Automotive Radar Systems
Prof. Dr. Hermann Rohling, Hamburg University of Technology
Driving a car is a dangerous task! There are about 5000 fatalities on German streets every year, which are absolutely too many. Drivers have strong limitations in the ability to measure precisely the distance and the speed difference between cars, which is the reason for several accidents. The all-weather-capability as well as the capability of measuring target range and radial velocity simultaneously are some of the essential features, which make radar systems suitable for automotive applications.
Radio Detection and Ranging (RADAR) is a worldwide well-known sensor technique since more than 110 years. Collision avoidance between ships was the first application for this new technique. Today we come back to the collision avoidance application however now between cars in a normal road environment.
The general requirement on an automotive radar sensor in the 24 and 79 GHz frequency domain is to measure the target range R and radial velocity vr simultaneously and unambiguously with high accuracy and resolution even in multi target situations, which is a matter of the appropriate waveform design. Several new waveforms have been developed for this application in the last years. In any continuous wave (CW) radar the receive signal is directly down-converted into baseband by the instantaneous transmit frequency. The receive signal is then sampled and further processed for target detection and parameter estimation. The resulting beat frequency fB will be measured with high accuracy by an FFT procedure.
The aim of the tutorial is to introduce multiple CW waveforms and describe their performance figures. With a single chirp waveform for example the target range and radial velocity cannot be measured in multiple target situations. Therefore several alternatives have been developed to fulfill the given requirements. Chirp sequence waveforms show good performance figures in this respect. The computation complexity will also be discussed.
Prof. Dr. Hermann Rohling is the Head of the Institute of Telecommunications at Hamburg University of Technology, where he has developed an international reputation for mobile communications and automotive radar systems. Prof. Rohling has started his career at the AEG Research Institute, Ulm, Germany, as a researcher working in the area of digital signal processing for radar and communication applications. Nowadays his research interests include signal theory, radar waveform design, digital radar signal processing, detection, and estimation. He is the inventor of the OS-CFAR technique and for the new waveforms for automotive applications. But his research interest covers also wideband mobile communications based on multicarrier transmission techniques (OFDM) for future broadband systems (4G), and differential GPS for high precision navigation. He is a worldwide well-known expert in automotive radar systems for more than 20 years.
Prof. Rohling is the President of the German Institute of Navigation (DGON), a member of Informationstechnische Gesellschaft (ITG), and a Fellow of IEEE. Every year he is the organizer and chairman of the International Radar Symposium (IRS). Prof. Rohling was the Vice President of the Hamburg University of Technology, Germany for more than six years.