高动态环境下扩频系统的快速同步方案  

A fast synchronization scheme for spread spectrum system under high dynamic circumstance

作　　者：陈晨[1] 钱良[1] 杨峰[1] 王炜[1] 

机构地区：[1]上海交通大学电子信息与电气工程学院,上海200240

出　　处：《信息技术》2011年第5期40-44,48,共6页Information Technology

摘　　要：提出了一种应用于高动态环境下扩频系统的快速同步方案,通过优化帧结构设计,利用PN序列自相关达到快速的帧捕获,通过对鉴频环路的结构修改,采用FLL和PLL协同工作的方式,利用四相鉴频器跟踪频率变化,进行大频率搜索;利用叉积自动频率跟踪算法联合Costas环作为载波跟踪算法;环路滤波器采用扩展卡尔曼滤波技术,在提升信号捕获速率的同时,降低噪声的影响,提高捕获精度。经仿真验证,可以在相对较低的复杂度下获得良好的性能。This paper optimizes the synchronization loop,for spread spectrum system,by using self correlation for frame synchronization and implementing PLL/FLL combined frequency recovering loop.It uses four-quadrant frequency discriminator to acquire the coarse frequency-shift;then use CDAFC associated with Costas loop to track the carrier frequency.For the loop filter,extended Kalman filter is applied to increase the acquisition accuracy from increasing the acquire speed as well as reducing the noise impact.From the simulation,this method can obtain a relative better performance with lower complexity.

关 键 词：高动态 四相鉴频 叉积鉴频 扩展卡尔曼滤波器 

分 类 号：TN914[电子电信—通信与信息系统]