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In the European Union, with approximately 567 vehicles per thousand inhabitants and an average vehicle mileage of 28,000 kilometers annually, vehicles are significant for people's mobility. As automation in the automotive industry continues to advance, enhancing safety for passengers, energy efficiency, and driving experience is essential. For this purpose, vehicles are equipped with several systems that assist the driver, resulting in an automated vehicle. Two key technologies on the path to fully automated vehicles are radar and vehicular-to-everything (V2X) communication technologies. Both V2X and radar are essential for the development of autonomous vehicles. Their combination could even unlock a new realm of possibilities. Franz Lampel’s PhD research has given insights in this combination.  

Modern cars are fitted with radar, lidar, or cameras, enabling advanced driver-assistance systems such as obstacle recognition, blind spot detection, lane departure warning, or traffic sign recognition. The ongoing automation of vehicles aims to eventually achieve full autonomy without requiring driver interaction. Nowadays, vehicles typically feature multiple radars, sometimes up to ten, positioned around the vehicle. These radars collectively create a ‘cocoon’ effect, enabling continuous environmental monitoring. The integration of V2X communication enhances the capabilities of automated vehicles by providing additional information beyond onboard sensors. For instance, radar offers some angular selectivity, while V2X broadcasts messages in all directions. If radar could also communicate, it could serve as a complementary communication method. This would establish directional links between vehicles, potentially reducing the risk of interference and enhancing the overall safety of autonomous driving. Moreover, V2X allows for cooperative driving, where vehicles collectively plan and execute maneuvers, effectively increasing efficient and safe traffic.

Single waveform

This thesis revolves around the question of how radar and V2X communications technology can be combined into a single waveform, a so-called joint radar and communication(JRC) waveform. Firstly Franz Lampel focused on a radar-centric approach, that is, modifying radar to concurrently serve as a radar and communication waveform. In particular, he investigate the potential use of frequency-modulated continuous wave (FMCW) radars, the defacto state-of-the-art radar technology for automotive radar, as a JRC waveform. A FMCW-based JRC waveform was created by mixing the radar waveform with a communication waveform. To avoid interference of the communication signal in the radar processing, a novel processing technique that allows the radar receiver to separate the two waveforms again on receive was developed.

Reduce computational complexity

The second part of the thesis shifts to a communication-centric approach by utilizing a recently introduced communication waveform, orthogonal time frequency space (OTFS) modulation, as a JRC waveform. OTFS has been motivated by challenges encountered in communication in high-mobility scenarios. The researcher provided a complete description of OTFS by utilizing the so-called Zak transform. The Zak transform provides the foundation of OTFS and establishes a direct link between OTFS and so-called pulse-Doppler radars. Thus, OTFS inherently features JRC capabilities. The bottleneck of OTFS in its practical application, however, is its computational complexity. Novel techniques were developed that substantially reduce complexity for both radar and communication processing of OTFS.

Project

i-CAVE (P4) funded by NWO.

Title of PhD thesis: . Supervisors: Prof. Frans Willems and Prof. Alex Alvarado.