伪码调相线性调频复合引信调制技术研究

【作者】 尚浩强；

【导师】 赵惠昌；

【作者基本信息】 南京理工大学 ， 通信与信息系统， 2009， 硕士

【摘要】 由于伪码信号的多普勒敏感性,伪码调相连续波体制引信在弹目接近速度较大时定距性能大大降低,减少了伪码调相引信的应用范围。伪码调相线性调频复合引信是通过对回波信号的延时伪码做相关处理实现对目标的定距,利用回波信号中的差频信号降低多普勒效应的影响,并提取多普勒信号实现对目标的测速。本文在对伪码调相线性调频复合引信的工作原理详细分析的基础上,讨论了复合引信的性能,确定了复合引信各个参数选取的原则。分析了复合引信回波信号的时频域波形,使用Matlab软件仿真了回波信号的相关接收处理,分析了复合引信信号的抗干扰性能和抗噪声性能。讨论了复合引信调制部分的电路设计,使用XC95144XL型CPLD的产生伪码信号和控制DDS芯片产生锯齿波调频信号,并利用ModelSim软件对DDS与CPLD之间的串口数据传输进行了仿真;仿真设计了DDS输出所需的带通滤波器。使用锁相频率合成芯片ADF4360-1实现频率源,最后利用AD8349完成复合引信调制信号的产生。更多还原

【Abstract】 Because of the Doppler sensitivity of Pseudo-random code, the ranging ability of Pseudo_random code phase modulation fuse is significantly reduced when the speed between the bomb and the target is high. Therefore, the application of Pseudorandom code phase modulation fuse is limited.The ranging of Pseudo-random code phase modulation combined with linear frequency modulation fuze is achieved by correlating the echo from the target using the delayed Pseudorandom code, and the velocity is measured using the difference frequency signal which is also can reduce the impact of Doppler effect.In this paper, the operating principle of the complex modulation fuze using pseudo random code phase modulation and linear frequency modulation is introduced in detail, and then the performance and the principle of parameters selection of the complex modulation fuze are discussed. In addition ,time-frequency domains of target echo signal is analyzed,and then the process of target echo signal is simulated by using the software Matlab. Besides, anti-interference performance and anti-noise performance of the complex modulation fuze is analyzed,and then the modulation circuit of the complex modulation fuze is designed. Moreover,by using the CPLD chip XC95144XL pseudo-code signals and the control signal of DDS chips AD9852 which supply sawtooth FM signal is produced. Furthermore ,by using the software ModelSim serial communication between DDS and CPLD is simulated,and then the bandpass filter for the DDS output is designed. Finally,by using ADF4360-1 chip the carrier wave is produced, and then By using AD8349 the transmitting signal of the complex modulation fuze is realized.更多还原