【作者】 刘琦；

【导师】 郭黎利；

【作者基本信息】 哈尔滨工程大学 ， 通信与信息系统， 2002， 硕士

【摘要】 扩频通信是具有广阔发展前景的通信方式之一，它由于具有独特的性能而广泛运用于军事和民用通信中，并日益受到重视。 扩频序列的同步问题是扩频通信的重点也是难点。随着数字器件的飞速发展，数字系统的优势也越来越突出。本文将讨论用数字化方法实现扩频序列的同步方案。不同于一般的理论分析以及解调后数字相关器的讨论，本文通过理论分析与仿真结果，选用了非相干相关同步的基本结构，并加以改进，不需要解调和载波的信息，将本地序列与接受信号直接相关后进行采样，通过软件的方法，实现同步。该方案具有硬件电路简单，调试、改进方便，并可采用多种同步方法的特点。由于采用软件来实现同步，还可方便地将捕获功能加入锁定环路当中。 本文第四章介绍了该方案实现所做的具体工作：建立硬件平台，定义软件功能模块，研究数据积累处理的方法。所采用的主要器件是现场可编程门阵列FPGA和数字信号处理器DSP，其组成的系统具有很强的实时处理功能。更多还原

【Abstract】 Spread Spectrum (SS) communication is one of communication methods, which have vast vista. For its particular capability, it is widely used in the fields of military and civil communication.The synchronization of Spread Spectrum (SS) sequence is the most important but much more difficult one. With the rapid development of digital devices, the advantages of the digital system are becoming more and more attractive. The paper will discuss the scheme of spread spectrum synchronization by digital method. Other than traditionally theory analyze and discussion of digital correlator which is laid after demodulator, a scheme based on non-interrelated correlative DLL will be discussed in this paper after referencing the theory and the result of simulation. The demodulated data and the information of carrier are not need in this plan. We sample the result of correlation between local sequences and the received signal, then realizing the code synchronization by software. The system has the advantages of having simpler hardware circuit, easier to debug and improvement. It also can be introduced more synchronize scheme. Because of its main body is realized by software, it is convenient to add acquisition function to the DDL.In the fourth chapter, we introduce the special work in this paper. It contains constructing hardware platform, defining software module, researching the method of data accumulating.更多还原