Smart antennas are antenna arrays that use digital signal processing to optimize performance by steering beams towards desired signals and nulling interference. They can enhance capacity, coverage, transmission efficiency and interference rejection for applications in military communications, satellite communications, mobile communications, wireless sensor networks, and terrestrial television reception. Future applications include 5G networks with data rates over 10 Gbps using multiple smart antennas in mobile devices. Smart antennas represent a promising technology for resolving traffic capacity issues in future broadband wireless networks.

1. SMART ANTENNA

2. OUTLINE
 Introduction
 Antenna and its Parameters
 Smart antenna and its evolution
 Adaptation algorithms
 Applications
 Future Scope
 Conclusion

3. INTRODUCTION
Performance and capacity are the two major
impairments in Wireless Communication.
Can be achieved by overcoming Multipath and
Interference.
Smart antenna is a promising technology that ensures
higher capacity in wireless networks.
Employs SDMA (Space Division Multiple Access).

4. ANTENNA AND ITS
PARAMETERSprovides a means for radiating or
Antenna is a device that
receiving radio waves.
o Transmitting Antenna
o Receiving Antenna
o Radiation pattern
o Isotropic antenna

5. Omni-directional pattern: f (θ, φ) = f (θ)
o Pattern lobes
o Side lobe level
o Beam width- HPBW and FNBW

6. o Radiation intensity
o Directivity
o Radiation efficiency
o Gain
o Beam efficiency
o Antenna Impedance
o Antenna Polarization

7. SMART ANTENNA & ITS EVOLUTION
 Omni-directional antenna: radiates and receives well in
all directions.
Top View
Antenna

8.  Directional antenna: has certain fixed preferential
transmission and reception directions.
Top View
Antenna
Array

9. TYPE Omnidirectional Directional
LIMITATION Element element
Gain LOW HIGH
Frequency
reuse
NONE
Interference
Rejection

10.  Antenna diversity: uses two or more antennas to
improve the quality and reliability of a wireless link.
Multiple versions of the same signal may be transmitted
and/or received and combined in the receiver.
o Spatial diversity
o Polarization diversity
o Pattern diversity

11. TYPE DIVERSITY
COMBINING SYSTEM
LIMITATION
Gain VERY GOOD
Capacity HIGH
Interference
LOW
Rejection

12. Smart Antenna
An intelligent antenna system which is an antenna array
that integrates the simultaneous operation of diversity
schemes along with a digital signal processing capability to
transmit and receive data.
“Smart” >> digital signal processing facility

13. Smart antenna functions
o Direction of arrival estimation
o Beam steering

14. Benefits of Smart antenna
o Capacity enhancement
o Coverage extension
o Increase in transmission efficiency
o Reduction of Co-channel interference (CCI) and
Multipath fading
o Reduction of Bit Error Rate (BER)
o Reduction in Handoff

15. Smart Antenna types
 Switched beam array: consists of either a number of
fixed beams with one beam turned on towards the
desired signal or a single beam that is steered towards
the desired signal.
Active
Beam
Antenna
Array
Coverage pattern

16. Block diagram of Switched beam system

17.  Adaptive antenna array: consists of an array of multiple
antenna elements with the received signals weighted and
combined to maximize the SINR.
Desired
User
Interfering
User
Antenna
Array
Coverage pattern

18. Block diagram of Adaptive array system

19. Comparison b/n Switched beam and Adaptive array systems
CRITERIA SWITCHED BEAM ADAPTIVE ARRAYS
INTEGERATION • Easy to implement • Transceiver complexity
• Low cost • High cost
• Less hardware
redundancy
RANGE/COVERAGE • More coverage • More coverage
compared to compared to switched
conventional systems beam system
• Less coverage
compared to adaptive
array
INTERFERENCE • Difficulty in • Focusing is narrower
REJECTION distinguishing between • Capable of nulling
desired signal and interfering signals
interferer
• Does not react to the
movement of interferers.

20. ADAPTATION ALGORITHMS
Continuous Adaptation: Automatically adjust weights
as the incoming data is sampled and updates it such that
it converges to an optimal solution, uses a reference
signal.
E.g. The Least Mean Square algorithm (LMS), The
Recursive Least Square algorithm (RLS).
Blind Adaptive algorithm: Adjustment of weights
without the benefit of reference signal information.
E.g. The Constant modulus algorithm (CMA).

22. o LMS algorithm generates better main lobes in desired user
direction but do not nullify co channel interference.
o Interference rejection is better in CMA because nulls are
produced towards interfering signals. Hence nullifies co
channel interference but bears maximum errors.
o RLS algorithm has better response towards co channel
interference, generates better main lobe in desired direction
and has faster convergence rate than LMS, hence the best of
all.

23. APPLICATIONS
MILITARY APPLICATION
o Makes the battlefield communication easier.
o Power consumption is reduced on high speed multimedia
battle field networks due to reduction in battery drain.
o Spoofing is avoided.
o Light weight video displays with in-built smart antenna used
in warfare to exchange real time maps and pictures.

24. SATELLITE COMMUNICATION
o SATCOM employs Space Division Multiple Access (SDMA).
o more perspective for satcom systems for low (1500km)
and middle (till 10000km) orbits.
o Base stations are employed with smart antenna
technology.

25. MOBILE COMMUNICATION
o Economical to use adaptive antenna in base station
rather than at each mobile station.
o Capacity problem is overcome by using multiple adaptive
antennas on mobile handsets.
o Improves call reliability.
o Suppress the interference signals.
o mitigation against dead zones
E.g. Quadrifilar helix antenna (QHA) produced by Surrey
University and small solid state antenna as manufactured
by Antenova

26. WIRELESS SENSOR NETWORKS
o Increased gain result from smart antenna which preserve
connectivity in sensor network and better usage of nodes
energy source.
o Increase in Network life cycle due to improvements in SNR
and BER.
o Avoid sensor network resource depletion by usage of
switched beam array antennas.

27. TERRESTRIAL TELEVISION RECEPTION
o Increase in BER would compromise with video or audio or
sometimes result in no reception.
o By employing automatic mechanism can adjust antenna gain
and direction without user intervention.
o Here smart antenna functions by changing relative gain and
phase of internal elements.
o Offers high degree of optimization for both signal capture and
interference rejection.

28. FUTURE SCOPE
o MIMO systems employing smart antennas that fulfill IMT-
advanced requirements is the core of 4G systems with
1Gbit/s data rate and freq 20-100MHz.
o MIMO systems fulfilling beyond IMT-advanced standard
forms the 5G systems with more than 10 Gbit/s data rate
and with a frequency of 200MHz.
o Use of multiple smart antennas in mobile handsets to
achieve much better performance.
o Smart antenna based on UWB technology to detect
malignant tumors.

29. CONCLUSION
 Smart antennas are the intelligent antenna systems that
vastly improve the efficiency of wireless transmission.
 For applications including MIMO, Software Defined Radio
- SDR, and Cognitive Radio - CR requiring antenna
systems to be more adaptive and provide greater levels of
adaptivity Smart antenna technology is of wide use.
 Promising technology to resolve the traffic capacity
bottlenecks in future high-speed broadband wireless
access networks and reduce RF pollution.
 Efficient utilization of the scarcest resource of today’s
wireless communication, the RF spectrum.

30. REFERENCES
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systems”, IEEE Transaction of Antennas and propagation, vol. 52, pp. 2810-2824, 2004.
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
Chryssomallis, M., 2008. Smart antennas, IEEE Antennas and Propagation
Magazine, 42(3): 129- 136.
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Sensor Networks using Smart Antennas”, IEEE International Conference on Sensor
Networks, Ubiquitous, and Trustworthy Computing, 2010, pp 261-267.
Luca Bencini, Giovanni Collodi, Divide Di Palma, Gianfranco Manes, Antonio Manes,” An
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