Anti-interference Signal For Collision Avoidance Radar Based On Embedded System

Since 1960s-1970 s, radar technology has been applicated in civil economy which the automotive collision avoidance radar has been the rapidest development, and modern vehicles equipped with radar system has become an inevitable trend. But for the reason of limied spectrum bandwidth using for automotive radar, single type of waveform and increment of the quantity of car year by year, the automotive radar systems adopting millimeter wave as signal source inevitably interfere with each other that causing the interfering system and interfered system can not work properly with misjudgment and false alarm, and reducing safety radar systems. This kind of system will be affect people’s living and property safety and car radar interference problem when the radar in the work process begins to receive widespread attention of scholars and engineers. Thus, it’s greatly significant to make research of generation and processing of anti-interference signal at automotive advanced driver assistance systems(ADAS) using a proprietary computer functions of embedded systems. In order to improve the ability of anti-interference and process automotive radar signals properly in onboard radar system, the paper has carried out in the following studies.This paper describes the current situation between the millimeter-wave automotive radar systems interfering with each other, and future problems, and discusses signal waveform forms and existing automotive radar system design using frequency modulated continuous wave which is Frequency Modulating Continue Wave, including anti-car hit the radar of the performance index, the working band, detection methods and other issues.Then the velocity and distance principle of radar system were described, radar signal generation method was analyzed, the principle of interference among signals were discussed in general radar system and the method of anti-interference and generating anti-interference signal was paid much attention. Comparing and analyzing the way to generate signal using MCU, FPGA, PLL or any combination of two of the components, we use Arm microprocessor of embedded system and digital frequency synthesizer to generate anti-interference signal relative simply which can save time costing, increase its flexibility and on this basis, can generate anti-interference arbitrary waveform by modifying code on the host computer side.Finally, the designed signal source was applied to radar systems design and echo signal is collected and processed. After making a detailed comparison and explanation from interference, phase noise and randomcity, we can conclude that the design of arbitrary interference signal based on embedded system can effectively suppress the interference between the growing popularity of automotive radar and the resolution of the target has been significantly improved. And the distance and velocity can be detected relatively accurate using the FFT spectrum after processing the radar signal. This technology has a broad prospect in automotive applications for advanced driver assistance systems.