1. Digital Signal Processing
Shi Ping
School of Information Engineering
CUC
Copyright © Shi Ping CUC

2. Text books ： 《数字信号处理教程》 （第三版） 清华大学出版社，程佩青 2006年
Course outline
Text books ：
《数字信号处理教程》 （第三版）
清华大学出版社，程佩青 2006年
Reference books：
<Digital Signal Processing Using MATLAB>英文影印版 科学出版社
Vinay K. Ingle John G. Proakis
Copyright © Shi Ping CUC

3. Copyright © 2005. Shi Ping CUC
Course outline
Reference books：
王世一 《数字信号处理》北京理工大学出版社,1997年
A.V.奥本海姆 R.W.谢弗 J.R.巴克 编著 刘树堂 黄建国 译《离散时间信号处理》（第2版）西安交通大学出版社 2001年
胡广书《数字信号处理－理论、算法与实现》（第二版）清华大学出版社2003年
Copyright © Shi Ping CUC

4. Relationship with other courses About MATLAB Software Requirements
Course outline
Relationship with other courses
About MATLAB Software
Requirements
Copyright © Shi Ping CUC

5. Chapter 1 Introduction to DSP
Content
Signal, System, Signal Processing
The Constitution of DSP System
How to implement the DSP
The Application of DSP
The advantages of DSP
Copyright © Shi Ping CUC

6. Signal, System, Signal Processing
A signal is a function of independent variables such as time, distance, position, temperature and pressure
Signals play an important role in our daily life.
Most signals we encounter are generated naturally. However, a signal can also be generated synthetically or by a computer.
Depending on the nature of the independent variables and the value of the function, we can classify the signals as follows
Copyright © Shi Ping CUC

7. Signal, System, Signal Processing
scalar signal
A signal generated by a single source
vector signal (or multichannel signal)
A signal generated by multiple sources
one dimensional (1-D) signal
A function of a single independent variable
multidimensional (M-D) signal
A function of more than one independent variables
sound
Image
Video
Copyright © Shi Ping CUC

8. Signal, System, Signal Processing
continuous-time signal
The independent variable is continuous
see
discrete-time signal (sequence)
The independent variable is discrete
analog signal
A continuous-time signal with a continuous amplitude
quantized-boxcar signal
A continuous-time signal with a discrete-value amplitude
digital signal
A discrete-time signal with a discrete-value amplitude
Sampled-data signal
A discrete-time signal with a continuous amplitude
Copyright © Shi Ping CUC

9. Signal, System, Signal Processing
deterministic signal
A signal that can be uniquely determined by a well-defined process, such as a mathematical expression or rule, or table look-up.
random signal
A single that is generated in a random fashion and cannot be predicted ahead of time.
Copyright © Shi Ping CUC

10. Signal, System, Signal Processing
periodic signal
A signal that repeats itself in a periodic fashion from negative to positive infinity.
aperiodic signal
A signal that extends to both positive and negative infinity without repeating in a periodic pattern.
Copyright © Shi Ping CUC

11. Signal, System, Signal Processing
power signal
An infinite energy signal with finite average power.
energy signal
An finite energy signal with zero average power.
周期信号及随机信号一定是功率信号，而非周期的绝对可积（可和）信号一定是能量信号
a periodic sequence — power signal
a finite-length sequence — energy signal
Copyright © Shi Ping CUC

12. Signal, System, Signal Processing
A system is any process that produces an output signal in response to an input signal.
Depending on the types of the signal processed, we can classify the systems as follows:
Copyright © Shi Ping CUC

13. Signal, System, Signal Processing
analog system
input and output analog signals
digital system
input and output digital signals
continuous-time system
input and output continuous-time signals
discrete-time system
input and output discrete-time signals
Copyright © Shi Ping CUC

14. Signal, System, Signal Processing
A signal carries information !
The objective of signal processing:
To extract, enhance, store and transmit the useful information carried by the signal.
Digital signal processing:
To implement the signal processing by a digital means.
return
Copyright © Shi Ping CUC

15. The Constitution of DSP System
Equivalent to an analog signal processor
ADC
DAC
DSP
PrF
PoF
analog
waveform
PrF: antialiasing filtering
PoF: smooth out the staircase waveform
example
return
Copyright © Shi Ping CUC

16. How to Implement the DSP
To handle the DSP algorithms in a general-purpose microprocessor by means of software programming
To handle the DSP algorithms in a specifically designed Digital Signal Processors (DSPs)
return
Copyright © Shi Ping CUC

17. Copyright © 2005. Shi Ping CUC
The Application of DSP
The main tasks of DSP
Signal Analysis
Measurement of signal properties
Spectrum (frequency/phase) analysis
Target detection, verification, recognition
Signal Filtering
Signal-in-signal-out, filter
Removal of noise/interference
Separation of frequency bands
Copyright © Shi Ping CUC

18. Copyright © 2005. Shi Ping CUC
The Application of DSP
DSP application examples
Telecommunications
Multiplexing
Compression
Echo control
Audio Processing
Music
Speech generation
Speech recognition
Copyright © Shi Ping CUC

19. Copyright © 2005. Shi Ping CUC
The Application of DSP
DSP application examples
Echo Location
Radar
Sonar
Reflection seismology
Image Processing
Medical
Space
Commercial Imaging Products
Copyright © Shi Ping CUC

20. Copyright © 2005. Shi Ping CUC
The Application of DSP
Demonstration
FM synthesis of sound
chirp
clarinet
brass
bell
Digital image processing
Deblurring
Brass 铜管乐器
Clarinet 单簧管
Bell 钟
Edge detection
Noise reduction
return
Copyright © Shi Ping CUC

21. Copyright © 2005. Shi Ping CUC
The Advantages of DSP
Absence of drift in the filter characteristics
Improved quality level
Reproducibility
Ease of new function development
Multiplexing
Modularity
Total single chip implementation using VLSI technology
return
Copyright © Shi Ping CUC

22. Copyright © 2005. Shi Ping CUC
The sound signal is an example of a 1-D signal where the independent variable is time
return
Copyright © Shi Ping CUC

23. Copyright © 2005. Shi Ping CUC
A black-and-white image signal is an example of a 2-D signal where the 2 independent variables are the 2 spatial variables.
Copyright © Shi Ping CUC

24. Copyright © 2005. Shi Ping CUC
A color image signal is a 3-channel signal composed of three 2-D signals representing the three primary color: red, green and blue (RGB)
return
Copyright © Shi Ping CUC

25. Copyright © 2005. Shi Ping CUC
A black-and-white video signal is an example of a 3-D signal where the 3 independent variables are the 2 spatial variables and the time variable.
Copyright © Shi Ping CUC

26. Copyright © 2005. Shi Ping CUC
A color video signal is a 3-channel signal composed of three 3-D signals representing the three primary color: red, green and blue (RGB)
return
Copyright © Shi Ping CUC

27. Copyright © 2005. Shi Ping CUC
return

28. Copyright © 2005. Shi Ping CUC
return
Copyright © Shi Ping CUC

29. Copyright © 2005. Shi Ping CUC
Original Image
Restored Image
Blurred Image
return
Copyright © Shi Ping CUC

30. Copyright © 2005. Shi Ping CUC
return
Copyright © Shi Ping CUC

31. Copyright © 2005. Shi Ping CUC
return
Copyright © Shi Ping CUC