1 / 4

Information & Coding Theory

Channel (errors). Information & Coding Theory. Information. Information. . Symbols s 1 ,…,s q. Encoding Source/Channel. signal. Decoding Channel/Source. Source. signal + noise. Symbols s 1 ,…,s q. Destin- ation. Noise. Example : Morse Code. telegraph wire. transmitter.

xenia
Download Presentation

Information & Coding Theory

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Channel (errors) Information & Coding Theory Information Information  Symbols s1,…,sq Encoding Source/Channel signal Decoding Channel/Source Source signal + noise Symbols s1,…,sq Destin- ation Noise Example: Morse Code telegraph wire transmitter receiver Encoding Decoding dots, dashes spaces ∙ ─ _ A, …, Z A, …, Z keyer recognizer shortwave radio Example: ASCII Code seven-bit blocks Telephone wire seven-bit blocks keyboard modem modem terminal screen Character character

  2. Information Source – the symbols are undefined, and the “meaning” of the information being sent is not dealt with – only an abstract measure of the “amount” or “quantity. • Examples • text of various forms – reports, papers, memos, books, scientific data (numbers) • pictures of various forms – diagrams, art, photographic images, scientific data (e.g. from satellites) • sound of various forms – music, speech, noises, recorded sound, radio • animation of various forms – moving pictures, film, video tape, video camera, television • equations representing mathematical ideas or algorithms – two textual representation systems with graphical output: Tex & Mathematica

  3. Analog vs. Digital sound (amplitude versus time) picture (amplitude versus space) Examples of (apparently) analog sources of information: pressure: + →  granularity – molecular intensity: [0, 1]  [0, 1] → + granularity – crystalline microphone → tape recorder → speaker lenses → film (negative) → print (positive) Examples of (apparently) digital sources of information: Text a′ ? B sequences of characters different languages have different characters (often the typeface or writing style conveys additional meaning or information)

  4. Examples of composites (some digital and analog) • color printing (as opposed to photography) • television intensity unquantized, temporally discrete • color spatially discrete spatially discrete (dots) spectrum discrete (color separation) intensity discrete (dot or no dot) random signal contains largest amount of information

More Related