摘要FM-DCSK是一种基于发射参考的非同步混沌通信方式。接收端由于不需要恢复初始信号,只需要前后半码元信号的相关处理,因前后半码元信号通过相同信道,系统对多径和畸变等失真不敏感。FM-DCSK结构简单,且结合了FM信号功率均匀的优点,可用于WLAN等近距离宽带通信场合。目前,由于FM-DCSK系统的研究比较多,但对其多址通信的研究较少。本文在讨论FM-DCSK系统原理的基础上,重点研究FM-DCSK多址方式系统及基于FPGA的实现方法。79783
第一部分论文讨论了Logistic信号等几种混沌信号的产生方法,并通过仿真验证了方法的可行性及信号的相关性能。
第二部分对FM-DCSK理论通信系统进行了分析和Simulink仿真,探讨了基于FPGA的实现方法。
第三部分主要研究基于频分多址和基于波分多路的FM-DCSK通信方式,运用Simulink对多址系统的信号互相关、位数互相关和PN码加权特性进行了仿真,统计了误码率。提出了一种新的FM-DCSK波分通信方法,经对比测试,此法有效降低了误码率。
毕业论文关键词 混沌信号 FM-DCSK Matlab\Simulink 多址 FPGA
Title The FPGA Implementation of Chaotic Signals based on FM-DCSK
Abstract FM-DCSK chaotic communication system is a asynchronous system based on the transmitting reference principle。 The demodulator is a correlator。 Without recovering the original signal, we just need comparing the two parts of one bit。 It is not sensitive to channel distortions or multi-path because both the reference and the information-bearing part of the FM-DCSK signal pass through the same channel。
FM-DCSK system have a simple structure, composed with FM modulator, the signal is power-stable。It offers a simple solution for wide-band communications applications such as Wireless Local Area Networks (WLAN)。 Nowadays, this communication system is reachable, However, the methods of multi-path is lack。
This project point on the way to multi-path based on the systematic principle of FM-DCSK。
In the first part, many common types of chaotic signal are discussed, especially the basal Logistic-signal。
Secondly, we analysis and simulate the characteristics of the FM-DCSK chaotic system , and give the way to realize it by FPGA。
Thirdly, the project aim at the way to multiple-address based on frequence and wave。 With Simulink, we test the effect of cross-correlation, different bits and PN weighting among signals。Compare the BER with other ways ,the method put forward is more excellent 。
Keywords: chaotic signals FM-DCSK Matlab\Simulink multiple access FPGA
目 次
1 引言(或绪论) 1
1。1 混沌通信特点及前景 1
1。2 国内外研究状况 1
1。3 本文主要的研究问题及成果 2
2 常见的混沌信号 4
2。1 Matlab分析Logistic信号的特点 4
2。1。1 映射关系 4
2。1。2 频谱分析 5
2。1。3 自相关特点 6
2。2 Logistic信号的实现 6
2。2。1 Logistic信号离散数字实现 6
2。2。2 Logistic信号Simulink实现