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摘要短波电报一经问世即成为战术应急通信的重要通信手段，准确实时的自动报文检测和识别技术也成为一直以来的研究重点。本文针对低噪声背景下的摩斯码的实时检测和识别技术进行了相关研究。
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本文介绍了摩斯码信号的相关概念，比较了摩斯码信号与各类常见的噪声信号的特征区别。经过特征分析发现摩斯码信号在时域和频域特征均十分明显，但一经噪声干扰，时域特性便不能较好体现。但在频域内摩斯码信号伴随明显能量突变，基于这一特征我们提出对短波信号进行复数谱方差检测，设置自适应阈值方法进行摩斯码信号检测。
根据摩斯码方差图特征，方差图尖峰位置所在频带即为摩斯码存在频带，滤除其余频带信号即可对摩斯码实现去噪处理。根据码速不同确定不同界定值确定点信号平均长度、码间隔平均长度、划信号、字间隔、词间隔长度下限，对信号点划进行判别。点划判别后树通过形搜索量化系统实现对摩斯码信号的译码输出。19352
最后，本文通过DSP平台实现对摩斯码的实时自动检测和识别。
关键词 摩斯码 信号检测识别 谱方差 DSP
毕业论文设计说明书（论文）外文摘要
Title Morse code recognition system design based on DSP
Abstract
Shortwave cable becomes a tactical emergency communication as it comes to the important means of communication.Accurate real-time automatic message detection and recognition technology has become the research emphasis .In this thesis,the Mores telegraph code real-time detection and recognition in low noise background is investigated.
This paper introduces the concepts of Morse code signals and compares the difference of Morse code signals and all kinds of common noise signal.Through characteristics analysis we found that the characteristics of Morse code signals in time domain and frequency domain are very obvious.According to the characters of variogram Morse code,we found that the variogram peak position in the band is band Morse code is.We can deal with the noise of Morse code signals by filtering out the rest of the band signal.According to different determining the different values determine code speed signal average code length, interval, average length of the signal word, word spacing, interval length limit.
Finally, we realize automatic detection and identification of Morse code through the DSP platform.
Keywords
Morse code signal detection and identification
spectral variance DSP
目 次
1 绪论 1
1.1 研究背景 1
1.2 研究内容 1
1.3 结构组织框架 2
2 摩斯码信号检测基本原理及算法 3
2.1摩斯码信号及噪声信号基本特征 3
2.2摩斯码信号自动检测基本原理 6
2.3小结 14
3 摩斯码信号识别基本原理及算法 15
3.1 摩斯码信号识别原理概述 15
3.2 摩斯码信号的去噪处理 15
3.3 摩斯码信号的点划信号判决 18
3.4 摩斯码信号点划译码 19
3.5 小结 20
4 基于DSP的检测识别系统设计 21
4.1 DSP开发背景 21
4.2信号处理阶段 23
4.3码字识别阶段 31