Receiving And Processing Method And Implementation Of FMCW AM Laser Array

As an active imaging detection technology,laser 3D imaging can be realized by obtaining the depth information and 3D coordinate information of the detected target.On the other hand,fiber phased array based on lithium niobate phase modulator has the advantage of an extreme high beam scanning rate,and its output light field has multi-beam characteristics.Combining with laser 3D imaging technology,the imaging frame frequency and imaging distance can be further improved.At the same time,the multi-channel data receiving method can effectively improve the data acquisition speed and improve the image frame rate.Therefore,using fiber phased array and linear mode array APD detector as the transmitting and receiving modules of the laser 3D imaging system,employing the FMCW laser ranging mode,can not only improve the imaging frame rate,ranging range and accuracy,but also effectively suppress the background light.Aiming at the problems of large amount of receiving signal channels and long processing time of the 3D imaging system based on fiber phased array,this work presents the design,development,and testing of a multi-channel high-speed signal processing system based on FPGA.Firstly,a high speed serdes transceiver integrated with FPGA,an AD9680 bcpz-1000 chip and the JESD204 B protocol are used to realize the single-channel data acquisition at the rate of 1Gsaps,which meets the data sampling requirements of no less than 750 Msaps.Secondly,the XCKU040-2FFVA1156 I of the Kintex Ultra Scale series of Xilinx Inc.,which is capable of processing eight-channel signals,is selected.The lane rate can reach more than12.5Gbps and meet the requirements of 64-channel signals receiving and processing.Then,the UDP data communication scheme and implementation process are designed.The data transmission requirement of 100 Mbps between each module is realized,as well as the FMCW data demodulation processing of echo data.Moreover,in order to improve the running rate of the imaging algorithm,a DSP-based imaging algorithm processing hardware system is developed.The FPGA data demodulation acquisition board is designed to realize the acquisition and processing of 64-channel echo data,the data acquisition rate is 1Gsaps,and the demodulation processing delay time is 16μs.The remainder of this dissertation then details the testing and analysis of the multi-channel high-speed signal processing system equipped in a laser 3D imaging system.The system was carried out with 8×8 element fiber array and 8×8 element array APD detector as transmitter and receiver,respectively.As a result,the entire imaging system can theoretically achieve a distance resolution of 0.75 m,and the imaging frame rate can reach 30 Hz.The research in this paper can provide a reference for the subsequent design,optimization and system performance testing of similar systems.