ETSI ETS 300 575 ed.1 (1994-09)

European digital cellular telecommunications system (Phase 2); Channel coding (GSM 05.03)

DE/SMG-020503P

Evropski digitalni celični telekomunikacijski sistem (faza 2) – Kodiranje kanalov (GSM 05.03)

General Information

• Status: Published
• Publication Date: 12-Sep-1994
• Technical Committee: SMG 2 - Radio
• Current Stage: 12 - Completion
• Due Date: 03-Oct-1994
• Completion Date: 13-Sep-1994
• Mandate: T-172-1
• Ref Project: SIST ETS 300 575 E1:2003 - European digital cellular telecommunications system (Phase 2); Channel coding (GSM 05.03)

Standards Content (Sample)

SLOVENSKI STANDARD
01-december-2003
(YURSVNLGLJLWDOQLFHOLþQLWHOHNRPXQLNDFLMVNLVLVWHPID]D±.RGLUDQMHNDQDORY
*60
European digital cellular telecommunications system (Phase 2); Channel coding (GSM
05.03)
Ta slovenski standard je istoveten z: ETS 300 575 Edition 1
ICS:
33.070.50 Globalni sistem za mobilno Global System for Mobile
telekomunikacijo (GSM) Communication (GSM)
35.040 Nabori znakov in kodiranje Character sets and
informacij information coding
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN ETS 300 575
TELECOMMUNICATION September 1994
STANDARD
Source: ETSI TC-SMG Reference: GSM 05.03
ICS: 33.060.30
European digital cellular telecommunications system, Global System for Mobile communications
Key words:
(GSM)
European digital cellular telecommunications system (Phase 2);
Channel coding
(GSM 05.03)
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
F-06921 Sophia Antipolis CEDEX - FRANCE
Postal address:
650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
Office address:
c=fr, a=atlas, p=etsi, s=secretariat - [e-mail]
X.400: Internet:
Tel.: [phone] - Fax: [phone]
Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and the
foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 1994. All rights reserved.
New presentation - see History box

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ETS 300 575: September 1994 (GSM 05.03 version 4.1.3)
Whilst every care has been taken in the preparation and publication of this document, errors in content,
typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to
"ETSI Editing and Committee Support Dept." at the address shown on the title page.

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ETS 300 575: September 1994 (GSM 05.03 version 4.1.3)
Contents
Foreword.5
1.1 Scope .7
1.2 Normative references .7
1.3 Definitions and abbreviations.7
2. General .8
2.1 General Organization.8
2.2 Naming Convention.8
3 Traffic Channels (TCH) .10
3.1 Speech channel at full rate (TCH/FS).10
3.1.1 Parity and tailing for a speech frame.10
3.1.2 Convolutional encoder.11
3.1.3 Interleaving.11
3.1.4 Mapping on a Burst .11
3.2 Speech channel at half rate (TCH/HS).12
3.3 Data channel at full rate, 12.0 kbit/s radio interface rate (9.6 kbit/s services
(TCH/F9.6)).12
3.3.1 Interface with user unit.12
3.3.2 Block code.12
3.3.3 Convolutional encoder.12
3.3.4 Interleaving.12
3.3.5 Mapping on a Burst .13
3.4 Data channel at full rate, 6.0 kbit/s radio interface rate (4.8 kbit/s services (TCH/F4.8)) . 13
3.4.1 Interface with user unit.13
3.4.2 Block code.13
3.4.3 Convolutional encoder.13
3.4.4 Interleaving.13
3.4.5 Mapping on a Burst .13
3.5 Data channel at half rate, 6.0 kbit/s radio interface rate (4.8 kbit/s services
(TCH/H4.8)).14
3.5.1 Interface with user unit.14
3.5.2 Block code.14
3.5.3 Convolutional encoder.14
3.5.4 Interleaving.14
3.5.5 Mapping on a Burst .14
3.6 Data channel at full rate, 3.6 kbit/s radio interface rate (2.4 kbit/s and less services
(TCH/F2.4)).14
3.6.1 Interface with user unit.14
3.6.2 Block code. 14
3.6.3 Convolutional encoder.14
3.6.4 Interleaving.15
3.6.5 Mapping on a Burst .15
3.7 Data channel at half rate, 3.6 kbit/s radio interface rate (2.4 kbit/s and less services
(TCH/H2.4)).15
3.7.1 Interface with user unit.15
3.7.2 Block code.15
3.7.3 Convolutional encoder.15
3.7.4 Interleaving.15
3.7.5 Mapping on a Burst .15

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ETS 300 575: September 1994 (GSM 05.03 version 4.1.3)
4. Control Channels.15
4.1 Slow associated control channel (SACCH) .15
4.1.1 Block constitution.15
4.1.2 Block code.16
4.1.3 Convolutional encoder.16
4.1.4 Interleaving .16
4.1.5 Mapping on a Burst .16
4.2 Fast associated control channel at full rate (FACCH/F).17
4.2.1 Block constitution.17
4.2.2 Block code.17
4.2.3 Convolutional encoder.17
4.2.4 Interleaving .17
4.2.5 Mapping on a Burst .17
4.3 Fast associated control channel at half rate (FACCH/H) .17
4.3.1 Block constitution.17
4.3.2 Block code.17
4.3.3 Convolutional encoder.18
4.3.4 Interleaving .18
4.3.5 Mapping on a Burst .18
4.4 Broadcast, Paging, Access grant and Cell broadcast channels (BCCH, PCH, AGCH,
CBCH).19
4.5 Stand-alone dedicated control channel (SDCCH) .19
4.6 Random access channel (RACH).19
4.7 Synchronization channel (SCH) .20
4.8 Handover Access Burst.20
Annex A (informative): Summary of Channel Types .23
Annex B (informative): Summary of Polynomials Used for Convolutional Codes .24
History .25

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ETS 300 575: September 1994 (GSM 05.03 version 4.1.3)
Foreword
This European Telecommunication Standard (ETS) has been produced by the Special Mobile Group
(SMG) Technical Committee (TC) of the European Telecommunications Standards Institute (ETSI).
This ETS specifies the channel coding of used within the European digital cellular telecommunications
system (Phase 2).
This ETS correspond to GSM technical specification, GSM 05.03 version 4.1.3.
The specification from which this ETS has been derived was originally based on CEPT documentation,
hence the presentation of this ETS may not be entirely in accordance with the ETSI/PNE rules.
Reference is made within this ETS to GSM Technical Specifications (GSM-TSs) (NOTE).
NOTE: TC-SMG has produced documents which give the technical specifications for the
implementation of the European digital cellular telecommunications system. Historically,
these documents have been identified as GSM Technical Specifications (GSM-TSs).
These TSs may have subsequently become I-ETSs (Phase 1), or ETSs (Phase 2),
whilst others may become ETSI Technical Reports (ETRs). GSM-TSs are, for editorial
reasons, still referred to in GSM ETSs.

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ETS 300 575: September 1994 (GSM 05.03 version 4.1.3)
Blank page
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ETS 300 575: September 1994 (GSM 05.03 version 4.1.3)
1.1 Scope
A reference configuration of the transmission chain is shown in GSM 05.01. According to this reference
configuration, this technical specification specifies the data blocks given to the encryption unit.
It includes the specification of encoding, reordering, interleaving and the stealing flag. It does not specify
the channel decoding method.
The definition is given for each kind of logical channel, starting from the data provided to the channel
encoder by the speech coder, the data terminal equipment, or the controller of the MS or BS. The
definitions of the logical channel types used in this technical specification are given in GSM 05.02, a
summary is in Annex A.
1.2 Normative references
This ETS incorporates by dated and undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply
to this ETS only when incorporated in it by amendment or revision. For undated references, the latest
edition of the publication referred to applies.
[1] GSM 01.04 (ETR 100): "European digital cellular telecommunication system
(Phase 2); Definitions, abbreviations and acronyms".
[2] GSM 04.08 (ETS 300 557): "European digital cellular telecommunication system
(Phase 2); Mobile radio interface layer 3 specification".
[3] GSM 04.21 (ETS 300 562): "European digital cellular telecommunication system
(Phase 2); Rate adaption on the Mobile Station - Base Station System (MS -
BSS) interface".
[4] GSM 05.01 (ETS 300 573): "European digital cellular telecommunication system
(Phase 2); Physical layer on the radio path General description".
[5] GSM 05.02 (ETS 300 574): "European digital cellular telecommunication system
(Phase 2); Multiplexing and multiple access on the radio path".
[6] GSM 06.10 (ETS 300 580-2): "European digital cellular telecommunication
system (Phase 2); Full rate speech transcoding".
1.3 Definitions and abbreviations
Definitions and abbreviations used in this specification are listed in GSM 01.04.

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ETS 300 575: September 1994 (GSM 05.03 version 4.1.3)
2. General
2.1 General Organization
Each channel has its own coding and interleaving scheme. However, the channel coding and interleaving is
organized in such a way as to allow, as much as possible, a unified decoder structure.
Each channel uses the following sequence and order of operations:
- The information bits are coded with a systematic block code, building words of information +
parity bits.
- These information + parity bits are encoded with a convolutional code, building the coded bits.
- Reordering and interleaving the coded bits, and adding a stealing flag, gives the interleaved
bits.
All these operations are made block by block, the size of which depends on the channel. However, most of
the channels use a block of 456 coded bits which is interleaved and mapped onto bursts in a very similar
way for all of them. Figure 1 gives a diagram showing the general structure of the channel coding.
This block of 456 coded bits is the basic structure of the channel coding scheme. In the case of speech
TCH, this block carries the information of one speech frame. In case of control channels, it carries one
message.
In the case of Fast ACCH, a coded message block of 456 bits is divided in to eight sub-blocks. The first
four sub-blocks are sent by stealing the even numbered bits of four timeslots in consecutive frames used
for the TCH. The other four sub-blocks are sent by stealing the odd numbered bits of the relevant timeslot
in four consecutive used frames delayed 2 or 4 frames relative to the first frame. Along with each block of
456 coded bits there is, in addition, a stealing flag (8 bits), indicating whether the block belongs to the TCH
or to the fast ACCH. In the case of slow ACCH, BCCH or CCCH, this stealing flag is dummy.
Some cases do not fit in the general organization, and do not use the block of 456 coded bits. They are
the random access messages of the RACH on uplink and the synchronization information broadcast on the
SCH.
2.2 Naming Convention
For ease of understanding a naming convention for bits is given for use throughout the technical
specification:
- General naming
"k" and "j" for numbering of bits in data blocks and bursts.
"K " gives the amount of bits in one block, where "x" refers to the data type
x
"n" is used for numbering of delivered data blocks where
"N" marks a certain data block
"B" is used for numbering of bursts or blocks where
"B " marks the first burst or block carrying bits from the data block with n = 0 (first data block in the
transmission)
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ETS 300 575: September 1994 (GSM 05.03 version 4.1.3)
- Data delivered to the encoding unit (interface 1 in figure 1):
d (n, k) or d (k) for k = 0,1,.,K -1
d
n = 0,1,.,N,N+1,.
- Data after the first encoding step (block code, cyclic code; interface 2 in figure 1):
u(n,k) or u (k) for k = 0,1,.,K -1
u
n = 0,1,.,N,N+1,.
- Data after the second encoding step (convolutional code ; interface 3 in figure 1):
c(n,k) or c(k) for k = 0,1,.,K -1
c
n = 0,1,.,N,N+1,.
- Interleaved data:
i(B,k) for k = 0,1,.,K -1
i
B = B , B +1,.
0 0
- Bits in one burst (interface 4 in figure 1):
e(B,k)for k = 0,1,.,114,115
B = B , B + 1,.
0 0
3 Traffic Channels (TCH)
Two kinds of traffic channel are considered: speech and data. Both of them use the same general
structure (see fig.1), and in both cases, a piece of information can be stolen by the fast ACCH.
3.1 Speech channel at full rate (TCH/FS)
The speech coder delivers to the channel encoder a sequence of blocks of data. In case of a full rate
speech TCH, one block of data corresponds to one speech frame. Each block contains 260 information
bits,including 182 bits of class 1 (protected bits), and 78 bits of class 2 (no protection), (see Table 2).
The bits delivered by the speech coder are received in the order indicated in GSM 06.10 and have to be
rearranged according to Table 2 before channel coding as defined in 3.1.1 to 3.1.4. The rearranged bits
are labelled {d(0), d(1),., d(259)}, defined in the order of decreasing importance.
3.1.1 Parity and tailing for a speech frame
a) Parity bits:
The first 50 bits of class 1 are protected by three parity bits used for error detection. These parity
bits are added to the 50 bits, according to a degenerate (shortened) cyclic code (53,50,2), using the
generator polynomial:
g(D) = D + D + 1
The encoding of the cyclic code is performed in a systematic form, which means that, in GF(2), the
polynomial:
52 51 3 2
d(0)D + d(1)D +. + d(49)D + p(0)D + p(1)D+ p(2)
where p(0), p(1), p(2) are the parity bits, when divided by g(D), yields a remainder equal to
1 + D + D
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ETS 300 575: September 1994 (GSM 05.03 version 4.1.3)
b) Tailing bits and reordering:
The information and parity bits of class 1 are reordered, defining 189 information + parity + tail bits
of class 1, {u(0), u(1),., u(188)} defined by:
u(k) = d(2k) and u(184-k) = d(2k+1) for k = 0,1,.,90
u(91+k) = p(k) for k = 0,1,2
u(k) = 0 (tail bits) for k = 185, 186, 187, 188
3.1.2 Convolutional encoder
The class 1 bits are encoded with the 1/2 rate convolutional code defined by the polynomials:
3 4
G0 = 1 + D + D
3 4
G1 = 1 + D + D + D
The coded bits {c(0), c(1),., c(455)} are then defined by:
- class 1 : c(2k) = u(k) + u(k-3) + u(k-4)
c(2k+1) = u(k) + u(k-1) + u(k-3) + u(k-4) for k = 0,1,.,188
u(k) = 0, k < 0
- class 2 : c(378+k) = d(182+k) for k = 0,1,.,77
3.1.3 Interleaving
The coded bits are reordered and interleaved according to the following rule :
i(B,j) = c(n,k), for k = 0,1,.,455
n = 0,1,.,N,N+1,.
B = B + 4n + k mod (8)
j = 2[(49k) mod 57] + [(k mod 8) div 4]
The result of the interleaving is a distribution of the reordered 456 bits of a given data block, n = N, over 8
blocks using the even numbered bits of the first 4 blocks (B = B + 4N + 0, 1, 2, 3) and odd numbered bits
of the last 4 blocks (B = B + 4 N + 4, 5, 6, 7). The reordered bits of the following data block, n = N+1,
use the even numbered bits of the blocks B = B + 4N + 4, 5, 6, 7 (B = B + 4(N+1) + 0, 1, 2, 3) and the
0 0
odd numbered bits of the blocks B= B + 4(N+1) + 4, 5, 6, 7. Continuing with the next data blocks shows
that one block always carries 57 bits of data from one data block (n = N) and 57 bits of data from the next
block (n = N+1), where the bits from the data block with the higher number always are the even numbered
data bits, and those of the data block with the lower number are the odd numbered bits.
The block of coded data is interleaved "block diagonal", where a new data block starts every 4th block and
is distributed over 8 blocks.
3.1.4 Mapping on a Burst
The mapping is given by the rule :
e(B,j) = i(B,j) and e(B, 59+j) = i(B,57 + j) for j = 0,. 56
and
e(B,57) = hl(B) and e(B,58) = hu(B)
The two bits, labelled hl(B) and hu(B) on burst number B are flags used for indication of control channel
signalling. For each TCH/FS block not stolen for signalling purposes:
hu(B) = 0 for the first 4 burst (indicating status of even numbered bits)
hl(B) = 0 for the last 4 bursts (indicating status of odd numbered bits)
For the use of hl(B) and hu(B) when a speech frame is stolen for signalling purposes see section 4.2.5.

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ETS 300 575: September 1994 (GSM 05.03 version 4.1.3)
3.2 Speech channel at half rate (TCH/HS)
To be defined for a future evolution of the system.
3.3 Data cha
...