SMART ANTENNAS

DHARAMSOTH SANTHOSH

B090652EC

SMART ANTENNAS

PRESENTED BY

DHARAMSOTH SANTHOSH

B090652EC

Agenda

History

Introduction

What is smart antenna?

Functioning of smart antenna.

Types of smart antenna.

Digital beam forming

DOA estimation

Advantages

Application and conclusion

References

History

The Smart Antenna was developed for “Military Communications” and

“Intelligence gathering”.

New opportunities were created for smart antenna in the year 1990 by

satellite broadcasting industries.

Introduction

Antenna is electrical device which converted electric power into

electromagnetic waves.

A smart Antenna consist of an antenna array, that changes the array

pattern in response to signal environment to improve the performance of

a communication channel.

Smart antenna is not smart, it is the digital signal processing, along with the

antennas, which makes the system smart.

What is Smart Antenna?

A Smart Antenna system combines an antenna array with a digital signal

processing capability to transmit and receive in an adaptive manner.

Difference between regular antenna

and smart antenna?

Regular antenna(omnidirectional): generates beams in all directions.

Having directional pattern in orthogonal plane and non-directional

pattern in given plane.

Smart antenna: adaptive antenna utilizes adaptive DSP based techniques

and digital technology.

Co-channel interference

Co-channel interference:

Is a crosstalk from two different radio transmitter using same frequency.

CCI arises in the cellular mobile networks owing to this phenomenon of

frequency reuse.

Functioning of Smart Antennas

The functioning of smart antennas is still far from being well defined, and

many concepts are subject to thorough studies.

Technical aspects involve number of elements, fed with signals which are

adaptively processed by space or space-time filtering.

Functioning of SA cont…….

Potential demands (generally hard to fulfil) are put on the functioning of

smart antennas:

1. Increased number of subscribers(higher system capacity)

2. Higher data transmission rate.

3. Better spectral efficiency

4. Extended range

5. Processing of multipath propagated signals

6. Flexibility of channel transfer

Types of Smart antennas

There are three types of smart antennas are there:

1. Adaptive array antenna

2. Switched beam array antenna

Adaptive array antennas

Has become a core system component in future generation mobile

networks.

Adaptive array allow the antenna to steer the beam to any direction of

interest while simultaneously nulling interfering signals.

This antennas can track and locate signals.

Antenna architecture of AAS

Switched beam array antennas

They have several available fixed beam patterns.

Decision has to be made which beam has to be access at any given point of time.

Overall goal of the switched beam system is to increase gain according to the location of

user.

Antenna

Array

Active

Beam

Block diagram of switched beam

antenna

Comparison b/w switched and

adaptive array antenna

Digital Beam Forming

The digital beam forming segment of the smart antenna comprises two

modules:

1. communication and calibration signal processing.

2. Beam forming processors.

DBF cont…..

In communication and calibration signal processing needs a very high

data rate and calls for a large computational power.

In the beam forming processor needs a lower rate of weight update which

usually ranges up to a few kHz.

DOA(Direction Of Arrival)

estimation

It is direction of arrival

The smart antenna estimates the direction of arrival of the signal, using

technique such as MUSIC(Multiple Signal Classification) estimation of signal

parameters via Matrix pencil method or one of their derivatives.

They involve finding a spatial spectrum of the antenna and calculating the

DOA from the peaks of this spectrum.

Advantages of smart antennas

Reduction in co-channel interference.

Range improvement

Increase in capacity

Reduction in transmitted power.

Reduction in handoff.

Applications

Mobile communications

Cellular and wireless network.

Satellite communication.

Wireless sensor network.

Military.

Electronic warfare

Future scope

In mobile handsets to achieve much better performance.

4G system with 1 Gbit/s data rate and frequency 20-100Mhz.

Detect malignant tumours

conclusion

Smart antenna are the intelligent antenna systems that improve the

efficiency of wireless transmission.

Promising technology to resolve the traffic capacity.

Efficient utilization of the scarcest resource of todays wireless

communication.

References

[1] Dau-Chyrh Chang and Cheng-Nan Hu, “Smart Antennas for Advanced

Communication Systems”-vol.100,no.7, July 2012.

[2] Daniel J Bern, Pawel Kabacik,-”Smart Antennas for Mobile Communication

Systems”.

[3]Nihad A. A. Elhag, Islam M Osman, Alaa A Yassin, Tsneem B Ahmed,”Angle

of Arrival Estimation in Smart Antenna Using MUSIC method for Wideband

Wireless Communication” IEEE 2013.

[4]T. Nageswara Rao, V. Srinivasa Rao, “Evaluation of MUSIC algorithm for a

Smart Antenna system for Mobile Communications”.

Thank you