Post on 05-Apr-2018
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7/31/2019 Is 95 Standard
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02PearsonEducation,
Inc.Commercialuse,
distribution,or
saleprohibited.
IS 95 occupies 1.25 MHz of spectrum on
each one way link
Different modulation and spreading
technique for the forward and reverse link On forward link user data transmits
simultaneously along with pilot carrier
All mobile use coherent detection
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02PearsonEducation,
Inc.C
ommercialuse,
distribution,or
saleprohibited.
On reverse link all mobiles respond in
asynchronous fashion and have constantpower level
IS 95 uses Qualcomm 9600 bps QCELPcoder
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2002PearsonEducation,
Inc.C
ommercialuse,
distribution,or
saleprohibited.
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Inc.C
ommercialuse,
distribution,or
saleprohibited.
Frequency and channelspecification
Forward link 869-894
reverse link 824-849 Forward link and reverse link separated by
45 MHz
Maximum user data 9.6kb/s
On the forward link user data is encoded
using rate convolution code,interleaved, and spread by one of sixtyfour orthogonal spreading sequence
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2002PearsonEducation,
Inc.C
ommercialuse,
distribution,or
saleprohibited.
The base station and subscriber uses
RAKE receiver to resolve multipathcomponents
The soft handoff is given from base station,the mobile receives the signal from twobase station and processed as multipath
components
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2002PearsonEducation,
Inc.C
ommercialuse,
distribution,or
saleprohibited.
FORWARD CDMA CHANNEL Pilot channel
acquire timing for the forward CDMAchannel
phase reference for coherent detection
provides each mobile with a means forsignal strength comparison for handoff
Synchronization channel Broadcasts synchronization message to all
mobiles at 1200bps
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2002PearsonEducation,
Inc.C
ommercialuse,
distribution,orsaleprohibited.
Paging channel
send control information and pagingmessages from base station to mobiles
,operates at 9600,4800,and2400bps. The forward traffic channel
It supports variable user data rates
9600,4800,2400 or 1200 bps
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002PearsonEducation,
Inc.C
ommercialuse,
distribution,orsaleprohibited.
Convolutional encoder and repetion circuit
encoded using half rate convolutional encoderwith constant length 9
generator vectors Go(753) octal and G1(561)
constant base band symbol rate 19.2kbps
4800 repeat one time
2400 repeat three time1200 repeat seven times
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002PearsonEducation,
Inc.C
ommercialuse,
distribution,orsaleprohibited.
Long PN sequence Direct sequence
PN sequence long 242 -1 chips period P(x)=x42+x35+x33+x31+x27+x26+x25+x22+x21+
x19+x17+x16+x10+x7+x6+x5+x3+x2+s1+1
Intial state id 1after 41 consecurive 0s
Two types of mask
public mask-ESNPrivate mask-MIN
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002PearsonEducation,
Inc.C
ommercialuse,
distribution,orsaleprohibited.
Public long code
M41 through M32 is set to 1100011000
M31 through M0 is permutated ESN
Private long codeM41 and M40 set 01
M39 through M0 are set by privateprocedure
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002PearsonEducation,
Inc.C
ommercialuse,
distribution,orsaleprohibited.
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002PearsonEducation,
Inc.C
ommercialuse,
distribution,o
rsaleprohibited.
Data scrambler
1.2288 MHz PN sequence is applied to adecimator, keeps only first bit of every sixty fourconsecutive PN sequence
Power control sub channel
Power control updates are sent by basestation for every 1.25ms
increase or decrese in 1dB steps
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002PearsonEducation,
Inc.C
ommercialuse,
distribution,o
rsaleprohibited.
Power control
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002PearsonEducation,
Inc.C
ommercialuse,
distribution,o
rsaleprohibited.
Orthogonal covering
spreaded with a walsh function with afixed chip rate of 1.2288Mcps
64 binary sequence length of 64 all areorthogonal to each other
the walsh sequence repeats every
52.083 s,equal to one coded data symbol
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002PearsonEducation,
Inc.C
ommercialuse,
distribution,o
rsaleprohibited.
64 by 64 walsh function Hadamard matrix
H1=0 H2= 0 0
0 1
H4= 0 0 0 0 H2N= HN HN0 1 0 1
0 0 1 1 HN HN
0 1 1 0
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002PearsonEducation,
Inc.C
ommercialuse,
distribution,o
rsaleprohibited.
Quadrature Modulation 215-1 is used for modulation
The short spreading sequence
PI(x) =x15+x13+x9+x8+x7+x5+1
PQ(x)= x15+x12+x11+x10+x6+x5+x4+x31
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002PearsonEducation,
Inc.Commercialuse,
distribution,o
rsaleprohibited.
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2002PearsonEducation,
Inc.Commercialuse,
distribution,o
rsaleprohibited.
Reverse CDMA channel AC Acess channel
RTC Reverse traffic channel RTC/AC identified by long distinct user code
AC mobile to initiate call and respond to paging
channel
32 ACs per supported paging channel
ACs fixed data rate 4800bps
RTC variable data rate
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Inc.Commercialuse,
distribution,o
rsaleprohibited.
Convolutional encoder
557,663,771 Block interleaver
span 20ms array with 32 rows and 18 columns
64 walsh functionwalsh function is selected according to
c0+2c1+4c2+8c3+16c4+32c5
Transmitted at rate of 28.8kbpsx64walsh chips/6coded bits=307.2kbps
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Inc.Commercialuse,
distribution,o
rsaleprohibited.
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Inc.Commercialuse,
distribution,o
rsaleprohibited.
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Inc.Commercialuse,
distribution,orsaleprohibited.
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Inc.
Commercialuse,
distribution,orsaleprohibited.
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Inc.
Commercialuse,
distribution,orsaleprohibited.
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Inc.
Commercialuse,
distribution,orsaleprohibited.
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Inc.
Commercialuse,
distribution,orsaleprohibited.
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2002PearsonEducation,
Inc.
Commercialuse,
distribution,orsaleprohibited.
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2002PearsonEducation,
Inc.
Commercialuse,
distribution,
orsaleprohibited.
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2002PearsonEducation,
Inc.
Commercialuse,
distribution,
orsaleprohibited.