umts lte technologies
DESCRIPTION
A introduction to various radio core and access technologies.TRANSCRIPT
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Giuseppe Bianchi
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Giuseppe Bianchi
Use top & bottom as additional guard
! "
# $ %&&'( "
Frequency [MHz]
890
915
935
960
UPLINKMS BS
DOWNLINKBS MS
890.2
890.4
guard band
1 2 3 4 5 6 7 8
( ) ( )[ ]( ) ( )[ ]MHz12.02.935
MHz12.02.890+=
+=
nnF
nnF
dwlink
uplink
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Giuseppe Bianchi
35dB60dB
Specification: 9dBIn practice, due to power control and shadowing, adjacent channelsCannot be used within the same cell
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Giuseppe Bianchi
!"#$% &
&)&( " *+', !!!( " -
&'()
&'"
)&. / +&'0
timetimeslot0
577 s
timeslot7
1 frame = 60/13 ms = 4.615 ms26 frames = 120 ms (this is the key number)
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Giuseppe Bianchi
! "#$! "#$%%$$
& '( & '(
time577us 577us 577us 577us 577us 577us 577us 577us
frequency
200 KHz200 KHz200 KHz200 KHz200 KHz200 KHz
200 KHz200 KHz
200 KHzslot
Total n. of channels: 992
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Giuseppe Bianchi
$)*+,,$)*+,,
$"*
1 2 34 51 +"
1710-1785 MHz uplink; 1805-1880 MHz downlink #6 78 9 " .
1740-1785 MHz uplink; 1835-1880 MHz downlink%&$%+,
A total of 374 carriers (versus124 in GSM)-%+
: . . .
First and second operators @ 900 MHz; Third etc @1800 MHzDCS 1800 deployment (1996+):
15 MHz (=75 carriers) to Wind; 7.5 (=37 carriers) to first and second operator (plus existing 27 GSM 900 carriers)
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Giuseppe Bianchi
-- ""
.$%/.0$%1
2 ( , , $0
; ( 0 $0 &
23
*'$+'&
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Giuseppe Bianchi
$./$./
0 1 2 3 4 5 6 7UPLINK
0 1 2 3 4 5 6 7 DOWNLINK
- MS uses SAME slot number on uplink and downlink
- Uplink and downlink carriers always have a 45 MHz separation-I.e. if uplink carrier is 894.2 downlink is 919.2
-3 slot delay shift!!
MS: no need to transmit and receive in the same time on two different frequencies!
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Giuseppe Bianchi
0#( /0#( /0011
f1f2f3f4f5f6f7
Hopping sequence (example): f1 f2 f5 f6 f3 f7 f4 f1
Slow = on a per-frame basis- 1 hop per frame (4.615 ms) = 217 hops/second
. ; = * > -
! ""
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Giuseppe Bianchi
GP8.25
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34
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Giuseppe Bianchi
2/"2/"
6'7
7 .
8 A . A " . ; . $) ;
7 D " ( ;
(58
; " *, 6 > : A " -
.
E . F
Because channel estimate reliable ONLY when the radio channel sounding is taken!
Multipath fading rapidly changes the channel impulse response
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Giuseppe Bianchi
/(/(
Different codes used in adjacent cells! Avoids training sequenceDisruption because of co-channel interference.
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Giuseppe Bianchi
0 34 50 34 5
7.6 bits 4.9 bits
156.75 bits; 162.2 bits
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Giuseppe Bianchi
&,"5&&3
G6 . .
A . )
. . !H )
G6 A . !H )
2,,+59
d
1 2 3 4BTS downlink tx
MS downlink rx 1 2 3 4
1
1
MS uplink rx
BTS uplink rx1
Expected RX time!
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Giuseppe Bianchi
6/6/
BTS timeMS time
dwlink slot 1 dwlink slot 4
dwlink slot 1 dwlink slot 4
uplink slot 1
uplink slot 1
Maximum cell radius:
KmCGTcd
c
dCGT
rate
bits
rate
bits 5.42708332
25.83000002
2
==
Is there something wrong? (GSM says that cells go up to 35 km)
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Giuseppe Bianchi
# 6# 6
&5*/1
5. . "
G6 A
&" / $&!
.
6 7"
6 7/ A
I.e. transmit after 468.75 bitsafter downlink slot
6 7/ &!
Transmit after 405.75 bits time
TA (transmitted in the SACCH)
dwlink slot 4
uplink slot 1MS timeTA
dwlink slot 4
uplink slot 1uplink slot 1
BTS time
TA avoids collision!
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Giuseppe Bianchi
/1 /1
":++53
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;+:++53
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;+:"3
)$6 7
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6 7/ )
&&,+,3
[ ][ ] [ ] [ ]kmskmsbitsbits
cTAd 89.34/300000
/2708335.31
2===
8.25 bits Guard time additionally available for imperfect sync (+/- error)
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Giuseppe Bianchi
0707505088
TB8
Trainingsequence
41
Data36
TB3
88 bit burst156.25 bit (0.577 ms)
Access burst
Solution: USE A DIFFERENT BURST FORMATAccess Burst: much longer Guard Period availabledrawback: much less space for useful information
GP68.25
No collision with subsequent slot for distances up to 37.8 km
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Giuseppe Bianchi
-" -"
,,*
B . G
7
G
C> : G
G
. . G
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Giuseppe Bianchi
#( )5#( )5
/6'
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Giuseppe Bianchi
9 9 #)5#)5030377 1 1 :":"
?8&
) . . >
: . E.g. Fc + Pi/2 Fc Pi/2
% /&&%, 51
. > . *> A / A -
) . . A 1 = vary phase of Pi/2 in 1 bit symbol0 = vary phase of Pi/2 in 1 bit symbol
5 A " #B 6 7B 6 7B 1 4 2 > A . I
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Giuseppe Bianchi
9 9 #)5#)5030377 1 1 :":"
$% /$&&%, 51
7
G A "
?. @ > A
J
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Giuseppe Bianchi
9 9 #)5#)5030377 1 1 :":"
Advantage: continuous phase modulation = lower spectrum occupancyDisadvantage: ISI
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Giuseppe Bianchi
$ 5$ 5
;,*6--!
$&+"6--!
#. %; G: :
GP8.25
TB3
TB3
Dummy BurstTraining
sequence26
Fixed bit pattern58
Fixed bit pattern58
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Giuseppe Bianchi
65 65
558# " . I
>
,3: . .
i.e. synchronize frame counter : G#: *G # : %&" -
3 bits network code (operator) Important at international boundary, where same frequencies
can be shared by different operators3 bits color codeTo avoid listening a signal from another cell, thinking it
comes from the actual one!
GP8.25
TB3
TB3
Synchronization BurstTraining
sequence64
Sync data39
Sync data39
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Giuseppe Bianchi
5
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Giuseppe Bianchi
;/;/11
6 . K A >
#. % %.
> %
%> %
5
G
#; . " ; G
Physical channels(FDMA/TDMA)
Logical channels(traffic channels, signalling (=control) channels)
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Giuseppe Bianchi
;/;/
/ /
frequency
Physical Channel: data rate r, time slot i
frequency
#
$ %
Logical channel A: data rate r/3, time slot i, frame 3kLogical channel B: data rate 2r/3, time slot i, frame 3k+1, 3k+2
Frame 8 Frame 9 Frame 10 Frame 11 Frame 12
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Giuseppe Bianchi
/ /
MS BSSC FACCH MS BSS ; SACCH MS BSS $ SDCCHDedicated Control channel (DCCH)BSSMS5PCH BSSMS7
J AGCH MSBSS3 . 7
RACHCommon Control channel (CCCH)BSSMS SCHBSSMSC> : FCCH BSSMSG BCCHBroadcast channelMS BSS6 : 3TCH/HMS BSS6 : TCH/FTraffic channel (TCH)
Additional logical channels available for special purposes(SMS, group calls, )
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Giuseppe Bianchi
. 11/. 11/////
Setup for an incoming call (callarriving from fixed network part -MS responds to a call)
Steps:- paging for MS- MS responds on RACH- MS granted an SDCCH- authentication & ciphering on SDCCH- MS granted a TS (TCH/FACCH)- connection completed on FACCH- Data transmitted on TCH
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Giuseppe Bianchi
7,,
55
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Giuseppe Bianchi
)!
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Giuseppe Bianchi
//
Analogvoice
A/D conversion8000 samples/s13 bit/sample
Digital voice104 kbps
160 voice samples(20 ms)
(2080 bits)
Speech CODER(8:1 compression) 260 bits block13 kbps
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Giuseppe Bianchi
$ $
%+&+&@*/@1
D A " L .
6 A A *, . -
AB.
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Giuseppe Bianchi
))/))/
182 bits 78 bits
260 bits260 bits block divided into-Class I: important bits (182)
-Class Ia: Most important 50-Class Ib: Less important 132
-Class II: low importance bits (78)50 bits 3 132 bits 4
Parity bitsTail bits(0000)
First step: block coding for error detection in class Ia (errordiscard frame)Second step: convolutional coding for error correction
378 bits
Convolutional coding, r=1/2
78 bits
456 bits
Coding: needed to move from 10-1 to 10-3 radio channel native BERdown to acceptable range (10-5 to 10-6) BER
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Giuseppe Bianchi
531/531/
0 1 2 3 4 5 6 7
8 9 10 11 12 13 14 15
16 17 18 19 20 21 22 23
.. .. .. .. .. .. .. ..
.. .. .. .. .. .. .. ..
.. .. .. .. .. .. .. ..
.. .. .. .. .. .. .. ..
448 449 450 451 452 453 454 455
8
57
B1 B2 B3 B4 B5 B6 B7 B8
8 blocks, each with 57 bits
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Giuseppe Bianchi
$/1/$/1/
B1 B3B2 B4 B5 B7 B8B6 B1 B3B2 B4 B5 B7 B8B6 B1 B3B2 B4 B5 B7 B8B6
Block n-1 Block n Block n+1
nn BB 11
5 / nn BB 4
18 /
115 /
+nn BB 148 /+nn BB
%%""1/1/
GP8.25
TB3
S1
S1
Trainingsequence
26TB3
1=
n
xB nxB 4=
PRICE TO PAY: delay!! (block spreaded over 8 bursts 37 ms)
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Giuseppe Bianchi
5# 5#
A3
C. . "
B
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Giuseppe Bianchi
0))0))
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
TCH/F(07) TCH/F(07)
SACCH(07) IDLE frame
SACCH-0 SACCH-1 SACCH-2 SACCH-3 SACCH-4 SACCH-5 SACCH-6 SACCH-7
1 SACCH burst (per TCH) every 26 frames (120 ms)
4 . 6 .
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Giuseppe Bianchi
))!"3))!"3
55Block coding adds 40 bits (=224)4 tail (zero) bits (=228)1/2 Convolutional encoding (=456 bits)
B*53
, " ( +"
37:
. .
I.e. which message to send in case of many messages, and on which paging slot (4 bursts)
. " 3M
To monitor PAGCH for Immediate Assignment message detection
B&&5&G+
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Giuseppe Bianchi
7 7
"%&*&&&
8 ( A %; "
&&,&
2"/,1
**+%,
4 : : MS1ID1
MS2
ID2
BTS
ID1leave
continues
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Giuseppe Bianchi
//// %% ==
MS BTS BSC MSC
Immediate_assignment
Initial_message
MS ID (IMSI or TMSI), MS capabilities(=classmark), establishment cause
Initial_message_ack (UA)Copy of Initial message (including MS ID)
Establishment_indication
Further signaling: MSC to MS
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Giuseppe Bianchi
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184 bits / (51*8*15/26 ms) = 598/765 kbps ~ 782 bit/s 7: : A . .
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SDCCH/4 for smallcells SDCCH shares
BCCH+PAGCH channel- see before -