针对深空通信中采用固定速率进行数据传输会影响通信质量和系统吞吐量的问题,提出了一种基于CCSDS协议标准的收发机自适应传输方案。该方案主要根据接收信号的质量,动态地改变数据传输的码速率,即通过实时地估计接收端信噪比,对信号传...针对深空通信中采用固定速率进行数据传输会影响通信质量和系统吞吐量的问题,提出了一种基于CCSDS协议标准的收发机自适应传输方案。该方案主要根据接收信号的质量,动态地改变数据传输的码速率,即通过实时地估计接收端信噪比,对信号传输速率做出调整,从而在保证系统误码率的前提下提高系统的通信质量和吞吐量。在此基础上,利用以Xilinx Virtex5FPGA芯片为核心的硬件平台对系统方案进行实现及验证,并分析比较了系统吞吐量。实验结果表明,该系统方案实现结构简单,在0 d B以上的高斯白噪声背景下,能实现接收端信噪比的实时估计和整个系统速率的自适应调整。展开更多
Deep space communication is quite different from conventional ground communication due to its time-varying,complexity and large signal delay,which consequently affects communication quality and system efficiency.Adjus...Deep space communication is quite different from conventional ground communication due to its time-varying,complexity and large signal delay,which consequently affects communication quality and system efficiency.Adjusting the transmission parameters when the channel environment changes during the communication can guarantee the performance index of the system,and therefore improve communication efficiency. An adaptive transmission scheme of transceiver based on Consultative Committee for Space Data Systems(CCSDS)protocols is proposed in this paper. According to the variation of the deep space channel,the symbol rate of transmission data is adjusted dynamically by estimating the signal-to-noise ratio(SNR) of the receiver in real time and adjusting the channel environment. This scheme can improve the channel utilization and system throughput under the premise of limiting the system bit error rate. Furthermore,this scheme is successfully implemented in Xilinx Virtex-5 FPGA board.展开更多
针对小样本条件下的盲信噪比估计误差较大问题,结合信号子空间分解方法,提出一种基于有限样本信息准则(finitesample information criterion,FSIC)的盲信噪比估计算法,并推导出基于FSIC盲信噪比估计算法的最大似然形式。在小样本情况下,...针对小样本条件下的盲信噪比估计误差较大问题,结合信号子空间分解方法,提出一种基于有限样本信息准则(finitesample information criterion,FSIC)的盲信噪比估计算法,并推导出基于FSIC盲信噪比估计算法的最大似然形式。在小样本情况下,FSIC的引入克服了传统信息论方法产生的过拟合和欠拟合问题,降低计算复杂度。在不需要已知信号调制方式、载波频率、波特率等先验知识的前提下,能够在加性高斯白噪声信道(AWGN)和多径信道(Rayleigh)下对常用调制信号进行有效的信噪比估计。在信噪比-25 dB～25 dB范围内,其平均估计误差小于1 dB,表明该算法可有效应用于小样本盲信噪比估计。展开更多
文摘针对深空通信中采用固定速率进行数据传输会影响通信质量和系统吞吐量的问题,提出了一种基于CCSDS协议标准的收发机自适应传输方案。该方案主要根据接收信号的质量,动态地改变数据传输的码速率,即通过实时地估计接收端信噪比,对信号传输速率做出调整,从而在保证系统误码率的前提下提高系统的通信质量和吞吐量。在此基础上,利用以Xilinx Virtex5FPGA芯片为核心的硬件平台对系统方案进行实现及验证,并分析比较了系统吞吐量。实验结果表明,该系统方案实现结构简单,在0 d B以上的高斯白噪声背景下,能实现接收端信噪比的实时估计和整个系统速率的自适应调整。
文摘Deep space communication is quite different from conventional ground communication due to its time-varying,complexity and large signal delay,which consequently affects communication quality and system efficiency.Adjusting the transmission parameters when the channel environment changes during the communication can guarantee the performance index of the system,and therefore improve communication efficiency. An adaptive transmission scheme of transceiver based on Consultative Committee for Space Data Systems(CCSDS)protocols is proposed in this paper. According to the variation of the deep space channel,the symbol rate of transmission data is adjusted dynamically by estimating the signal-to-noise ratio(SNR) of the receiver in real time and adjusting the channel environment. This scheme can improve the channel utilization and system throughput under the premise of limiting the system bit error rate. Furthermore,this scheme is successfully implemented in Xilinx Virtex-5 FPGA board.
