23373910 Design Implementation and Optimisation of Cdma Networks Rf Planning

8/10/2019 23373910 Design Implementation and Optimisation of Cdma Networks Rf Planning

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DESIGN, IMPLEMENTATION AND OPTIMISATION OFCDMA NETWORKS (RF PLANNING)

DEEPRA BHATTACHERJEE, ABHRA MAZUMDAR, EEE 06Project Guide: Ashok R !" s# $%, EEE De&t'

CDMA stands for "Code Division Multiple Access." It is a form of spread-

spectrum, an advanced digital wireless transmission technique. Instead of using

frequencies or time slots, as do traditional technologies, it uses mathematical codes to

transmit and distinguish between multiple wireless conversations. Its bandwidth is much

wider than that required for simple point-to-point communications at the same data rate

because it uses noise-li e carrier waves to spread the information contained in a signal ofinterest over a much greater bandwidth. !owever, because the conversations ta ing place

are distinguished b digital codes, man users can share the same bandwidth

simultaneousl .

#$ %&A''I'( deals with the air interface between the )A*+ #A'*C+I +#

* A I ' / the M )I&+ 0'I . It also involves designing and optimi1ing the networ

in order to provide a high qualit service to customers.

he ob2ective of the pro2ect is to plan, design / optimi1e a cell site at BA(GARPET'

he main purpose of the planning is fewer base stations per networ , greater s stem

efficienc and capacit , improved voice qualit and a reduction or elimination of drop

outs and multi path problems. All of which result in improved services and greatl

reduced networ cost.

THE VARIOUS STAGES INVOLVED IN CDMA RFPLANNING & OPTIMISATION

3. MAR)ET *UR+E : Depending on the mar eting feedbac , a thorough surve is

conducted to define the area of coverage / potential candidate sites are listed out. he

mar et surve also gives the area morpholog -terrain and clutter information. he

purpose of the mar et anal sis is to collect all the information from the mar et that

affects the design of the #$ 'etwor . he following information is gathered4


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a5 Classification of various t pes of morphologies in the area

b5 Ma2or points of interest

he e6act locations of the important places of the town were recorded using a (& )A&

% *I I 'I'( *7* +M 8I as shown below.

- titude -o!"itude-oc tio!39.:;;.3


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$I(0#+ 3. )A'(A#%+ %# % *+D *I + C +#A(+ CA&C0&A I ' 0*I'(%&A'+ +After Clutter classification is done, the location of the cell site is derived based on the

information gathered. )ased on the information collected, design process is carried out

as shown4


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$I(0#+ 9. D+*I(' %# C+** B%#+ A'A&7*I*5

he penetration median losses, standard deviations, and fade margins calculated on this

basis below are ta en directl to the lin budgets to be used in later cell planning.

C/MP/* TE PR/BAB - T /4 *ER+ CECA&C0&A I'( #+ 0I#+D $AD+ MA#(I'

+' I# 'M+'7%+

B M #%! & (7E5

)0I&DI'(%+'+ #A I '

0 D # C M% *I + A&

M+DIA'& **,D)

* D.D+ .F,D)

* D.D+ .F, D)

A#+AA AI&I)I&I 7

A#(+ ,G

$AD+MA#(I'BD)5

D+'*+ 0#)A')&D(.

9= ; ; :=GH>?G +D(+ >.?G +D(+ >.?G +D(+ >.?G +D(+ >.


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$I(0#+ K. ! #IL ' A& %&

$I(0#+ @. +# ICA& %&


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$I(0#+ ?4 )A'(A#%+ A'A& ( %#+DIC I ' B #IA&5

CDMA re5erse i!k ! %sis: he + reverse lin anal sis computes the probabilit

that a mobile user , with the abilit to transmit at the ma6 +#% specified b ou, is able

to close the reverse lin . #everse lin closure is computed as the probabilit of receiving

a mobile unit s signal at the serving siteBs5

ith sufficient mobile unit traffic channelBreverse lin target5 +bH't for acceptable call

qualit . he reverse lin anal sis incorporates the statistical nature of the processes and

computes the probabilit of closing the lin for each handoff t pe. Closing the reverse lin in no handoff is predicted in terms of a single

probabilit . hile the various softE handoff configurations are computed in terms of

2oint probabilities that at least one of the contributing entities will receive adequate

signal.


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CDMA 4or# rd i!k ! %sis 4 his anal sis verifies that the specified threshold

B NADD or ND# % specified for each cellHsector5 for pilot channel coverage has been

met or e6ceeded before a cellHsector is considered to be a valid contributor. he hand-off

contributors are based on the strongest pilot signals at each bin.

7' R4 MP-EME(TAT /(: nce the proposed cell site has been finali1ed, #$

implementation team swings into action wherein the proposed cell site is ph sicall

implemented.

$I(0#+


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8' (ET1/R) PER4/RMA(CE M/( T/R (G: nce the base station is set up, its

performance is continuousl monitored. his process is called drive testing. he tool is

called +M* I' +* I(A # from +#IC** '. he drive test s stem is placed in a

vehicle / driven throughout the coverage area of potential site. It actuall gives a

subscriber s point of view of the networ . It can evaluate call - processing operations,

perform call processing functions and signal qualit of received base station signal.

Dri5e test 9or $ode c i r tio!: A significant number of t pical sites are evaluated

using the test transmitter / receiver to determine signal deca rates and to get a fairl

accurate understanding of the effects of t pical clutter in the area. ests are also

conducted to evaluate the additional attenuation which the signal suffers during

penetration of t pical buildings and vehicles. he focus is on developing models

generall applicable to the area, not on performance of specific individual sites.

Dri5e test 9or site e5 u tio!: Although propagation models for an area alread have

been refined coverage of a particular site is so critical, or its environment so variable due

to urban clutter that it is essential to actuall measure the coverage and interference it will

produce. he focus is on this specific site.

CDMA Per9or$ !ce !dic tors:

!dic tor ; o O hat does it meanP

h can t we 2ust use the handset s received power level to guide handoffsP

)ecause it is a simple total #$ power measurement, the total of all sectors

reaching the mobile. e need a wa to measure the signal strength of each sector

individuall , / we must be able to measure it quic l / simpl . he solution is to use

each sector s pilot B alsh =5 as a test signal to guide handoffs.


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At the mobile, if the pilot of a certain sector is ver strong / clean, that means we

also should be able to hear a traffic channel on that sector, so handoff would be a good

idea.

If the pilot of a certain sector is wea , then we probabl won t be able to get much

benefit from using a traffic channel on that sector.

6' P/*T A(A- * * 4 he drive test data is loaded into a post anal sis tool. It assesses

the end-to-end performance of the networ infrastructure. It can be used to anal 1e the

benchmar drive data to compare the performance of their own networ with those of

competitors. & uses +M* D+*8CA as the post anal sis tool. e get the following

parameters4 +cHIo, 6 power, #6 power and $+#.

$I(0#+ >4 CDMA %A#AM+ +#* $# M +M* I' +* I(A #


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$I(0#+ ;4 +CHI %&

Starting optimization on a new systemR4 co5er "e co!tro

r to contain each sectors coverage, avoiding gross spillover into other

sectors.

Too s 4 %' plots, !andoff state plots, mobile 6 plots.

(ei"h or ist tu!i!"

r to groom each sector s neighbor to onl those necessar but be alert to

special needs due to topograph / traffic.ools4 %*MM data from mobilesQ propagation prediction.

*e rch #i!do# setti!"s

$ind best settings for *#C!N I'NA,N',N#


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+speciall optimi1e *#C!N I'NA per sector using collected finger

separation dataQ has ma2or impact on pilot search speed.

ACCE** 9 i ures, dro&&ed c ! %sis

$inall , iterative corrections until within numeric goals.

35 %erformance monitoringHgrowth management

95 )enchmar e6isting performance

K5 Identif problem cells / clusters

@5 &oo for signs of overload

?5 raffic trending / pro2ection

hese steps must be continuousl applied to guide needed growth.

CONCLUSION he construction of the cell site at )angarpet was completed. he site became full

operational in the first wee of APR -, .006' he pro2ect wor is carried out for A A

elecom.


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PARTIAL DISCHARGE MEASUREMENT FOR HIGHVOLTAGE CA LE TERMINATIONS

A#0' 80MA#, )!A#A .(, *0MI 80MA#, +++ =

23373910 Design Implementation and Optimisation of Cdma Networks Rf Planning

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