摘要GMSK（高斯最小频移键控）技术以其相位的连续性，频谱的低带外辐射性， 包络的幅值恒定性而发挥卓越性能。扩频通信技术以其强抗干扰能力和保密性能， 良好的多址与测距能力及较低的截获率而从无线局域网、移动通信到卫星定位、 深空探测等领域都被广泛应用。将二者结合——直扩 GMSK 调制技术的研究有重要 的科研意义、积极的应用价值。68432

首先阐述直扩与 GMSK 调制原理。应用以上理论并基于自顶向下的模块化设计 思想，构造了直扩 GMSK 调制系统，主要由组帧、直扩、高斯滤波、相位成型及中 频调制等模块级联而成。用 Matlab 软件构建了直扩 GMSK 调制系统模型，通过仿 真得出其可行性并展现其优越性。对于 FPGA 硬件实现的精准性，使用 Verilog 语 言通过 Quartus II 软件对各模块及全系统进行了时序仿真。

毕业论文关键词 GMSK 调制器 直接序列扩频 FPGA

Title Design of DS-GMSK Modulator based on FPGA

Abstract

GMSK（Gaussian Filtered Minimum ShiftKeying）technology brings it’s excellent superiority into full play because of the phase with the property of continuance，spectrum with the property of reduced out-of-band radiation and envelope with the property of constant amplitude. Spread Spectrum Communication technology is widely used from Wireless Local Area Networks， mobile communication to satellite communications and deep space detection as a result of nice performance of anti-jamming and security ，nice performance of multiple access and distance measurement，and low probability of intercept.Roll into one—the DS-GMSK technology is developed,it has the important research meaning and positive application value to research on the DS-GMSK.

In the first place，the principles of direct sequence spread spectrum and GMSK modulation are expounded.And then the DS-GMSK modulation system is designed with the theories and the top-down thought of module.The system mainly consists of framing,direct sequence spread spectrum,gaussian filtering and phase forming modules which are cascaded.Next the DS-GMSK modulation system model is designed by Matlab,the system gets its feasibility and shows its excellent performance through the simulation.As to the accuracy in the FPGA hardware realization,every module and the whole system are verified by the timing simulation by the software –Quartus II by Verilog HDL language.

Keywords GMSK modulator direct sequence spread spectrum FPGA

目 次

1 引言„1

1.1 直扩 GMSK 调制的研究背景1

1.2 课题的研究目的、方法与意义„2

1.3  本文结构及主要工作3

2 直扩  GMSK  调制的原理4

2.1 直接序列扩频原理„4

2.2  GMSK 调制原理9

2.3    小结13

3 直扩 GMSK 调制器的 Matlab 建模与仿真14

3.1  直扩  GMSK  调制器系统建模与结构介绍14

3.2     组帧模块„14

3.3    扩频模块„15

3.4     高斯滤波模块„18