wideband code division multiple access and wcdma for umts

8/10/2019 Wideband Code Division Multiple Access and WCDMA for UMTS

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Wideband Code Division Multiple Access(WCDMA) for UMTS

Kari AhoSenior Research Scientist

[email protected]


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Disclaimer

Effort has been put to make these slides as correct as possible,however it is still suggested that reader confirms the latestinformation from official sources like !"" specs #http$%%www. gpp.org%Specification&'umbering ()aterial represents the views and opinions of the author and not

necessaril* the views of their emplo*ers+se%reproduction of this material is forbidden without apermission from the author
http://www.3gpp.org/Specification-Numberinghttp://www.3gpp.org/Specification-Numbering


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Readings related to the sub ect

!eneral readings- D)A for +)/S 0 1. 1olma, A. /oskala1SD"A%1S+"A for +)/S 0 1. 1olma, A. /oskala! Evolution & 1S"A and 2/E for )obile 3roadband & E. Dahlman, S."arkvall, 4. Sk5ld and ". 3eming,

'etwork planning orientedRadio 'etwork "lanning and 6ptimisation for +)/S 0 4. 2aiho, A.-acker, /. 'ovosad+)/S Radio 'etwork "lanning, 6ptimi7ation and 8oS )anagement9or "ractical Engineering /asks 0 4. 2empi:inen, ). )anninen


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6utline

3ackground-ideband ode Division )ultiple Access #- D)A(- D)A "erformance Enhancements

)ultimedia 3roadcast )ulticast Service #)3)S(9emtocells

onclusions


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3ackground

Why new radio access for UMTS Frequency Allocations

Standardization WCDMA background and e olution

! olution of Mobile standards

Current WCDMA "arkets


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-h* new radio access s*stem for +)/S#;%ible utili7ation of the spectrum


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-h* new radio access s*stem for +)/S#


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9re?uenc* allocations for +)/S

9re?uenc* plans ofEurope, 4apan andKorea are harmoni7ed+S plan isincompatible

Spectrum is currentl*used for the +S

=)/&


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Standardi7ation #;%


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Standardi7ation #


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- D)A 3ackground and Evolution #;%


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Evolution of )obile standards

EDGE

GPRSGSMHSCSD

cdmaOne(IS-95)

WCDMAFDD

HSDPA/HSUPA

cdma2000

TD-SCDMATDD CR

cdma2000!"E# - DO

cdma2000!"E# - D#

TD-CDMA TDD HCR

HSDPA/HSUPA

TE


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urrent - D)A markets #;%


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urrent - D)A markets #


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-ideband ode Division )ultiple Access#- D)A(

* er iew Codes

UMTS Architecture$adio +ro+agation, fading and recei ers

Di ersity

'ower Control-ando ersChannels


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- D)A S*stem #;% (

- D)A is the most common radio interface for +)/S s*stems-ide bandwidth, . G )cps #)egachips per second(

)aps to )17 due to pulse shaping and small guard bands betweenthe carriers

+sers share the same )17 fre?uenc* band and time

+2 and D2 have separate )17 fre?uenc* bands+sers are separated from each other with codes and thus fre?uenc*reuse factor e?uals to ;

1igh bit rates-ith Release L theoreticall* < )bps/he higher implemented is however G kbps


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- D)A S*stem #


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- D)A S*stem # % (

)ultiple>ing of different services on a single ph*sical connectionSimultaneous support of services with different 8oS re?uirements$

Real&time, #voice, video telephon*(Streaming #video and audio(=nteractive #web&browsing(3ackground #e&mail download(


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odes in - D)A #;%G(

hanneli7ation odes #Mshort codes(Defines how man* chips are used to spread a single information bitand thus determines the end bit rate

2ength is referred as spreading factor

+sed for$Downlink$ Separation of downlink connections to different users within onecell+plink$ Separation of data and control channels from same terminal

Same channeli7ation codes in ever* cell % mobilesadditional scrambling code is needed


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odes in - D)A #


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odes in - D)A # %G(

C/anne)i5ationcodes separate

differentconnection

Do3n)in6

Scram7)in8codes separate

ce))s sectors

Up)in6


data contro)c/anne)s


different mo7i)es


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odes in - D)A #G%G(

SpreadingFactor (SF)

Channelsymbol

rate(kbps)

Channelbit rate(kbps)

DPDCHchannel bitrate range

(kbps)

Maximum userdata rate with -

rate coding(approx.)

512 7.5 15 36 13 kbps256 15 30 1224 612 kbps128 30 60 4251 2024 kbps64 60 120 90 45 kbps32 120 240 210 105 kbps16 240 480 432 215 kbps8 480 960 912 456 kbps4 960 1920 1872 936 kbps

4, with 3parallelcodes

2880 5760 5616 2.3 Mbps

-alf rate s+eech

Full rate s+eech

&.. kb+s(/. kb+s

0 Mb+s

S9m7o) rate ;C/ip rate S.


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8uestions

/o what purpose channeli7ation codes are used in the downlink/o what purpose scrambling codes are used in the uplink


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+)/S /errestrial Radio Access 'etwork #+/RA'(Architecture #;% (

'ew Radio Access networkneeded mainl* due to newradio access technolog*ore 'etwork # '( isbased on !S)%!"RSRadio 'etwork ontroller

#R' ( corresponds roughl*to the 3ase Stationontroller #3S ( in !S)'ode 3 correspondsroughl* to the 3ase Stationin !S)

R !

ode"

ode"

ode"#$ !

R !

#$

Uu interface?u7 interface

?ur interface

UT(A@


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+)/S /errestrial Radio Access 'etwork #+/RA'(Architecture #


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+)/S /errestrial Radio Access 'etwork #+/RA'(Architecture # % (

'ode 3)ain function to convert the data flow between +u and =ubinterfacesSome RR) tasks$

)easurements=nnerloop power control


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Radio propagation, fading and receivers#;%G(

-hen transmitted radio signaltravels in the air interface it isaltered in man* wa*s before itreaches the receiver

reflections, diffractions,attenuation of the signalenerg*, etc.

/hese different multipathcomponents of the transmittedsignal arrive at different timesto the receiver and can causeeither destructive orconstructive addition to thearriving plane waves


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Radio propagation, fading and receivers#ample of the fast fading

channel in the function of timeis in the right hand figure=llustrates, for instance, deepfades in the channel thatpower control would need toreact to


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di i f di d i


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Radio propagation, fading and receivers#G%G(

.in8er %

.in8er 2

.in8er $

Transmitteds9m7o)

(ecei>eds9m7o) ateac/ times)ot

'/asemodified usin8t/e c/anne)estimate

Com7ineds9m7o)


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Diversit* #;%ists different t*pes diversit* which can be used to improve the?ualit*, e.g.$

)ultipath

Reflections, diffractions, attenuation of the signal energ*, etc.)acro

Different basestations or 'ode3s send the same information

Site Selection Diversit* /ransmission #SS/D()aintain a list of available basestations and choose the best one, from which thetransmission is received and tell the others not to transmit


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Diversit* #


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8uestions

-hat does R' stand for and what it is responsible for-hat is Rake and how it improves the signal ?ualit*


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"ower ontrol in - D)A #;%G(

/he purpose of power control #" ( is toensure that each user receives andtransmits ust enough energ* to prevent$

3locking of distant users #near&far&effect(E>ceeding reasonable interference levels

UE%UE2

UE$

UE%

UE2

UE$

UE% UE2 UE$

Wit/out 'C recei>edpo3er )e>e)s 3ou)d

7e uneBua)

?n t/eor9 3it/ 'Crecei>ed po3er )e>e)s

3ou)d 7e eBua)


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"ower ontrol in - D)A #


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"ower ontrol in - D)A # %G(

losed loop power control can also be divided into two parts$=nnerloop power control

)easures the signal levels and compares this to the target value and ifthe value is higher than target then power is lowered otherwise power isincreased

6uterloop power control

Ad usts the target value for innerloop power controlan be used to control e.g. the 8ualit* of Service #8oS(


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"ower ontrol in - D)A #G%G(

E>ample of inner looppower control behavior$

-ith higher velocitieschannel fading is morerapid and ; BB 17 powercontrol ma* not besufficient


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- D)A 1andovers #;% (

- D)A handovers can be categori7ed into three different t*peswhich support different handover modes=ntra&fre?uenc* handover

- D)A handover within the same fre?uenc* and s*stem. Soft, softer and hard handover supported

=nter&fre?uenc* handover

1andover between different fre?uencies but within the same s*stem. 6nl*hard handover supported

=nter&s*stem handover1andover to the another s*stem, e.g. from - D)A to !S). 6nl* hard handover supported


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- D)A 1andovers #


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- D)A 1andovers # % (

Softer handover1andover within thecoverage area of one basestation but betweendifferent sectors"rocedure similar to soft

handover

UE%


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- D)A 1andovers #G% (

1ard handover/he source is released first and then new one is addedShort interruption time

/erminolog*Active set #AS(, represents the number of links that +E is connectedto'eighbor set #'S(, represents the links that +E monitors which arenot alread* in active set


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1andover parametersAdd windowRepresents a value of how much worse a new signal can be compared tothe best one in the current active set in order to be added into the setAdding link to combining set can be done onl* if ma>imum number oflinks is not full *et #defined with parameter(.)oreover a new link is added to the active set onl* if the differencebetween the best and the new is still at least as good after the Oadd timerLis e>pired. /imer is started when the signal first reaches the desired level.

Drop windowRepresents a value of how much poorer the worst signal can be whencompared to the best one in the active set before it is dropped outSimilarl* to adding, signal which is to be dropped needs to fulfill the dropcondition after the corresponding drop timer is e>pired.


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- D)A 1andovers #C% (

Replace windowRepresents a value for how much better a new signal has to be comparedto the poorest one in the current active set in order to replace its placeReplace event takes place onl* if active set is full as otherwise add eventwould be appliedSimilarl* to add and drop events, also with replace event there e>ist areplace timer

) d % (


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E>ercises$Replace O/hresholdP;L, O/riggering timeP;L, etc with correct handoverparameter names.-hich event is missing from the e>ample

(ecei>edsi8na)stren8t/


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8uestions

/o which parts can the fast i.e. closed loop power control bedived into/o how man* base stations +E is connected to when it makes ahard handover

D)A h l # %C(


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- D)A hannels #;%C(

=n - D)A there e>ists two t*pes of transport channels$Dedicated hannels #D 1s(Resources are reserved for a single user onl* #continuous andindependent from the D 1s of other +Es(

ommon channels Resources are shared between users

/he main transport channels used for packet data transmissionsin - D)A are called

D 19orward Access hannel #9A 1(

D)A h l #


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- D)A hannels #


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- D)A hannels # %C(

=f downlink rate matching is used then data bits are eitherRepeated to increase the rate"unctured to decrease the rate

-ith D/Q the transmission is off during part of the slot

9A 1 is a downlink transport channel used to carr*"acket data)andator* control information, e.g. to indicate that random accessmessage has been received b* 3/S

Due to the reason that 9A 1 carries vital control information9A 1 has to have such a low bit rate that it can be received b*all +Es in the cell

D)A hannels #G%C(


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- D)A hannels #G%C(

1owever, there can be more than one 9A 1 in a cell which makesit possible to have higher bit rates for the other 9A 1s/he 9A 1 does not support fast power control

=n addition to 9A 1 there are five different common channels in- D)A$

3roadcast hannel #3 1(+sed to transmit information specific to the +/RA network or for a givencell, e.g. random access codeshannel needs to be reached b* all +Es within the cell

"aging hannel #" 1(arries data relevant to the paging procedure, i.e. when the network wantsto initiate communication with the terminal/erminals must be able to receive the paging information in the whole cellarea

D)A hannels # %C(


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- D)A hannels # %C(

Random Access hannel #RA 1(+plink transport channel intended to be used to carr* control informationfrom the terminal, such as re?uests to set up a connection

+plink ommon "acket hannel # " 1(E>tension to the RA 1 channel that is intended to carr* packet&baseduser data in the uplink direction

Dedicated Shared hannel #DS 1(arries user data and%or control information it can be shared b* severalusers

D)A hannels #C%C(


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- D)A hannels #C%C(

9rom the common channels DS 1 was optional feature that wasseldom implemented b* the operators and later replaced inpractice with 1igh Speed Downlink "acket Access #1SD"A(

!"" decided to take DS 1 awa* from Release specificationsonwardsAlso " 1 has been taken out of the specifications from RelL

onwards as it was not implemented in an* of the practical networks


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- D)A "erformance Enhancements

Multi"edia %roadcast Multicast Ser iceFe"tocells

)ultimedia 3roadcast )ulticast Service


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#)3)S( 0 3ackground #;%


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#)3)S( 0 3ackground #


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#)3)S( 0 =ntroduction #;% (

Allows different forms of multimedia content to be deliveredefficientl* b* using either broadcast or multicast mode

)obile /I, weather reports, local information, /he term broadcast refers to the abilit* to deliver content to all userswho have enabled a specific broadcast service and find themselvesin a broadcast area

)ulticast refers to services that are delivered solel* to users whohave oined a particular multicast group. )ulticast group can be, fore>ample, a number of users that are interested in a certain kind ofcontent, such as sports


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)ultimedia 3roadcast )ulticast Service


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#)3)S( 0 =ntroduction # % (

%&t&% %&t&'

M


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)ultimedia 3roadcast )ulticast Service#)3)S( 0 8 li * f S i # %G(


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#)3)S( 0 8ualit* of Service #


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#)3)S( 0 8ualit* of Service # %G(

)ultimedia 3roadcast )ulticast Service#)3)S( 0 8 lit* f S i #G%G(


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#)3)S( 0 8ualit* of Service #G%G(

)3)S performance in - D)A networks


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) ) p )

Ce)) t/rou8/put 3it/ 2*

antenna termina) and softcom7inin8 %#00*2#00 67ps; %2*20 x %2 67ps T

c/anne)s

Ce)) t/rou8/put 3it/ %*

antenna termina) and softcom7inin8 !00*%000 67ps ; #*

x %2 67ps T c/anne)s

9emtocells


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)ore and more consumers want to use their mobile devices at home,even when thereLs a fi>ed line available

"roviding full or even ade?uate mobile residential coverage is a significantchallenge for operators)obile operators need to sei7e residential minutes from fi>ed line providers,and compete with fi>ed and emerging Io=" and -i9i services MH /here istrend in discussing ver* small indoor, home and campus 'ode3 la*outs

9emtocells are cellular access points #for limited access group( thatconnect to a mobile operatorLs network using residential DS2 or cablebroadband connections9emtocells enable capacit* e?uivalent to a full ! network sector at ver*low transmit powers, dramaticall* increasing batter* life of e>istingphones, without needing to introduce -i9i enabled handsets

8uestions


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-hat does multicast mean1ow the lack of uplink transmissions with )3)S can becompensated so that the 8oS is improved-hat are femtocells


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onclusions

onclusions #;%G(


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'eed for universal standard and improved packet datacapabilities were among the ke* factors towards a new radionetwork interface, -ideband ode Division Access #- D)A(!"" is currentl* the main standardi7ation bod* in charge of- D)A and its evolutions)arket share for - D)A is growing rapidl*

)ore than GB million - D)A subscribers9ueled b* various services such as mobile&/I and Io="

onclusions #


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odes in - D)Ahanneli7ation odes

Spreads the information signalSeparates of downlink connections #D2( or data and control channels fromsame terminal #+2(

Scrambling codesDoes not spread the signal

Separates different cells%sectors #D2( or different mobiles #+2(+/RA'

'eeded mainl* due to new radio access technolog*'ode 3 #base station( responsible of handling connections to andfrom the +ER' responsible of radio resource management

Each of those fingers can receive individual multipath components


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onclusions #G%G(


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- D)A hannels)ain data channels are D 1 and 9A 1D 1 is using dedicated resources while 9A 1 relies on sharedresources

)3)S was introduced to more efficient utili7ation of limited radionetwork resources with multimedia content provision

=mproved even further with macro diversit* combining and diversit*techni?ues

9emtocells were introduced to improve the mobile convergenceand performance in small offices or at home, for instance


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'e>t lecture

6utline


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1igh Speed Downlink "acket Access1igh Speed +plink "acket Accessontinuous "acket onnectivit* #Io="(=nternet&1S"A

-S'A e olution


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/hank *ouT

wideband code division multiple access and wcdma for umts

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