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Recently, the autonomous driving industry in China has been gradually shifting its focus from individual-vehicle intelligence to vehicle‒infrastructure cooperation. This shift has brought significant opportunities for the intelligent transportation industry. Although research on vehicle‒infrastructure cooperative sensing is still in its early stage in China, it shows a strong dedication to technological innovation, indicating significant potentials for future growth. This study examines the development status of vehicle‒infrastructure cooperative sensing and thoroughly explores the characteristics and status of core technologies that support vehicle‒infrastructure cooperative sensing. It discusses ongoing advancements in this field, investigates future technology trends, and proposes a range of recommendations for further development. Research indicates that vehicle‒infrastructure cooperative sensing is evolving toward the integration of multi-source data. Presently, its development directions mainly focus on the optimization of pure visual cooperative sensing, upgrades in LiDAR point cloud processing, advancements in multi-sensor spatiotemporal information matching and data fusion, as well as the establishment of a standards system for vehicle‒infrastructure cooperative sensing technologies. To further boost the rapid growth of vehicle‒infrastructure cooperation in China, increasing investment in the research and development of relevant technologies is advised. Enhancing partnerships among different industry sectors, establishing unified standards for processing perception data, and expediting the broad application of these technologies are also key recommendations. These strategies aim to position China advantageously in the global market of autonomous driving, contributing to the sustainable development of the industry.

Smart highways are vital for actively coping with various challenges regarding traffic safety, operation efficiency, service level, and management capabilities of current road networks, and for realizing the high-quality development of road networks in China. This study clarifies the implications and characteristics of smart highways and proposes an overall structure of smart highways based on national conditions and development realities. Subsequently, it summarizes the development status of smart highways in China, clarifies the development challenges in terms of cognition and planning, standards and norms, policies and regulations, and governance mechanisms, and proposes the short-, medium-, and long-term goals of smart highway construction in China. Moreover, key tasks for smart highway construction in China include intelligent construction, infrastructure digitization, automatic driving based on vehicle – road collaboration, new-generation intelligent systems for highway tax and fee collection, intelligent maintenance, intelligent service areas, intelligent emergency response, and integration of infrastructure, communications, energy, and service networks for intelligent highways. Further efforts should focus on the formulation of industry guidance documents, improvement in collaborative promotion mechanisms, development of standards and norm systems, study of highway mileage tax reforms, and implementation of supportive industrial policies and measures. Results of this study are systematic, forward-looking, and implementable, and are hoped to promote the healthy development of smart highways and deepen the research and application of relevant technologies.

A hybrid solar and RF energy harvester is proposed for applications in self-powered wireless sensor nodes. A planar slot antenna array backed by substrate integrated waveguide (SIW) cavity is produced for RF energy harvesting. A designed rectifier connected to the antenna array converts the received RF energy into DC energy. Solar cells are placed on the rest of the antenna array except slots, fully utilizing the array's surface. The solar cell coverage ratio reaches 87%. The measurement results indicate that under solar simulator illumination, the solar energy harvester has a short-circuit current of 15.7 A, an open-circuit voltage of 0.542 V, and a maximum output power of 5.81 W. Under the RF power density of 85.5 μW/cm2, the RF energy harvester reaches its peak power conversion efficiency (PCE) of 69%. All simulated and measured results are in good agreement, verifying the capabilities of the designed hybrid harvester. [ABSTRACT FROM AUTHOR]

This paper presents a low-profile reconfigurable antenna array capable of five radiation-pattern modes for vehicular communication applications. The antenna array consists of four antenna elements, each containing four square patches. Exciting one of the square patches generates a broadside radiation. A square parasitic patch is added at the rear of the excited patch, and two square parasitic patches are placed at the front. By optimizing the design of these parasitic patches, including the treatment of center slotting and addition of shorting pins, the antenna element achieves an end-fire beam with a certain tilt angle. On this basis, a reconfigurable feeding network is designed with 1:1 and 1:4 output modes. By connecting the reconfigurable feeding network to the four antenna elements and altering the on/off states of the PIN diodes in the feeding network, a reconfigurable antenna with four end-fire beams and one omnidirectional beam in its radiation pattern is realized. Measurement results demonstrate an excellent impedance bandwidth, radiation pattern, and gain performance in all modes. The four end-fire and one omnidirectional radiation characteristics make it highly suitable for vehicular communication applications. [ABSTRACT FROM AUTHOR]

This paper presents K-band-stepped, double-ridged square horn antennas fabricated by metallic 3D printing technology in copper (85% copper and 15% stannum) and aluminum alloy (89.5% aluminum, 10% silicon, and 0.5% magnesium). Compared with the popular dielectric 3D-printed horn antenna, the metallic counterpart features better mechanical robustness in terms of material. Moreover, the metallic horns are printed in one piece in one run, different from the dielectric horns that are printed in split pieces and electroplated, they simplify the process and thus result in reduced cost. The agreement between the simulation and measurement results verified the antenna's performance. Both the 3D-printed copper and aluminum alloy antenna have an impedance bandwidth across the K-band, with a maximum gain of 13.23 dBi @ 25 GHz and 13.5 dBi @ 24 GHz, respectively. The metallic, 3D-printed horn antennas are preferable alternatives to replace traditionally-fabricated antennas. [ABSTRACT FROM AUTHOR]