Parameter Optimization Analysis of Moving-Average Filtering in FMCW Detection

Relationship between harmonics and distance in frequency modulated continuous wave (FMCW) detection is widely used as a time-domain ranging method, where the envelope extraction part plays an important role, because the envelope quality affects the accuracy and timeliness of the subsequent detection method. In this paper, smoothness and latency are taken as two indices of the envelope quality, and using Moving-Average Filtering (MAF) to extract the envelope in dual-channel harmonic detection is discussed. The MAF parameter-selection algorithm based on mathematical models is proposed to filter a specific high-frequency component and reduce the latency theoretically. The window length and the sampling frequency of the MAF are two parameters discussed in the algorithm. The FPGA simulation result of using the parameters selected by the algorithm and that of using the parameters in another paper are compared, and the amplitude of the high-frequency component and the latency both keep lower when using the parameters selected by the algorithm, proving the effectiveness of the algorithm.