[工学]DSP-Introduction+第2章.ppt

USST Introduction Introduction Digital Signal Processing (DSP) is used in a wide variety of applications. Introduction Signals A signal can be defined as a function that conveys information. Signals are presented mathematically as functions of one or more independent variables. for example: a speech signal would be represented mathematically as a function of one time variable------f(t); ----- One-dimensional (1-D) signal 一维信号 a picture would be represented mathematically as a brightness function of two spatial variables------f(x,y). ------ Two-dimensional (2-D) signal 二维信号 a color video signal (a RGB television signal) is a 3-D signal. -----Multidimensional (M-D) signal 多维信号 Introduction What is Digital Signal Processing? Digital Signal Processing is the science to process signals by digital means. This includes a wide variety of goals: filtering, transformation, recognition, enhancement, compression, and much more. DSP is one of the most powerful technologies that will shape science and engineering in the twenty-first century. Suppose we attach an analog-to-digital converter to a computer, and then use it to acquire a chunk of real world data. Introduction 简单的说，数字信号处理是利用计算机或专用处理设备，以数值计算的方法对信号进行采集 、变换、综合、估值与识别等加工处理，借以达到提取信息和便于应用的目的。 Introduction Digital signal processing includes two meanings: Processing analog signals in a digital way. Processing digital signals. Advantages: High reliability（可靠性） High agility (灵活性好，易于实现系统性能） High precision（高精度） Low cost （成本低） … Introduction Main tools: Discrete-time signal representations. Discrete transforms and their fast algorithms (z transform, DFTFFT). Design and implementation of digital filter (IIR（无限长单位冲激响应）FIR （有限长单位冲激响应）filter). Multirate systems（多率系统）, filter banks（滤波器组）, and wavelets（小波）. Implementation of digital signal processing systems. References 程佩青，数字信号处理教程，清华大学出版社 胡广书，数字信号处理——理论、算法与实现，清华大学出版社 高西全，丁玉美，阔永红，数字信号处理——原理、实现及应用，电子工业出版社 … Chapter 2