Designing a wireless Designing a wireless communication Systemcommunication System

Presented by:Presented by:Shalini KapoorShalini Kapoor

MacArthur HS ,Aldine ISDMacArthur HS ,Aldine ISD

Faculty Mentor: Faculty Mentor:

Dr. Tie LiuDr. Tie Liu

“ “Information theory & coding Information theory & coding for wireless broadcast for wireless broadcast network”network”

Grad. Assistance:Grad. Assistance:

NeeharikaNeeharika MarukalaMarukala

History of communicationHistory of communication

• The history of The history of communication communication began with the began with the use of visual use of visual signals like smoke signals like smoke signals, torch signals, torch signals and signals and flashing mirrors.flashing mirrors.

• Those early communication techniques were replaced by telegraph invented by Thomas Edison in 18th century.

History contd..History contd..

• In 1870 Alexander In 1870 Alexander Graham Bell Graham Bell invented invented telephone.telephone.

• In 1896, Marconi In 1896, Marconi demonstrated the first demonstrated the first radio transmission and radio transmission and radio commission was radio commission was born.born.

Wireless communication Wireless communication introductionintroduction

• Wireless communication is the transfer of information Wireless communication is the transfer of information over a distance without the use of enhanced electrical over a distance without the use of enhanced electrical conductors or wires.conductors or wires.

• It permits the services such as long range It permits the services such as long range communications, that are impossible or impractical to communications, that are impossible or impractical to implement with the wires.implement with the wires.

Where we use wireless Where we use wireless communicationcommunication

• Examples of wireless technology include GPS, Examples of wireless technology include GPS, Garage door opener, computer peripherals, Garage door opener, computer peripherals, computer networks, television remote controls, computer networks, television remote controls, Internet, modem, bluetooth, Wi-Fi and security Internet, modem, bluetooth, Wi-Fi and security systems.systems.

• Cellular phone systems Cellular phone systems

have experienced exponential have experienced exponential

growth over last decade.growth over last decade.

BandwidthBandwidth

• Wireless communication uses electromagnetic Wireless communication uses electromagnetic transmission.transmission.

• Electromagnetic transmission operates over a Electromagnetic transmission operates over a range of spectrum.range of spectrum.

• This range of spectrum is Bandwidth which is a This range of spectrum is Bandwidth which is a key concept in wireless communication key concept in wireless communication systems.systems.

BandwidthBandwidth

• Bandwidth is a valuable and limited resource.Bandwidth is a valuable and limited resource.

• For example, a FM radio receiver’s tuner spans a limited For example, a FM radio receiver’s tuner spans a limited range of frequencies (87.5-108mHz).range of frequencies (87.5-108mHz).

• FCC , a government agency in US apportions regionally FCC , a government agency in US apportions regionally available bandwidths to licensed broadcasters so that available bandwidths to licensed broadcasters so that their signals do not interfere.their signals do not interfere.

• Each transmitter owns a slice of bandwidth.Each transmitter owns a slice of bandwidth.

• Bandwidth is a highly regulated commodity and it is Bandwidth is a highly regulated commodity and it is highly expensive.highly expensive.

Impact of BandwidthImpact of Bandwidth

• Basic Communication SetupBasic Communication Setup

• Pulse shaping filterPulse shaping filter

Basic Communication SetupBasic Communication Setup

Information Source

Destination

Transmitter

Modulator

Receiver

Demodulator

Channel

DACDigital analog Converter

ADCAnalog Digital converter

Physical Medium

bits

waveform

voltage

bits

voltage

waveform

DistortionDistortion

Pulse shaping filterPulse shaping filter

• The voltages are converted into waveforms The voltages are converted into waveforms using a pulse shaping filter.using a pulse shaping filter.

• This is the place where bandwidth comes into This is the place where bandwidth comes into play.play.

• Its purpose is to make transmitted signal better Its purpose is to make transmitted signal better suited to the communication channel by suited to the communication channel by limiting the effective bandwidth of the limiting the effective bandwidth of the transmission.transmission.

Sinc Pulse Shaping FilterSinc Pulse Shaping Filter

• Time DomainTime Domain • Frequency domainFrequency domain

Raised Cosine Pulse Shaping Raised Cosine Pulse Shaping FilterFilter

• Time domainTime domain • Frequency domainFrequency domain

Research ActivitiesResearch Activities

• Given a bandwidth, the number of channel Given a bandwidth, the number of channel uses per second is fixed.uses per second is fixed.

• The goal of transmitter/receiver design is to The goal of transmitter/receiver design is to maximize the number of bits that can be maximize the number of bits that can be reliably communicated per channel use.reliably communicated per channel use.

• Reliable communication in the presence of Reliable communication in the presence of noise.noise.

Design objectivesDesign objectives

• Energy efficientEnergy efficient

• Bandwidth Bandwidth efficientefficient

• ReliableReliable

• The energy spent on The energy spent on transmission is transmission is proportional to the number proportional to the number of bits transmitted.of bits transmitted.

• The number of bits The number of bits transmitted is proportional transmitted is proportional to the channel uses.to the channel uses.

• The probability of error The probability of error decreases as a function of decreases as a function of the number of bits the number of bits transmitted.transmitted.

AcknowledgementAcknowledgement

• I acknowledge my sincere thanks to E3 program coordinators I acknowledge my sincere thanks to E3 program coordinators to give me opportunity to come along with this wonderful to give me opportunity to come along with this wonderful experience and to enhance my knowledge in Engineering experience and to enhance my knowledge in Engineering which will help to motivate my students to choose which will help to motivate my students to choose “Engineering” as their career.“Engineering” as their career.

• I would like to thank National Science Foundation(NSF), Nuclear I would like to thank National Science Foundation(NSF), Nuclear Power Institute(NPI), Texas Workforce Commission(TWC) and Power Institute(NPI), Texas Workforce Commission(TWC) and Chevron for their support to this program.Chevron for their support to this program.

• Finally I would like to thank Dr. Liu and Neeharika , whose Finally I would like to thank Dr. Liu and Neeharika , whose continual support led to this presentation.continual support led to this presentation.