Comment S1: I摘 要随着社会信息化程度的加强，人们对通信质量要求越来越高。扩频通信技术具备了现代通信系统的诸多优点的，如容量足够大、传输距离足够远、保密性能好，而且还有 提高频谱利用率、选择性寻址能力强、截获概率低、抗多径干扰、易于组网等优点。扩频通信技术广泛应用于众多领域，包括现代军事通信、移动通信、卫星通信、军事战术及指挥控制通信。扩频通信按工作方式分类可分为直接序列扩频、跳变频率扩频、跳变时间扩频和混合扩频四种。跳频直接序列混合扩频适应于多址通信或离散寻址和多路 复用等。扩频通信系统完成的信号处理变得越来越复杂，电路的处理速度也必须相应提高。 早期的分立器件自身体积大、消耗功率高，模拟器件受环境影响较大，在设计中不易实现。把电路集成后也存在成本高、采购困难等弊端。近几年，EDA 技术和微电子技术发 展势头强劲，跳频通信的实现大多是利用 EDA 技术，因此其成为数字信号处理领域的新 生力量。基于上述现状，本次设计是用 VHDL 语言对直接序列跳频系统进行编程实现，在 QuartusII 软件环境下进行仿真，结果验证了设计的正确性。关键词：VHDL；直接序列扩频；跳变频率扩频；Quartus IIABSTRACTWith the strengthening of social information degree, people demand more and more high quality of communication.Spread spectrum communication technology has many advantages of modern communication system, such as transmission distance far enough capacity is large enough Security performance is good, but also improve the utilization rate of spectrum selective addressing capability Low probability of intercept Resistance to multipath interference The advantages of easy to networking.Spread spectrum communication technology is widely applied in many fields, including modern military communication mobile satellite communications military tactics and command and control communications.Spread spectrum communication according to the classification of works can be divided into direct sequence spread spectrum frequency hopping spread spectrum jump time four frequency hopping spread spectrum and hybrid spread spectrum mixed direct sequence spread spectrum adaptation on multiple access communication or discrete addressing and multiplexing, etc.Spread spectrum communication system to accomplish the signal processing is becoming more and more complex, processing speed of the circuit must also improve the early discrete device corresponding high volume consumed power, analog devices are greatly influenced by the environment, in the design is not easy to achieve the goal of integrated circuit after have drawbacks such as the high cost of purchasing difficulty Development momentum in recent years, the EDA technology and microelectronic technology, the realization of frequency hopping communication is mostly using EDA technology, so it become a new force in the field of digital signal processing Based on the above situation, this design is to direct sequence fh system with VHDL language programming, under the environment of QuartusII software simulation, the results verify the validity of the design.II目 录摘 要.I ABSTRACT.I 1 绪论.1 1.1 课题研究背景及意义.1 1.2 国内外相关领域的研究状况及趋势.2 1.3 本论文结构.2 2 扩频通信技术基础.4 2.1 扩频通信系统的基本概念.4 2.1.1 扩频通信系统理论基础.4 2.1.2 扩频通信系统的特点.4 2.1.3 扩频通信系统的分类及应用.5 2.2 直接序列扩频通信 .5 2.2.1 直接序列扩频通信的定义.6 2.2.2 直接序列扩频通信系统的特点.7 2.3 跳频通信.7 2.4.1 跳频通信的定义.7 2.4.2 跳频通信系统的特点.8 3 直跳通信系统的理论设计.9 3.1 跳频器跳频系统的核心.9 3.2 m 序列生成器.10 3.3 频率合成器.10 3.4 调制解调技术.11 3.5 汉明码编译码技术.12 3.6Quartus II 软件仿真平台.1