数字视频图像传输系统实现中几个问题的研究

【作者】 张杰；

【导师】 是湘全；

【作者基本信息】 南京理工大学 ， 通信与信息系统， 2003， 硕士

【摘要】 本文针对数字视频图像传输中的两个典型问题，即信源的编码压缩和数据的调制传输，进行了原理上和工程实现上的讨论，并且重点放在其具体实现上。首先，归纳、介绍了数字视频图像编码压缩的基本原理和常用方法，并重点就MPEG进行了必要的阐述。就其实现而言，本文采用基于微机的AV-8视频采集卡，实现了图像数据的采集和编码压缩。更进一步，论文采用Verilog HDL语言来描述MPEG的运算核心部分：离散余弦变换(DCT)／反离散余弦变换(IDCT)，其主要内容是小数的乘加运算在可编程器件中的实现。其次，论文对视频图像传输中普遍采用的数字调制传输方式，有二相移相键控调制(BPSK)、四相移相键控调制(QPSK)和正交幅度调制(QAM)等，进行了MATLAB程序的仿真比较。随后，针对QPSK，详细讨论了其基本原理和具体的实现算法，并进行了仿真验证，然后选用HSP50215数字上变频芯片和HSP50214B数字下变频芯片，设计了数字调制、解调器的实现方案。最后，作为对整个数字视频图像传输系统的宏观认识，利用MATLAB中的实时建模仿真Simulink库对典型的视频图像传输系统一数字视频广播系统(DVB)，进行了建模、仿真和初步的分析，结果表明：在高斯白噪声的传输环境下，系统采取的一系列抗干扰措施，包括内、外码级联的信道纠错编码和先进的调制技术(OFDM)等，保证了信源信息传输的有效进行。更多还原

【Abstract】 This paper mainly investigates two important problems of digital image and video transmission. One is compression; the other is digital modulation. Here we discuss the basic theory and their realization, and mainly concentrate on their realization. First of all, the paper discusses the basic theory and means of image and video compression, then attaches more importance to the standards of image and video compression, such as MPEG. As for its realization, there are two ways: soft and hard. Here we try out a hard way with video card to realize it. In the second place, we discuss some ways of digital modulation in transmission of image data, for example BPSK, QPSK, QAM, and so on. Here the paper compares the differences of these ways of modulation, and gives some simulation results, and chooses two integrated circuits: HSP50215 and HSP50214B, then designs the structure of QPSK’s realization. Finally as a special example of the system of image transmission, the paper discusses the structure of digital video broadcasting system, and manages to complete its simulation in MATLAB, and gives the simulation results, so that we can have an overall recognition.更多还原