Transcript Smart Antenna Presentationx

SMART ANTENNA
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HUMAN HEARING SYSTEM – AN ANALOGY FOR SMART
ANTENNA
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DEFINITION
 A smart antenna system combines multiple antenna
elements with a signal processing capability to
optimize its radiation and/or reception pattern
automatically in response to the signal environment.
 Beam the radio signal directly at a user to follow the
user as they move.
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SDMA
 Space Division Multiple Access implies that more
than one user can be allocated to the same physical
communications channel simultaneously in the same
cell, provided they are separated by an angle.
 In systems providing full SDMA, there will be much
more
intracell
handovers
and
therefore
more
monitoring by the network is necessary.
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WHY SMART ANTENNA..?
 MULTI-PATH
PROPAGATION
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Fading
Different delays
Inter Symbol Interference
To reject or stimulate multipath
components by changing the
radiation patterns
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 CO-CHANNEL
INTERFERENCE
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Interference from other
directions than wanted user
Increased noise level
To suppress unwanted user
by placing nulls in directions
of unwanted signals
To improve transmission
quality and system capacity
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TYPES OF SMART ANTENNA
 Switched lobe or switched beam:
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Simplest technique
Basic switching function between
separate directive antennas or
predefined beams of an array
The setting that gives the best
performance, usually in terms of
received power, is chosen
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 Dynamically phased array:
Generalization of the switched lobe concept
 Includes a direction of arrival (DoA) algorithm for the
signal received from the user
 Continuous tracking can be achieved
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 Adaptive array:
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DoA to determine the direction
towards interferers is added
Radiation pattern can then be
adjusted to null out the interferers
Maximize the signal to interference
ratio by special algorithms & space
diversity
techniques
(receive
multipath signals & combine)
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How can an antenna be made more
intelligent..?
Modifying the physical design by adding more
elements
II. Antenna system can shift the signals before
transmission at each of the successive elements for a
composite effect
I.
 Controlling signal phases
 A DSP weighting scheme
This basic hardware and software concept is known
as the ‘phased array antenna’
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MIMO
(MULTIPLE INPUT MULTIPLE OUTPUT)
 It’s the use of multiple antennas at both the transmitter
and receiver to improve communication performance.
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ADVANTAGES
 Increased signal gain
Better range/coverage
Fewer base stations are needed which in turn reduces
infrastructure cost
 Interference rejection & load balancing
Increased capacity
 Spatial diversity
Multipath resolution
Higher data rates
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Conventional
Smart
Antenna
Power Distribution
Legacy
RF System
Patented
Smart Antenna
Software
Power
Distribution
Low Capacity
High Capacity
Signal
Interference from other users
High Complexity
Signal
128W
Interference from other users
Low Complexity
2W
Power Level
Power Amplifier Module
Power Level
Power Amplifier
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APPLICATIONS
Applications
Description
RADAR
Phased array RADAR; air traffic control; synthetic aperture
RADAR
SONAR
Source location and classification
Communications
Smart antenna systems; Directional transmission and
reception; sector broadcast in satellite communications
Imaging
Ultrasonic; optical; tomographic
Geophysical Exploration
Earth crust mapping; oil exploration
Astrophysical Exploration
High resolution imaging of universe
Biomedical
Neuronal spike discrimination; fetal heart monitoring;
tissue hyperthermia; hearing aids
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