数字信号处理教学课件：1-2 Typical Signal Processing and Applications

1、1 Signals and Signal Processing1.2 Typical Signal Processing and Applications Whats signal processing?to extract useful informationto change signals for desired purpose.normally work as a system. SystemExciting(Input signal)Response(Output signal)1 Signals and Signal ProcessingDSP-Processing signals

2、 in digital form.ASP-Processing signals in analog form.1.2.1 Digital Signal Processing Analog SystemExciting(Analog signal)Response(Analog signal)Its generally used for the digital processing of an analog signal analog signals digital signals(binary)1.2.2 How to do DSP?1 Signals and Signal Processin

3、gFigure 1.42 Scheme for the digital processing of an analog signalDigital Processor: Hardware(VLSI) and Softwares.1 Signals and Signal ProcessingDSP Solution1 Signals and Signal Processing（1）Programmability Analog system：Modify hardware design. Digital system：Modify software. Example：Analog filter,

4、digital filter, adaptive filter1 Signals and Signal Processing1.3 Why DSP?（2）Precision Analog system：component specification: resistors have a tolerance 5%; capacitors 20% or worse Digital system：ADC bits, CPU word width and algorithm1 Signals and Signal Processing（3）Stability Analog system：the char

5、acteristics of analog system components, resistors, capacitors and operational amplifiers will change along with temperature, humidity Digital system：will show no variation with temperature throughout their guaranteed operation range.1 Signals and Signal Processing(4) Anti-noise1 Signals and Signal

6、ProcessingAmplify AAmplify BSignal generatorcomputer Acomputer B(5) Repeatability1 Signals and Signal Processing（6）VLSI (Very Large Scale Integrated circuit)1 Signals and Signal Processing(7) Error Correcting CodesData retrieval and transmission systems suffer from a number of potential forms of err

7、or.With information in a digital or binary form, we may easily build into the data stream additional “redundant” bits that are used to detect when an error has occurred.1 Signals and Signal Processing(8) Data Transmission and StorageThe Internet, Compact Disc (CD) and Digital Video Disc (DVD) brough

8、t information based on trouble-free high-quality text, audio and video into the office and home.The fidelity of the digital medium is greater than that of the analog one.1 Signals and Signal ProcessingWe still need analog processing（1）Real-Time Processing Analog system：Besides the delay introduced b

9、y the circuit, the processing is in real-time. Digital system：Decided by the processor speed.1 Signals and Signal ProcessingWe still need analog processing（2）Processing very high frequency signals Analog system：may process microwave, mini-meter-wave, even light wave signals. Digital system：By the Ny

10、quist Rule，the processing speed is limited by the S/H, A/D and processor speed.1 Signals and Signal ProcessingWe still need analog processing(3)The most signals in real world are analog.If we want to process these analog signals with digital signal processing system, we must change them into digital

11、 form first by mixed signal processing.1 Signals and Signal Processingtransmitted signalTransmmiterReceiverintermediateinputsignalreceived signaloutputsignalSpeech,Text,Audio,Video Voltage, current,Electromagnetic Speech,Text,Audio,Video With InformationApplications of DSP: CommunicationsApplication

12、s of DSP: Image Processingsource 1source 2source 3source 4source 5observ. 1observ. 2observ. 3observ. 4observ. 5Given five random mixtures of five source images, whatre the source images?Nonnegative Blind Source Separation 11 T.-H. Chan, W.-K. Ma, C.-Y. Chi and Y. Wang, “Blind separation of non-negat

13、ive sources by convex analysis: effective method using linear programming,” IEEE ICASSP-2008 pp. 3493-3496.Applications of DSP: Image ProcessingImage Deblurring 22 M. Afonso, J. Bioucas-Dias, and M. Figueiredo, “An Augmented Lagrangian Approach to the Constrained Optimization Formulation of Imaging

14、Inverse Problems,” IEEE Trans. Imag. Process., 2011, pp. 681-695Applications of DSP: Image ProcessingImage Inpainting 22 M. Afonso, J. Bioucas-Dias, and M. Figueiredo, “An Augmented Lagrangian Approach to the Constrained Optimization Formulation of Imaging Inverse Problems,” IEEE Trans. Imag. Process., 2011, pp. 681-695Applications of DSP: Speech ProcessingCocktail Party