Real-Vehicle Electromagnetic Compatibility Evaluation of V2X Communication Equipment
Article information
Abstract
This paper presents a real-vehicle electromagnetic compatibility (EMC) evaluation method for dual-mode vehicle-to-everything (V2X) systems supporting WAVE and LTE-V2X. Unlike conventional EMC tests that are limited to assessing regulatory compliance, the proposed method quantifies the effects of electromagnetic interference on communication quality based on packet error rate (PER), latency, and throughput. A dual-mode V2X module comprising an 8-layer printed circuit board and a software stack was tested under DSRC, C-V2X, and GNSS conditions in accordance with EN 301 standards. The results confirm full compliance with emission limits and robust immunity, maintaining 0% PER and stable performance even at 30 V/m. Compared with single-mode systems, the proposed dual-mode design demonstrates superior resilience, offering a performance-centric framework for EMC validation of future autonomous and cooperative driving applications.
I. Introduction
With recent advancements in autonomous driving technology, the importance of vehicle-to-everything (V2X) communication, which supports both vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) links, has grown significantly. Conventional single-mode V2X systems (e.g., DSRC-only or LTE-V2X-only) offer both advantages and disadvantages. While dedicated short-range communications (DSRC) excels at low-latency communication, its performance may degrade in congested traffic environments. Conversely, LTE-V2X provides wider coverage, but at the cost of network dependency and latency challenges. In contrast, a dual-mode architecture supporting both of these technologies can ensure a stable connection, which is integral for autonomous driving systems, by leveraging their complementary strengths to enhance communication link availability and reliability.
However, existing automotive electromagnetic compatibility (EMC) standards primarily focus on verifying the operational integrity of individual electronic devices [1], thereby failing to adequately assess their impact on actual communication performance. This poses a limitation in verifying communication reliability under autonomous driving environments. Consequently, a new evaluation methodology is needed to quantitatively analyze the effects of electromagnetic interference (EMI) on V2X message-based applications.
To overcome these limitations, this study proposes a real-vehicle-based EMC evaluation methodology. Specifically, it introduces an approach that quantitatively evaluates immunity in EMI environments by measuring the packet error rate (PER)—a key communication performance indicator—in real time. For this purpose, an empirical testbed was established by integrating a dual-mode V2X system with high-performance hardware and a complete software stack, along with a PER analysis tool capable of real-time analysis. The proposed methodology not only provides enhanced reliability compared to single-mode systems but also differentiates itself from previous research through its capability to evaluate new EMC challenges, such as coexistence issues pertaining to WAVE and LTE-V2X. The objective of this study is to present a performance-centric, real-vehicle-based EMC evaluation methodology for experimentally validating the immunity and stability of next-generation V2X systems.
II. Hardware Design of the V2X Communication Equipment
Fig. 1 presents a system block diagram illustrating the design and implementation of the V2X communication equipment used in this study.
Block diagram of V2X communication equipment for vehicular applications.
The proposed device supports a wide input voltage range of 5–36 V, which accommodates various vehicular power systems, and comprises a DC/DC converter that consistently provides stable output voltages of 3.8 V, 3.3 V, and 5 V. The main processing unit of the system is centered around a microcontroller unit, while the storage subsystem includes both embedded multimediacard (eMMC) and NOR flash memory. In addition, LPDDR4 memory is employed as the main system memory to achieve high-speed data processing and system stability, which are critical for real-time communication in autonomous vehicle environments. In terms of communication functionality, the device is equipped with an IEEE 802.11p [2]-based WAVE modem and a 3GPP Release 14/15 [3, 4]-based LTE-V2X modem. For backward compatibility with the existing LTE infrastructure, a legacy LTE module compliant with LTE CAT.4 specifications is also integrated. Notably, since each communication module can operate independently, the device also supports multichannel processing and protocol diversity for various deployment scenarios. This hardware design ensures the functional integration, scalability, and reliability of the V2X system, making it suitable for real-world cooperative intelligent transport systems (C-ITS) applications and large-scale deployment in autonomous driving technologies.
1. Hardware and MCU-based Control Design for V2X
To ensure reliable performance of the V2X software stack and the C-ITS system, the base station of the V2X communication equipment required a high-performance processor. For this purpose, NXP’s i.MX8Qxp processor, which is an automotive-grade component, was adopted. This processor features a multicore architecture that integrates a quad-core ARM Cortex-A35 and a Cortex-M4, providing performance suitable for high-speed computation and real-time control. The system memory was configured with 3 GB of LPDDR4 as the main memory and 32 GB of eMMC as the non-volatile storage, ensuring both sufficient data processing speed and storage stability. Moreover, the hardware platform was designed to support a variety of I/O interfaces, including 1 Gbps Ethernet, USB 3.0/2.0, CAN 2.0, uSD, UART, I2C, and SPI, thereby guaranteeing expandability and compatibility with external devices.
System booting was performed using a bootloader based on eMMC. Furthermore, a Linux-based operating system was employed to enable integrated operations, such as system initialization, driver loading, and application execution. In summary, the hardware platform was optimized to meet the performance and functional requirements of hybrid V2X communication environments.
2. Power Supply Design of V2X Communication Equipment
The power supply system of the V2X communication equipment was designed by accounting for the temperature conditions and component reliability standards of automotive-grade electronic systems. All components in the power circuitry were carefully selected to meet automotive-grade specifications, ensuring that the system could withstand electrical stress and disturbances that are commonly encountered in actual vehicle environments. For electrical performance validation, the design accounted for several key automotive test items, including over-voltage, reverse voltage, transient voltage, and EMC tests. In response, protective elements, such as TVS diodes, varistors, and EMI filters, were integrated at the power input stage. Notably, these components are essential for protecting systems from damage caused by electrical noise or surge events.
A DC/DC converter was employed to handle the system’s power conversion, while a dedicated PMIC ensured stable power delivery to the core components, including the MCU, LPDDR4, and eMMC. Power distribution was optimized based on the specific voltage and current requirements of each component to guarantee both high power efficiency and system stability. Specifically, the DC/DC conversion was implemented using the MPQ4317 series from MPS, which is compliant with automotive-grade standards. For power management, the PF8100 PMIC from NXP Semiconductors was employed to supply regulated voltages to key subsystems. This power design enhanced the overall electrical reliability of the system, ensuring high durability and stability under automotive operating conditions. The main system power of 3.8 V was designed to supply a maximum current of 7 A from a 12-V input. Furthermore, as shown in Eq. (1), the output voltage was determined by the ratio of the 100 kΩ (Rf1) and 27.3 kΩ (Rf2) feedback resistors. The switching frequency was set to 410 kHz. Additionally, an identical converter with a maximum capacity of 6 A was used to deliver a stable 3.3 V supply to the peripheral circuits, with its output voltage precisely controlled using 100 kΩ and 31.6 kΩ resistors.
3. LTE-V2X Modem Configuration and Secure Communication Features
The LTE-V2X communication modem employed in this study was designed based on the SECTON-Cut3 chipset developed by Autotalks. The modem was developed by integrating the PLUON2 RFIC and the SKYA21043 power amplifier module, thereby forming a complete RF transmission and reception path suitable for automotive V2X applications. Notably, the SECTON-Cut3 chipset complies with the LTE-V2X specifications defined in 3GPP Releases 14 and 15. It also supports direct V2V communication through the PC5 side-link interface. Furthermore, it conforms to key intelligent transport system (ITS) standards, including SAE J2945/1 and SAE J3161/4 [5, 6], enabling safe messaging and application services between vehicles. With regard to security, the modem was equipped with a built-in elliptic curve digital signature algorithm (ECDSA) hardware accelerator capable of verifying more than 2,000 digital signatures per second. This feature is essential for secure real-time processing in high-frequency V2X message exchanges. The SECTON-Cut3 chipset, which has been certified as Automotive Grade 2, also incorporates a dedicated hardware security module (HSM), which ensures secure storage of credentials and efficient cryptographic operations. This enhanced the overall security robustness of the system with regard to automotive reliability standards. An SPI connection was employed for the modem to interface with the main processor, enabling control signal transmission and data exchange. Overall, this hardware architecture supports high-reliability V2X communication and serves as a robust platform for deployment in real-world vehicular environments.
The system architecture of the V2X communication equipment was designed to integrate the modem chipset with a variety of peripheral interfaces and expansion features. While the primary connection to the main processor was established via an SPI bus, dedicated UART and GPIO ports enabled flexible integration with external cellular modules. In addition, a dedicated console port was added for system diagnostics, and a pulse-per-second input terminal was included to ensure precise time synchronization with external global navigation satellite system (GNSS) modules. The proposed system also supports peripheral expansion through additional I2C and SPI interfaces, enabling connectivity with sensors and memory devices. This modular interface design enhanced the flexibility and scalability of the system by addressing the functional limitations of a single chipset and ensuring stable and versatile V2X operation in real vehicular environments.
4. Legacy LTE Communication Module
To support legacy LTE communication, the AG35E LTE Category 4 module developed by Quectel was incorporated into the system. Notably, this module was designed in accordance with LTE Category 4 [7] specifications, thereby offering high-speed data transmission and broad compatibility with various cellular network infrastructures. The module interfaces with the main system processor via a USB 2.0 host connection and communicates using the Qualcomm MSM Interface driver [8]. Through this configuration, efficient management of network access, data transmission, and real-time status monitoring can be achieved, thus supporting the operational stability of the V2X system. The AG35E module supports multiple LTE frequency bands that are currently in service in South Korea, including Band 1 (2,100 MHz), Band 3 (1,800 MHz), Band 5 (850 MHz), Band 7 (2,600 MHz), and Band 8 (900 MHz). In other words, the module enables wide compatibility with major domestic mobile network operators, ensuring robust connectivity across diverse deployment scenarios. Given these capabilities, the legacy LTE module can serve not only as a primary communication interface but also as a reliable backup link for V2X systems, enhancing overall communication reliability and system availability in real-world operating conditions.
III. PCB Design for EMC Compliance in LTE-V2X Communication Equipment
To ensure EMC, the printed circuit board (PCB) of the LTE-V2X communication equipment was designed to meet high reliability standards from the initial development phase. To meet the system’s emission and immunity requirements, the PCB layout and signal integrity were carefully implemented based on reference matching guidelines provided by NXP Semiconductors. The PCB consists of eight layers, with the stack-up optimized to maintain the integrity of high-speed signals while minimizing coupling noise between the power and ground planes. This multilayer structure proved effective in suppressing electromagnetic radiation from high-frequency signals while also enhancing the overall EMC performance across the system. Through this design approach, the equipment was expected to satisfy EMC regulatory requirements, including both emission and immunity standards, for in-vehicle communication environments [9]. In other words, the hardware was prepared to pass formal EMC testing for automotive certification processes.
1. Multilayer PCB Stack-Up Design for V2X Communication Equipment
As shown in Fig. 2, the PCB developed for the V2X communication module proposed in this study features an eight-layer stack-up structure. The total PCB thickness was 1.4 mm, with each layer functionally segregated to maintain high-speed signal integrity and minimize power-to-ground interference. Specifically, signal routing was implemented on Layers 1, 3, 6, and 8, while Layers 2 and 7 were dedicated to ground (GND), and Layers 4 and 5 were used for power distribution. This layer separation contributed significantly to EMI suppression and ensured consistent signal quality, which is critical in high-frequency communication environments such as V2X. Furthermore, different dielectric constant (Dk) values were selected based on the electrical characteristics required for each layer. For the outer signal layers (Layers 1 and 8), materials with a dielectric constant of Dk 4.2 were used, while materials with Dk 4.3 were employed for the inner layers. This stratified dielectric design resulted in optimized signal propagation characteristics and enhanced the board’s EMC performance. Overall, this multilayer PCB structure provides a robust and reliable hardware foundation for V2X communication systems and plays a vital role in maintaining operational stability and environmental resilience under real vehicular deployment conditions.
An 8-layer PCB stack-up configuration for V2X communication equipment.
2. PCB Impedance Matching for High-Speed Signal Integrity
In the proposed design, PCB impedance matching was carefully applied to optimize signal transmission characteristics by maintaining a separation between single-ended and differentialpair lines. For single-ended lines, a 50 Ω impedance was applied to general high-speed digital signal traces with the aim of minimizing signal reflection and maintaining signal integrity. Notably, this is the standard matching value in most high-frequency PCB applications. Meanwhile, a 42 Ω impedance was specifically applied to LPDDR4 memory data lines, given the memory’s electrical characteristics and signal timing requirements. This ensured optimal matching between the controller and the memory package during high-speed operations. For differential-pair lines, a 90 Ω impedance was applied to USB 2.0 data lines, in accordance with the USB specification for balanced signal propagation and low noise. In the case of LPDDR4 high-speed synchronization signals, such as DQS and CK lines, a 100 Ω differential impedance was applied to maintain stable timing alignment and reduce skew during memory access.
The impedance matching results for each signal type are summarized in Tables 1 and 2, numerically verifying the impedance values targeted during the layout design phase. This impedance design strategy effectively suppressed reflections and minimized transmission delays, thereby guaranteeing signal fidelity under high-speed operating conditions, making it suitable for automotive-grade V2X communication systems.
Impedance matching layout for single-ended, high-speed traces on the multilayer PCB used in V2X communication equipment
Impedance matching layout for differential-pair, high-speed traces on the PCB design used in V2X communication equipment
IV. Architecture and Core Features of the V2X Software Stack
This section introduces the architecture and core functionalities of a software stack designed for V2X systems that enables both V2V and V2I communications. The proposed V2X software complies with major standards, including IEEE 802.11, IEEE 1609.2 and 1609.3 [10, 11], 3GPP Release 14, and SAE J2945/1. The software was designed to run on Linux-based embedded systems, and can be implemented as a shared library operating in user space. The stack comprises three main components: standard-compliant V2X protocol libraries, utility programs for device control and testing, and sample applications for developer reference. This modular design offers flexibility and portability across a wide range of hardware platforms. Furthermore, to facilitate efficient packet handling, the software provides common data structures, such as V2X_PacketParseData, that can manage parsed message content in an integrated manner. This allows higher-level applications to process data efficiently without being tightly coupled to protocol-specific parsing logic. This section systematically describes the entire architecture and each component of the V2X software, focusing on functional roles, implementation methods, and practical usage in embedded environments.
1. j2945/1 Library for Designing SAE J2945/1-Based V2X Services
The j2945/1 library is a core software module that supports V2X communication services in compliance with the SAE J2945/1 standard. The library is primarily responsible for the transmission and reception of basic safety messages (BSMs). It also integrates additional functionalities, such as GNSS data processing, vehicle status recognition, hard-braking event detection, and identity/certificate management. BSMs are transmitted periodically, and applications receive incoming messages by registering a callback function. GNSS data are collected via the ZED-F9K module, and acceleration values are corrected using a Butterworth filter to reduce noise. The system also incorporates time synchronization and buffer structures to minimize transmission and reception latency. The message structure includes path history and path prediction fields, as defined in the SAE J2735 standard, which describe a vehicle’s recent trajectory and anticipated movement, respectively. When a hard-braking event is detected, this information is appended to the outgoing BSM to enhance situational awareness among nearby vehicles. Furthermore, for secure communication, ID and certificate replacement are performed automatically under predefined conditions. Additionally, the library provides interfaces for receiving user-defined data externally, supporting flexible integration with high-level applications. Designed for both conformance with the SAE standard and practical usability in test and real-world vehicular environments, the j2945/1 library serves as an essential module for high-reliability V2X communication services (Fig. 3).
Software architecture of the SAE J2945/1-based V2X message handling library in the V2X communication system.
2. dot2 Library for Designing IEEE 1609.2-based Secure Messages
The dot2 library is a security module designed to support secure message handling in V2X communication systems based on the IEEE 1609.2 standard. It performs key functions within the V2X security framework, including certificate management, message signing and verification, and security profile configuration. At the core of its architecture is the crypto material handle (CMH), which is a structure that manages in-device security credentials. To reduce runtime overhead, a file-based cache variant called CMHF can also be implemented. The library provides interfaces for generating and verifying secured protocol data units (SPDU) to verify the integrity and authenticity of V2X messages. Additional features include certificate revocation checking using certificate revocation lists (CRL), security policy management through configurable security profiles, and support for both software- and hardware-based cryptographic operations, including OpenSSL and HSM. Designed to support multi-certificate environments and real-time security requirements, the dot2 library functions as a critical module for ensuring the trustworthiness and robustness of V2X communication systems under operational conditions.
3. dot3 Library for Designing IEEE 1609.3-based V2X Messages
The dot3 library is a software module designed for processing V2X messages in compliance with the IEEE 1609.3 standard. It equips upper-layer applications with a set of APIs that help implement essential V2X communication functions, including message generation and parsing, service registration, channel configuration, and message filtering, based on application requirements. The initialization process for this module is performed using the Dot3_Init API, which sets up internal message and service management tables. In addition, it automatically registers default provider channel information (PCI) for 13 frequency channels corresponding to the V2X spectrum allocated in Korea. The library supports both WAVE short message (WSM) and MAC protocol data unit (MPDU) formats encoded in the ASN.1 UPER format. Furthermore, the Dot3_ConstructWSM and Dot3_ParseWSM APIs can be used to generate and parse WSMs, while Dot3_Construct WSMMPDU and Dot3_ ParseWSM MPDU handle encapsulated MAC-layer messages. The library is also responsible for handling WAVE service advertisement (WSA) messages. It creates WSA messages containing service information and processes received WSA messages to determine the available services (UAS). The decision to register or invalidate a UAS entry is based on parameters such as the received channel power indicator (RCPI) and frequency of WSA reception. Service management in the dot3 library is performed through five key data structures: WSR for filtering received messages based on PSID, PSR for registering provided services, PCI for defining radio channel parameters, USR for managing user service requests, and UAS for maintaining the available services generated from the received WSA content. UAS entries are evaluated periodically using an internal timer mechanism to maintain their validity over time. Moreover, all operations can be terminated through the Dot3_Release API, which releases internal resources and stops associated timers. This library is a core component of the V2X communication software stack and plays a vital role in ensuring reliable, standard-compliant operations in autonomous driving systems.
4. LTE-V2X HAL Library for Designing 3GPP Release 14-based Communication
The libltev2x-hal.so library provides a hardware abstraction layer (HAL) for implementing LTE-V2X communication functionality in accordance with the 3GPP Release 14 specifications. Designed to interface with the SECTON V2X modem, this library offers a set of APIs that handle essential communication tasks, including module initialization, packet transmission and reception, MAC address configuration, transmit flow registration, and callback management. The transmission function supports both semi-persistent scheduling and ad-hoc modes, allowing dynamic resource allocation and transmission prioritization based on the selected mode. Meanwhile, packet reception is managed through an internal thread that delivers received MAC service data unit (MSDUs) to the application layer via user-registered callback functions, ensuring low latency and real-time responsiveness. For module authenticity and security, the library includes a module identification mechanism for verifying a unique encrypted ID stored in the device’s EEPROM. This serves to enhance the system’s trust model by enabling proper hardware–software pairing and preventing unauthorized device usage. Built with a focus on flexibility and scalability, the LTE-V2X HAL library can potentially be extended to support other LTE-V2X chipsets. It is optimized for delivering robust performance in real-vehicle deployments, thus serving as a foundational component for building reliable and secure V2X communication systems.
5. Test Software Design for Message-based Performance Evaluation in LTE-V2X Systems
This section describes the structure and operational mechanisms of the test software developed to quantitatively evaluate message-based communication performance in LTE-V2X environments (Fig. 4). The operation of the proposed system is based on message exchanges between a test system (TS) and a device under test (DUT), where probe vehicle data (PVD) messages are used to collect reception logs and compute the PER. In this study, the PVD message is defined based on the SAE J2735 [12] standard and implemented in ASN.1 format. It includes a msgLogs field capable of storing up to 20 reception records. The DUT records the received messages in the PVD structure at one-second intervals and transmits them to the TS. The TS then analyzes the reception timestamps and identifies any missing messages to calculate the PER. Notably, PER is defined as the ratio of lost packets to the total number of transmitted packets (the sum of received and missing messages). PER calculation was performed with high precision by analyzing timing intervals based on message reception timestamps and transmission intervals. The proposed software supports both TS and DUT modes, and allows configuration of various parameters, such as PSID, transmission interval, and logging level (Fig. 5). Designed for flexibility, the tool can be applied in both realvehicle environments and simulation-based testing setups. Overall, this test software serves as an effective tool for quantitatively assessing message-level communication quality in LTE-V2X systems, and is suitable for use in field validation and standard compliance testing.
Functional structure of the module identification system implemented in the LTE-V2X hardware abstraction layer library.
Test architecture for evaluating packet error rate based on probe vehicle data messages in a V2X communication system.
V. Implementation of Electromagnetic Environment Solutions for V2X in Real-Vehicle Conditions
The objective of this study is to establish a performance evaluation framework for V2X communication systems in autonomous vehicles and to implement a corresponding EMC testing environment (Fig. 6). Accordingly, the primary task is constructing an on-vehicle EMC test environment consistent with EN 301 series standards that enables performance verification and conformity assessment of V2X communication equipment. For this purpose, a real-vehicle EMC evaluation was conducted in the full anechoic chamber at the Korea Transportation Safety Authority (KATRI). The chamber’s dimensions are 20.0 m × 13.0 m × 7.0 m. This facility provided a controlled environment suitable for measuring the emission and immunity characteristics of automotive electronic devices under standardized test conditions.
Implementation scheme for in-vehicle electromagnetic compatibility evaluation of V2X communication systems.
1. DSRC EMC Environment Implementation
The DSRC for V2X systems is based on the IEEE 802.11p standard, which has been designed to support low-latency and high-mobility vehicular networking. In this study, the DSRC test environment was configured with reference to the EN 301 489-17 [13] standard. The evaluation criteria were maintaining a PER below 10% at 20 dBm transmit power and −62 dBm (±6 dB) receive sensitivity.
2. C-V2X EMC Environment Implementation
C-V2X based on LTE side-link communication provides high reliability and low latency, which are integral for safety-critical vehicular applications. The real-vehicle EMC test for C-V2X was set up in compliance with the EN 301 489-52 [14] standard. The evaluation threshold was established as 5% or less PER at a maximum transmit power of 23 dBm and a receive sensitivity of −71.1 dBm (±3 dB).
3. Implementation of GNSS EMC Environment
GNSS is a critical component of location-based services in autonomous driving. The real-vehicle EMC environment for GNSS was implemented with reference to EN 301 489-19 [15], with a target input level of −108 dBm (±3 dB) in the GPS L1 frequency band.
VI. EMC Test Results and Discussion
Radiated emission (RE) and radiated immunity (RI) tests were conducted to verify the EMC of the dual-mode V2X communication equipment and to quantitatively analyze the impact of EMI on actual communication performance. Table 3 summarizes the real-vehicle EMC test configurations, which were established in accordance with the CISPR 12 [16] and ISO 11451-2 [17] standards to simulate a realistic driving environment.
Summary of real-vehicle EMC test configurations
1. Radiated Emission Test Analysis
The RE test was performed in accordance with the CISPR 12 standard. The results are shown in Fig. 7 (narrowband) and Fig. 8 (broadband).
Radiated emission test results of the V2X communication equipment measured in the narrowband frequency range, conducted in a full anechoic chamber in accordance with the CISPR 12 standard.
Radiated emission test results of the V2X communication equipment measured in the broadband frequency range, conducted in a full anechoic chamber in accordance with the CISPR 12 standard.
In each graph, the x-axis represents the frequency (MHz), and the y-axis denotes the electric field strength (dBμV/m), with the red solid line indicating the regulatory limit. The measurement results confirm that the proposed device satisfied the regulatory thresholds across all frequency bands, maintaining a compliance margin of 2–6 dB in most areas. A peak value approaching the limit line was observed in the low-frequency range (30–100 MHz), which can be attributed to common-mode currents from the vehicle’s power supply and cable harness. Nevertheless, the maximum value remained approximately 2 dB below the limit, confirming that the system could operate reliably within specified limits under real-vehicle conditions (Fig. 9). Table 4 provides a quantitative summary of the compliance margin for the V2X equipment’s RE, which was tested according to the CISPR 12 standard.
Real-vehicle radiated emission test environment of the V2X communication system in a full anechoic chamber.
Compliance margin of the V2X equipment in RE testing
2. Radiated Immunity and V2X Performance Impact Analysis
The RI test was designed to evaluate the impact of external EMI on V2X communication quality (Fig. 10). Electric field strengths up to 30 V/m were sequentially applied across the 20–2,000 MHz range under both vertical and horizontal polarizations, while PER, latency, and throughput were monitored in real time. The PER remained at 0% throughout the entire test, indicating no packet loss, even under maximum EMI exposure. Table 5 provides a detailed statistical summary of the results, including confidence bounds, confirming that device performance remained well below the acceptance thresholds for DSRC (10%) and C-V2X (5%). The average latency stayed constant at 7.5 ms (±0.3 ms), while the throughput remained stable at 6 Mbps, with a coefficient of variation of 2.1%. More importantly, no communication degradation was observed, even when GNSS reception and WAVE/LTE-V2X message exchange occurred simultaneously.
Real-vehicle radiated immunity test environment for the V2X communication system in a full anechoic chamber.
V2X performance under RI testing
VII. Conclusion
In this study, the EMC of a V2X communication device was evaluated in a real-vehicle environment. By conducting RE and RI tests, the impact of EMI on actual communication performance was quantitatively analyzed.
The RE test results confirmed that the proposed system satisfies the regulatory limits across all frequency bands. Although peaks approaching the limit line were observed in some low-frequency regions, they remained stable within specified limits, verifying that the system could be safely operated in a real-vehicle environment.
In the RI test, a PER of 0% was maintained under electric field strength conditions of up to 30 V/m. Furthermore, no difference in communication latency and throughput was observed before and after the test. In addition, no performance degradation occurred even under complex conditions, such as when GNSS reception and WAVE/LTE-V2X message exchange were performed simultaneously.
These results confirm that the proposed device not only complies with EMC specifications but also guarantees stable V2X quality of service in real driving environments. Furthermore, the EMC robustness validation conducted in this study has significant implications for future autonomous driving technologies. Level 4+ autonomous driving systems completely rely on cooperative perception and decision making via V2X, which means that communication disruption in such contexts is unacceptable. The results of this study prove that the proposed system is suitable for such safety-critical environments. Moreover, the evaluation methodology shows potential for scalability to multi-vehicle cooperative scenarios, such as platooning, where electromagnetic robustness and reliable connectivity are indispensable.
Overall, this study experimentally proves that EMC evaluation is a key element in the verification of V2X communication reliability, and it can serve as a valuable reference for future certification and standardization research on V2X systems in autonomous vehicles.
Notes
This work was supported by the Korea Agency for Infrastructure Technology Advancement (KAIA) grant funded by the Ministry of Land, Infrastructure and Transport (Grant No. RS-2021-KA162963).
References
Biography
Seung-Kyu Choi, https://orcid.org/0009-0007-3006-1487 received his B.S. degree in electronic engineering from Hanseo University, Korea, in 2009. He is currently a senior engineer in the Automotive Electronics R&D Center at Highgain Antenna Co., Ltd., located in Ansan, Korea. His current research interests include the design and development of V2X communication systems and patch antennas for electronic toll collection systems (ETCS).
Ju-Won Lee, https://orcid.org/0009-0005-0230-4184 received his B.S. degree in electronic engineering from Cheongju University, Korea, in 1998. He is currently a principal engineer in the Automotive Electronics R&D Center at Highgain Antenna Co., Ltd., located in Ansan, Korea. His current research interests include the design of V2X communication systems and rear occupant alert (ROA) systems for automotive safety applications.
Jong-Ho Kim, https://orcid.org/0009-0009-4352-2857 received his B.S. degree in computer engineering from Konyang University, Korea, in 2005. He is currently a principal engineer in the Automotive Electronics R&D Center at Highgain Antenna Co., Ltd., located in Ansan, Korea. His current research interests include software development for V2X communication systems and electronic toll collection systems (ETCS).