摘要数字调制技术在现代通信系统中运用的越来越广泛，现在主流调制方式已经由模拟调制逐渐过度到数字调制。数字通信具有模拟通信不可比似的优势。 数字调制是指用数字基带信号对载波的某些参数进行控制，使载波的这些参量随基带信号而变化。根据控制的载波参量的不同，数字调制可分为调幅，调相和调频三种基本形式。35982
数字调制是现代通信的重要方法，它与模拟调制相比有许多优点。数字调制具有更好的抗干扰性能，更强的抗信道损耗，以及更好的安全性；数字传输系统中可以用到差错控制技术，支持复杂信号条件以及处理技术，比如加密技术、信源编码等。在数字调制中，调制信号可以表示为符号或脉冲的时间序列。
毕业论文关键词：数字调制、抗干扰性、抗信道损耗
Abstract
  In modern communication systems, digital modulation technology is more and more widely, the existing communication system in the transition from analog mode to digital mode. Digital communication technology using digital technology to encryption and error control, easy to integrate, so digital communication has analog communication than the advantage. Digital modulation refers to the use of digital  signal to control some parameters of carrier, the carrier of these parameter varies with the change of the signal changes. According to different control parameters of the carrier, the digital modulation amplitude modulation, frequency modulation and phase modulation of three basic forms, and can derive a variety of other forms.
  Digital modulation is an important way of modern communication, it has many advantages compared with analogue modulation. Digital modulation has better anti-jamming performance, stronger resistance to channel loss, and better security; Digital transmission system can be used in the error control technology, support conditions and complex signal processing technology, such as source code, encryption technology, and balanced. In digital modulation, the modulation signal can be represented as a symbol or pulse time series, in which each symbol can have m kind of finite state, and each symbol n bits can be used to represent.
Keywords：digital modulation、anti-interference、Channel resistance loss
目录    2
摘要    4
Abstract    4
第一章绪论    5
1.1引言    5
1.2课题的意义    5
1.3国内外研究现状与水平    5
1.4发展趋势    6
1.5 参数    6
1.5.1误码率    6
1.5.2对信道特性变化的敏感性    7
1.5.3设备的复杂程度    7
1.6本章小结    7
第二章 MATLAB    8
2.1简介    8
2.2发展历程    8
2.3软件特点    8
2.4.软件优势    9
2.5 Simulink简介    9
第三章 数字调制    10
3.1引言    10
3.2数字调制的基本内容：    10
3.3ASK以及基带频移键控    11
3.3.1ASK    11
3.3.2FSK    12
3.3.3MSK    13
3.3.4GMSK    14
3.3.5仿真结果    15
3.4基带相移键控    15
3.4.1BPSK    16
3.4.2QPSK    17
3.4.3OQPSK    17
3.4.4仿真结果    18
第四章 信道仿真研究    19
4.1信道简介    19
4.2加性高斯白噪声信道    19
4.3BPSK在高斯白噪声信道中的传输性能    19 Matlab不同数字调制方式在信道中的性能仿真研究:http://www.751com.cn/tongxin/lunwen_34226.html