Download - 3G Basic Issue 1-3 OVSF Code Thai
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3rd Generation of Mobile Communications Advanced Info Service PLC.
1 | P a g e Radio Access BKK Composed by: Wutthilert Rungchai February 2010 Edit by: Bunjong Yosapa
ISSUE 1-3
Code CDMA (Code) ( FDMA
TDMA ) Spread
Scrambling
Scrambling Code
Scrambling Code
Channelization Code
Spreading
Scrambling
De-Spreading
De-Scrambling
Voice
Data
Voice
Data
1 code spreading scrambling
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3rd Generation of Mobile Communications Advanced Info Service PLC.
2 | P a g e Radio Access BKK Composed by: Wutthilert Rungchai February 2010 Edit by: Bunjong Yosapa
Scrambling Spread ( spreading )
Modulate Bit Rate
Bit Rate Spread
Spreading & Modulation
2 Spreading Despreading
2 (Data) (Spreading) ()
Spreading Code ( Channelization code
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3rd Generation of Mobile Communications Advanced Info Service PLC.
3 | P a g e Radio Access BKK Composed by: Wutthilert Rungchai February 2010 Edit by: Bunjong Yosapa
channel ) Spreading Signal Spreading Signal Despread
Spreading Code
Spreading (Data) Exclusive OR Spreading
Code Output Spreading Code Chip Rate
Spreading Code
Code WCDMA Code
(Channel) OVSF code (Orthogonal Variable
Spreading Factor) Code
Spreading Factor (SF) )
3 Code tree
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3rd Generation of Mobile Communications Advanced Info Service PLC.
4 | P a g e Radio Access BKK Composed by: Wutthilert Rungchai February 2010 Edit by: Bunjong Yosapa
3 OVSF Code Code
Spread Factor (SF) SF= 1 SF=256 (UL)/512 (DL)
Code CSF, No. 0 C1,1 (SF=1, No.=1) 00 C2,1 (SF=2, No.=1)
Code generation
(RNC)
WCDMA
A
A,A
A,-A 4 code
Code Code A Code
Code A A, A Code A Code A, -A
Code (A) Code Invert A Code A 1010 (SF=4) code
SF SF=8 = A,A = 10101010 A,-A = 10100101
WCDMA Code Spread Chip Rate 3.84 Mega chip per
second (Mcps) Code SF Mod Spread
3.84 Mcps
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3rd Generation of Mobile Communications Advanced Info Service PLC.
5 | P a g e Radio Access BKK Composed by: Wutthilert Rungchai February 2010 Edit by: Bunjong Yosapa
SF SF SF= 8 User Throughput
SF SF=128 User Throughput
SF SF SF = 4
chip Radio
SF SF
SF
Radio
Spreading Factor Spreading Factor
User throughput
User
User throughput
User
Correlation
Despreading
Correlation
(Code) CDMA
0 -1 () 1 +1 () 1
Exclusive OR ( 1 1)
[-1 +1] =0, [+1+1]=2, [-1-
1]=-2 Code ()
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3rd Generation of Mobile Communications Advanced Info Service PLC.
6 | P a g e Radio Access BKK Composed by: Wutthilert Rungchai February 2010 Edit by: Bunjong Yosapa
-1
+1
0
-1
-1 1 -1 1 1 1-1 1 -1 1 1 1
+1
0
-1
-1 1 -1 1 1 1
+1
0
-1 1 -1 1 1 1
1 1 1 1 1 1= +1+1+1+1+1+1= 6/6=1
5 Correlation
Exclusive OR ( = 0 -1
= 1) (1+1+1+1+1+1)/ = 6/6 = 1 Correlation
-1
+1
0
-1
-1 1 -1 1 1 11 1 -1 1 -1 1
+1
0
-1
-1 1 -1 1 1 1
+1
0
1 1 -1 1 -1 1
-1 1 1 1 -1 1
=-1+1+1+1-1+1= 2/6 = 0.33 6 2 ()
5 6 Function exclusive OR
Correlation = 0.33 2 6 Correlation 1
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3rd Generation of Mobile Communications Advanced Info Service PLC.
7 | P a g e Radio Access BKK Composed by: Wutthilert Rungchai February 2010 Edit by: Bunjong Yosapa
-1
+1
0
-1
-1 1 -1 1 1 11 1 1 1 -1 1
+1
0
-1
-1 1 -1 1 1 1
+1
0
1 1 -1 1 -1 1
-1 1 -1 1 -1 1
=-1+1-1+1-1+1= 0/6 = 0 7 Correlation 0 (zero) correlation
7 Zero Correlation
( ) Orthogonal
Orthogonal
Spread
Code
1 Correlation Auto Correlation Zero Correlation
Cross Correlation
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3rd Generation of Mobile Communications Advanced Info Service PLC.
8 | P a g e Radio Access BKK Composed by: Wutthilert Rungchai February 2010 Edit by: Bunjong Yosapa
Despreading
Code SF4,4(0110)
Input
output
8 Spreading Spreading code SF4,4
(Input) 2 1 0 Spreading Code Spreading Factor = 4
Code 4 ( Code tree code 0110 0 1
) -111-1 () Output
-111-11-1-11 ( 01101001) ()
Received
Code SF4,4(0110)
output
-1 1 1-1 1-1-1 1
-1 1 1-1 -1 1 1-1
1 -1
9
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3rd Generation of Mobile Communications Advanced Info Service PLC.
9 | P a g e Radio Access BKK Composed by: Wutthilert Rungchai February 2010 Edit by: Bunjong Yosapa
() = [Received SF code]/Code length = [-1 1 1-1 -1 1 1-1]/4 =
[1+1+1+1]/4 = 4/4 = 1
= [1-1-1 1 -1 1 1-1]/4 = [-1-1-1-1]/4 = -4/4 = -1
Exclusive OR 0 () -1
1
Received
Code SF4,4(0110)
output
-1 1-1-1 1-1 1 1
-1 1 1-1 -1 1 1-1
0.5 -0.5
10 despreading
1
= [-1 1-1-1 -1 1 1-1]/4 = [1+1-1+1]/4 = 2/4 =0.5
= [1-1 1 1 -1 1 1-1]/4 = [-1-1+1-1]/4 = -2/4 = -0.5
Correlation 1 1 (0)
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3rd Generation of Mobile Communications Advanced Info Service PLC.
10 | P a g e Radio Access BKK Composed by: Wutthilert Rungchai February 2010 Edit by: Bunjong Yosapa
Code Despread
Received
Code SF4,3(0101)
output
-1 1 1-1 1-1-1 1
-1 1-1 1 -1 1-1 1
0 0
11 SF code despread
Despread code (
) SF4,3 (0101)
= [-1 1 1-1 -1 1-1 1]/4 = [1+1-1-1]/4 = 0/4 = 0
= [1-1-1 1 -1 1-1 1]/4 = [-1-1+1+1]/4 = 0/4 =0
1 0 Idle
Orthogonal SF4,4 SF,4,3 orthogonal
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3rd Generation of Mobile Communications Advanced Info Service PLC.
11 | P a g e Radio Access BKK Composed by: Wutthilert Rungchai February 2010 Edit by: Bunjong Yosapa
Channelization code
Code
Code Spread Channelization Code Code
01
0101
0110
01010101
01011010
01100110
01101001
0110100101101001
0110100110010110
SF2 SF4 SF8 SF16
12 code
Code Code Code
Code
Code Code 00110011 (SF=8) Code
0011001100110011 0011001111001100 (SF=16) Code (SF=32,
64,..) Code 0011 Code Code 00111100
Resource planning
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3rd Generation of Mobile Communications Advanced Info Service PLC.
12 | P a g e Radio Access BKK Composed by: Wutthilert Rungchai February 2010 Edit by: Bunjong Yosapa
code Uplink SF 4 256 Downlink (DL)
SF 4 512 R99 EUL (Enhance UL) SF 2
Scrambling Code
Scrambling Code Channelization Code
Scrambling Code Downlink Channelization
Channel Scrambling Scrambling Code
Channelization code (SFn,m)
Channelization code (SFn,m)
Scrambling codeData in
Data in
13 Channelization code scrambling code
Scrambling Code BSIC Code
512 Code Uplink (UE) Scrambling Code RNC
Code UE Code Code 1 RNC
UE RNC ( RNC) Code
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3rd Generation of Mobile Communications Advanced Info Service PLC.
13 | P a g e Radio Access BKK Composed by: Wutthilert Rungchai February 2010 Edit by: Bunjong Yosapa
Scrambling Code Scrambling
Scrambling Spreading
Code Scrambling Code
(SC) Channelization Code
HSPA Carrier
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3rd Generation of Mobile Communications Advanced Info Service PLC.
14 | P a g e Radio Access BKK Composed by: Wutthilert Rungchai February 2010 Edit by: Bunjong Yosapa
Code UMTS
Synchronization
Codes
Channelization
Codes
Scrambling
Codes, UL
Scrambling
Codes, DL
Type
Gold Codes
Primary Synchronization
Codes (PSC) and
Secondary
Synchronization Codes
(SSC)
Orthogonal Variable
Spreading Factor
(OVSF) codes
sometimes called
Walsh Codes
Complex-Valued
Gold Code Segments
(long) or Complex-
Valued S(2) Codes
(short)
Pseudo Noise (PN)
codes
Complex-Valued
Gold Code
Segments
Pseudo Noise
(PN) codes
Length 256 chips 4-512 chips 38400 chips /
256 chips 38400 chips
Duration 66.67 s 1.04 s -
133.34 s 10 ms / 66.67 s 10 ms
Number of
codes
1 primary code / 16
secondary codes
spreading factor
4 ... 256 UL,
4 ... 512 DL
16,777,216
512 primary / 15
secondary for
each primary
code
Spreading No, does not change
bandwidth
Yes, increases
bandwidth
No, does not change
bandwidth
No, does not
change
bandwidth
Usage
To enable terminals to
locate and synchronize to
the cells' main control
channels
UL: to separate
physical data and
control data from same
terminal
DL: to separate
connection to different
terminals in a same
cell
Separation of terminal Separation of
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3rd Generation of Mobile Communications Advanced Info Service PLC.
15 | P a g e Radio Access BKK Composed by: Wutthilert Rungchai February 2010 Edit by: Bunjong Yosapa
WCDMA for UMTS Wiley
http://www.umtsworld.com/technology/codes.htm
3GPP TS 25.201, 25.213, 25.223