Novel pulse-sequences design enables multi-user collision-avoidance vehicular radar

A new, so-called chaotic pulse-sequence radar (CPSR) has been developed and implemented for short-range vehicular radar, designed to warn the driver of close-by overtaking vehicles (so-called ´blind-spot´ warning). It employs a novel design of randomized signal generation and processing which overcomes problems of long-range returns from large reflecting structures and high-levels of interference from both similar and dissimilar radars in the same frequency channel/band. The new technique involves generation of long, non-deterministic pulse trains, composed of a large number of successive, relatively-short pulse-sequences having specially designed correlation properties, separated by random gaps. The statistically-defined unpredictability of such composite pulse trains required in a multi-user scenario is derived from a very large number of pulse-sequences processed in the radar receiver to obtain near-vehicle range estimates. Field tests of a prototype radar confirm good and reliable performance of the technique, including its interference rejection capabilities.