遥感相机快视高速可靠传输系统的设计与实现

针对遥感相机数据输出速率较高、快视系统传输带宽不足的问题,提出了一种基于万兆网的高速可靠传输系统并加以实现。传输系统前端采用FPGA作为主控制器,在其内部构建可靠传输协议栈,通过确认重传算法实现高速数据的UDP可靠传输,并通过流量控制机制提高传输效率。由于重传算法需消耗较多缓存资源,采用DDR3多端口控制器对传输协议栈中已发送但未被确认的数据帧进行缓存,同时对前端高速数据流进行速率平滑,减少FPGA片上RAM资源使用率。实验结果表明:当上位机CPU负载较小时,传输系统可可靠传输高达1 000 MB/s的连续数据流;当CPU负载较大时,传输速率亦在600MB/s以上。系统传输速率高,工作稳定,扩展性强,已成功应用于遥感相机快视系统中,为超高速遥感相机的研制测试提供了保障。

Design and implementation of high speed and reliable transmission platform in fast view system

Aiming at the problem of the high data rate of remote sensing satellite cameras and the insufficient transmission bandwidth of fast view system, a new high speed reliable transmission system based on 10 Gb/s Ethernet was proposed and performed. The front end of the transmission system adopted FPGA as the main control unit that constructed the reliable transmission protocol stack. The transmission system achieved the reliable transmission for high speed data stream by ack-resend algorithm and flow control in application layer. The DDR3 multi-port front end was used to cache the frames that had been sent but not acknowledged at the transmission protocol stack due to that retransmission algorithm needed to consume more cache resources. The high speed data stream of the front end was smoothed at the same time. Experiment results indicate that the transmission system can transform reliable high speed data stream up to 1000 MB/s when the CPU load is small; When CPU load is heavy, the speed reduces to 600 MB/s. This system works at high speed with reliable performance, and costs low, and it is easy to expand to multi-channel transmission system. It has been successfully applied in a fast view system.