Smart Antenna My1

8/8/2019 Smart Antenna My1

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SUBMITTED BY

SHAKSHI MISHRA


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IntroductionWhat is Smart Antenna ?Types of Smart Antenna systems

And their working processArchitecture of Smart AntennaWhy smart Antenna?Who can use Smart Antenna?

Goals of a Smart AntennaAdvantagesConclusion


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A smart antenna system combines multipleantenna elements with a digital signal-processing capability to optimize itsradiation and/or reception pattern

automatically in response to the signalenvironment.


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Smart antenna systems are customarilycategorized, as

Switched beam a finite number offixed, predefined patterns or combiningstrategies (sectors)

Adaptive array an infinite number ofpatterns (scenario-based) that are

adjusted in real time


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A switched-beam antenna system consists ofseveral highly directive, fixed, pre-defined beams.

Beams are formed to have high sensitivity inparticular fixed directions or sectors.

Antenna systems detect signal strength, choosefrom one of several predetermined, fixed beams,and switch from one beam to another as the usermoves throughout the sector.


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Figure- Switched Beam SystemCoverage Patterns (Sectors)


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Intra cell-hand offs

Call loss

Interference


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Incapacity for providing protection frommulti-path components arriving near thedesired signal. i.e. cannot discriminate

between multipaths at close AoA. Cannot take advantage of path diversity

by combining coherent multi-pathcomponents. Desiredsignal

Interference

Interference


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top view(horizontal)

interference

user

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345

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1112 13

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Adaptive antenna technology represents the mostadvanced smart antenna approach by using avariety of new signal-processing algorithms.

Use sophisticated signal-processing algorithms to: Distinguish between desired signals, multi-path and

interfering signals. Update its beam pattern.

By combining adaptive digital signal processingwith spatial processing techniques, adaptive arraysystems can achieve greater performanceimprovements than attainable using switched

beam systems. It provides optimal gain while simultaneously

identifying, tracking, and minimizing interferingsignals.


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Fig 3: Fully adaptive spatial processing, supporting twousers on the same conventional channelsimultaneously in the same cell.

ADAPTIVE ARRAY

SYSTEM


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ADAPTIVE ARRAY

SYSTEM

Fig : Performance evaluation


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Adaptive beamforming

Beam-patterns change to maximize SINR

Relatively hard to implement

Can null out the interference

Can achieve fading reduction effect

Switched beamforming

Fixed beam patterns

Easy to implement

Cannot acquire nulling effect

Cannot achieve fading reduction effect

SIGNAL

INTERFERENCE

INTERFERENCEBEAMFORME

R WEIGHTS

SIGNALOUTPUTBEAMSELECT

SIGNAL

BEAMFO

RME

R

SIGNALOUTPUT


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Benefits of Switched

Beam and AdaptiveArray systems

Integration.

Range or coverage.

Interference suppression.


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Architecture of smart

antenna system

Switched beam and adaptive array

systems enable a base station tocustomize the beams they generate foreach remote user effectively by means

of internal feedback control. Listening to the cell.(uplink processing).

Speaking to the users(downlink

processing).


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It enables operators of PCS, cellular, and

wireless local loop (WLL) networks to

realize significant increases in signalquality, capacity, and coverage.

It is basically used incase of military

communication because of its widecoverage area & better signal quality


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The goals of a smartantenna system The purpose of a smart antenna system

is to augment the signal quality of theradio-based system through morefocused transmission of radio signals

while enhancing capacity throughincreased frequency reuse.

The features of a smart antenna system

are

- signal gain.

- inference rejection.

- ower efficienc .


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Integration.

Range or coverage and capacity.(traffic/area)

Interference suppression.

Standard Coverage

Extended Coverage


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Frequency reusability Accurate user positioning.

Reduction in transmission power

Fixed cell shape Dynamic cell shape


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Phased arrays are mainly being studiedfor point-to-point wireless systems, e.g.,for wireless local loops.

Adaptive arrays are being considered oncellular terminals where local scatteringcauses wide angular spread.

In the TDMA system ANSI-136 adaptive

antenna algorithms have been widelydeployed.


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With different structures, adaptive array antennas play importantroles in the evolution of wireless communications systems .

Applications where cost and power consumption are the main limitedfactors, parasitic array antennas are suitable.

DBF array antennas and phased array antennas dominate in theapplications such as satellite communications, where highperformance is desired.

In addition to combating fading, diversity antennas can also be

employed to realize high-speed MIMO wireless transmissions.Beam forming antenna systems improve wireless network performance

-increase system capacity and save power

-improve signal quality

-suppress interference and noise


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Thank You!!!

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Smart Antenna My1