Detection of Vulnerable Road Users based on Spread Spectrum Modulated Millimeter Wave Tags

Vulnerable road users such as pedestrians, cyclists or scooter users have a low radar cross-section and are, therefore, difficult to be detected by the automotive radars due, among other reasons, to the strong clutter in urban environments. To enhance their detection, a semi-passive millimeter wave identification (MMID) tag is proposed. A proof-of-concept prototype at 24 GHz is designed. The MMID tag consists of two MMIC (Monolithic Microwave Integrated Circuit) amplifiers connected between two antennas. To improve tag identification, a spread spectrum sequence based on Barker code is used. A low-power blind-spot Doppler radar installed in the car is used as the reader. Experimental results in urban environments with the tag attached to a scooter are presented.