基于DDS的多模式信号发生器的设计与实现.pdf

华中科技大学
硕士学位论文
基于DDS的多模式信号发生器的设计与实现
姓名:林静宜
申请学位级别:硕士
专业:通信与信息系统
指导教师:王宏远
20070601
摘要
随着无线电通信技术的发展,对信号的保真度、频率的准确性、幅度的稳定性
等提出了越来越高的要求,而作为通信系统必不可少的组成部分的信号源,在很大
程度上决定了通信系统的性能。同时,计算机和微电子技术的迅速发展使得频率合
成技术有了新的突破,出现了直接数字频率合成DDS技术。DDS具有很高的频率捷
变速度、很宽的相对带宽、很高的频率分辨率、输出相位连续、可编程和全数字化
便于单片集成等许多优点。
本文给出了一种基于软件无线电思想和DDS技术的多模式信号源的设计。
首先,本文简要介绍了当前通信系统中信号源系统的发展趋势,并分析了频率
合成技术的发展,以及多模式信号源的研究价值;然后本文详细介绍了DDS的基本
原理和基本架构,研究了DDS信号杂散来源以及克服DDS信号杂散的主要方法,如
吞脉冲信号拟和,压缩ROM容量,CORDIC算法等。
接着本文简要介绍了多模式信号源的系统整体架构和主要应用芯片,并在此基
础上,着重介绍了系统的软件架构和设计思想,并认真分析了模拟调制、数字调制
特别是跳频等信号模式的设计和实现方法。在研究前人信号系统处理算法的基础上,
本文给出了一种通用的正交模型,即将各种不同的信号模式均转化为通用的正交模
型来实现,并在FPGA逻辑设计中成功的引入了NIOS II软核处理器,达到了用FPGA
实现信号处理的目的。

关键词:软件无线电,多模式信号源,直接数字频率合成,正交调制,跳频






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ABSTRACT
With the development of radio technology, munication system is raising the
ever-increasing demands for the signal fidelity, frequency accuracy and amplitude stability,
while the signal generator which is the ponent of munication system
determines the e of the systems to a large extent. Meanwhile, frequency synthesis
technique makes new breakthrough because of the mushroom growth puter and
micro-electronics technology, and then the theory of direct digital frequency synthesis
(DDS) is proposed. DDS has many obvious advantages such as high frequency-agile
speed, wide relative bandwidth, high frequency resolution, continuity of output phase,
programmable and all-digital architecture that is easy for monolithic integration.
This article presents a method of the design and implement of mutil-mode siginal
generator based on the technology of software defined radio (SDR) and DDS.
Firstly, the growth of frequency synthesis technology is analyzed, and the value of
multi-mode signal source is illuminated. Then the basic principle and structure of DDS is
introduced, and the DDS signal stray is studied in detail. Then the main methods of
ing signal stray are raised, such as fitting of swallowing pu