Investigation Of FPGA-based Radar Signal Frequency Measurement Systems

Attention is more and more paid to the system of digital radar signal frequency measurement as one of the most important parts of electronic detection system. At present, a lot of digital signal processing chips in digital radar signal frequency measurement systems could not match the high-speed A/D converters. Therefore, based on FPGA and its mode of parallel signal processing, the system of digital radar signal frequency measurement is of important value to match the high speed of A/D converters. Thus, the algorithm design and FPGA implantation of system studied were outlined as follows.First of all, in order to make the needs of speed and precision of digital detection system, signal detection with phase frequency measurement algorithms of the system are respectively carried out based on instantaneous self-correlation theory, unifying phase frequency measurement with FFT-Rife frequency measurement algorithms. The core algorithm of instantaneous self-correlation algorithm firstly was obtained by high speed of the system, and phase measurement and FFT-Rife frequency measurement algorithms then were realized for frequency measurement. The results show that phase measurement of self-correlation signals has a high computing speed and fewer operation times, but lower precise under the condition of small SNR background. The FFT-Rife frequency measurement is more precise than that of self-correlation; however it needs more complex operations and longer time. As a result, the combination of phase frequency measurement and FFT-Rife algorithms could obtain better trade off effect.In order to realize the FPGA hardware algorithms of digital frequency measurement system, employing FPGA and its character of parallel signal processing, Verilog HDL complying program was designed to realize the system. The parallel signal processing character of FPGA and parallel procedure of Verilog HDL could achieve parallel instantaneous self-correlation to some extent. Thus, the speed of the system's operation was improved. In addition, owing to IP cores reuse ability of the FPGA signal processing, interchange of IP core technology, the developing time of system was decreased.The algorithm design and FPGA hardware implantation of this digital radar signal frequency measurement system will lay the foundation of practice methods and technical requirement for the control module of smart microware absorbing structures.