1. ITGD3101Modern Telecommunications Lecture-5- Pulse Code Modulation week 5- q-2/ 2008 Dr. Anwar Mousa University of Palestine Faculty of Information Technology

2. 02-02-2008UP-Copyrights reserved2 Contents Sampling theorem Quantization Pulse Code Modulation

3. 02-02-2008UP-Copyrights reserved3 Aperiodic signal representation by Fourier Transform

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6. 6 Today, we are going to talk about: The first important step in any DCS: Transforming the information source to a form compatible with a digital system

7. UP-Copyrights reserved7 Encode Transmit Pulse modulate SampleQuantize Demodulate/ Detect Channel Receive Low-pass filter Decode Pulse waveforms Bit stream Format Digital info. Textual info. Analog info. Textual info. Analog info. Digital info. source sink Formatting and transmission of baseband signal

8. UP-Copyrights reserved8 Format analog signals To transform an analog waveform into a form that is compatible with a digital communication, the following steps are taken: 1.Sampling 2.Quantization and encoding 3.Baseband transmission

9. UP-Copyrights reserved9 Sampling theorem

10. UP-Copyrights reserved10 Sampling theorem

11. UP-Copyrights reserved11 Aliasing effect LP filter Nyquist rate aliasing

12. UP-Copyrights reserved12 Sampling theorem

13. UP-Copyrights reserved13 Sampling theorem Sampling theorem: A bandlimited signal with no spectral components beyond, can be uniquely determined by values sampled at uniform intervals of The sampling rate, is called Nyquist rate. Sampling process Analog signal Pulse amplitude modulated (PAM) signal

14. UP-Copyrights reserved14 Sampling theorem

15. UP-Copyrights reserved15 Sampling theorem

16. UP-Copyrights reserved16 Pulse Code Modulation (PCM).

17. UP-Copyrights reserved17 Pulse Code Modulation (PCM).

18. UP-Copyrights reserved18 Pulse Code Modulation (PCM).

19. UP-Copyrights reserved19 Quantization example t Ts: sampling time x(nTs): sampled values xq(nTs): quantized values boundaries Quant. levels 111 3.1867 110 2.2762 101 1.3657 100 0.4552 011 -0.4552 010 -1.3657 001 -2.2762 000 -3.1867 PCM codeword 110 110 111 110 100 010 011 100 100 011 PCM sequence amplitude x(t)

20. UP-Copyrights reserved20 Pulse Code Modulation (PCM).

21. UP-Copyrights reserved21 Pulse Code Modulation (PCM).

22. UP-Copyrights reserved22 Pulse Code Modulation (PCM).

23. UP-Copyrights reserved23 Advantages of Digital Communications

24. UP-Copyrights reserved24 Advantages of Digital Communications

25. UP-Copyrights reserved25 Advantages of Digital Communications

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31. 02-02-2008UP-Copyrights reserved31 Summary We have studies the following topics: Sampling theorem Quantization Pulse Code Modulation

32. 02-02-2008UP-Copyrights reserved32 Contents Principles of Digital Data Transmission Line coding ON-OFF Polar BIPOLAR HDB-3

33. UP-Copyrights reserved33 Today, we are going to talk about: Principles of Digital Data Transmission

34. UP-Copyrights reserved34 Principles of Digital Data Transmission

35. UP-Copyrights reserved35 Line Coder

36. 02-02-2008UP-Copyrights reserved36 Line Coder

37. 02-02-2008UP-Copyrights reserved37 Line Coder

38. 02-02-2008UP-Copyrights reserved38 Line Coding

39. 02-02-2008UP-Copyrights reserved39 Line Coding