1 / 29

Communication Theory

Communication Theory. Prof. Deli Qiao Department of Communications Engineering. Instructor Information. Office: 245 Email: dlqiao@ce.ecnu.edu.cn Web: http://faculty.ecnu.edu.cn/s/2915/main.jspy Phone: 54345492 Office Hours: Mon. & Fri. 0:30pm~1:30pm. Textbook. J. Proakis. 樊昌信改编.

gertrudisf
Télécharger la présentation

Communication 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. Communication Theory Prof. Deli Qiao Department of Communications Engineering

  2. Instructor Information • Office: 245 • Email: dlqiao@ce.ecnu.edu.cn • Web: http://faculty.ecnu.edu.cn/s/2915/main.jspy • Phone: 54345492 • Office Hours: Mon. & Fri. 0:30pm~1:30pm

  3. Textbook J. Proakis 樊昌信改编

  4. Reading Materials • 通信原理(Principles of Communications), Lecture Notes, Prof. Meixia Tao, Shanghai Jiao Tong University.[http://iwct.sjtu.edu.cn/Personal/mxtao/teaching.html] • Introduction to analog and digital communications, Lecture Notes, Ohio State University. [http://www2.ece.ohio-state.edu/~schniter/ee501/index.html]

  5. Course Objective • The primary objective of this course is • to introduce the basic techniques used in modern communication systems, and • to provide fundamental tools and methodologies in analysis and design of these systems • After this course, the students are expected to • understand the information flow in communication systems and the theories and techniques of modulation, coding and transmission, and • analyze the merits and demerits of current communication systems and to eventually perform research and development (R&D) related to new systems

  6. Outline • Introduction • Signal, random variable, random process and spectra • Analog modulation • Analog to digital conversion • Digital transmission through baseband channels • Signal space representation • Optimal receivers • Digital modulation techniques • Channel coding • Synchronization • Information theory*

  7. Grades • Quiz (15%) • About 10-15 times, each one and only one problem. • Homework (15%) • About 4-7 times, including Matlab simulation problems. • Mid-term Exam (20%) • In-class open book. • Final Exam (50%)

  8. In-Class Rules • Shutdown smartphone and donot put on desk! • No food/drink in class and put your drinking bottle aside the desk! • No mutual conversation ! • Prepare, make notes and review frequently! • Practice makes perfect!

  9. Maxim (格言)

  10. Outline • Introduction • Signal, random variable, random process and spectra • Analog modulation • Analog to digital conversion • Digital transmission through baseband channels • Signal space representation • Optimal receivers • Digital modulation techniques • Channel coding • Synchronization • Information theory

  11. Introduction The fundamental problem of communication is that of reproducing at one point either exactly or approximately a message selected at another point. ---Claude E. Shannon 1948

  12. Introduction • Historic signal (smoke, flag, horn) • After electricity • 1838: telegraph (S. Morse) • 1876: telephone (A. Bell) • 1863: electromagnetic wave (J. Maxwell, found 1887 by Hertz) • 1895: radio (G. Marconi) • 1901: transatlantic transmissions (Marconi, 2200 miles) 1909 Nobel Prize

  13. Introduction • Early 20th century • Most communication systems including the early version of cellular systems developed in 1940s are analog. • Engineering designs are ad-hoc, tailored for each specific application.

  14. Introduction Modern Communication Systems

  15. Introduction • General questions • Is there a general methodology for designing communication systems? • Is there a limit to how fast one can communicate?

  16. Introduction

  17. Introduction

  18. Introduction • System diagram

  19. Introduction

  20. Introduction

  21. Introduction

  22. Introduction • Wireless channel free-space propagation

  23. Introduction • The additive noise channel • Linear time-invariant (LTI) filter channel

  24. Introduction • Linear time-variant filter channel • A multi-path channel

  25. Introduction • Analog communication systems • Digital communication systems

  26. Introduction

  27. Introduction

  28. Introduction • Why digital systems? • Robustness to channel noise and external interference • Security of information during its transmission from source to destination • Integration of diverse source information into a common format • Low cost DSP chips by very cheap VLSI designs

  29. Introduction • Performance metrics of communication systems • Reliability: SNR for analog; Bit error rate (BER) for digital • Efficiency: Spectral efficiency vs. Energy efficiency

More Related