Digital Signal Processing Lecture 1 PDF

Misr Higher Institute For Commerce & Computers Computer Sciences Department Digital Signal Processing DSP DR. Lobna Mohamed Abouelmagd  Course Contents  Introduction to Digital Signal Processing  Signal Sampling and Quantization  Digital Signals and Syst...

Misr Higher Institute For Commerce & Computers Computer Sciences Department Digital Signal Processing DSP DR. Lobna Mohamed Abouelmagd  Course Contents  Introduction to Digital Signal Processing  Signal Sampling and Quantization  Digital Signals and Systems  Discrete Fourier Transform and Signal Spectrum  The z-Transform  Lab : matlab Grades  100 degrees  60 final  20 midterm  20 (sheets + Lab + quiz)  Introduction to Digital Signal Processing Topics  Basic Concepts of Digital Signal Processing  Basic Digital Signal Processing Examples  Digital Filtering  Signal Frequency (Spectrum) Analysis  Overview of Typical Digital Signal Processing in Real-World Applications  Digital Crossover Audio System  Interference Cancellation in Electrocardiography  Speech Coding and Compression  Compact-Disc Recording System  Digital Photo Image Enhancement  Digital Signal Processing Applications Imagine the life without Digital Signal Processing !!!!!!  we would not have digital/Internet audio or video; digital recording; CD, DVD, and MP3 players; digital cameras; digital and cellular telephones; digital satellite and TV;  or wire and wireless networks.  Medical instruments would be less efficient or unable to provide useful information for precise diagnoses if there were no digital electrocardiography (ECG) analyzers or digital x-rays  We would also live in many less efficient ways, since we would not be equipped with voice recognition systems, speech synthesis systems, and image and video editing systems.  Without DSP, scientists, engineers, and technologists would have no powerful tools to analyze and visualize data and perform their design, and so on. Signal: A signal is any physical quantity that carries information, and that varies with time, space, or any other A digital signal any sequence of numbers that can be stored in a computer memory or a piece of hardware. System: It is defined as the physical device that performs an operation upon the signal. Signal Processing: - The operation which one carried out in the signal by the system one called as signal processing. Analyze: understand the information carried by the signal and perhaps extract some more high level description. Synthesize: create a physical phenomenon that contains a certain amount of information, that we want to put out  The difference between digital and analog signal Digital Signals Analog Signals Digital signal have two or more states Analog signal is continuous and time and in binary form. varying. Troubleshooting of digital signals are Troubleshooting of analog signals are easy. difficult. These are stable and less prone to Easily affected by the noise. noise. Digital signals use discrete values to Analog signals use continous values to represent the data. represent the data. Accuracy of the digital signals are Accuracy of the analog signals may be immune from the noise. affected by noise. Digital signals are not affected during Analog signals may be affected during data transmission. data transmission. Digital signals use less power. Analog signals use more power. Components like transistors, logic Components like resistors, Capacitors, gates, and micro-controllers are used in Inductors, Diodes are used in analog Digital circuits. circuits. Digital Signal Schema Current voltage temperature pressure. Usually a transducer (sensor) is used to convert the nonelectrical signal to the analog electrical signal (voltage). Digital Signal Schema The purpose of filtering is to significantly attenuate aliasing Distortion The band-limited signal at the output of the analog filter Analog to Digital Converter (ADC) It converts analog signal to digital data. Digital Signal Schema Digital signal processor (DS) the DS processor unit is a special type of digital computer and can be a general-purpose digital computer, a microprocessor, or an advanced microcontroller; DSP rules can be implemented using software in general. With the DS processor and corresponding software, a processed digital output signal is generated. This signal behaves in a manner according to the specific algorithm used. Digital Signal Schema Digital to analog converter (DAC ) Converts the processed digital signal to an analog output signal.  Digital Filtering  a digitized noisy signal obtained from digitizing analog voltages (sensor output) containing a useful low-frequency signal and noise that occupies all of the frequency range. After ADC, the digitized noisy signal x(n), where n is the sample number, can be enhanced using digital filtering.  Since our useful signal contains the low-frequency component, the high frequency components above that of our useful signal are considered as noise, which can be removed by using a digital lowpass filter.  1.2.2 Signal Frequency (Spectrum) Analysis  certain DSP applications often require that time domain information and the frequency content of the signal be analyzed. a digitized audio signal and its calculated signal spectrum (frequency content), defined as the signal amplitude versus its corresponding frequency for the time being via a DSP algorithm, called fast Fourier transform (FFT). Digital Signal Processing in Real-World Application 1.3.1 Digital Crossover Audio System  1.3.2 Interference Cancellation in Electrocardiography 1.3.3 Speech Coding and Compression 1.3.5 Digital Photo Image Enhancement DSP Applications