final sdr que paper

8/13/2019 Final Sdr Que Paper

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Assignment number:-02

Name:-

M.E.(VLSI & Embedded system)

R!! n.:- " SEM:-I

Sub:- S#t$are %e#ined Radi.


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uestin 'a'er (*+)-+,

ME(VLSI & Embedded system)

S#t$are %e#ined Radi E!eti/e-IV)

Setin-I

. a) 1at is s#t$are de#ined radi3 4$ te ne't # S%R is bui!d3 E5'!ain temti/atin beind te S%R3

Ans:- Software-Defined Radio (SDR) refers to the technology wherein software modules

running on a generic hardware platform consisting of DSPs and general purpose microprocessors

are used to implement radio functions such as generation of transmitted signal (modulation) attransmitter and tuning/detection of received radio signal (demodulation) at receiver

An ideal !software radio " is a system that performs analog-to-digital conversion directly afterthe antenna and then does all signal processing re#uired in the digital domain on a platform that

supports reconfiguration !Software-defined radio " (SDR) is the term used for a more realistic

approach in which part of the processing is still done in the analog domain A side effect of this

rapid growth is an e$cess of mo%ile system standards &herefore' the SDR concept is emergingas a potential pragmatic solution t aims to %uild fle$i%le radio systems' which are

multipleservice' multi-standard' multi-%and' re-configura%le and reprogramma%le' %y software

6ne't:

SDR was strongly influencing the future of wireless and mo%ile communications&his standard the Software *ommunications Architecture (S*A) specifies rules on how to

develop'deploy and configure SDRs &he S*A allows radios to %e interopera%le' as they can %e

reconfigured in real-timeto use different communications protocols and fre#uency %ands &heS*A also serves to reduce radio terminal costs %y ena%ling the use of commercial off-the-

shelf(*+&S) hardware

Mti/atin # S%R

, *ommercial wireless communication industry is currently facing pro%lems due to constant

evolution of lin-layer protocol standards (.0' 10' and 20)

. 3$istence of incompati%le wireless networ technologies in different countries inhi%iting

deployment of glo%al roaming facilities

1 Pro%lems in rolling-out new services/features due to wide-spread presence of legacy

su%scri%er handsets

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. b) %ra$ ard$are ariteture # S%R & e5'!ain it in detai!3

ANS: SDR hardware architecture , %loc diagram


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4 D5*: Digital upconverter DD*: Digital downconverter

4 *6R: *rest factor reduction DPD: Digital predistortion

4 PA: Power amplifier 78A: 7ow noise amplifier

8o fre#uency conversion is used in this configuration as the A.D and D.A conversion taesplace at the fre#uency of operation Apart from the control and management software and its

associated hardware' a software defined radio (SDR) can %e considered to contain a num%er of

%asic functional %locs as detailed %elow:

RF Amplification: &hese elements are the R6 amplification of the signals travelling to

and from the antenna +n the transmit side the amplifier is used to increase the level of

the R6 signal to the re#uired power to %e transmitted t is unliely that direct conversion

%y the DA* will give the re#uired output level +n the receive side signals from theantenna need to %e amplified %efore passing further into the receiver f antenna signals

are directly converted into digital signals' #uantisation noise %ecomes an issue even f the

fre#uency limits are not e$ceeded

Frequency conversion: n many designs' some analogue processing may %e re#uired

&ypically this may involve converting the signal to and from the final radio fre#uency nsome designs this analogue section may not %e present and the signal will %e converted

directly to and from the final fre#uency from and to the digital format Some intermediate

fre#uency processing may also %e present


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Digital conversion: t is at this stage that the signal is converted %etween the digital and

analogue formats &his conversion is in many ways at the heart of the e#uipment

9hen undertaing these conversions there are issues that need to %e considered +n thereceive side' the ma$imum fre#uency and num%er of %its to give the re#uired #uantisation

noise are of great importance +n the transmit side' the ma$imum fre#uency and the

re#uired power level are some of the maor issues

Baseband processor: &he %ase%and processor is at the very centre of the software

defined radio t performs many functions from digitally converting the incoming or

outgoing signal in fre#uency &hese elements are nown as the Digital 5p *onverter(D5*) for converting the outgoing signal from the %ase fre#uency up to the re#uired

output fre#uency for conversion from digital to analogue +n the receive side a Digital

Down *onverter (DD*) is used to %ring the signal down in fre#uency &he signal alsoneeds to %e filtered' demodulated and the re#uired data e$tracted for further processing

+ne of the ey issues of the %ase%and processor is the amount of processing power

re#uired &he greater the level of processing' the higher the current consumption and in

turn this re#uired additional cooling' etc &his may have an impact on what can %eachieved if power consumption and si;e are limitations Also the format of any

processing needs to %e considered - general processors' DSPs' AS*s and in particular

6P0As may %e used 6P0As are of particular interest %ecause they may %e reconfiguredto change the definition of the radio

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.2 a) 1at are te ty'ia! m'nent re7uirement # S%R3

ANS:&ypical *omponents of SDR

, Analog Radio 6re#uency (R6) receiver/transmitter in the .; to multi-gigahert;range

. >igh-speed A/D and D/A converters to digiti;e a wide portion of the spectrum at . to.,< =samples/sec

1 >igh-speed front-end signal processing including Digital Down *onversion (DD*)consisting of one or more chains of mi$ ? filter ? decimate or up conversion

2 Protocol-specific processing such as 9ide%and *ode Division =ultiple Access (9-*D=A) or +6D=' including spreading/de-spreading' fre#uency-hop-and chip-rate

recovery' code/decode functions' including modulation/demodulation' carrier and sym%ol

rate recovery' and channel interleaving/de-interleaving

Data communications interface with carrier networs and %ac%one for data /+ andcommand-and-control processing' usually handled %y general purpose AR= or PowerP*

processors and Real-&ime +perating System (R&+S)

9hat is a software-defined radio@ According to the SDR 6orum it is a collection of hardware

and software technologies that ena%le reconfigura%le system architec-tures for wireless networsand user terminalsSDR provides an efficient and omparatively ine$pensive solution to the

pro%lem of %uilding multi-mode' multi-%and' multi-functional wireless devices that can %e

enhanced using software upgrades t is applica%le across a wide range ofareas within the

wireless industry


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6or a commercial %ase station' SDR re#uirements will vary depending on the users position

in the value chain As such' the needs of the networ operator are different to those of the

original- e#uipment-manufacturer (+3=) %ase-station-e#uipment manufacturer radio-resource-management issues needs SDR to:

4 =a$imi;e e#uipment longevity to minimi;e costs %y deploying early with-out rising

incapa%ility with standards as they evolve4 Deploy new services #uicly

4 +ptimi;e Buality of Service (BoS) %y dynamically modifying resource allo-cation tomaintain desired BoS over radio channels4 Provide fle$i%le spectrum allocation A %ase-station e#uipment vendor' on the other hand'

needs SDR to:

4 Provide economies of scale SDR provides for consolidation of product variants onto

reconfigura%le product platforms4 Simplify %ug fi$es and software updates

4 Reduce time to maret Reconfigura%le SDR reduces the amount of new intellectual property

(P) that needs to %e created' ma$imi;es the reuse of e$isting P' and ena%les hardware/softwarecodesign for reduced time to maret

4 6acilitate adaptive-antenna support for third-generation (10) technology

Support for smart-antenna su%systems on second-generation (.0) %ase stationsis often implemented through use of a front-end appli#uC to the e$isting e#uip-

ment >owever' this approach is infeasi%le for 10 %ase-station systems

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. 2 b) E5'!ain te im'rtane # A%6 and %A6 in S%R

Ans:

A software-defined radio receiver uses an analog-to-digital converter (AD*) to digiti;e the

analog signal in the receiver as close to the antenna as practical' generally at an intermediatefre#uency (6) +nce digiti;ed' the signals are filtered' demodulated' and separated into

individual channels Similarly' a software-defined radio transmitter performs coding'

modulation' etc in the digital domain n the final output 6 stage' a digital-to-analog converter(DA*) is used to convert the signal %ac to an analog format for transmission

AD* and DA* components often mae or %rea an SDR system n general' as speed goes up'resolution goes down >igher conversion rates allow more %andwidth to %e digiti;ed' %ut higher-

resolution converters provide more dynamic range (the difference in amplitude %etween the

strongest and weaest signals that can %e simultaneously digiti;ed)

As AD* and DA* technologies improve' they will continue to lead the way for higher efficiency'

reconfigura%le' and multistandard radios

AD* technology allows sampling of high fre#uencies providing improvements in performance

AD* provides wide SpuriousFree Dynamic Range (SFDR)and S8R to meet the receivers needs

SDRs are well suited for multi-carrier applications since they employ a highly oversampled AD* with

ample availa%le %andwidthDA* is used to reconstruct multiple signals&o get good performance from thetransmitter' the %andwidth must %e very high &he %andwidth re#uirements of DA* are more stringent

DA* allows %oth comple$ and real outputsDA* provides high S8R

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. a) 1at are te /arius arateristis # S%R & E5'!ain tem in detai!3

software defined radios or SDRs' do have characteristics that mae them uni#ue from other types

of radios As the name implies' a SDR is a radio that has the a%ility to %e transformed throughthe use of software or re-defina%le logic Buite often this is done with general purpose DSPs or

6P0As as discussed later in the chapter n order to tae advantage of such digital processing'

traditional analog signals must %e converted to and from the digital domain &his isaccomplished using analog-to-digital (AD*) and digital-to-analog converters (DA*) &o tae

full advantage of digital processing' SDRs eep the signal in the digital domain for as much of

the signal chain as possi%le' digiti;ing and reconstructing as close to the antenna as possi%le'

which allows digital techni#ues to perform functions traditionally done %y analog components aswell as others not possi%le in the analog domain &here are limits to this however Despite the

fact that an AD* or DA* connected directly to an antenna is a desira%le end goal' there are

issues with selectivity and sensitivity that an analog front end can remedy &he alternative todigiti;ing at the antenna is the use of a completely fle$i%le analog front end (A63) capa%le of

translating a wide range of fre#uencies and %ands to that which the data converters themselves

can ade#uately process

SDRs are ideal candidates to %e used for multi-carrier' single-carrier' single-%and' multi%and

and multi-mode transceivers Some of these issues will %e covered later &he ey point is that

SDRs have the a%ility to go %eyond simple single channel' single mode transceiver technologywith the a%ility to change modes ar%itrarily %ecause the channel %andwidth' rate' and modulation

are all fle$i%ly determined through software &hese characteristics may %e changed %y direct

input' floppy dis' over the air download or through the use of careful signal analysis todetermine analytically how the information is coded through a process termed as *ognitive

Radio Regardless of the means %y which the radio is reconfigured' a fully implemented SDR

will have the a%ility to navigate a wide range of fre#uencies with programma%le channel%andwidth and modulation characteristics &he ta%le %elow lists some of the possi%le

characteristics of a SDR n addition to R6 tuning' a transceiver must include the a%ility to taeadvantage of one or more of these characteristics to %e considered as an SDR

,*hannel andwidth

.Data Rate

1=odulation &ype

2*onversion 0ain

As'ets # s#t$are de#ined radi

As the ta%le a%ove indicates' there are a num%er of characteristics that an SDR possesses 9hileit is not re#uired that an SDR have all of these characteristics' having one or more of them is

Additionally' the categories a%ove can %e further %roen down as detailed %elow t should %eept in mind that since software defined implies a high degree of fle$i%ility and varia%ility' the

list %elow is not all encompassing and su%ect to change over time' %ut serves as a starting point

at understanding the different facets of what SDR can %e

Multi-Band


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=ost traditional radio architectures operate on a single %and or range of fre#uencies &here are

many applications where multiple fre#uencies of operations are desired &hese include cellular

communications' government and non-government agencies' and intelligence collection to list afew 9here these situations e$ist' the norm is to utili;e multiple radiosE each designed to operate

in one specified %and A multi-%and radio has the a%ility to operate on two or more %ands either

se#uentially or simultaneously as in the case of a %asestation that may %e lining handsets fromdifferent %ands

Multi-Carrier

A multi-carrier or multi-channel radio has the a%ility to simultaneously operate on more than one

fre#uency at a time &his may %e within the same %and or in the case of a multi%and radio' in two

different %ands at the same time Buite often' multi-carrier applies to a %asestation that may %eservicing many users at once' %ut can also apply to a user terminal that my %e processing %oth

voice and data on different R6 carriers

Multi-Mode

=ulti-mode implies the a%ility to process several different inds of standards 3$amples of

standards include A=' 6=' 0=SF' *D=A %ut is limited to none of these An SDR has thea%ility to wor with many different standards and %e continuously reprogrammed &herefore' a

%etter term than multi-mode' which implies a discrete num%er of modes' may %e varia%le mode'

which implying a continuously changea%le mode of operation As with other characteristics'these modes may %e se#uentially or simultaneously in the case of a multi-carrier radio

Mu!ti-Rate

=ulti-rate is closely related to multi-mode A multi-rate radio is one that either processes

different parts of the signal chain at different samples rates as in a multi-rate filter or one wherethe radio has the a%ility to process different modes that re#uire different data rates An e$ample

of a multi-rate radio would %e one that can process 0S= at .G


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communications' government and non-government agencies' and intelligence collection to list a

few 9here these situations e$ist' the norm is to utili;e multiple radiosE each designed to operate

in one specified %and A multi-%and radio has the a%ility to operate on two or more %ands either

se#uentially or simultaneously as in the case of a %asestation that may %e lining handsets from

different %ands

2) Mu!ti-6arrier

A multi-carrier or multi-channel radio has the a%ility to simultaneously operate on more than one

fre#uency at a time &his may %e within the same %and or in the case of a multi-%and radio' in

two different %ands at the same time Buite often' multi-carrier applies to a %asestation that may

%e servicing many users at once' %ut can also apply to a user terminal that my %e processing %oth

voice and data on different R6 carriers

) Mu!ti-Mde

=ulti-mode implies the a%ility to process several different inds of standards 3$amples of

standards include A=' 6=' 0=SF' *D=A %ut is limited to none of these An SDR has the

a%ility to wor with many different standards and %e continuously reprogrammed &herefore' a

%etter term than multi-mode' which implies a discrete num%er of modes' may %e varia%le mode'

which implying a continuously changea%le mode of operation As with other characteristics'

these modes may %e se#uentially or simultaneously in the case of a multi-carrier radio

;) Mu!ti-Rate

=ulti-rate is closely related to multi-mode A multi-rate radio is one that either processes

different parts of the signal chain at different samples rates as in a multi-rate filter or one wherethe radio has the a%ility to process different modes that re#uire different data rates An e$ample

of a multi-rate radio would %e one that can process 0S= at .G


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. b) 1at are te /arius 'ressing ste's re7uired in transmitter & reei/er # R; measurement

filter shall record a power of less than J,1 dm

) @ransmitter S'urius Emissins

Spurious emissions are emissions that are caused %y unwanted transmitter effects' such as

harmonic emissions' parasitic emissions' intermodulation products' and fre#uency conversion

products' %ut e$clude out-of-%and emissions 6or a 5=&S %ase station the re#uirement applies atfre#uencies that are more than ,. =>; under the first carrier fre#uency used and more than

,. =>; a%ove the last carrier fre#uency used Part of the re#uirement states that in the ,; to 1< =>; region spurious emissions shall %e lessthan J1M dm in a ,; measurement %andwidth

;) @ransmitter Intermdu!atinntermodulation performance is a measure of the capa%ility of the transmitter to inhi%it

the generation of signals in its nonlinear elements caused %y the presence of the wanted signal

and an interfering signal reaching the transmitter via the antenna

6or a 5=&S %ase station the intermodulation level is the power of the intermodulationproducts when a 9*D=A modulated interference signal is inected into an antenna connector at

a level of 1< d lower than that of the wanted signal &he fre#uency of the interference signal

can %e =>;' ,< =>;' or , =>; offset %elow the first or a%ove the last carrier fre#uency usedin the transmitter &he transmit intermodulation level must not e$ceed the out-of-%and emission

or the spurious emission re#uirements

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-.; a) 1at are te /arius #atrs $i su!d be nsidered $i!e designing dynami

range # sdr reei/er design3

Ans$er:- . Sensiti/ityis the minimum receiver input power measured at the antenna input

connector for which the 3R does not e$ceed a specified value &he 5=&S %ase station receiversensitivity specification is J,., dm' given a data rate of ,.. F%ps and a 3R of less than


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%e a%le to handle an interfering signal power of J. dm' given that the interferer is either

=>; a%ove or %elow the wanted signal

;.8!>ingis a measure of the receivers a%ility to maintain performance for a wanted

signal in the presence of an interferer &he interferer is located on any fre#uency other than the

adacent channel or those coinciding with the receivers spurious responses 6or e$ample' in the,'K.


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adverse terminal conditions where station mo%ility' dynamic networing' and operational

fle$i%ility are re#uired using a variety of wireless and networ interfaces

&he SDR 6orum is not a standards %ody such as the &A or 3&SE however' it doesdevelop recommendations that may' in the future' turn into standards if enough commercial

cooperation is developed

.+ a) %esribe aim & re7uirements # S6A.

&he Software *ommunications Architecture' or S*A' provides a set of specifications !that

facilitate porta%ility' interopera%ility and configura%ility of the software and hardwarecomponents used in the manufacturing of radio systems"N &he original technologies for these

specifications were developed in the late ,KH


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. Node: &his software may comprise such applications as %ootstrapping and access to

hardware

1 Application: &his type of software is used particularly for the signal processing

3$amples of this may include waveform generation' demodulation' fre#uency translation'

etc

+f these three different S*A software categories only the application software can %e re-used

%etween different platforms &he other two need to directly interface with the platform hardwareand are therefore platform specific

Despite the fact that only the application S*A software can %e transported this nevertheless

produces very significant cost savings 0enerating the software for a specific waveform is a verycostly e$ercise re#uiring very many man-years of software effort in development and then in

rigorous testing Additionally' the a%ility of %eing a%le to port it across several platforms means

that any inconsistencies should not %e noticea%le and cause any pro%lems %ecause all radios willwor in the same manner

S6A summary

S*A Software *ommunications Architecture is an ideal standard to use for large SoftwareDefined radio SDR proects where different software elements may %e %rought in from different

software houses t provides a ro%ust interface %etween the different software modules thatallows components to communicate together relia%ly in a nown standard format >owever the

use of S*A Software *ommunications Architecture does place an overhead on the comple$ity of

the system &his may mean that S*A may not %e the right choice for many smaller proects9hether to use S*A or not is a design choice that needs to %e made at the %eginning of the

proect

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.* a) $at is r!e # %SD in S%R3

Ans: =oores 7aw is now widely accepted as part of the microprocessor vernacularE it

relates to the compound dou%ling of computer processing power that has %een o%served to occur

appro$imately every ,H months or so &hese advances have %een possi%le due to improvingdesigns and chemical processes that have shrun the si;e of transistors (halving every ,H

months)' increased clocing speeds (dou%ling every ,H months)' and reduced power

consumption

&here are theories that this e$ponential improvement will hit a ceiling due to physical effects

such as unreali;a%le cloc speed or gamma radiation entering the silicon chip and causing false

logic state changes So far this has proved not to %e the case' and recent reports indicate that=oores 7aw will %e a%le to support another decade of improvement at least

0ordon =oore reported this trend in ,KM and since then it has %een mostly associated withgeneral-purpose microprocessors DSPs have followed a similar trend' as illustrated in 6igure'

where million multiply and accumulations per second (==A*S) are plotted over time for the

&e$as nstruments range of DSPs &he =A* is a good overall performance indication for theDSP as applied to software radio' %ecause many radio functions are multiply and accumulation

intensive


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&herefore' on average' every ,H months we can e$pect a dou%ling in processing power for

the same volume' power consumption' and cost &his e#uates to an order of magnitude (or ,

Ans.

a) Ariteture /er/ie$

A graphical depiction of the relationships %etween the +3 (*6 and *+&S) and SDRnoncore components is provided in 6igure G1E this details the ey elements and D7 interfaces

for the *6 &he SDR software structure shows that the noncore components are a%stracted away

from the underlying hardware' and all entities are connected via a logical software %us %y using*+RA Adapters are provided to allow non-*+RA modem' security' and /+ components to

interface with the *+RA components via the *+RA %us

&he software architecture is capa%le of operating using *+&S hardware %us

architectures (eg' I=3' cP*' and so on)E however' the actual implementation

will %e determined %y the derived performance re#uirements of the noncore

components (eg' data %andwidth and timing)


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*+&S operating systems (+Ss) with real-time em%edded capa%ilities such as preemptive

multitasing are e$pected to %e suita%le for SDR &he +S is also assumed to %e porta%le

operating system interface (P+SQ) compliant and the S*AS recommends the use of P+SQ,


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) Net$r>ing /er/ie$

&he S*AS includes specification of the e$ternal protocols that define communication

%etween an S*AS-compliant software radio and its peer systems Although the S*AS referencesmany military protocols' it also considers the popular S-KA *D=A mo%ile cellular standard as

an e$ample 6igure GG illustrates how the S*AS APs map onto the +S seven layer networingmodel &his mapping is not dissimilar to that used in the cellular mo%ile world' where the 5=&S

(10PP) and *D=A.


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ase application interfaces (Port, LifeCycle, TestableObject, Property- Set, PortSupplier,

ResourceFactory, andResource)' which can %e used %y all software applications

6ramewor control interfaces (DomainManager, DeiceManager, !pplication,

!pplicationFactory, Deice, Loa"ableDeice, #$ecutable- Deice, and !ggregate)'which provide control of the SDR

6ramewor services interfaces' which support %oth core and noncore applications

(FileSystem, File, FileManager, and Timer)

A domain profile' which descri%es the properties of hardware devices (device profile) andsoftware components (software profile) in the SDR

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.,) 1at are te #atrs $i su!d be ta>en in aunt $i!e se!eting R@S3 E5'!ain

any ne #rm #!!$ing in detai!.

a) LINFG & R@LINFG

b) V51r>s

) SE

d) MG

e) %SD H 8ISAns. 9

a)LINFG & R@ LINFG

785Q is a free 58Q type of operating system that is made availa%le under the 085general pu%lic license t was originally developed %y 7inus &orvlads in ,KK,' when it was

released as version


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worldwide to contri%ute to 785Q' with the result that the operating system is now very

widespread and increasing in popularity at an e$ponential rate

9hile 785Q has %een particularly popular in the P* world' it is generally not suita%lefor hard real-time em%edded systems Standard 785Q taes up to M


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=PS) and DSPs (&*M$' &*$' &*2$' &*1$' and ADSP.,


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6igure K1Smart antenna system using software radio

System capacity can also %e e$panded %y cell splitting (ie' macrocells are divided into many

more microcells) &his re#uires more &S sites' and in situations where it is impossi%le to

operate more sites (eg' community opposition) the only option may %e to e$pand e$isting site

capacity %y the addition of a smart antenna capa%ility

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. b) %esribe any !$ st e5'erimenta! S#t$are Radi '!at#rm3

Ans: ntroduction

&he design issues associated with the development of a software radio' with particular

emphasis on the 10 cellular mo%ile standards 9e now provide implementation-level detail for

an e$perimental software radio platform

Platform Re#uirements

&he system re#uirements were to design and implement software radio functionality in a high-

level software language %y using a low-cost platform &he hardware was re#uired to receiveradio fre#uency signals in the several =>; range' demodulate' and audio amplify them

System Architecture

&he &e$as nstruments *MG


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form-factor for installation in a P* &he *MGS,.


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6ig:System hardware architecture

0 b) 1rite Srt nte n BSDEAeasyC

Ans:-SP3AFeasy'a oint proect of the %ranches of the 5Smilitary 'was one of the first attempts

to create a formali;ed software radio architecture and launched the 5Smilitarys continuinginvolvement in software radios SP3AFeasy was the %eginning of a long-term strategy %y the

military to advance software radio technology and to decrease costs to leveraging the

commercial mass maret

SP3AFeasy is a successful implementation of a software-defined radio (SDR) for military

applications t permits general-purpose digital hardware to communicate over a wide range offre#uencies' modulation techni#ues' data encoding methods' cryptographic types' and other

communication parameters

&he SP3AFeasy program started with a phase where functions such as programma%ility'

fle$i%ility' reconfigura%ility' and the use of signal processors were illustrated t showed the

3valuation of SDR &echnology SDR &echnology 6e%ruary .6 antennas covering the K


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initial phase lead to a continuation in ,KK where the o%ective was set to develop field capa%le

prototypes with full R6 capa%ility &he implementation had to include commercial off the shelf

(*+&S) components' the use of non-proprietary %uses' open architecture' 86+S3* andwide%and data waveforms 7acing additional funding the SP3AFeasy program was

restructured in ,KKG as all the tass related to the wide%and capa%ility were eliminated >owever'

there was sufficient interest to initiate a new programmed and the oint &actical Radio Systemsprogram was esta%lished to investigate the re#uirements for scala%ility' the porta%ility of

waveforms' and the development of a common software communications architecture (S*A) thatwould facilitate the simple e$change of waveforms

&he SP3AFeasy program was %roen into two phases Phase was a proof-of-concept proect to

demonstrate the feasi%ility of software radios and the suita%ility reconfigura%le modem phase

sought to create a via%le implementation of a software radio and to formali;e a completesoftware radio architecture

SDEAeasy 'ase I

6rom ,KK. to ,KK' the goal was to produce a radio for the 5S Armywhich could operate from

. =>;to . 0>;' and operate with ground force radios (fre#uency-agile I>6' 6='andS8*0ARS)' Air 6orce radios (I>6 A=)' 8aval Radios (I>6 A=and >6SSteleprinters)

and satellites(microwaveBA=) Some particular goals were to provide a new signal format in

two wees from a standing start' and demonstrate a radio into which multiple contractors couldplug parts and software

&he proect was demonstrated at &6-QQ Advanced 9arfighting 3$ercise' and met all these

goals &here was some discontent with certain unspecified features ts cryptographicprocessor

could not change conte$t fast enough to eep several radio conversations on the air at once tssoftware architecture' though practical enough' %ore no resem%lance to any other

&he %asic arrangement of the radioreceiverused anantennafeeding an amplifierand down-

converter (see 6re#uency mi$er) feeding anautomatic gain control' which fed ananalog to

digital converterthat was on a computer I=3%uswith a lot of digital signal processors(&e$asnstruments*2


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&he goal was to get a more #uicly reconfigura%le architecture (ie several conversations at

once)' in an opensoftware architecture' with cross-channel connectivity (the radio can %ridge

different radio protocols) &he secondary goals were to mae it smaller' cheaper' and weigh less

&he proect produced a demonstration radio only fifteen months into a three-year research

proect &he demonstration was so successful that further development was halted' and the radio

went into production with only a 2 =>; to 2; range

&he software architecture identified standard interfaces for different modules of the radio: radiofre#uency control to manage the analog parts of the radio' modem control managed resources

for modulationand demodulationschemes (6=' A=' SS' BA=' etc)' waveform processing

modules actually performed the modemfunctions' ey processing and cryptographic

processing managed the cryptographic functions' a multimedia module did voice processing'a human interface provided local or remote controls' there was a routing module for networ

services' and a control module to eep it all straight

&he modules are said to communicate without a central operating system nstead' they sendmessages over the P*computer %usto each other with a layered protocol

As a military proect' the radio strongly distinguished red (unsecured secret data) and %lac

(cryptographically-secured data)

&he proect was the first nown to use6P0As(field programma%le gate arrays) for digital

processing of radio data &he time to reprogram these was an issue limiting application of theradio &oday' the time to write a program for an 6P0A is still significant' %ut the time to

download a stored 6P0A program is around .< milliseconds &his means an SDR could change

transmission protocols and fre#uencies in one fiftieth of a second' pro%a%ly not an intolera%leinterruption for that tas

&he Phase architecture also formed a more structured solution to incorporating %oth secureand unsecure modules into a single architecture &he primary goal of Phase architecture were

to

mplement a reconfigura%le architecture

mplement an open architecture

Active cross-channel connectivity and secondary goals were to

ncorporate more commercial off the shelf components

Reduce the form factor to a si;e deploya%le in the field

ncorporate reconfigura%le hardware

mprove the *TPRS chips conte$t switching time

SP3AFeasy program was motivated %y interoperata%ility and cost issues associated with

the 5Smilitarys radio Phase demonstrated that reprogramma%le devices weresufficiently powerful and power efficient for use in software radio and that software

radios had the potential to solve the militarys interoperata%ility issuesPhase designed
http://en.wikipedia.org/wiki/Modulationhttp://en.wikipedia.org/wiki/Demodulationhttp://en.wikipedia.org/wiki/Modemhttp://en.wikipedia.org/wiki/Modemhttp://en.wikipedia.org/wiki/Peripheral_Component_Interconnecthttp://en.wikipedia.org/wiki/Computer_bushttp://en.wikipedia.org/wiki/FPGAhttp://en.wikipedia.org/wiki/FPGAhttp://en.wikipedia.org/wiki/Modulationhttp://en.wikipedia.org/wiki/Demodulationhttp://en.wikipedia.org/wiki/Modemhttp://en.wikipedia.org/wiki/Peripheral_Component_Interconnecthttp://en.wikipedia.org/wiki/Computer_bushttp://en.wikipedia.org/wiki/FPGA


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and implemented a complete software architecture and incorporate reconfigura%le

hardware

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final sdr que paper

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