1. Introduction ADCES & BM MUET1

2. Course Description Title of Subject : Analog & Digital Communication Disciplines : Electronic Engineering Term : (6th Term) Effective : 09ES-Batch and onwards Pre-requisites : - Co-requisite: - Assessment : Sessional Work: 20% Written Examination: 80% Marks : Theory: 100 Practical: 50 Credit Hours : 4 2 Minimum Contact Hours : 52 26 ADCES & BM MUET2

3. Sessional Work ?? Quizzes ?? Assignments 2 Class tests (Aims & objectives of this course + recommended books available on the website: http://www.muet.edu.pk/departments/electronics- engineering/course-outline) ADCES & BM MUET3

4. About me Khuhed Memon (Lecturer Dept of ES & BM MUET) MS Signal Processing (Nanyang Technological University, Singapore) BE Electronics (Pakistan Navy Engineering College, National University of Sciences & Technology, Pakistan) ADCES & BM MUET4

5. Class style Interactive: Discussions + questions in class, email, office….. ADCES & BM MUET5

6. Contact Info: Office: LEADERS @ IT Building E-mail: khuhedkk@hotmail.com *best way to communicate : e-mail ADCES & BM MUET6

7. Enjoy the course ADCES & BM MUET7

8. ADCES & BM MUET8 This lecture Concept of Signal Processing Introduction to Signals Classification of Signals Basic elements of SP System Analog to Digital Conversion –Sampling –Quantization Nyquist Theorem Applications of Signal Processing

9. ADCES & BM MUET9 Signal Processing Representation, transformation, manipulation of signals and the information they contain. Classification: Depends upon the type of signal to be processed. Analog Signal Processing Digital Signal Processing

10. ADCES & BM MUET10 Signal Processing Analog SP Continuous time signals are processed. Digital SP Discrete - time discrete - valued signals processed by digital computers or other data processing machines.

11. ADCES & BM MUET11 Signal?? Any indication / information A change in which some information is residing

12. ADCES & BM MUET12 Classification of Signals Continuous-time / Discrete-time Signals Continuous-valued / Discrete-valued Signals Deterministic / Random Signals One-dimensional / Multi-dimensional Signals

13. ADCES & BM MUET13 Fundamental SP system Most signals – Analog in nature. Analog to Digital Converter is used as an interface between analog signal and Digital Signal Processor. A/D ConverterD/A Converter Digital Signal Processor Analog Input Signal Analog Output Signal

14. ADCES & BM MUET14 A-D Conversion 1.Sampling First step in going from analog to digital. In signal processing, sampling is the reduction of a continuous signal to a discrete signal. A common example is the conversion of a sound wave (a continuous- time signal) to a sequence of samples (a discrete-time signal).

15. ADCES & BM MUET15 Sampling

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18. ADCES & BM MUET18 Nyquist Theorem In order the samples represent correctly the analog signal, the sampling frequency must be greater than twice the maximum frequency of the analog signal: f s ≥2F M The limiting frequency 2F M is called Nyquist rate.

19. ADCES & BM MUET19 Aliasing (Time Domain)

20. ADCES & BM MUET20 Aliasing (Frequency Domain)

21. ADCES & BM MUET21 Methods of avoiding Aliasing To avoid aliasing, there are two approaches: One is to raise the sampling frequency to satisfy the sampling theorem. The other is to filter off the unnecessary high- frequency components from the continuous-time signal. We limit the signal frequency by an effective low-pass filter, called anti-aliasing prefilter, so that the highest frequency left in the signal is less than half of the intended sampling rate.

22. ADCES & BM MUET22 General DSP System

23. ADCES & BM MUET23 Quantization Slide 143 CCN module 2 MIT OCW

24. Companding or Non-linear Encoding Companding = compressing + expanding Why companding? Quantization levels not evenly spaced Reduces overall signal distortion Can also be done by companding ADC24ES & BM MUET

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29. ADCES & BM MUET29 Applications of SP RADAR SONAR Medical Image Processing –Pattern recognition –Edge detection Audio Signal Processing –Speech generation –Speech recognition –Speaker identification Telecommunications –Multiplexing –Compression –Echo control