1. Chapter 1. Introduction Husheng Li The University of Tennessee

2. Course Contents 1.Basics of communications 2.Signals and noise 3.Amplitude modulation 4.Phase and frequency modulations 5.Pulse modulation 6.Analog communication system

3. Textbook  Communication Systems: An Introduction to Signals and Noise in Electrical Communication, by A. B. Carlson and P. B. Crilly, McGraw Hill, 5 th edition, 2008

4. Logistics  Homework: 20% (4 problems every Friday; turn in your homework in two weeks)  Midterm and final exams: 40%  Quiz: 15% (will be 5 quizzes)  Experiments: 25%

5. Office hour and TA  2:15 --- 3:15pm, MWF, MK644  TA: Jingchao Bao, jbao2@utk.edujbao2@utk.edu  Course website: go to my personal website http://web.eecs.utk.edu/~husheng/

6. Experiments  Experiment 1: Matlab simulation for amplitude modulations.  Experiment 2: Matlab simulation for frequency and phase modulations.  Experiment 3: USRP hardware board experiment

7. Concepts  A communication system conveys information from its source to a destination some distance away.  Some concepts: Information, analog, digital, transducer

8. Elements of Communication Systems  The transmitter involves modulation and coding.  The transmission channel is the medium for communications, which could be wireless, optical or even sound.  The receiver carries out demodulation and decoding

9. Negative Factors in Communications  Distortion: Waveform perturbation caused by imperfect response of the system to the desired signal itself.  Interference: Contamination by extraneous signals  Noise: Random and unpredictable electrical signals.

10. Fundamental Limitations  Communications are limited by bandwidth and noise.  Bandwidth: the width of frequency band used for the communications.  Noise: The signal-to-noise ratio (SNR; S/N) is important.  When the noise is Gaussian, the channel capacity is given by

11. Modulation  Modulation involves two waveforms: a modulating signal and a carrier wave. Modulating signal Amplitude Modulation Pulse train With AM

12. Coding  Coding is a symbol processing operation for improved communication when the information is digital or can be approximated in the form of discrete symbols (actually there is also analog coding).  Source coding converts source information into a series of bits.  Channel coding: add redundancy to improve the robustness of transmission.

13. EM Transmission  there are several effects that enable light as well as electromagnetic (EM) waves to propagate around obstructions or beyond the earth’s horizon

14. Multipath and Fading  In wireless communications, the signal could be received by the receiver after reflections.  The superposition of signals from different paths could strengthen or weaken each other.

15. Emerging Developments  Circuit / packet switching  Multiple access: TDMA, CDMA, OFDMA.  Ultra-wideband (UWB)  Computer Networks: WiFi (IEEE 802.11) and WiMAX (IEEE 802.16)  Software defined radio

16. Some History (1)

17. Some History (2)

18. Some History (3)

19. Some History (4)

20. Some History (5)

21. Some History (6)

22. Assignment  Read chapter 1