扩频码双级快速捕获系统设计及性能分析  

Design and Performance Analysis of a Novel Two-stage Fast Code Acquisition Scheme

作　　者：王家勇[1] 陈寅健[1] 梁旭文[1] 杨根庆[1] 

机构地区：[1]中国科学院上海小卫星工程部,上海200050

出　　处：《应用科学学报》2002年第3期326-330,共5页Journal of Applied Sciences

摘　　要：提出了一种改进的伪随机码双级快速捕获系统 .前级捕获机构采用匹配滤波器 ,通过 1bit量化解决常规匹配滤波器硬件复杂、功耗大的问题 ;后级捕获采用相关器组 ,长相关积分时间以减少虚警概率 ,相关器组由多个独立的相关器组成 ,目的是减少后级相关器的阻塞概率 .基于通信网络中的排队论 ,研究该双级捕获系统的捕获性能 ,优化系统结构参数 .最后给出了捕获系统性能结果 .该捕获系统适用于移动卫星突发扩频通信中 .A novel two stage code acquisition scheme for direct sequence spread spectrum communication is presented in this paper. The acquisition scheme uses a passive matched filter as an acquisition aiding device in the first stage. The matched filter has rapid search capability but the hardware is always excessive. In order to reduce the hardware requirement,the 1 bit quantization method is used. In the second stage, a bank of active and mutual independent correlators are employed, and the long active correlators contribute to decision reliability. In addition, the bank of mutual independent active correlators solve the problem of engaged correlators which usually exist in the traditional two stage scheme. An analytical model based on queuing and detection theory is developed and optimization of the scheme is treated. Finally, the numerical results of theoretical performance are presented. This code acquisition scheme can be used in burst direct sequence spread spectrum communication, especially in mobile satellite burst communication.

关 键 词：扩频码 双级快速捕获系统 扩频通信 排队论 匹配滤波器 CDMA通信系统 移动通信 系统设计 

分 类 号：TN929.533[电子电信—通信与信息系统] TN914.42[电子电信—信息与通信工程]