Millimeter-Wave Radar Scheme With Passive Reflector for Uncontrolled Blind Urban Intersection

Abstract

Modern millimeter-wave automotive radars are employed to keep a safe distance between vehicles and reduce the collision risk when driving. Meanwhile, an on-board radar module is supposed to operate in the line-of-sight condition, which limits its sensing capabilities in intersections with obstructed visibility. Therefore, this paper investigates the scheme with passive reflector, enabling the automotive radar to detect an approaching vehicle in the non-line-of-sight (blind) urban intersection. First, extensive radar measurements of the backscattering power are carried out with the in-house assembled millimeter-wave radar equipment. Next, the measured data is employed to calibrate an accurate analytical model, deduced and described in this paper. Finally, the analytical models are deployed to define the optimal parameters of the radar scheme in the particular geometry of the selected intersection scenario. Specifically, it is found that the optimal angular orientation of the reflector is 43.5°, while the 20 m curvature radius shows better performance compared to a flat reflector. Specifically, the curved convex shape increases scattering power by 20 dB in the shadow region and, thus, improves the detection probability of the vehicle, approaching the blind intersection.

Holistic Enlightening of Blackspots With Passive Tailorable Reflecting Surfaces for Efficient Urban mmWave Networks

“…Using several reflectors with optimized deployment, it has further been shown that even a less dense mmWave site deployment becomes feasible, even when using simpler non-reconfigurable passive reflectors [35]. Whereas these can also be deployed in the scope of 6G-enabled sensing services, as shown in [36], passive reflectors are typically considered for communication-centric purposes in the literature due to their simplistic set of features compared to other approaches, cf. Table I.…”

A millimeter-wave automotive radar with high angular resolution for identification of closely spaced on-road obstacles

“…Compared with LiDAR (light detection and ranging), cameras and optical sensors, the cost of millimeter-wave radar is low, since it only consists of an integrated circuit (IC) and printed antennas. Moreover, compared to traditional camera imaging systems, millimeter-wave radars are more effective in bad weather conditions (fog and rain) and nonline of sight (NLOS) target detection (curves on roads) 3,4 . Frequency-modulated continuous wave (FMCW) and fast chirp modulation (FCM) radars can be used to inherently measure ranges and relative velocities between a radar and targets 5,6 .…”