基于混沌同步的低信噪比BPSK信号接收技术

发布时间：2018-03-02 17:23

本文选题：低信噪比BPSK信号　切入点：混沌理论　出处：《哈尔滨工业大学》2014年硕士论文　论文类型：学位论文

【摘要】：在数字调制技术领域，BPSK(Binary Phase Shift Keying)调制方式是一种最基本、最常用的调制技术。而即使是数字调制信号，在复杂的环境中传输，不可避免的会受到强噪声的影响。传统的BPSK信号接收技术，只能解调信噪比为0dB以上的BPSK信号，这已经不能满足现今通信传输的要求。研究低信噪比BPSK信号接收技术的目的，是为了在强噪声背景下解调出BPSK信号。本文从混沌理论的概念出发，研究混沌系统的基本特性的同时，列举了几个经典的混沌模型。尤其针对Duffing系统，研究了其对噪声的免疫能力以及外加信号的相位和频率对它的影响。并提出了基于Duffing系统的低信噪比BPSK信号的接收方法，在通过仿真分析验证此系统可行性的同时也发现此系统存在较为棘手的问题。在此基础上，本文将同步控制算法与混沌系统相结合，提出了一种基于混沌同步算法接收低信噪比BPSK信号的方法。此方法主要分为两个部分，第一部分是利用Duffing方程和快速梯度法将低信噪比的BPSK信号进行波形恢复，提高信号波形的信噪比；第二部分是利用传统的相干解调的方法，将恢复好的波形进行解调。本文利用Matlab/Simulink构建了混沌同步系统的模型，并进行了仿真分析，验证了此方法的可行性。其中，本论文的核心所在是波形恢复部分。针对这部分算法，本论文不仅要利用Matlab进行仿真分析，同时将通过Verilog HDL语言，编写混沌同步系统的模块，并调用ROM IP核来产生低信噪比的BPSK信号，最后利用ISE软件进行行为仿真，得出仿真结果，进行仿真分析，，进一步验证了基于混沌同步的低信噪比BPSK信号接收技术的可行性。
[Abstract]:In the field of digital modulation technology, BPSK Phase binary Phase Shift Keying is one of the most basic and commonly used modulation techniques, and even digital modulation signals are transmitted in complex environments. The traditional BPSK signal receiving technique can only demodulate the BPSK signal whose SNR is above 0 dB, which can not meet the requirement of communication transmission. The purpose of this paper is to demodulate the BPSK signal under strong noise in order to demodulate the BPSK signal with low signal-to-noise ratio (SNR). In this paper, the basic characteristics of chaotic system are studied based on the concept of chaos theory. Several classical chaotic models are listed, especially for Duffing system, the immune ability to noise and the effect of the phase and frequency of external signal on it are studied. The method of receiving BPSK signal with low signal-to-noise ratio based on Duffing system is proposed. At the same time, the feasibility of the system is verified by simulation analysis. On the basis of this, the synchronization control algorithm is combined with the chaotic system. This paper presents a method to receive BPSK signal with low SNR based on chaotic synchronization algorithm. The method is divided into two parts. In the first part, the waveform of BPSK signal with low SNR is recovered by using Duffing equation and fast gradient method. The second part is to demodulate the recovered waveform by using the traditional coherent demodulation method. In this paper, the model of chaotic synchronization system is constructed by using Matlab/Simulink, and the simulation analysis is carried out. The feasibility of this method is verified. The core of this paper is waveform recovery. In view of this algorithm, this paper not only uses Matlab to simulate and analyze, but also compiles the module of chaotic synchronization system through Verilog HDL language. The ROM IP core is used to generate the BPSK signal with low SNR. Finally, the behavior simulation is carried out by using ISE software, and the simulation results are obtained and analyzed. The feasibility of the low signal-to-noise ratio (BPSK) signal receiving technology based on chaos synchronization is further verified.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN911.25

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