Data Communication Theory & Coding 1 Ya Bao

2 Website: Methods of Teaching and Learning : Lectures, Tutorials and Workshops Assessment of the Module : 2-hour written examination -- 70% Laboratory report -- 30% Lecturer: Ya Bao and J G Zhang Lab tutor: Ya Bao and Vincent Siyau. Ya Bao

Text Books 3 Ya Bao

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Chapter 1. Introduction 5 Ya Bao

table_01_01a 1.1 Historical Background 6 Ya Bao

1.2 The Block Diagram of a Communication Systems 7 Ya Bao

1.3 Channel Characteristics 8 Types of transmission channels Electromagnetic wave propagation channels (wireless) Guided electromagnetic wave channels (wired) Optical links Ya Bao

1.4 System analysis techniques 9 a.Time-domain and frequency-domain analyses Signal frequency and signal bandwidth, Fourier Analysis b.Modulation and communication theories Changing some parameter of a carrier wave in accordance with the message signal. c.Detection theory d.Probability theory Ya Bao

The Electromagnetic Spectrum 1. Electromagnetic Waves and Energy Velocity: speed at which the energy travels through Frequency: the number of oscillations or cycles per second (hertz, abbreviated Hz) of the waveform Wavelength : the distance between peaks of the oscillations of the energy wave

Ya Bao 11 Wavelength can also be measured as the distance between the negative peaks, zero points.

Ya Bao 12 speed of light: The propagation velocity is less in any medium other than vacuum  In wire, it is anywhere from 60% to 85% of c  a common type of cable used for cable TV has a propagation factor of 75% of c. Example 1 What is the wavelength in vacuum for a frequency of 1 million hertz? Example 2 What is the frequency when the measured wavelength is 6 m?

Ya Bao T HE E LECTROMAGNETIC S PECTRUM

Ya Bao 14 Frequency RangeDesignations Hz ‑ HzELF 0.3 kHz ‑ --3 kHzVF 3 kHz----- ‑ 30 kHzVLF 30 kHz ‑ kHzLF 0.3 MHz ‑ -3 MHzMF 3 MHz ‑ MHzHF 30 MHz MHzVHF 0.3 GHz ‑ --3 GHzUHF 3 GHz ‑ GHzSHF 30 GHz ‑ GHzEHF 0.3 THz ‑ ---3 THzInfrared light 3 THz ‑ THzInfrared light 30 THz ‑ THzInfrared light 0.3 PHz ‑ ---3 PHzVisible light 3 PHz ‑ PHzUltraviolet light 30 PHz ‑ PHzX ‑ rays 0.3 EHz ‑ ---3 EHzGamma rays 3 EHz ‑ EHzCosmic rays 1 kilohertz (kHz)= 10 3 Hz, 1 megahertz (MHz)= 1*10 6 Hz 1 gigahertz (GHz)= 1*10 9 Hz, : terahertz (THz); : petahertz (PHz); : exahertz (EHz);