DESIGNING WIRELESS COMMUNICATION SYSTEM Troy Lynn Bullock – Reagan High School Houston Independent School District Faculty Mentor : Dr. Tie Liu Information Theory and Coding for Wireless Broadcast Networks Electrical Electronics & Communications Engineering Graduate Assistant: Neeharika Marukala
Designing Wireless Communication System. Troy Lynn Bullock – Reagan High School Houston Independent School District Faculty Mentor : Dr. Tie Liu Information Theory and Coding for Wireless Broadcast Networks - PowerPoint PPT Presentation
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DESIGNING WIRELESS COMMUNICATION SYSTEM
Troy Lynn Bullock – Reagan High School Houston Independent School District
Faculty Mentor : Dr. Tie Liu Information Theory and Coding for Wireless Broadcast Networks Electrical Electronics & Communications Engineering Graduate Assistant: Neeharika Marukala
Communication
Communication is a term that comes from Greek, it means, ‘communicating at a distance’ through signals of varied nature coming from a transmitter to a receiver.
Communication
In ancient time communication began with the use of visual
signals such as; smoke, semaphore telegraphs, and signal flags,
and audio signals such as; drumbeats, lung blown horns, or loud
whistles.
Communication In the modern age, the true ‘jump’ in terms of quality
came with the advent of electricity. Electromagnetic energy, in fact, is able to transport information in an extremely fast way (ideally to the speed of light), in a way that previously had no equals in terms of costs and reliability.
Wireless Communication
Wireless communication is the transfer of information over a distance without the use of wires.
Some examples of wireless technology:- Security Systems- Television remote control- Cellular telephone (phones and modems)
- Wi-Fi
- Wireless energy transfer
Bandwidth Wireless communication uses electromagnetic
transmission.
Electromagnetic transmission operates over a range of spectrum called, bandwidth.
Bandwidth is a highly regulated commodity.
Bandwidth is extremely expensive.
Bandwidth Bandwidth is a valuable and limited resource.
For example, an FM radio receiver’s tuner spans a limited range of frequencies (87.5 – 108 MHz)
A government agency, the FCC (Federal Communications Commission) in the United States may apportion the regionally available bandwidth to licensed broadcasters so that their signals do not mutually interfere.
Each transmitter owns a slice of bandwidth, a valuable (if intangible) commodity.
Impact of Bandwidth
Basic Communication Setup
Pulse –shaping Filters
Basic Communication SetupInformation
sourceDestination
Modulator Demodulator
Physical Medium
bits
transmittervoltage
s
bits
voltages
waveforms
waveforms
DACDigital Analog
Converter
ADCAnalog Digital
Converter
receiver
distortion
channel
Pulse Shaping Filter The voltages are converted into
waveforms using a pulse shaping filter.
This is where bandwidth comes into play.
Its purpose is to make the transmitted signal better suited to the communication channel by limiting the effective bandwidth of the transmission.
Sinc Pulse Shaping Filter
Time Domain Frequency Domain
Raised Cosine Pulse Shaping Filter
Time Domain Frequency Domain
Research Activities Given a bandwidth, the number of
channel uses per second is fixed.
The goal of transmitter/receiver design is to maximize the number of bits that can be reliably communicated per channel use.
Reliable communication in the presence of noise.
Design Objectives Energy efficient: The energy spent
on transmission is proportional to the number of bits transmitted.
Bandwidth efficient: The number of bits transmitted is proportional to the channel uses.
Reliable: The probability of error decreases as a function of the number of bits transmitted.