SMART ANTENNAS

PRESENTATION BY

apoorva k. Shetti 2bu09ec006

UNDER THE GUIDANCE OF

Lect. AMARJEETSINGH THAKUR

SMART ANTENNAS

PRESENTED BY areez irfan

& bilal ahmad

CONTENTS

INTRODUCTION TYPES OF SMART ANTENNAS COMPARISION BETWEEN SWITCHED BEAM AND ADAPTIVE ARRAY SDMA(SPACE DIVISION MULTIPLE ACCESS) ADVANTAGES AND DISADVANTAGES APPLICATION CONCLUSION REFERENCES

INTRODUCTIONAntenna is electrical device which converts electric power

into electromagnetic waves or vice versa.Omni directional and directional antennas.

Multipath and Co channel Interference.

Figure A:Omni directional antenna B. Directional antenna coverage pattern coverage pattern

What is SMART ANTENNA ? A smart antenna consists of an antenna array, that changes the

array pattern in response to signal environment to improve the performance of a communication system.

Figure : Smart antenna analogy with human

THE AIM OF SMART ANTENNA SYSTEM

To maximize the antenna gain in the

desired direction.

To minimize the gain in directions of interferers.

TYPES OF SMART ANTENNA

SWITCHED BEAM ANTENNA

- a finite number of fixed ,predefined patterns. ADAPTIVE ARRAY ANTENNA

- an infinite number of patterns (scenario based) that are adjusted in real time.

SWITCHED BEAM ANTENNAS

This systems form multiple fixed beams with heightened sensitivity in particular directions.

When incoming signal detected it determines the beam which is best aligned based on SOI and switches to that beam to communicate with user.

As the mobile unit moves throughout the cell, the switched-beam system detects the signal strength and continually switches the beams as necessary.

Figure- Switched Beam System Coverage Patterns (Sectors)

It subdivides sector into many narrow beams, then each beam is considered as individual sector serving user or group of users.

Figure : Block diagram of Switched beam systems

PSN, which forms multiple beams looking in certain directions.

RF Switch actuates the right beam in the desired direction.

The selection of right beam is made by control logic which is governed by an algorithm.

The algorithm which scans all the beams and selects the one strongest receiving signal based on a measurement made by the detector.

The overall goal of the switched-beam system is to increase the gain according to the location of the user.

ADAPTIVE ARRAY ANTENNAS

Systems are really smart because they are able to dynamically react to the changing RF environment with its infinite scenario based patterns.

They can direct the main beam toward the SOI(Signal Of Interest) while suppressing the antenna pattern in the direction of the interferers.

It can customize an appropriate radiation pattern for each individual user.

Dynamically adjust the antenna pattern to enhance reception while minimizing or fully rejecting interference .

This provides optimal gain while simultaneously identifying, tracking, and minimizing interfering signals.

Figure- Adaptive Array System Coverage Pattern

Figure : Block diagram of Adaptive array systems

D/C : Converts from RF to IF.

ADC : Converts Analog to Digital for further processing.

W’s : It contains amplification and phase information

SPACE DIVISION MULTIPLE ACCESS Among the most sophisticated utilization of smart antenna

technology.

Beams are sliced to keep different users in different beams at the same frequency which allows reuse of frequency.

This technology achieves superior levels of interference suppression and reduces RF pollution.

It employs advanced technique to, in effect, locate and track fixed and mobile terminals.

This is the next step in an evolutionary path towards increasing the capacity of cellular systems

Figure: SDMA technology(general and actual mechanism)

COMPARISION OF SWITCHED BEAM ANTENNA AND ADAPTIVE ARRAYS

CRITERIA SWITCHED BEAM ADAPTIVE ARRAYS

INTEGERATION • Easy to implement

• Low cost

• Transceiver complexity

• High cost

RANGE/COVERAGE • More coverage compared to conventional systems• Less coverage compared to adaptive array

• More coverage compared to switched beam system

INTERFERENCE REJECTION

•Difficulty in distinguishing between desired signal and interferer • Does not react to the movement of Interferers.

• Focusing is narrower

• Capable of nulling interfering signals

ADVANTAGES OF SMART ANTENNA

Enhance coverage through Range extension.

Fully controllable by software so less manual operations. Reduction in transmitted power. Reduce co-channel interference (CCI) and multipath

interference.

Provides high security.

Improve system capacity. Compatibility, it can be applied to various multiple access

techniques such as TDMA,FDMA ,and CDMA.

Smart Antenna’s Drawbacks

Their transceivers are much more complex than traditional base station transceivers.

Expensive.

APPLICATION

Cellular and wireless networks

Electronic warfare (EWF) as a countermeasure to electronic jamming

Satellite systems

CONCLUSION

Smart antennas are the intelligent antenna systems that vastly improve the efficiency of wireless transmission.

SAS can achieve high transmission data rate and coverage area by effectively reducing multipath and co channel interference.

Smart antenna systems are software-controllable, remotely configurable.

Promising technology to resolve the traffic capacity .

References[1].R. H .Roy, “An overview of smart antenna technology and its

application on wireless communication systems,” Proc .IEEE conf.personal wireless comm.,2007, pp. 234 – 238

[2].Chryssomallis, M., 2008. Smart antennas , IEEE Antennas and Propogation Magazine, 42(3): 129 -136

[3].S. F. Shaukat , Mukhtar ul Hassan, R. Farooq, H. U. Saeed and Z. Saleem, “Sequential studies of beam forming algorithms for smart antenna systems”, world applied sciences journal , vol .6, no. 6, pp 754-758,2009

[4].http://www.iec.org

[5].http://www.smartantennas.googlepages.com

Any Questions