Radar waveform for automotive radar systems and applications

This paper describes three different continuous wave (CW) radar waveforms which are applied in automotive radar sensors. The radar sensor should be able to detect all objects inside the observation area and to estimate range, radial velocity and azimuth angle simultaneously even in multi target situations. A classical Linear Frequency Modulation (LFM) waveform provides a very high range and velocity resolution. But in multiple target situations so-called ghost targets will occur. Alternatively, a Frequency Shift Keying (FSK) waveform delivers a very high velocity resolution and avoids any ghost target situation but will not resolve targets in range direction. Finally, a combination between LFM and FSK provides simultaneously a high range and velocity resolution, extremely short measurement time and avoids any ghost target situation. It combines the advantages of both FSK and LFM waveforms. In all three cases the azimuth angle estimation is based on two receive antennas and the monopulse technique.