Digital Signal Processing
http://ee.sjtu.edu.cn:8080/
Textbook：
DISCRETE-TIME SIGNAL PROCESSING (2nd
Edition)
Alan V. Oppenheim
Reference for experiment：
基于MATLAB的系统分析与设计------信号处理
楼顺天 西安电子科技大学出版社
Textbook in Chinese：
数字信号处理
刘兴钊 李力利 电子工业出版社 29 元
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Prof Wen Chen
1. Website: wnt.sjtu.edu.cn
2. Email: wenchen@sjtu.edu.cn
3. Phone: 34204585
5. Office: #1-520, Dianxin Building, SJTU
6. TAs: ***
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Marking
1. Assignment 10pt, one after each chapter.
3. Experiment10分，Using Matlab。
7. Mid-term25pt。
8. Final 50pt。
9. Additional feeling 5pt.
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CHAPTER 1 INTRODUCTION
1.what is digital signal
2.what is digital signal processing
3.character of digital signal processing
4.Application of digital signal processing
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1.what is digital signal
x(t)
x[n]
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Example: the storage of voice signal in different materials
vocal cord shakes
air pressure changes and spreads
Recorded using analog signals
the voltage of microphone changes
Recorded using digital signals
(1) magnetic tape：Recorded according to the intensity of magnetism
analog signals
(2) ethane-resin disc： Recorded according to the undulant channels
(3) disk： Recording 0 or 1 according to the direction in which
the mote is magnetized
digital signals
(4) CD： Recording 0 or 1 according to the accidented surface
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2. what is digital signal processing
R
Continuous-time low pass filter
C
x(t)
y(t)
x[n]
y[n]
-1
z
a
Discrete-time low pass filter
y[n]  x[n]  ay[n  1]
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2D low pass
 0 1/ 5 0 


1
/
5
1
/
5
1
/
5


 0 1 / 5 0 
2D high pass
  1 / 2  1 / 2  1 / 2



1
/
2
5

1
/
2


 1 / 2  1 / 2  1 / 2
Digital signal processing:
additions, multiplications, delaying
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Realization method
(A) software
flexible; slowly
(B) hardware
Fast,small; no flexibility
(C)hardware and software
programmable DSP chip
fast，flexible
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Example of hardware and software realization
AD1848
ADSP2181
PC
DISK
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3.character of digital signal processing
(1)higher precision
(2) higher flexibility
(3) more process abilities
(4)higher reliability (programmable)
(5)cheaper
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The advantage of digital TV:
DTV
ATV
source coding
MPEG2
PAL/NTSC/SECAM
transport and receiving
digital
analog
Subjective quality
Studio, nearly;
Only relative to compression;
Advanced transport
technologies (channel coding,
modulation) to wipe off the
influence from environment
(multipath interference);
Can not achieve the effect
of SDTV;
Influenced by
environment;
resource
Save power (10%) and
spectrum;
an analog channel transports
4 SDTV (or 1 HDTV)
Forbidden channels, the
channels nearby can not
be used, 2 channels
transport 1 program;
function
Stereo surround;
Transport data;
VOD;
Mobile broadcast;
One track/dimensional
sound;
Transport only a little data;
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Be not mobile;
4.Application of digital signal processing
(A) communications
(B) entertainment
(C) medicine
(D) military
(E) exploration
(F) archaeology
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Digital products:
DAT（digital tape recorder）
CD
MD（mini-dick）
MP3
VCD
DVD
Digital camera
Digital vidicon
Digital phone
Digital scanner
PDA
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Digital TV
Digital movie
Digital broadcasting station
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Digital communication
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Digital network：
Internet;
LAN in offices
bluetooth
infobahn
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Virtual Reality Technology
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electronic paper:
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This course includes 3 major parts
(1) basis of discrete-time signal and systems
(2) structure and designing of filter
(3) the discrete Fourier transform and FFT
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