扩频信号的BPSK调制仿真

《控制系统CAD与数字仿真》2014～2015学年第一学期

学院（部）电子电气工程学院

学号*********

姓名纪辰

授课教师陈剑雪

扩频信号的BPSK调制仿真

摘要：随着数字信号处理技术的不断发展，数字化软件无线电接收机已经成为趋势，调制/解调技术是数字通信系统中的核心技术。现代计算机科学技术快速发展，使得通信系统仿真的设计和分析过程变得相对直观和便捷，由此也使得通信系统仿真技术得到了更快的发展。通信系统仿真具有广泛的适应性和极好的灵活性,有助于更好地研究通信系统性能。

本文介绍了数字化调制解调技术的现状发展及其应用，然后介绍了BPSK数字调制解调的理论基础，重点分析了BPSK数字调制和解调的原理。

本文利用MATLAB强大的仿真功能,在其仿真环境下建立了直扩系统和BPSK调制解调系统仿真模型，给出各路观察波形,证实了解调算法的可行性。

最后，本文对所做研究工作进行了总结，并且提出了今后的工作和研究方向。

关键词：BPSK；调制解调器；MATLAB ；直扩系统

The simulation of spread spectrum signal with BPSK digital modulation

Abstract：With digital signal processing technology continues to evolve, digital software radio receiver has become a trend, modulation/demodulation technology is the core technology in digital communication system。The rapid development of modern computer science and technology, makes the communications system simulation design and analysis process become relatively intuitive and convenient, which also makes the communication system simulation technology has been faster development. Communication system simulation with wide adaptability and excellent flexibility, helps to better study the communication system performance.

This paper introduces the digital modem technology situation and development.Then introduced digital modulation and demodulation of BPSK theoretical foundation, including analysis of the BPSK digital modulation and demodulation principle.

In this paper, based on the powerful simulation using MATLAB function in its environment designed the spread spectrum signal system and the BPSK modulation demodulation system simulation model, and through the constellation confirmed that the demodulation algorithm. Finally, this paper made a summary of the research work, and proposed future work and research directions.

Key words: BPSK, Modem, MATLAB, Spread spectrum signal system

目录

一、引言............................................. - 5 -

1.1 研究背景及其意义.............................. - 5 -

1.2 数字化调制解调技术的现状发展及其应用 .......... - 5 -

1.3 MATLAB的简介.................................. - 6 -

二、BPSK调制解调原理................................. - 7 -

2.1 BPSK信号调制原理.............................. - 7 -

2.2 BPSK 信号解调原理............................. - 9 -

三、扩频信号的BPSK调制系统设计仿真................. - 10 -

3.1基本扩频系统仿真流程图........................ - 10 -

3.2 生成m序列及m序列性质 (11)

3.3 生成50位随机待发送二进制比特序列及进行扩频编码 .. 12

3.4 对扩频前后信号进行BPSK调制并观察其时域波形 (13)

3.5 计算并观察扩频前后BPSK调制信号的频谱 (13)

四、总结与展望 (14)

4.1 总结 (14)

4.2 展望 (15)

参考文献 (16)

附录 (17)