Husheng Li The University of Tennessee Course Contents Basics of communications Signals and noise Amplitude modulation Phase and frequency modulations Pulse modulation Analog communication system ID: 491465
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Slide1
Chapter 1. Introduction
Husheng Li
The University of TennesseeSlide2
Course Contents
Basics of communications
Signals and noise
Amplitude modulation
Phase and frequency modulations
Pulse modulation
Analog communication systemSlide3
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, 2008Slide4
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%Slide5
Office hour and TA
2:15 --- 3:15pm, MWF, MK644
TA:
Jingchao
Bao, jbao2@utk.edu
Course website: go to my personal website
http://
web.eecs.utk.edu
/~
husheng
/Slide6
Experiments
Experiment 1:
Matlab
simulation for amplitude modulations.
Experiment 2:
Matlab simulation for frequency and phase modulations.Experiment 3: USRP hardware board experimentSlide7
Concepts
A communication system conveys information from its source to a destination some distance away.
Some concepts: Information, analog, digital, transducerSlide8
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 decodingSlide9
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.Slide10
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 bySlide11
Modulation
Modulation involves two waveforms: a modulating signal and a carrier wave.
Modulating
signal
Amplitude
Modulation
Pulse train
With AMSlide12
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.Slide13
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 Slide14
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.Slide15
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 radioSlide16
Some History (1)Slide17
Some History (2)Slide18
Some History (3)Slide19
Some History (4)Slide20
Some History (5)Slide21
Some History (6)Slide22
Assignment
Read chapter 1