高速卫星通信中全数字载波同步算法的研究  

Study of high speed satellite digital carrier synchronization algorithm

作　　者：沈宙[1] 马忠松[1] 

机构地区：[1]中国科学院空间应用工程与技术中心,北京100094

出　　处：《国外电子测量技术》2014年第4期36-39,共4页Foreign Electronic Measurement Technology

摘　　要：为满足在高速率卫星通信中全数字化中频解调的要求,对全数字化载波同步算法进行了深入研究,根据奈奎斯特采样定理以及中频采样定理,分析了利用高速中频调制BPSK/QPSK信号恢复本地同步相干解调载波算法的可行性。同时给出了全数字锁相环算法及720MHz中频调制信号下全数字载波同步算法的设计与实现,对其关键组成模块:鉴相器、数控振荡器和环路滤波器等给出了详细的设计方法,并最终使用MATLAB对算法进行了功能仿真,仿真结果表明该算法能够很好地实现数字解调端的载波同步功能,能够完成1MHz以内频偏锁相的功能,相位误差较小,达到了卫星通信系统接收端载波同步的性能要求。In order to meet the requirements of all digital IF demodulation in high rate satellite communications,we make a deep study of the algorithm of all digital carrier synchronization.According to Nyquist sampling theorem and IF sampling theorem,we analyze the feasibility of restoring local synchronous coherent demodulation carrier using a high rate IF frequency modulation signal of BPSK or QPSK.Meanwhile the paper presents the design and implementation of all digital phase locked loop algorithm and all digital carrier synchronization algorithms under 720 MHz IF modulation signal.For the key modules：the discriminator,numerical control oscillator and loop filter detailed design methods are given,and finally simulate the function using MATLAB.The simulation result shows that this algorithm can achieve carrier synchronization function well in digital demodulation,can complete phase lock within 1 MHz frequency offset and the phase error is small,meeting the requirements of satellite communication system synchronization.

关 键 词：载波同步 全数字化 采样定理 

分 类 号：TN914.3[电子电信—通信与信息系统]