apoorva k. Shetti
UNDER THE GUIDANCE OF
Lect. AMARJEETSINGH THAKUR
Mr. apoorva k. Shetti
TYPES OF SMART ANTENNAS
COMPARISION BETWEEN SWITCHED BEAM AND ADAPTIVE
SDMA(SPACE DIVISION MULTIPLE ACCESS)
ADVANTAGES AND DISADVANTAGES
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
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
THE AIM OF SMART ANTENNA SYSTEM
To maximize the antenna gain in the desired
To minimize the gain in directions of interferers.
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.
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.
Figure- Switched Beam System Coverage Patterns
It subdivides sector into many narrow beams, then each beam is
considered as individual sector serving user or group of users.
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 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 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
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
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
SPACE DIVISION MULTIPLE ACCESS
Among the most sophisticated utilization of smart antenna
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.
This is the next step in an evolutionary path towards increasing
the capacity of cellular systems
Figure: SDMA technology(general and actual mechanism)
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
• Less coverage compared
to adaptive array
• More coverage
compared to switched
between desired signal
• Does not react to the
• Focusing is narrower
• Capable of nulling
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
Provides high security.
Improve system capacity.
Compatibility, it can be applied to various multiple access
techniques such as TDMA,FDMA ,and CDMA.
Smart Antenna’s Drawbacks
Their transceivers are much more complex than traditional
base station transceivers.
Cellular and wireless networks
Electronic warfare (EWF) as a countermeasure to
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
Smart antenna systems are software-controllable, remotely
Promising technology to resolve the traffic capacity .
.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
Propogation Magazine, 42(3): 129 -136
.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