the vertical pattern and horizontal pattern are expressed as equations (15) and (16).

Equation (15)

Equation (16)

here, means vertical and horizontal 3 dB bandwidth, is the sidelobe level limit, means the maximum attenuation value. For vertical patterns, It satisfies the corresponding conditions, and in the case of a horizontal pattern, satisfies the conditions. Additionally, to confirm the antenna gain of 3D beamforming, a single antenna configuration of a uniform rectangular panel array and an antenna array with each panel's row and column having (8, 8) elements are constructed and compared.

Figure 10 shows a 3D antenna pattern to which antenna parameters are applied, and an additional gain of 18dBi can be confirmed.

Figure 11 is a graph showing VUE throughput applying dynamic ICIC and CS CoMP according to an embodiment of the present invention.

Referring to Figure 11, the proposed technologies are evaluated to maximize the throughput performance of the proposed hybrid RSU method. For evaluation, we use MATLAB-based SLS to check throughput values and analyze throughput performance. The values in <Table 2> apply to the main SLS parameters.

<Table 2>

In the case of Figure 11, the BS/UE/Hybrid RSU throughput graph results confirm the throughput performance when applying dynamic ICIC and CS-CoMP, which are resource cooperation management technologies, to a single BS-type RSU, and apply the resource cooperation management technology to the hybrid RSU method. Compare and confirm with the throughput value when ordered. The dotted line graph represents the value before applying a specific technology, and the solid line graph represents the throughput graph after applying the resource cooperation management technology. According to the graph, when applying (Dynamic ICIC + CS CoMP) to a single BS-type RSU, the throughput improved by about 10% from 1.528 [Mb/s] to 1.68 [Mb/s], and resource cooperation in the hybrid RSU method was achieved. When applying the management technology, throughput performance improves by 24% from 3.02 [Mb/s] to 3.768 [Mb/s].

Figure 12 is a graph showing VUE throughput applying cell range expansion according to an embodiment of the present invention.

Referring to FIG. 12, the performance is compared by applying the cell expansion technique to the UE-type RSU, and the performance when simultaneously applied with the previously proposed resource cooperation management technique is compared. When checking the throughput at 50% CDF, which is an evaluation item when applying CRE in the hybrid RSU method, it can be seen that the throughput increases from 3.02 [Mb/s] to 4.246 [Mb/s], which corresponds to a 40% performance improvement. . Additionally, when CRE technology is applied along with (dynamic ICIC + CS-CoMP) technology in the hybrid RSU, throughput increases from 3.768 [Mb/s] to 4.537 [Mb/s], which corresponds to a performance improvement of about 20%. However, as the CDF value increases, the throughput value has a similar average throughput value to the case where CRE technology is not applied, which means that CRE technology particularly affects the performance improvement of users with low throughput values, but for users with high throughput values. We can confirm that this was not the case in VUE.

Figure 13 is a graph showing VUE throughput applying 3D beamforming according to an embodiment of the present invention.

Referring to Figure 13, the performance is compared after applying 3D beamforming to the previously applied technology, and when 3D beamforming is applied to a single BS-type RSU, the throughput increases from 1.762 [Mb/s] to 3.276 [Mb/s]. You can see that there is an 85% improvement. When applying 3D beamforming with the dynamic ICIC, CS CoMP, and CRE technologies proposed simultaneously with the hybrid RSU method, the throughput increases from 4.54 [Mb/s] to 5.85 [Mb/s], resulting in a 28% performance improvement. see.

The device described above may be implemented with hardware components, software components, and/or a combination of hardware components and software components. For example, devices and components described in embodiments may include, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), etc. , may be implemented using one or more general-purpose or special-purpose computers, such as a programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. A processing device may execute an operating system (OS) and one or more software applications that run on the operating system.　 Additionally, a processing device may access, store, manipulate, process, and generate data in response to the execution of software.　 For ease of understanding, a single processing device may be described as being used; however, those skilled in the art will understand that a processing device includes multiple processing elements and/or multiple types of processing elements. It can be seen that it may include.　 For example, a processing device may include a plurality of processors or one processor and one controller.　 Additionally, other processing configurations, such as parallel processors, are possible.

Software may include a computer program, code, instructions, or a combination of one or more of these, which may configure a processing unit to operate as desired, or may be processed independently or collectively. You can command the device.　 Software and/or data may be used on any type of machine, component, physical device, virtual equipment, computer storage medium or device to be interpreted by or to provide instructions or data to a processing device. It can be embodied in .　 Software may be distributed over networked computer systems and stored or executed in a distributed manner. Software and data may be stored on one or more computer-readable recording media.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium.　 The computer-readable medium may include program instructions, data files, data structures, etc., singly or in combination.　 Program instructions recorded on the medium may be specially designed and configured for the embodiment or may be known and available to those skilled in the art of computer software.　 Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. -Includes optical media (magneto-optical media) and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, etc.　 Examples of program instructions include machine language code, such as that produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc.　

As described above, although the embodiments have been described with limited examples and drawings, various modifications and variations can be made by those skilled in the art from the above description.　 For example, the described techniques are performed in a different order than the described method, and/or components of the described system, structure, device, circuit, etc. are combined or combined in a different form than the described method, or other components are used. Alternatively, appropriate results may be achieved even if substituted or substituted by an equivalent.

Therefore, other implementations, other embodiments, and equivalents of the claims also fall within the scope of the claims described below.

Claims (8)

By applying the BS-type and UE-type together, RSU (Road Side Unit) is placed in a wrap around method in the network layout, and VUE (Vehicle User) is placed on the road according to the spatial location process (Spatial Poisson Process). Creating a deployed network layout, antenna model, channel model, and physical layer;
Allocating a V2X message through a hybrid RSU that selectively uses BS-type and UE-type to secure efficient user service using the generated network layout, antenna model, channel model, and physical layer; and
Step of applying resource cooperation management technology, CRE (Cell Range Expansion) technology, and 3D beamforming method in communication between terminal and RSU
Resource management method including. According to paragraph 1,
The step of creating the network layout, antenna model, channel model, and physical layer is,
The antenna models are configured differently depending on the BS-type and UE-type RSU,
Construct a channel model using propagation loss according to BS-type and UE-type RSU,
By calculating user throughput using specific modulation and coding levels, the PER (Packet Error Rate) for each packet in the channel is obtained to form the physical layer.
Resource management methods. According to paragraph 1,
The step of allocating a V2X message through a hybrid RSU that selectively uses BS-type and UE-type to secure efficient user service using the generated network layout, antenna model, channel model, and physical layer is,
Identifying the RSU with the highest received SINR using the BS-type and UE-type of the hybrid RSU with different transmission power and parameters and selecting the RSU to provide service to the VUE
Resource management methods. According to paragraph 3,
The BS-type applies resource cooperation management to satisfy the QoS (Quality of Service) required in vehicle communication,
The UE-type applies Cell Range Expansion to support spectral efficiency and energy efficiency in HetNet (Heterogeneous Networks) consisting of macro cells and small cells.
Resource management methods. By applying the BS-type and UE-type together, RSU (Road Side Unit) is placed in a wrap around method in the network layout, and VUE (Vehicle User) is placed on the road according to the spatial location process (Spatial Poisson Process). A model creation unit that generates a deployed network layout, antenna model, channel model, and physical layer; and
Using the created network layout, antenna model, channel model, and physical layer, V2X messages are allocated through a hybrid RSU that selectively uses BS-type and UE-type to secure efficient user service, and Resource allocation department that applies resource cooperation management technology, CRE (Cell Range Expansion) technology, and 3D beamforming method in communications
Resource management system including. According to clause 5,
The model creation unit,
The antenna models are configured differently depending on the BS-type and UE-type RSU,
Construct a channel model using propagation loss according to BS-type and UE-type RSU,
By calculating user throughput using specific modulation and coding levels, the PER (Packet Error Rate) for each packet in the channel is obtained to form the physical layer.
Resource management system. According to clause 5,
The resource allocation unit,
Identifying the RSU with the highest received SINR using the BS-type and UE-type of the hybrid RSU with different transmission power and parameters and selecting the RSU to provide service to the VUE
Resource management system. In clause 7,
The resource allocation unit,
For the BS-type, resource cooperation management is applied to satisfy the QoS (Quality of Service) required in vehicle communication,
For the above UE-type, Cell Range Expansion is applied to support spectral efficiency and energy efficiency in HetNet (Heterogeneous Networks) consisting of macro cells and small cells.
Resource management system.