Date post: | 10-Apr-2018 |
Category: |
Documents |
Upload: | shakshimishra |
View: | 227 times |
Download: | 1 times |
of 24
8/8/2019 Smart Antenna My1
1/24
SUBMITTED BY
SHAKSHI MISHRA
8/8/2019 Smart Antenna My1
2/24
IntroductionWhat is Smart Antenna ?Types of Smart Antenna systems
And their working processArchitecture of Smart AntennaWhy smart Antenna?Who can use Smart Antenna?
Goals of a Smart AntennaAdvantagesConclusion
8/8/2019 Smart Antenna My1
3/24
A smart antenna system combines multipleantenna elements with a digital signal-processing capability to optimize itsradiation and/or reception pattern
automatically in response to the signalenvironment.
8/8/2019 Smart Antenna My1
4/24
8/8/2019 Smart Antenna My1
5/24
Smart antenna systems are customarilycategorized, as
Switched beam a finite number offixed, predefined patterns or combiningstrategies (sectors)
Adaptive array an infinite number ofpatterns (scenario-based) that are
adjusted in real time
8/8/2019 Smart Antenna My1
6/24
A switched-beam antenna system consists ofseveral highly directive, fixed, pre-defined beams.
Beams are formed to have high sensitivity inparticular fixed directions or sectors.
Antenna systems detect signal strength, choosefrom one of several predetermined, fixed beams,and switch from one beam to another as the usermoves throughout the sector.
8/8/2019 Smart Antenna My1
7/24
Figure- Switched Beam SystemCoverage Patterns (Sectors)
8/8/2019 Smart Antenna My1
8/24
Intra cell-hand offs
Call loss
Interference
8/8/2019 Smart Antenna My1
9/24
Incapacity for providing protection frommulti-path components arriving near thedesired signal. i.e. cannot discriminate
between multipaths at close AoA. Cannot take advantage of path diversity
by combining coherent multi-pathcomponents. Desiredsignal
Interference
Interference
8/8/2019 Smart Antenna My1
10/24
top view(horizontal)
interference
user
1
2
345
6
7
8
9
10
1112 13
14
15
16
8/8/2019 Smart Antenna My1
11/24
Adaptive antenna technology represents the mostadvanced smart antenna approach by using avariety of new signal-processing algorithms.
Use sophisticated signal-processing algorithms to: Distinguish between desired signals, multi-path and
interfering signals. Update its beam pattern.
By combining adaptive digital signal processingwith spatial processing techniques, adaptive arraysystems can achieve greater performanceimprovements than attainable using switched
beam systems. It provides optimal gain while simultaneously
identifying, tracking, and minimizing interferingsignals.
8/8/2019 Smart Antenna My1
12/24
Fig 3: Fully adaptive spatial processing, supporting twousers on the same conventional channelsimultaneously in the same cell.
ADAPTIVE ARRAY
SYSTEM
8/8/2019 Smart Antenna My1
13/24
ADAPTIVE ARRAY
SYSTEM
Fig : Performance evaluation
8/8/2019 Smart Antenna My1
14/24
Adaptive beamforming
Beam-patterns change to maximize SINR
Relatively hard to implement
Can null out the interference
Can achieve fading reduction effect
Switched beamforming
Fixed beam patterns
Easy to implement
Cannot acquire nulling effect
Cannot achieve fading reduction effect
SIGNAL
INTERFERENCE
INTERFERENCEBEAMFORME
R WEIGHTS
SIGNALOUTPUTBEAMSELECT
SIGNAL
BEAMFO
RME
R
SIGNALOUTPUT
8/8/2019 Smart Antenna My1
15/24
Benefits of Switched
Beam and AdaptiveArray systems
Integration.
Range or coverage.
Interference suppression.
8/8/2019 Smart Antenna My1
16/24
Architecture of smart
antenna system
Switched beam and adaptive array
systems enable a base station tocustomize the beams they generate foreach remote user effectively by means
of internal feedback control. Listening to the cell.(uplink processing).
Speaking to the users(downlink
processing).
8/8/2019 Smart Antenna My1
17/24
8/8/2019 Smart Antenna My1
18/24
It enables operators of PCS, cellular, and
wireless local loop (WLL) networks to
realize significant increases in signalquality, capacity, and coverage.
It is basically used incase of military
communication because of its widecoverage area & better signal quality
8/8/2019 Smart Antenna My1
19/24
The goals of a smartantenna system The purpose of a smart antenna system
is to augment the signal quality of theradio-based system through morefocused transmission of radio signals
while enhancing capacity throughincreased frequency reuse.
The features of a smart antenna system
are
- signal gain.
- inference rejection.
- ower efficienc .
8/8/2019 Smart Antenna My1
20/24
Integration.
Range or coverage and capacity.(traffic/area)
Interference suppression.
Standard Coverage
Extended Coverage
8/8/2019 Smart Antenna My1
21/24
Frequency reusability Accurate user positioning.
Reduction in transmission power
Fixed cell shape Dynamic cell shape
8/8/2019 Smart Antenna My1
22/24
Phased arrays are mainly being studiedfor point-to-point wireless systems, e.g.,for wireless local loops.
Adaptive arrays are being considered oncellular terminals where local scatteringcauses wide angular spread.
In the TDMA system ANSI-136 adaptive
antenna algorithms have been widelydeployed.
8/8/2019 Smart Antenna My1
23/24
With different structures, adaptive array antennas play importantroles in the evolution of wireless communications systems .
Applications where cost and power consumption are the main limitedfactors, parasitic array antennas are suitable.
DBF array antennas and phased array antennas dominate in theapplications such as satellite communications, where highperformance is desired.
In addition to combating fading, diversity antennas can also be
employed to realize high-speed MIMO wireless transmissions.Beam forming antenna systems improve wireless network performance
-increase system capacity and save power
-improve signal quality
-suppress interference and noise
8/8/2019 Smart Antenna My1
24/24
Thank You!!!