210794299 Report on Smart Antenna

7/25/2019 210794299 Report on Smart Antenna

1/65

TECHNICAL SEMINAR REPORT

SMART ANTENNA

NAME BHARATH KUMAR V

USN 1PE10EC019


2/65

VISVESVARAYA TECHNOLOGICAL UNIVERSITYBelgaum-590014

Seminar ReportOn

SMART ANTENNASubmie! i" #a$ial %ul%illme" &% 'e $e(ui$eme") %&$ 'e VIII Seme)e$

Bace!or o" En#ineerin#

IN

ELECTRONICS AN$ COMMUNICATION EN%INEERIN%

&or te Aca'emic (ear)01*+)01,

B-

BHARATH KUMAR V

1*E10EC019UN$ER THE %UI$ANCE O&

Pro"e..or KAILASHNATH$ept/ o" ECE PESIT BSC/

+e#a$me" &% Ele,$&"i,) a"! ,&mmu"i,ai&" E"gi"ee$i"g

PESIT Ban#a!ore Sot Camp.HOSUR ROA$ BAN%ALORE+230100


3/65

PESIT Ban#a!ore Sot Camp.HOSUR ROA$

BAN%ALORE+230100

$EPARTMENT O& ELECTRONICS AN$ COMMUNICATION EN%INEERIN%

CERTIFICATE

This is to certify that the seminar entitledSMART ANTENNAis

a bonafide work carried out by BHARATH KUMAR V bearing registernumber 1PE10EC019 in partial fulfillment for the award of Degree of

Bachelors (Bachelors of Engineering) in Electronics and Communication

Engineering of Visvesvaraya Technological niversity! Belgaum during the

year "#$%&"#$'

Signatures:

eminar *uide +ead of the Dept

Mr/Kai!a.nat $r/ S4a. K!5arniHO$ ECE

PESIT BSC

Ban#a!ore+100

E6aminer.7

1/

)/


4/65

In'e6

Sl N& Ti, *age N&

1 ABSTRACT 1

. 1/- I"$&!u,i&"

0 ./- A"e""a a"! A"e""a S)em)

.1/-A"e""a

.11/- Om"i!i$e,i&"al A"e""a

.1./- +i$e,i&"al A"e""a

4 /-Sma$ A"e""a

1/- I"$&!u,i&" &% Sma$ A"e""a

./- Hi)&$ &% Sma$ A"e""a

/- T#e) &% Sma$ A"e""a

1/- A!a#i2e A$$a

./- S3i,'e! Beam

4/- Relai2e Be"e%i) &% S3i,'e! Beam a"!

A!a#i2e A$$a S)em)

5/- &$i"g &% Sma$ A"e""a

6/- Caeg&$ie) &% Sma$ A"e""a

7/- 8u",i&" &% Sma$ A"e""a

71/- Beam%&$mi"g

7./- +i$e,i&" &% A$$i2al+OA:

0;/- *a$amee$) a%%e,i"g A"e""a #e$%&$ma",e

9/- A##li,ai&") &% Sma$ A"e""a

10/- A!2a"age) a"! +i)a!2a"age) &% Sma$

A"e""a

11/-8eau$e)a"!

Be"e%i&%Sma$


5/65

A"e""a

5

4/-

C&",lu)i&"

6 Re%e$e",e)

+e# &% E


6/65

1/ Intro'ction

Wireless Communication is growing with a very rapid rate for several

years. The progress in radio technology enables new and improved

services. Current wireless services include transmission of voice, fax and

low-speed data. More bandwidth consuming interactive multimedia

services like video-on demand and internet access will be supported in

the future.

Wireless systems that enable higher data rates and higher capacities are

a pressing need. Wireless networks must provide these services in a wide

range of environments, dense urban, suburban, and rural areas.

Because the available broadcast spectrum is limited, attempts to increase

traffic within a fixed bandwidth create more interference in the system

and degrade the signal quality.

The solution to this problem is SMART ANTENNA. Today's modern

wireless mobile communications depend on adaptive "smart" antennas to

provide maximum range and clarity. With the recent explosive growth of

wireless applications, smart antenna technology has achieved widespread

commercial and military applications.

There is an ever-increasing demand on mobile wireless operators to

provide voice and high-speed data services. At the same time, operators

want to support more users per basestation in order to reduce overall

network cost and make the services affordable to subscribers. As a

result, wireless systems that enable higher data rates and higher

capacities have become the need of the hour.


7/65

+e# &% E


8/65

)/ Antenna an' Antenna S(.tem

.1 = A"e""a

Anantenna(oraerial) is a transducer designed to transmit or receive

electromagnetic waves. In other words, antennas convert electromagnetic

waves into electrical currents and vice versa. Antennas are used in

systems such as radio and television broadcasting, point-to-point radio

communication, wireless LAN, radar, and space exploration. Antennas

are most commonly employed in air or outer space, but can also be

operated under water or even through soil and rock at certain frequencies

for short distances.

Physically, an antenna is simply an arrangement of one or more

conductors, usually calledelementsin this context. . In transmission, an

alternating current is created in the elements by applying a voltage at the

antenna terminals, causing the elements to radiate an electromagnetic

field. In reception, the inverse occurs: an electromagnetic field from

another source induces an alternating current in the elements and a

corresponding voltage at the antenna's terminals. Some receiving

antennas (such as parabolic types) incorporate shaped reflective surfaces

to collect EM waves from free space and direct or focus them onto theactual conductive elements.

There are two fundamental types of antenna directional patterns, which,

with reference to a specific three dimensional (usually horizontal or

vertical) plane are either:

1.Omni-directional (radiates equally in all directions), such as avertical rod.

2. Directional (radiates more in one direction than in the other).


9/65

+e# &% E


10/65

.11- Om"i!i$e,i&"al A"e""a

Omni-directional usually refers to all horizontal directions with reception

above and below the antenna being reduced in favor of better reception

(and thus range) near the horizon.

Since the early days of wireless communications, there has been the

simple dipole antenna, which radiates and receives equally well in all

directions. To find its users, this single-element design broadcasts

omnidirectionally in a pattern resembling ripples radiating outward in a

pool of water. While adequate for simple RF environments where no

specific knowledge of the users' whereabouts is available, this unfocused

approach scatters signals, reaching desired users with only a small

percentage of the overall energy sent out into the environment.

Figure 2.1:- Omnidirectional Antenna and Coverage Patterns

Given this limitation, omnidirectional strategies attempt to overcome

environmental challenges by simply boosting the power level of the

signals broadcast. In a setting of numerous users (and interferers), this

makes a bad situation worse in that the signals that miss the intended

user become interference for those in the same or adjoining cells.

In uplink applications (user to base station), omnidirectional antennas

offer no preferential gain for the signals of served users. In other words,

Users have to shout over competing signal energy. Also, this single-


11/65

element approach cannot selectively reject signals interfering with those

+e# &% E


12/65

of served users and has no spatial multipath mitigation or equalization

capabilities.

Omnidirectional strategies directly and adversely impact spectral

efficiency, limiting frequency reuse. These limitations force system

designers and network planners to devise increasingly sophisticated and

costly remedies. In recent years, the limitations of broadcast antenna

technology on the quality, capacity, and coverage of wireless systems have

prompted an evolution in the fundamental design and role of the antenna

in a wireless system.

.1.- +i$e,i&"al A"e""a

A "directional" antenna usually refers to one focusing a narrow beam in a

single specific direction. A single antenna can also be constructed to have

certain fixed preferential transmission and reception directions. As an

alternative to the brute force method of adding new transmitter sites,

many conventional antenna towers today split, or sectorize cells. A 360

area is often split into three 120 subdivisions, each of which is covered

by a slightly less broadcast method of transmission.

All else being equal, sector antennas provide increased gain over a

restricted range of azimuths as compared to an omnidirectional antenna.

This is commonly referred to as antenna element gain and should not be

confused with the processing gains associated with smart antenna

systems.

While sectorized antennas multiply the use of channels, they do not

overcome the major disadvantages of standard omnidirectional antenna

broadcast such as co-channel interference


13/65

+e# &% E


14/65

All antennas radiate some energy in all directions in free space but

careful construction results in substantial transmission of energy in a

preferred direction and negligible energy radiated in other directions.

&i#re )/) 8

$irectiona! Antenna an' Coera#e Pattern


15/65

+e# &% E


16/65

*/ Smart Antenna

1- I"$&!u,i&" &% Sma$ A"e""a

Contrary to the name smart antennas consist of more than an antenna.

A Smart Antenna is an antenna system which dynamically reacts to its

environment to provide better signals and frequency usage for wireless

communications. There are a variety of smart antennas which utilize

different methods to provide improvements in various wireless

applications. This report aims to explain the main types of smart

antennas and there advantages and disadvantages.

The concept of using multiple antennas and innovative signal processing

to serve cells more intelligently has existed for many years. In fact,

varying degrees of relatively costly smart antenna systems have already

been applied in defense systems. Until recent years, cost barriers have

prevented their use in commercial systems. The advent of powerful low-

cost digital signal processors (DSPs), general-purpose processors (andASICs), as well as innovative software-based signal-processing techniques

(algorithms) have made intelligent antennas practical for cellular

communications systems.

Today, when spectrally efficient solutions are increasingly a business

imperative, these systems are providing greater coverage area for each cell

site, higher rejection of interference, and substantial capacity

improvements.


17/65

+e# &% E


18/65

Fig 3.1:- Smart Antenna System

&i#re */)+ B!oc5 $ia#ram o" Smart Antenna

+e# &% E


19/65


20/65

.- Hi)&$ &% Sma$ A"e""a

Early smart antennas were designed for governmental use in military

applications, which used directed beams to hide transmissions from an

enemy. Implementation required very large antenna structures and time-

intensive processing and calculation.

As personal wireless communications began to emerge, it was evident

that interference in wireless networks was limiting the total number of

simultaneous users the network could handle before unacceptable call

quality and blocking occurred. Since the narrow beams of the early

governmental smart antennas created less overall interference,

researchers began to explore the possibility of extending the use of smart

antennas to reduce overall network interference in commercial wireless

networks, thus increasing the total number of users a wireless system

could handle in a given block of spectrum. But the hardware andprocessing technologies required to perform the complex calculations in

the very small spaces of time available in personal wireless

communications would prove to be a hurdle that was extremely difficult

to overcome. A few select companies have successfully developed and

introduced smart antenna technologies into commercial wireless

networks.

Antennas were used in 1888 by Heinrich Hertz (1857-1894) to prove the

existence of electromagnetic waves predicted by the theory of James

Clerk Maxwell. Hertz placed the emitter dipole in the focal point of a

parabolic reflector.

The origin of the wordantennarelative to wireless apparatus is attributed

to Guglielmo Marconi. In 1895, while testing early radio apparatus in the

Swiss Alps, Marconi experimented with early wireless equipment.

A 2.5 meter long pole, along which was carried a wire, was used as a


21/65

radiating and receiving aerial element . Until then wireless radiating

+e# &% E


22/65

transmitting and receiving elements were known simply as aerials or

terminals. Marconi's use of the wordantenna(Italian forpole) would

become a popular term for what today is uniformly known as theantenna.

Smart Antennas Today

Today, smart antennas have been widely deployed in many of the top

wireless networks worldwide to address wireless network capacity and

performance challenges.

Several different versions of smart antennas are either in development or

available on the market today. Appliqu smart antenna systems can be

added to existing cell sites, enabling software-controlled pattern changes

or software-optimized antenna patterns that have produced capacity

increases of up to 35-94% in some deployments. Appliqu smart antenna

systems provide greater flexibility in controlling and customizing sector

antenna pattern beamwidth and azimuthal orientation over that of

standard sector antennas.

A second approach, embedded smart antennas, uses adaptive array

processing within the channel elements of a base station. The smart

antenna processing takes place in the base station signal path, using a

custom, narrow beam to track each mobile in the network. Embedded

smart antenna system trials have been proven to deliver 2.5-3 times the

capacity of current 2-2.5G base stations.

- T#e) &% Sma$ A"e""a

The following are distinctions between the two major categories of smart

antennas regarding the choices in transmit strategy:

1).Adaptive array- an infinite number of patterns (scenario-based) that

are adjusted in real time .


23/65

2).Switched beam- a finite number of fixed, predefined patterns or

combining strategies (sectors).

+e# &% E


24/65

1- A!a#i2e A$$a

Adaptive antenna technology represents the most advanced smart

antenna approach to date. Using a variety of new signal-processing

algorithms, the adaptive system takes advantage of its ability to

effectively locate and track various types of signals to dynamically

minimize interference and maximize intended signal reception.

Both systems attempt to increase gain according to the location of the

user; however, only the adaptive system provides optimal gain while

simultaneously identifying, tracking, and minimizing interfering signals.

&i#re */*7+ A'aptie Arra( S(.tem7+ Repre.entatie $epiction o" a Main Lo4e

E6ten'in# To:ar' a U.er/

.- S3i,'e! Beam

Switched beam antenna systems form multiple fixed beams with

heightened sensitivity in particular directions. These antenna systems

detect signal strength, choose from one of several predetermined, fixed

beams, and switch from one beam to another as the mobile moves

throughout the sector. Instead of shaping the directional antenna pattern

with the metallic properties and physical design of a single element (like a

sectorized antenna), switched beam systems combine the outputs of


25/65

+e# &% E


26/65

multiple antennas in such a way as to form finely sectorized (directional)

beams with more spatial selectivity than can be achieved with

conventional, single-element approaches.

&i#re */,7+S:itce' Beam S(.tem

4- Relai2e Be"e%i) &% S3i,'e! Beam a"! A!a#i2e A$$a

S)em)

Inte#ration

Switched beam systems are traditionally designed to retrofit widely

deployed cellular systems. It has been commonly implemented as an add-

on or appliqu technology that intelligently addresses the needs of

mature networks

Ran#e;coera#e

Switched beam systems can increase base station range from 20 to 200

percent over conventional sectored cells, depending on environmental

circumstances and the hardware/software used. The added coverage can

save an operator substantial infrastructure costs and means lower prices

for consumers. Also, the dynamic switching from beam to beam

conserves capacity because the system does not send all signals in all

directions. In comparison, adaptive array systems can cover a broader,

more uniform area with the same power levels as a switched beam

system.


27/65

+e# &% E


28/65

Inter"erence .ppre..ion

Switched beam antennas suppress interference arriving from directions

away from the active beam's center. Because beam patterns are fixed,

however, actual interference rejection is often the gain of the selected

communication beam pattern in the interferer's direction. Also, they are

normally used only for reception because of the system's ambiguous

perception of the location of the received signal (the consequences of

transmitting in the wrong beam being obvious). Also, because their

beams are predetermined, sensitivity can occasionally vary as the user

moves through the sector.

Adaptive array technology currently offers more comprehensive

interference rejection. Also, because it transmits an infinite, rather than

finite, number of combinations, its narrower focus creates less

interference to neighboring users than a switched-beam approach.

5-&$i"g &% Sma$ A"e""a

Traditional switched beam and adaptive array systems enable a base

station to customize the beams they generate for each remote user

effectively by means of internal feedback control. Generally speaking,

each approach forms a main lobe toward individual users and attempts

to reject interference or noise from outside of the main lobe.

Li)e"i"g & 'e Cell U#li" *$&,e))i"g:

It is assumed here that a smart antenna is only employed at the base

station and not at the handset or subscriber unit. Such remote radio

terminals transmit using omnidirectional antennas, leaving it to the basestation to separate the desired signals from interference selectively.

Typically, the received signal from the spatially distributed antenna

elements is multiplied by a weight, a complex adjustment of an amplitude


29/65

and a phase. These signals are combined to yield the array

+e# &% E


30/65

output. An adaptive algorithm controls the weights according to

predefined objectives. For a switched beam system, this may be primarily

maximum gain; for an adaptive array system, other factors may receiveequal consideration. These dynamic calculations enable the system to

change its radiation pattern for optimized signal reception.

S#eai"g & 'e U)e$) +&3"li" *$&,e))i"g:

The task of transmitting in a spatially selective manner is the major

basis for differentiating between switched beam and adaptive array

systems. As described below, switched beam systems communicate with

users by changing between preset directional patterns, largely on the

basis of signal strength. In comparison, adaptive arrays attempt to

understand the RF environment more comprehensively and transmit

more selectively.

The type of downlink processing used depends on whether the

communication system uses time division duplex (TDD), which transmitsand receives on the same frequency (e.g., PHS and DECT) or frequency

division duplex (FDD), which uses separate frequencies for transmit and

receiving (e.g., GSM). In most FDD systems, the uplink and downlink

fading and other propagation characteristics

may be considered independent, whereas in TDD systems the uplink and

downlink channels can be considered reciprocal. Hence, in TDD systems

uplink channel information may be used to achieve spatially selective

transmission. In FDD systems, the uplink channel information cannot be

used directly and other types of downlink processing must be considered.

6- Caeg&$ie) &% Sma$ A"e""a

A smart antenna is a digital wireless communications antenna system

that takes advantage of diversity effect at the source (transmitter), the

destination (receiver), or both. Diversity effect involves the transmission

and/or reception of multiple radio frequency (RF) waves to increase data


31/65


32/65

In conventional wireless communications, a single antenna is used at the

source, and another single antenna is used at the destination. This is

called SISO (single input, single output). Such systems are vulnerable to

problems caused by multipath effects. When an electromagnetic field

(EMfield)is met with obstructions such as hills, canyons, buildings, and

utility wires, the wavefronts are scattered, and thus they take many

paths to reach the destination. The late arrival of scattered portions of

the signal causes problems such as fading, cut-out (cliff effect), and

intermittent reception (picket fencing). In a digital communications

system like the Internet, it can cause a reduction in data speed and an

increase in the number of errors. The use of smart antennas can reduce

or eliminate the trouble caused by multipath wave propagation.

Smart antennas fall into three major categories:--

1).SIMO(single input, multiple output)

2).MISO(multiple input, single output)

3).MIMO(multiple input, multiple output).

SIMO

SIMO (single input, multiple output) is an antenna technology for

wireless communications in which multiple antennas are used at the

destination (receiver). The antennas are combined to minimize errors and

optimize data speed. The source (transmitter) has only one antenna.

SIMO is one of several forms ofsmart antennatechnology, the others

beingMIMO(multiple input, multiple output) andMISO(multiple input,

single output).

In digital communications systems such as wireless Internet, it can cause

a reduction in data speed and an increase in the number of errors. The

use of two or more antennas at the destination can reduce the trouble

caused by multipath wave propagation.
http://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci212055,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci212055,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci1025387,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci1025332,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci1025328,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci211571,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci1026138,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci1025328,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci1025332,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci212055,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci1025387,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci1025332,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci1025328,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci211571,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci1026138,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci1025328,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci1025332,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci212055,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci212055,00.html


33/65

SIMO technology has widespread applications in digital television (DTV),

wireless local area networks(WLANs),metropolitan area networks

+e# &% E


34/65

(MANs),and mobile communications. An early form of SIMO, known as

diversity reception, has been used by military, commercial, amateur, and

shortwave radio operators at frequencies below 30 MHz since the FirstWorld War.

MISO

MISO (multiple input, single output) is an antenna technology for

wireless communications in which multiple antennas are used at the

source (transmitter). The antennas are combined to minimize errors and

optimize data speed. The destination (receiver) has only one antenna.

MISO is one of several forms of smart antenna technology, the others

being MIMO(multiple input, multiple output) and SIMO(single input,

multiple output).


a reduction in data speed and an increase in the number of errors. The

use of two or more antennas, along with the transmission of multiple

signals (one for each antenna) at the source, can reduce the trouble

caused by multipath wave propagation.

MISO technology has widespread applications in digital television (DTV),

wireless local area networks (WLANs),metropolitan area networks(MANs),and mobile communications.

MIMO

MIMO (multiple input, multiple output) is an antennatechnology for

wireless communications in which multiple antennas are used at both

the source (transmitter) and the destination (receiver). The antennas at

each end of the communications circuit are combined to minimize errors

and optimize data speed. MIMO is one of several forms of smart antenna

technology, the others beingMISO(multiple input, single output) and
http://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci214083,00.htmlhttp://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci214083,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci211571,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci1025328,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci1025387,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci213899,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci213379,00.htmlhttp://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci214083,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci211571,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci1025332,00.htmlhttp://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci214083,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci211571,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci1025328,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci1025387,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci213899,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci213379,00.htmlhttp://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci214083,00.htmlhttp://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci214083,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci211571,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci1025332,00.html


35/65

SIMO(single input, multiple output).

+e# &% E


36/65


a reduction in data speed and an increase in the number of errors.

The use of two or more antennas, along with the transmission of multiplesignals (one for each antenna) at the source and the destination,

eliminates the trouble caused by multipath wave propagation, and can

even take advantage of this effect.

MIMO technology has aroused interest because of its possible

applications in digital television (DTV),wireless local area networks

(WLANs), metropolitan area networks (MANs), and mobile

communications.

7- 8u",i&" &% Sma$ A"e""a

Smart antennas(also known as adaptive array antennas, multiple

antennas and recently MIMO)are antenna arrayswith smart signal

processing algorithms used to identify spatial signal signature such as

the direction of arrival(DOA) of the signal, and use it to calculate

beamformingvectors, to track and locate the antenna beam on the

mobile/target.

Smart antennas have two main functions: DOA estimation and

Beamforming.

71- Beam%&$mi"g

Beamformingis a signal processingtechniqueused with arrays of

transmitting or receivingtransducersthat control the directionality of, or

sensitivity to, aradiation pattern.When receiving a signal, beamforming

can increase the receiver sensitivityin the direction of wanted signals

and decrease the sensitivity in the direction of interference and noise.

When transmitting a signal, beamforming can increase the power in the

direction the signal is to be sent. The change compared with an
http://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci213899,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci213379,00.htmlhttp://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci214083,00.htmlhttp://en.wikipedia.org/wiki/Multiple-input_multiple-output_communicationshttp://en.wikipedia.org/wiki/Antenna_arrayhttp://en.wikipedia.org/wiki/Direction_of_arrivalhttp://en.wikipedia.org/wiki/Beamforminghttp://en.wikipedia.org/wiki/Beamforminghttp://www.statemaster.com/encyclopedia/Signal-processinghttp://www.statemaster.com/encyclopedia/Transducershttp://www.statemaster.com/encyclopedia/Radiation-patternhttp://www.statemaster.com/encyclopedia/Sensitivityhttp://www.statemaster.com/encyclopedia/Noisehttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci213899,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci213379,00.htmlhttp://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci213379,00.htmlhttp://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci214083,00.htmlhttp://en.wikipedia.org/wiki/Multiple-input_multiple-output_communicationshttp://en.wikipedia.org/wiki/Antenna_arrayhttp://en.wikipedia.org/wiki/Direction_of_arrivalhttp://en.wikipedia.org/wiki/Beamforminghttp://en.wikipedia.org/wiki/Beamforminghttp://en.wikipedia.org/wiki/Beamforminghttp://en.wikipedia.org/wiki/Beamforminghttp://www.statemaster.com/encyclopedia/Signal-processinghttp://www.statemaster.com/encyclopedia/Transducershttp://www.statemaster.com/encyclopedia/Radiation-patternhttp://www.statemaster.com/encyclopedia/Sensitivityhttp://www.statemaster.com/encyclopedia/Noisehttp://www.statemaster.com/encyclopedia/Omnidirectional


37/65

omnidirectionalreceiving pattern is known as the receivegain(or loss).

The change compared with an omnidirectionaltransmissionis known as

+e# &% E


38/65

the transmission gain. These changes are done by creating beams and

nulls in the radiation pattern. In electronics, gain is usually taken as the

mean ratio of the signal output of a system to the signal input of thesystem.

Beamforming can be done with eitherradioorsoundwaves,and can

also be thought of as spatial filtering.As an everyday analogy, the

humanbrain uses a form of signal processing on its two sound

transducers (ears)and determines where the sound came from (sound

localization). In the comparable beamforming analogy,digital computers

use signal processing on an array of two (or generally more)

electromagneticsound transducers (microphones)to determine the

direction of maximum signalstrength,and thus the likely origin of the

sound. A microphone with a cord A microphone, sometimes called a mic

(pronounced mike), is a device that converts sound into an electrical

signal. In telecommunications, and particularly in radio, signal strength

is the measure of how strongly a transmitted signal is being received,

measured, or predicted, at a reference point that is a significant distance

from the transmitting antenna.

Beamforming takes advantage ofinterferenceto change the directionality

of the array. When transmitting, a beamformer controls the phaseand

relative amplitudeof the signal at each transmitter, in order to create a

pattern of constructive and destructive interference in the wavefront.

When receiving, information from different sensors is combined in such a

way that the expected pattern of radiation is preferentially observed.

Interference of two circular waves - Wavelength (decreasing bottom to top)

and Wave centers distance (increasing to the right).

In the receive beamfomer the signal from each antenna may be amplified

by a different "weight." Different weighting patterns (eg Dolph-Chebyshev)

can be used to achieve the desired sensitivity patterns. . A main lobe is
http://www.statemaster.com/graph-T/med_radhttp://www.statemaster.com/encyclopedia/Soundhttp://www.statemaster.com/encyclopedia/Waveshttp://www.statemaster.com/encyclopedia/Spatial-filteringhttp://www.statemaster.com/encyclopedia/Human-brainhttp://www.statemaster.com/encyclopedia/Human-brainhttp://www.statemaster.com/encyclopedia/Earshttp://www.statemaster.com/encyclopedia/Sound-localizationhttp://www.statemaster.com/encyclopedia/Sound-localizationhttp://www.statemaster.com/encyclopedia/Digital-computershttp://www.statemaster.com/encyclopedia/Electromagnetichttp://www.statemaster.com/encyclopedia/Microphoneshttp://www.statemaster.com/encyclopedia/Signal-strengthhttp://www.statemaster.com/encyclopedia/Signal-strengthhttp://www.statemaster.com/encyclopedia/Interferencehttp://www.statemaster.com/encyclopedia/Phasehttp://www.statemaster.com/encyclopedia/Amplitudehttp://www.statemaster.com/graph-T/med_radhttp://www.statemaster.com/encyclopedia/Soundhttp://www.statemaster.com/encyclopedia/Waveshttp://www.statemaster.com/encyclopedia/Spatial-filteringhttp://www.statemaster.com/encyclopedia/Human-brainhttp://www.statemaster.com/encyclopedia/Human-brainhttp://www.statemaster.com/encyclopedia/Human-brainhttp://www.statemaster.com/encyclopedia/Earshttp://www.statemaster.com/encyclopedia/Sound-localizationhttp://www.statemaster.com/encyclopedia/Sound-localizationhttp://www.statemaster.com/encyclopedia/Digital-computershttp://www.statemaster.com/encyclopedia/Electromagnetichttp://www.statemaster.com/encyclopedia/Electromagnetichttp://www.statemaster.com/encyclopedia/Microphoneshttp://www.statemaster.com/encyclopedia/Signal-strengthhttp://www.statemaster.com/encyclopedia/Signal-strengthhttp://www.statemaster.com/encyclopedia/Interferencehttp://www.statemaster.com/encyclopedia/Phasehttp://www.statemaster.com/encyclopedia/Amplitude


39/65

produced together with nulls and sidelobes. As well as controlling the

+e# &% E


40/65

main lobe width (the beam) and the sidelobe levels, the position of a null

can be controlled. This is useful to ignore noise or jammersin one

particular direction, while listening for events in other directions. Asimilar result can be obtained on transmission. Jammer can refer to: A

device used in electronic warfare to inhibit or halt the transmission of

signals.

Figure3.5:- BeamForming Lobe.

Figure3.6:- Figure show pattern of Beamforming
http://www.statemaster.com/encyclopedia/Jammerhttp://www.statemaster.com/encyclopedia/Jammer


41/65

+e# &% E


42/65

Beamforming techniques can be broadly divided into two categories:

A).Conventional (fixed) beamformers or switched beam smart

antennas.B).Adaptive beamformers or adaptive array smartantennas

Conventional beamformers use a fixed set of weightings and time-delays

(or phasings) to combine the signals from the sensors in the array,

primarily using only information about the location of the sensors in

space and the wave directions of interest. In contrast, adaptive

beamforming techniques, generally combine this information with

properties of the signals actually received by the array, typically to

improve rejection of unwanted signals from other directions. This process

may be carried out in the time or frequency domains. Smart Antenna

refers to a system of antenna arrays with smart signal processing

algorithms that are used to identify the direction of arrival (DOA) of the

signal, and use it to calculate beamforming vectors, to track and locate

the antenna beam on the mobile/target. ... Smart Antenna refers to a

system of antenna arrays with smart signal processing algorithms that

are used to identify the direction of arrival (DOA) of the signal, and use it

to calculate beamforming vectors, to track and locate the antenna beam

on the mobile/target. ...

As the name indicates, an adaptive beamformeris able to adapt

automatically its response to different situations. Some criterion has to

be set up to allow the adaption to proceed such as minimising the total

noise output. Because of the variation of noise with frequency, in wide

band systems it may be desirable to carry out the process in the

frequency domain.An adaptive beamformer is signal processing system

often used with an array of radar antennae (or phased array) in order to

transmit or receive signals in different directions without having to

mechanically steer the array. ... Frequency domain is a term used to
http://www.statemaster.com/encyclopedia/Smart-antennahttp://www.statemaster.com/encyclopedia/Smart-antennahttp://www.statemaster.com/encyclopedia/Smart-antennahttp://www.statemaster.com/encyclopedia/Smart-antennahttp://www.statemaster.com/encyclopedia/Adaptive-beamformerhttp://www.statemaster.com/encyclopedia/Frequency-domainhttp://www.statemaster.com/encyclopedia/Smart-antennahttp://www.statemaster.com/encyclopedia/Smart-antennahttp://www.statemaster.com/encyclopedia/Smart-antennahttp://www.statemaster.com/encyclopedia/Adaptive-beamformerhttp://www.statemaster.com/encyclopedia/Frequency-domainhttp://www.statemaster.com/encyclopedia/Frequency-domain


43/65

describe the analysis of mathematical functions with respect to

frequency.

+e# &% E


44/65

*/


45/65

calculation ofeigenvaluesandeigenvectorsof anautocorrelationmatrix

+e# &% E


46/65

of the input vectors from the receiving antenna array. These calculations

are computationally intensive. Matrix Pencil is very efficient in case of

real time systems, and under the correlated sources. In mathematics, a

number is called an eigenvalue of a matrix if there exists a nonzero vector

such that the matrix times the vector is equal to the same vector

multiplied by the eigen value.In linear algebra, the eigenvectors (from the

German eigen meaning own) of a linear operator are non-zero vectors

which, when operated on by the operator, result in a scalar multiple of

themselves.

9- A##li,ai&" &% Sma$ A"e""a

Smart Antenna is used in number of fields. It has number of

Applications. Here are some of the fields where Smart Antenna used:-

1). MOBILE COMMUNICATION.2).WIRELESS COMMUNICATION.

3). RADAR.

4).SONAR

A**LICATION O8 S>ART ANTENNAS TO >OBILECO>>UNICATIONS SYSTE>S

Smart or adaptive antenna arrays can improve the performance of

wireless communication systems. An overview of strategies for achieving

coverage, capacity, and other improvements is presented, and relevant

literature is discussed. Multipath mitigation and direction finding

applications of arrays are briefly discussed, and potential paths of

evolution for future wireless systems are presented. Requirements and

implementation issues for smart antennas are also considered.

Smart antennas are most often realized with either switched-beam or

fully adaptive array antennas. An array consists of two or more antennas

(the elements of the array) spatially arranged and electrically

interconnected to produce a directional radiation pattern. In a phased


47/65

array the phases of the exciting currents in each element antenna of the

+e# &% E


48/65

array are adjusted to change the pattern of the array, typically to scan a

pattern maximum or null to a desired direction.

A smart antenna system consists of an antenna array, associated RF

hardware, and a computer controller that changes the array pattern in

response to the radio frequency environment, in order to improve the

performance of a communication or radar system.

Switched-beam antenna systems are the simplest form of smart antenna.

By selecting among several different fixed phase shifts in the array feed,

several fixed antenna patterns can be formed using the same array. The

appropriate pattern is selected for any given set of conditions. An

adaptive array controls its own pattern dynamically, using feedback to

vary the phase and/or amplitude of the exciting current at each element

to optimize the received signal.

Smart or adaptive antennas are being considered for use in wireless

communication systems. Smart antennas can increase the coverage and

capacity of a system. In multipath channels they can increase the

maximum data rate and mitigate fading due to cancellation of multipath

components. Adaptive antennas can also be used for direction finding,

with applications including emergency services and vehicular traffic

monitoring. All these enhancements have been proposed in the literature

and are discussed in this paper. In addition, possible paths of evolution,

incorporating adaptive antennas into North American cellular systems,

are presented and discussed. Finally, requirements for future adaptive

antenna systems and implementation issues that will

influence their design are outlined.

Range extensionIn sparsely populated areas, extending coverage is often more important

than increasing capacity. In such areas, the gain provided by adaptive

antennas can extend the range of a cell to cover a larger area and more


49/65

users than would be possible with omnidirectional or sector antennas.

+e# &% E


50/65

Interference reduction and rejection

In populated areas, increasing capacity is of prime importance. Two

related strategies for increasing capacity are interference reduction on the

downlink and interference rejection on the uplink. To reduce interference,

directional beams are steered toward the mobiles. Interference to co-

channel mobiles occurs only if they are within the narrow beamwidth of

the directional beam. This reduces the probability of co-channel

interference compared with a system using omnidirectional base stationantennas.

Interference can be rejected using directional beams and/or by forming

nulls in the base station receive antenna pattern in the direction of

interfering co-channel users.

Interference reduction and rejection can allow N c (which is dictated by

co-channel interference) to be reduced, increasing the capacity of the

system.

Interference reduction can be implemented using an array with steered or

switched beams. By using directional beams to communicate with

mobiles on the downlink, a base station is less likely to interfere with

nearby co-channel base stations than if it used an omnidirectional

antenna.

There will be a small percentage of time during which co-channel

interference is strong, e.g., when a mobile is within the main beam of a

nearby co-channel base station.

This can be overcome by handing off the mobile within its current cell to

another channel that is not experiencing strong co-channel interference.

10- A!2a"age) a"! +i)a!2a"age) &% Sma$A"e""aA!2a"age)


51/65

+e# &% E


52/65

Increased number of users

Due to the targeted nature of smart antennas frequencies can be reused

allowing an increased number of users. More users on the same

frequency space means that the network provider has lower operating

costs in terms of purchasing frequency space.

Increased Range

As the smart antenna focuses gain on the communicating device, the

range of operation increases. This allows the area serviced by a smart

antenna to increase. This can provide a cost saving to network providers

as they will not require as many antennas/base stations to provide

coverage.

Geographic Information

As smart antennas use targeted signals the direction in which the

antenna is transmitting and the gain required to communicate with a

device can be used to determine the location of a device relatively

accurately. This allows network providers to offer new services to devices.

Some services include, guiding emergency services to your location,

location based games and locality information.

Security

Smart antennas naturally provide increased security, as the signals are

not radiated in all directions as in a traditional omni-directional antenna.

This means that if someone wished to intercept transmissions they would

need to be at the same location or between the two communicating

devices.

Reduced Interference


53/65

Interference which is usually caused by transmissions which radiate in

all directions are less likely to occur due to the directionality introduced

+e# &% E


54/65

by the smart antenna. This aids both the ability to reuse frequencies and

achieve greater range.

Increased bandwidth

The bandwidth available increases form the reuse of frequencies and also

in adaptive arrays as they can utilize the many paths which a signal may

follow to reach a device.

Easily integrated

Smart antennas are not a new protocol or standard so the antennas can

be easily implemented with existing non smart antennas and devices.

+i)a!2a"age)

Complex

A disadvantage of smart antennas is that they are far more complicated

than traditional antennas. This means that faults or problems may be

harder to diagnose and more likely to occur.

More Expensive

As smart antennas are extremelyprocessing technology they are far

antennas. However this cost must

frequency space.

complex, utilizing

the latest in more

expensive than

traditional be

weighed against

the cost of

Larger Size

Due to the

antenna arrays

which are utilized

by

smar

t

ante

nna

syste

ms,

they

are

muc

h

larg

er in size than

traditional systems.

This can be a

problem in a social

context as

antennas can be


55/65

seen as ugly or

unsightly. +e# &% E


56/65

Location

The location of smart antennas needs to be considered for optimal

operation. Due to the directional beam that swings from a smart

antenna locations which are optimal for a traditional antenna are not for

a smart antenna. For example in a road context, smart antennas are

better situated away from the road, unlike normal antennas which are

best situated along the road.

11- 8eau$e) a"! Be"e%i &% Sma$ A"e""a8eau$e &% Sma$ A"e""a

1).Signal gain- Inputs from multiple antennas are combined to optimize

available power required to establish given level of coverage.

2).Interference Rejection -Antenna pattern can be generated toward

co-channel interference sources, improving the signal-to-interference

ratio of the received signals.

3).Spatial diversity-Composite information from the array is used to

minimize fading and other undesirable effects of multipath propagation.

4).Power efficiency-Combines the inputs to multiple elements to

optimize available processing gain in the downlink (toward the user)

Be"e%i &% Sma$ A"e""a

1).Better range/coverage-Focusing the energy sent out into the cell

increases base station range and coverage. Lower power requirements

also enable a greater battery life and smaller/lighter handset size.

2).Increased capacity-Precise control of signal nulls quality and

mitigation of interference combine to frequency reuse reduce distance (or


57/65

cluster size),improving capacity. Certain adaptive technologies (such as

+e# &% E


58/65

space division multiple access) support the reuse of frequencies within

the same cell.

3).Multipath rejection-Can reduce the effective delay spread of the

channel, allowing higher bit rates to be supported without the use of an

equalizer.

4).Reduced expense-Lower amplifier costs, power consumption, and

higher reliability will result.

,/ Conc!.ion

This report aims to explain the basic concept of Smart Antenna and someof its Application.

First Question arises what is Smart Antenna?

A smart antenna combines an antenna array with a digital signal-

processing capability to transmit and receive in an adaptive, spatiallysensitive manner. Or In other words Smart Antenna is an Array ofantenna which is used to optimize its reception and transmit pattern.

There are two types of Smart Antenna:-

1). Switched Beam- Switched beam antenna systems form multiple fixedbeams with heightened sensitivity in particular directions. These antennasystems detect signal strength, choose from one of several predetermined,fixed beams, and switch from one beam to another as the mobile moves

throughout the sector.

2). Adaptive Array- Adaptive antenna technology represents the mostadvanced smart antenna approach to date. the adaptive system takesadvantage of its ability to effectively locate and track various types ofsignals to dynamically minimize interference and maximize intendedsignal reception.

Both systems attempt to increase gain according to the location of theuser; however, only the adaptive system provides optimal gain while

simultaneously identifying, tracking, and minimizing interfering signals.

Smart antenna works in two processes. First one is Uplinking and secondone is Downlinking

There are 2 categories of Smart Antenna:-


59/65

+e# &% E


60/65

1). SIMO (Single Input Multiple Output)

2). MISO (Multiple Input Single Output)

3).MIMO (Multiple Input Multiple Output)

Basically Smart antenna has two functions :-

1).Beamforming-

2).Direction of Arrival

Smart antenna is used in various fields the most important is named

below:-

1). Mobile Communication

2). Wireless Communication

3). RADAR

4).SONAR

There are some of the factors which affects the performance of SmartAntenna . These factors reduce the Quality of Smart Antenna.Factorsare:-

1).Resonant Frequency

2).Gain

3).Impedance

4).Bandwidth

5).Polarization

6).Transmission and Reception

Merits of Smart Antenna

1). Increased number of users.

2). Increased Range

3). Security

4). Reduced Interference.


61/65

+e# &% E


62/65

Demerits of Smart Antenna:-

1). Complex

2). Expensive

3). Large Size

4). Location

Re%e$e",e)

1).www.wikipedia.com

2).www.statemaster.com

3).www.iec.org

4).http://www.iec.org/online/tutorials/smart_ant/

5).W. L. Stutzman and G. A. Thiele, Antenna theory and

Design, John Wiley & Sons, New York, 1981.

6). D. Johnson and D. Dudgeon,Array Signal Processing,

Prentice-

Hall, Englewood Cli_s, NJ, 1993

7).http://www.smartanteenas.googlepages.com

8). Michael Chryssomallis Smart antennasIEEE antenna and

propagation magazineVol 42 No 3 pp 129-138, June 2000.9).

D. Johnson and D. Dudgeon,Array Signal Processing,

Prentice-

Hall, Englewood Cli_s, NJ, 1993

10). Special issue on blind identi_cation and estimation,"

IEEEProceedings, mid-1998.
http://www.wikipedia.com/http://www.statemaster.com/http://www.iec.org/http://www.iec.org/online/tutorials/smart_ant/http://www.smartanteenas.googlepages.com/http://www.wikipedia.com/http://www.statemaster.com/http://www.iec.org/http://www.iec.org/online/tutorials/smart_ant/http://www.smartanteenas.googlepages.com/


63/65

+e# &% E


64/65

11). R Kronberger,H Lindermerier,J Hopf Smart antenna

applications on vehicles with low profile array antennaProc

IEEEVol 53 pp1-3 September 2003.


65/65

+e# &% E

Documents

210794299 Report on Smart Antenna