Advanced Signal Processing for Automotive Radar Systems

Abstract

Recently, as automobile safety has been receiving considerable public attention, sensors devised for automobiles, such as sonar, vision, lidar, and radar systems, have become significant. Among these sensors, the radar is robust to harsh environmental conditions, such as no-light conditions or bad weather. The automotive radar systems, mounted on automobiles, perform special functions such as adaptive cruise control, autonomous emergency braking, and blind spot detection for driver safety and convenience. <br/> <br/> In this dissertation, advanced signal processing techniques for automotive radar systems are proposed. In general, frequency-modulated continuous wave (FMCW) radar systems are widely used for automotive radars. The main purpose of using the automotive FMCW radar is to extract the information of targets, such as relative distances, relative velocities, and angles. In automotive radar systems, estimating the angle of the target is a challenging problem because the number of receiving antenna elements is limited. Therefore, an enhanced target angle estimation method using signal-to-noise (SNR) compensation or array interpolation is proposed in this dissertation. In addition to basic target detection, automotive radar systems aim to perform more advanced functions. For example, the automotive radar should be able to classify the detected targets. Thus, a method to classify the targets, such as pedestrians, cyclists, and vehicles, is proposed in the dissertation. In addition, target detection performance of the automotive radar can be degraded in road structures, such as iron tunnels and soundproof walls. Therefore, this dissertation proposes a method to recognize such road structures and to suppress their adverse effects. Moreover, as the number of radar-equipped vehicles increases in the near future, mutual interference among automotive radars can cause a serious problem because it degrades the target detection performance. Therefore, a method for mitigating the mutual interference is also proposed in this dissertation.