高速多通道CCD图像数据处理与传输系统设计

Design of High-Speed and Multi-Channel CCD Image Data Processing and Transmission System

针对航天光学遥感成像系统输出通道多、输出速率高的特点,提出一种高速、多通道CCD图像数据并行处理与传输系统的设计方案。该方案以FPGA为数据处理和控制核心,采用基于FPGA区域并行处理的数据处理方法,运用FPGA内部块RAM构建高速多通道CCD图像的缓冲区,在存取控制上采取区域缓存和时分复用的策略完成对高速多通道CCD图像数据的实时处理;而对高速多通道CCD图像数据的传输采用基于Channel link高速差分串行传输技术,以高速差分串行的LVDS(Low Voltage Differential Signal)数据流替代传统的并行"TTL/COMS"信号进行传输,使系统高速传输能力大大加强,并且功耗低,抗干扰能力强。研究结果表明,该设计具有较好的稳定性、灵活性和通用性等,并已成功运用于某40通道高速CCD成像系统中,系统并行处理和传输的总数据率高达7.68Gbit/s。

In order to solve the problem that the data output of space optical remote sensing imaging system is multi-channel and high rate,a new design scheme for high-speed and multi-channel CCD（Charge Coupled Device） image data parallel processing and transmission system is proposed.The design uses field programmable gate arrays（FPGA） for the data processing and logic control.For high speed and multi-channel CCD image data processing,the paper adopts regional parallel processing based on FPGA.The FPGA inner block RAM is used to build high speed image data buffer and time-division multiplexing is put into operation to achieve high speed multi-channel image data integration and real-time processing.For high-speed multi-channel CCD image data transmission question involved,the paper analyzes in-depth low-voltage differential signal and high speed differential serial transmission technology,and put it in practice.Those technologies enhance the system high-speed transmission capacity,and lower power consumption,strengthen anti-interference ability.The result shows that the design has good stability,flexibility and versatility,which has already been successfully used in a 40-channels high-speed CCD imaging system with the data rate up to 7.68 Gbit/s.