8mm LFMCW Short-range Detection System Signal Detection And Processing

In this paper,an 8mm band LFMCW short range detection system based on triangular wave modulation is used as the application background.The signal processing part of the detection system is mainly studied focused on real-time ranging algorithm and hardware and software.The design scheme of the LFMCW short range detection system is proposed and the range principle of the detection system under the symmetrical triangular wave modulation is discussed.The selection principle of the relevant parameters of the system is analyzed and the influencing factors on the ranging performance are discussed.According to the linear relationship between the frequency signal and the target distance of the detection system,changing the object from frequency measurement to the ranging measurement."frequency-FFT" is a common method to process frequency measurement work in the Millimeter-wave frequency modulation detection system.However,the limitation of sampling rate and the inherent FFT effect of the fence makes the actual ranging accuracy low."Zoom FFT" algorithm can improve the accuracy of ranging to a certain extent.The algorithm analyzes the local area spectrum in detail resulting in the much more accurately estimate about the frequency of signal frequency.However,it can be found that computation of the complex modulation is complicated by the analysis of the Zoom FFT algorithm.The result may affect the real-time performance of the detection system and the effect of the fence effect still exists.In order to solve the problem,an improved high-precision real-time ranging algorithm based on the Zoom FFT algorithm is proposed in this paper.According to the related projects requirements,the TMS320VC5509A chip produced by TI Company is used as the core,designing the hardware circuit of the signal processing system.Three major functional modules of the DSP control are achieved in the condition of CCS development environment according to the C Language programming.The hardware and software reconfiguration of the entire FM ranging system,the debugging scheme and results of each module are given at last.The experimental dates are analyzed in detail to verify the effectiveness and feasibility of the system hardware and software design and related algorithms.