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类型 综合研究 预答辩日期 2018-05-11
开始(开题)日期 2014-05-30 论文结束日期 2018-01-21
地点 东南大学李文正楼 论文选题来源 学校自选项目    论文字数 7 (万字)
题目 深空探测接收机相关数字信号处理的研究
主题词 深空探测接收机系统,智能信号处理,自适应算法,软硬件协同设计
摘要 深空探测接收机作为深空网的重要组成部分,其作用是接收卫星以及其他宇航飞行器发送的电磁波信号用以导航,测距测速,定轨以及大气测量等多种科学实验任务。接收机系统的性能与科学实验结果息息相关。因此,研究具有高精度、强鲁棒性并具有一定通用性能的接收机系统具有十分重要的意义。 本文面向深空探测导航应用,重点研究了具有高精度、强鲁棒性的信号处理算法并设计了具有一定通用性的接收机系统。 本文重点开展了以下工作。首先,针对窄带信号参数估计算法的设计与实现,本文首先对几种常用的开环窄带信号分析算法进行改进,并在对比实验数据结果的基础上,提出了带宽可变自适应多级频率估计算法。算法在二级信号参数估计的过程中,根据信号多普勒的变化规律,自适应调整信号检测窗宽,减少了随机强噪声对开环多普勒测量的干扰,从而提高了系统的鲁棒性。对比试验结果表明,由于自适应搜索策略以及二级频率分析算法的处理分析,多级窄带信号参数估计算法在长时间的观测过程中,系统并未出现频繁的信号失锁情况。同时算法获得了较高的信号参数估计精度,但对于信号信噪比的要求却比基于时域的信号分析算法低很多。其中,窄带信号频率估计均方根误差约为0.01Hz,调频率误差约为0.02Hz/s,相位估计误差约为0.06rad。其次,针对系统的宽带信号时延估计应用需求,本文提出了二维多重互相关谱算法在预报数据不准确的条件下对宽带射电源信号实现参数估计。算法采用多重互相关运算对微弱的射电源互相关函数进行增强,并将增强后的结果映射至二维互相关谱图中,利用谱图结果获得粗略时延以及时延率数据,并最终通过多次多普勒补偿迭代获得信号的精确时延参数估计结果。在实验结果验证中,二维多重互相关谱图分析算法使系统在缺少预报数据的条件下,时延参数估计仍然可以使数据的相频曲线聚拢,从而获得干涉条纹。系统进而对所获得的干涉条纹进行分析,最终宽带二维互相关谱图时延参数估计结果误差约为0.1rad,获得了与具有准确预报数据条件下的参数估计相近的估计精度。在系统软件算法设计的同时,针对各算法中系统计算负担较重的问题,本文设计并实现了可变点大点数FFT协处理器。处理器基于2-D FFT分解算法,通过采用1k并行固定点数FFT处理子模块以及级联32点可变FFT子模块,将大点数FFT计算进行了分解,并在此基础上,使用FPGA并行实现,从而有效提高了系统的计算效率,在32k点的系统实际数据测试中,FFT协处理器的最大分析误差小于1%,处理时间仅为毫秒数量级,相较于MATLAB软件处理提高了近20倍。最后,为了增强所设计系统的智能信号处理能力,本文在系统中设计并实现了具有一定通用性的ANFIS协处理器。通过参数实时可调的非线性隶属度函数发生器以及结构可变的通用二叉树算数计算网络,所设计的ANFIS协处理器能够对不同结构的ANFIS网络结构进行加速计算。协处理器对于Mackey-Glass混沌时间序列的学习误差约为0.03,而处理时间仅为软件处理速度的五分之一。同时,在参考数据离线1分钟的实验中,在ANFIS协处理器的辅助下,系统成功抑制了绝大部分的开环积分角测量的累积误差。从而对智能信号处理算法及ANFIS协处理器的设计进行了验证。
英文题目 Research of deep space receiver and its signal processing
英文主题词 Deep space receiver system, signal processing, adaptive algorithm, SW-HW co-design
英文摘要 As the critical component of the deep space observation network, the receiver system observes the radio signals from satellite or spacecrafts for navigation, ranging, planetary atmospheric scientific research and etc. The current receiver systems have the problems of weak universality and low efficiency on signal processing speed. Therefore, the development of receiver system with high accuracy, strong robustness and generality is meaningful and necessary. In the paper, for deep space exploration applications, the signal processing algorithms with high accuracy, strong robustness is studied and the receiver system with generality is proposed. The main contribution of the paper is shown as follows. Firstly, on the research and implementation on the narrowband signal parameter estimation algorithm, several basic parameter estimation algorithms are improved. Then, based on the comparison results, the adaptive multi-stage parameter estimation algorithm is proposed. During the two-stages of parameter estimations, the proposed algorithm adjusts the signal detection window according to the current Doppler information. In this way, the interference of random noise is suppressed and the system robustness is enhanced. The experiment based on the real satellite data observations demonstrate that the system keeps a continuous observation results without any breakpoint during the long time of observations. Meanwhile, the high accuracy of the observation data is achieved but has less requirement of the signal SNR. The RMSE for narrowband signal frequency estimation, Doppler rate and phase estimation is about 0.01Hz, 0.02Hz/s and 0.06rad, respectively. Secondly, on the research and implementation of the wideband signal time delay estimations, to solve the wideband signal time delay estimations based on the inaccurate forecast data, a novel algorithm is proposed based on the multiple correlation and 2-D correlation chart analysis. Multiple correlation method is employed to enhance the SNR of the correlation function in the first place. Then, the results are represented on the 2-D contour map to acquire the correlation chart. After the rough delay results got from the chart, the Doppler compensation is applied to calculate the fine estimation results. The real data experiment demonstrates the effectiveness of the proposed method. The accurate time delay estimation results can still be acquired when the forecast data is inaccurate in the wideband signal time delay estimation. The fitting residue of the algorithm is about 0.1rad, which demonstrates the similar accuracy acquired by the estimation with accurate forecast data. On the research and implementation of the points changeable FFT processor, based on the 2-D FFT decomposition algorithm, the proposed FFT processor design decomposes the processor into 1k points parallel FFT sub-module and 32 points changeable sub-nodule. The processor design improves the FFT computation efficiency. The 32K FFT verification experiment demonstrate the maximum processing error for designed processor is less than 1%, the processing speed is nearly 20 times for FFT processor compared to the software processing. Finally, on the research and implementation of intelligent signal processing and general purpose ANFIS processor, a general purpose ANFIS processor for system intelligent signal processing algorithms is presented to improve the system computation efficiency. The universality of the processor is achieved through the design of parameter run-time tunable non-linear membership function generator and reconfigurable arithmetic computation network. The Mackey-Glass chaotic series data experiment demonstrates the learning RMSE for proposed ANFIS processor is 0.03 and the processing time is nearly 20% compared to the software processing implemented on MATLAB. Meanwhile, in the experiment simulates the reference data is off-line for 60 seconds, the proposed hybrid method with designed ANFIS processor suppress most of the accumulation error for open-loop integration phase measurement, which demonstrate the design of the hybird algorithm and ANFIS processor are effective.
学术讨论
主办单位时间地点报告人报告主题
东南大学射光所 2013.03.10 李文正楼会议室 唐继斐 深空探测接收机系统调研报告
东南大学射光所 2013.05.22 李文正楼会议室 王显海 宽带数字频谱仪设计研究
东南大学射光所 2014.06.30 李文正楼会议室 李东 高速低功耗SAR ADC研究
东南大学射光所 2014.09.17 李文正楼会议室 于泉涛 窄带信号参数估计算法研究
Texas A&M university 2015.04.25 Computer science center 唐继斐 A Survey of Dynamically Reconfigurable FPGA Devices
Texas A&M university 2016.05.07 Computer Engineering Center 唐继斐 Hybrid algorithm for open-loop Doppler receiver
Texas A&M university 2016.07.11 Computer Engineering Center Liu Yim Radio telecommunication system in South Africa ground stations
东南大学射光所 2017.10.10 李文正楼会议室 唐继斐 深空探测接收机系统
     
学术会议
会议名称时间地点本人报告本人报告题目
APCC 2014 2014.10.01– 2014.10.03 泰国 A robust signal estimation method for satellites and spacecrafts in the Radio Science Receiver
ICMEE 2014 2014.08.16– 2014.08.17 中国 A new method for weak quasar signal correlation and detection
     
代表作
论文名称
Quasar signal estimation and compensation for data processing in VLBI receiver
A robust signal estimation method for satellites and spacecrafts in the Radio Science Receiver
 
答辩委员会组成信息
姓名职称导师类别工作单位是否主席备注
刘陈 正高 教授 博导 南京邮电大学
周建江 正高 教授 博导 南京航空航天大学
王志功 正高 教授 博导 东南大学
李智群 正高 教授 博导 东南大学
李文渊 正高 教授 博导 东南大学
      
答辩秘书信息
姓名职称工作单位备注
黎飞 其他 讲师 东南大学