1) Smart antennas use antenna arrays that can change their radiation patterns in response to the signal environment to improve wireless system performance. 2) There are two main types of smart antennas: phased beam antennas which form a finite number of fixed patterns, and adaptive array antennas which can form an infinite number of patterns. 3) Adaptive array antennas can direct their main beam toward the desired signal while suppressing interference by adapting their pattern, allowing them to customize coverage for each user.

1. SMART ANTENNAS
PRESENTATION BY
apoorva k. Shetti
2bu09ec006
UNDER THE GUIDANCE OF
Lect. AMARJEETSINGH THAKUR
SMARTANTENNA

2. INTRODUCTION
Omni directional and directional antennas.
Omni directional antenna Directional antenna
coverage pattern coverage pattern
Antenna is electrical device which converts electric power into
electromagnetic waves or vice versa

3. WHAT IS A 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.

4. SMART ANTENNA DESCRIPTION
 In actual, antennas are not Smart
Antenna, systems are smart.
A smart antenna system combines an
antenna array with digital signal to
transmit and receive in an adaptive,
spatially sensitive manner.
In other words, such a system can
automatically change the directionality
of its radiation patterns in response to
its signal environment.
This can dramatically increase the
performance characteristics (such as
capacity) of a wireless system

5. AIMS OF SMART ANTENNAS?
A smart antenna is a multi-element antenna where
the signals received at each antenna element are
intelligently combined to improve the performance
of the wireless system
To maximize the antenna gain in the desired
direction.
To minimize the gain in directions of interferers
Increase signal range
Suppress interfering signals
Combat signal fading
Increase the capacity of wireless systems

6. WHAT MAKES SMART ANTENNAS
SMART?
A simple antenna works for a simple RF environment.
 Smart antenna solutions are required as the number
of users, interference, and propagation complexity
grow.
 Their smarts reside in their digital signal-processing
facilities

7. TYPES OF SMART ANTENNA
PHASED BEAM ANTENNA
- a finite number of fixed ,predefined
patterns.
ADAPTIVE ARRAY ANTENNA
- an infinite number of patterns

8. PHASED 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.

9.  There will be numerous
amount of fixed beams
amongst which one beam will
turn on or will be steered
towards the wanted signal.
This can be done only with the
help of adjustment in the
phase.
 An example of a phased beam
antenna in Alaska
EXAMPLE

10. BLOCK DIAGRAM OF THE PBA
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 PSN subdivides sector
into many narrow beams,
then each beam is considered
as individual sector serving
user or group of users.

11. OPERATING PRINCIPLE
 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.

12. ADAPTIVE ARRAY ANTENNAS
In this type of antenna, there will
be a change in the beam pattern
according to the movement of the
wanted user and the movement of
the interference
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.

13. COVERAGE PATTERN
 This provides optimal gain while simultaneously
identifying, tracking, and minimizing interfering
signals.
Figure- Adaptive Array System Coverage Pattern

14. BLOCK DIAGRAM OF AAS
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

15. COMPARISION OF PHASED BEAM ANTENNA
AND ADAPTIVE ARRAYS
CRITERIA PHASED 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

16. DIAGRAMATIC COMPARISON

17. SMART ANTENNAS FOR BASE
STATIONS
The idea of smart antennas is to
use base station antenna
patterns that are not fixed, but
adapt to the current radio
conditions
 Can be visualized as the
antenna directing a beam toward
the communication partner only

18. SPACE DIVISION MULTIPLE ACCESS
Among the most sophisticated utilization of smart
antenna technology is SDMA.
It employs advanced technique to, in effect, locate
and track fixed and mobile terminals, adaptively
steering transmission signal toward user and interferers.
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.

19. OVERVIEW OF SDMA

20. SPECIFICATIONS OF SDMA
 More than one user can be
allocated to the same
physical communications
channel simultaneously in
the same cell
 This is the next step in an
evolutionary path towards
increasing the capacity of
cellular systems

21. ADVANTAGES OF SMART ANTENNA
 Enhance coverage through Range extension.
 Fully controllable by software so less manual
operations.
 Reduction in transmitted power loss.
 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.

22. SMART ANTENNA’S DRAWBACKS
 Their transceivers are much more complex
than traditional base station transceivers.
 Expensive.
Diversity

23. OTHER APPLICATIONS OF SAS:
Cellular and wireless networks
Electronic warfare (EWF) as a countermeasure to electronic jamming
Satellite systems

24. CONCLUSION
Smart antennas are the intelligent antenna systems that vastly
improve the efficiency of wireless transmission.
SAS can achieve
 High transmission data rate
 Increased Coverage area
 Effectively reducing multipath and co channel interference.
 They are software-controllable, remotely configurable.
 Promising technology to resolve the traffic capacity .
Hence smart antenna system is indeed a modern age marvel