Short range automotive radar based on UWB pseudo-random coding

In this paper, a radar system for short range automotive application based on ultra-wideband (UWB) technology is studied. UWB uses very short pulses, so that the spectrum of the transmitted signals may spread over several Gigahertzes. In order to increase, from one part, the resolution in distance of this radar system and to avoid, from another part, multi-users interferences for an optimal detectability, we propose to improve the radar performances by using coding techniques. It consists on spreading out UWB signals by pseudo-noise codes in the transmitter unit. So the transmitted UWB signal is coded by pseudo-random sequences, such as Maximum Length Feedback Shift Register (MLFSR) or Gold codes. The receiver is based on numerical correlation. Many simulations, using different codes lengths, are realised in order to compare different UWB waveforms and to determine the convenient one according to the radar application. It is shown that Gaussian pulse associated to MLFSR code, offers better performance than other pseudo-noise codes, for UWB radar.