The Research Of Wavelet Transform Based On DSP In Radar Echo Signal Denoising

With the rapid development of high-tech, radar has been widely used in People’s Daily life.The application of radar domain has rapidly expanded from the initial military field to the weather forecast, resource exploration, environmental monitoring, industry and other fields.FMCW radar level instrument is widely used in the field of industrial production, which is mainly used for measure such as chemical industry, petroleum, cement and other material storage tank material. Because the radar level meter system is complex and the radar ranging environment differs in thousands ways, there is a lot of clutter, such as white noise, ground clutter and heat noise signal generated from the system hardware itself in the acquisition of the radar echo signal. Those signals affect the extraction of main frequency signal, which inevitably affects the precision of radar level meter instrument. When the situation is serious,they can cover the main frequency signal, which makes the radar do not work. Therefore, the research of radar echo signal in noise signal noise reduction is of great importance.This paper is mainly centered on the echo signal of FMCW radar level instrument which adopts the method of wavelet transformation noise reduction based on DSP. According to studying the main factors that affect the precision of radar ranging, and the characteristics of the radar echo signal, the time-frequency characteristics of wavelet transform is applied to echo signal noise reduction processing. With the same time, this paper designs the radar echo signal wavelet denoising system based on DSP.First, a brief introduction to the basic theory of wavelet transform is given, which laid a theoretical basis for the full text. After analyzing the main factors affecting radar ranging,this paper processes the echo signal adopting the method of synchronizing signal to retrace,which can reduce the clutter. This paper compares the high frequency coefficients of wavelet threshold denoising method of zero, the default threshold method and the hard or soft threshold method through experiment result, finally determines the optimal threshold denoising method, namely, compromise threshold denoising method, which is the innovation of this article. Finally, this paper gives the corresponding processing flow diagram, realizes the simulation processing on CCS3.3, and compares with the Matlab simulation data, the final results show that the echo signal of wavelet denoising realized by using DSP processing not only can well remove the noise in the radar echo signal, but also can satisfy the system real time requirements.