G.H RAISONI COLLEGE OF ENGINEERING (An Autonomous Institute Under UGC act 1956 & affiliated to R.T.M. Nagpur

University)Department Of Electronics & Telecommunication Engineering,

Session 2014-15

Presentation On

“Smart Antenna”

Submitted By:- AMIT V. LUTEM.Tech II SEM.

(Communication Engg.) Roll No. 13

What is Antenna??

• Antenna is electrical device which converts electric power into electromagnetic waves or vice versa.• In simple words antenna transmits and receives EM waves.• Antennas can be Omni directional or directional.

Fig:- 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.

• Smart antenna array with a digital signal processing capability to transmit and receive in an adaptive and spatially sensitive manner.

• The idea of smart antennas is to use base station antenna patterns that are not fixed, but adapt to the current radio conditions.

• This can be visualized as the antenna directing a beam toward the communication partner only.

Aim of Smart Antenna??

• To maximize the antenna gain in the desired direction.

• To minimize the gain in directions of interferers.

• To Reduced Multipath propagation.

• To provide More security.

• To improve the Potential to introduce new services.

• To provide improved link quality.

• Elements of a Smart Antenna1.number of radiating elements2.A combining/dividing network3.Control unit

•Types of Smart Antennas:1.SWITCHED BEAM ANTENNA2.ADAPTIVE ARRAY ANTENNA

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.

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

Figure:- Switched Beam System Coverage Patterns

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 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

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

Comparison of Switched Beam And Adaptive AntennaCRITERIA Switched Beam

AntennaAdaptive Array Antenna

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.

APPLICATIONS

• Cellular and wireless networks.

• Electronic warfare (EWF) as a countermeasure to electronic jamming .

• Satellite systems.

• It can be applied to various multiple access techniques such as TDMA,FDMA ,and CDMA.

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 .

THANK YOU…!!!!!!