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

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

3. INTRODUCTION
Antenna 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

4. 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

5. THE AIM OF SMART ANTENNA SYSTEM
 To maximize the antenna gain in the desired
direction.
 To minimize the gain in directions of interferers.

6. 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.

7. 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.

8. Contd…
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.

9. Contd...
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.

10. Contd…
 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.

11. 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 .

12. Contd…
 This provides optimal gain while simultaneously
identifying, tracking, and minimizing interfering signals.
Figure- Adaptive Array System Coverage Pattern

13. Contd…
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

14. SPACE DIVISION MULTIPLE ACCESS
 Among the most sophisticated utilization of smart antenna
technology.
 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.

15. Contd…
 This is the next step in an evolutionary path towards increasing
the capacity of cellular systems
Figure: SDMA technology(general and actual mechanism)

16. 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

17. 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.

18. Smart Antenna’s Drawbacks
 Their transceivers are much more complex than traditional
base station transceivers.
 Expensive.

19. APPLICATION
 Cellular and wireless networks
 Electronic warfare (EWF) as a countermeasure to
electronic jamming
 Satellite systems

20. 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 .

21. 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