ETSI TR 102 278 V1.1.1 (2008-08)

Satellite Earth Stations and Systems (SES); Satellite Component of UMTS/IMT-2000; Considerations on possible harmonization between A, C and G family Satellite Radio Interface features

DTR/SES-00090

General Information

• Status: Published
• Publication Date: 26-Aug-2008
• Technical Committee: SES MSS - SES WG on Mobile Satellite Systems
• Current Stage: 12 - Completion
• Due Date: 09-Sep-2008
• Completion Date: 27-Aug-2008

Standards Content (Sample)

Technical Report
Satellite Earth Stations and Systems (SES);
Satellite Component of UMTS/IMT-2000;
Considerations on possible harmonization between A, C and G
family Satellite Radio Interface features

2 ETSI TR 102 278 V1.1.1 (2008-08)

Reference
DTR/SES-00090
Keywords
CDMA, satellite, UMTS
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ETSI
3 ETSI TR 102 278 V1.1.1 (2008-08)
Contents
Intellectual Property Rights.5
Foreword.5
1 Scope.6
2 References.6
2.1 Normative references.6
2.2 Informative references.6
3 Definitions, symbols and abbreviations .8
3.1 Definitions.8
3.2 Symbols.8
3.3 Abbreviations.8
4 Presentation of (S)W-CDMA and SAT-CDMA .10
4.1 SW-CDMA.10
4.2 W-CDMA.10
4.3 SAT-CDMA.11
5 Commonalties and differences .12
5.1 Introduction.12
5.2 Commonalties and differences between SW-CDMA and SAT-CDMA .13
5.2.1 Physical channel structure.13
5.2.2 Channel coding and multiplexing .22
5.2.3 Spreading and Modulation.26
5.2.4 Physical layer procedure.27
5.3 Commonalties and differences between W-CDMA and SAT-CDMA.33
5.3.1 Physical channel structure.33
5.3.2 Channel coding and multiplexing .41
5.3.3 Spreading and Modulation.44
5.3.4 Physical layer procedure.46
6 Synthesis.53
6.1 SW-CDMA and SAT-CDMA .53
6.2 W-CDMA and SAT-CDMA .53
6.3 SW-CDMA and W-CDMA.54
7 SAT-CDMA new features with respect to WCDMA and expected added value for context and
service requirements.57
7.1 SAT-CDMA new features with respect to W-CDMA.57
7.1.1 Uplink random access.57
7.1.2 Dedicated Physical Channels.58
7.1.3 Uplink packet access.58
7.1.4 Downlink synchronization channel.58
7.1.5 Power control algorithm .59
7.1.6 TPC bits generation .60
8 Conclusion.61
Annex A: SAT-CDMA features technical assessment .63
A.1 Uplink random access .63
A.2 TFCI/TPC bits generation and transmission .65
A.3 FSW for path diversity from different satellites.65
A.4 Power control algorithm.66
A.5 Downlink short scrambling code and data scrambling for multi-user detection.69
A.6 Synchronization codes for downlink SCH in LEO constellation.69
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4 ETSI TR 102 278 V1.1.1 (2008-08)
A.7 Another comment.69
A.8 RACH Simulation.70
Annex B: W-CDMA radio interface parameters that need specific configuration for satellite
operation.72
B.1 Introduction.72
B.2 Random access.72
B.2.1 Preamble access.72
B.2.2 Preamble Acquisition Indicator reception .73
B.2.3 Message part reception.74
B.2.4 Performances.74
B.3 Power control.74
B.3.1 Open loop power control.74
B.3.2 Physical layer Closed loop power control .74
B.3.3 Slow closed loop power control (layer 3 power control).75
B.4 Timers adaptation.75
History .76

ETSI
5 ETSI TR 102 278 V1.1.1 (2008-08)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://webapp.etsi.org/IPR/home.asp).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Report (TR) has been produced by ETSI Technical Committee Satellite Earth Stations and Systems
(SES).
ETSI
6 ETSI TR 102 278 V1.1.1 (2008-08)
1 Scope
The present document identifies all differences and commonalities between the A, C and G family satellite radio
interfaces (ITU-R Recommendation M.1457 [i.13]) in order to asses harmonization.
It also includes a synthetic view of new features proposed by SAT-CDMA and SW-CDMA vs W-CDMA radio
interface and what are their expected benefits, with respect to the context (type of constellation and service
requirements)
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• Non-specific reference may be made only to a complete document or a part thereof and only in the following
cases:
- if it is accepted that it will be possible to use all future changes of the referenced document for the
purposes of the referring document;
- for informative references.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
For online referenced documents, information sufficient to identify and locate the source shall be provided. Preferably,
the primary source of the referenced document should be cited, in order to ensure traceability. Furthermore, the
reference should, as far as possible, remain valid for the expected life of the document. The reference shall include the
method of access to the referenced document and the full network address, with the same punctuation and use of upper
case and lower case letters.
NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee
their long term validity.
2.1 Normative references
The following referenced documents are indispensable for the application of the present document. For dated
references, only the edition cited applies. For non-specific references, the latest edition of the referenced document
(including any amendments) applies.
Not applicable.
2.2 Informative references
The following referenced documents are not essential to the use of the present document but they assist the user with
regard to a particular subject area. For non-specific references, the latest version of the referenced document (including
any amendments) applies.
[i.1] ETSI TS 101 851-1-2: "Satellite Earth Stations and Systems (SES); Satellite Component of
UMTS/IMT-2000; Part 1: Physical channels and mapping of transport channels into physical
channels; Sub-part 2: A-family (S-UMTS-A 25.211)".
[i.2] ETSI TS 101 851-2-2: "Satellite Earth Stations and Systems (SES); Satellite Component of
UMTS/IMT-2000; Part 2: Multiplexing and channel coding; Sub-part 2: A-family
(S-UMTS-A 25.212)".
ETSI
7 ETSI TR 102 278 V1.1.1 (2008-08)
[i.3] ETSI TS 101 851-3-2: "Satellite Earth Stations and Systems (SES); Satellite Component of
UMTS/IMT-2000; Part 3: Spreading and modulation; Sub-part 2: A-family
(S-UMTS-A 25.213)".
[i.4] ETSI TS 101 851-4-2: "Satellite Earth Stations and Systems (SES); Satellite Component of
UMTS/IMT-2000; Part 4: Physical layer procedures; Sub-part 2: A-family (S-UMTS-A 25.214)".
[i.5] ETSI TS 101 851-1-1: "Satellite Earth Stations and Systems (SES); Satellite Component of
UMTS/IMT-2000; Part 1: Physical channels and mapping of transport channels into physical
channels; Sub-part 1: G-family (S-UMTS-G 25.211)".
[i.6] ETSI TS 101 851-2-1: "Satellite Earth Stations and Systems (SES); Satellite Component of
UMTS/IMT-2000; Part 2: Multiplexing and channel coding; Sub-part 1: G-family
(S-UMTS-G 25.212)".
[i.7] ETSI TS 101 851-3-1: "Satellite Earth Stations and Systems (SES); Satellite Component of
UMTS/IMT-2000; Part 3: Spreading and modulation; Sub-part 1: G-family (S-UMTS-G 25.213)".
[i.8] ETSI TS 101 851-4-1: "Satellite Earth Stations and Systems (SES); Satellite Component of
UMTS/IMT-2000; Part 4: Physical layer procedures; Sub-part 1: G-family (S-UMTS-G 25.214)".
[i.9] TTAS.KO-06.0090: "IMT-2000 SAT-CDMA - Physical channel and mapping of transport
channels onto physical channels (Release A) (TTAE-3G-SAT-25.211)".
[i.10] TTAS.KO-06.0091: "IMT-2000 SAT-CDMA - Multiplexing and channel coding (Release A)
(TTAE-3G-SAT-25.212)".
[i.11] TTAS.KO-06.0092: "IMT-2000 SAT-CDMA - Spreading and modulation (Release A)
(TTAE-3G-SAT-25.213)".
[i.12] TTAS.KO-06.0093: "IMT-2000 SAT-CDMA - Physical layer procedure (Release A)
(TTAE-3G-SAT-25.214)".
[i.13] ITU-R Recommendation M.1457-6: "Detailed specifications of the radio interfaces of
International Mobile Telecommunications-2000 (IMT-2000)".
[i.14] ETSI TR 102 058: "Satellite Earth Stations and Systems (SES); Satellite Component of
UMTS/IMT-2000; Evaluation of the W-CDMA UTRA FDD as a Satellite Radio Interface".
[i.15] ETSI TS 125 331:" Universal Mobile Telecommunications System (UMTS); RRC Protocol
Specification (3G TS 25.331 version 3.3.0 Release 1999)".
[i.16] IEEE Journal on Selected Areas in Communications, Vol. 19, No. 2, February 2001.
[i.17] IEEE Journal on Selected Areas in Communications, Vol. 7, No.18, July 2000.
[i.18] IEEE Journal on Selected Areas in Communications, Vol. 17, No. 2, February 1999.
[i.19] ETSI TS 125 213: "Universal Mobile Telecommunications System (UMTS); Spreading and
modulation (FDD) (3GPP TS 25.213)".
[i.20] ETSI TS 125 214: "Universal Mobile Telecommunications System (UMTS); Physical layer
procedures (FDD) (3GPP TS 25.214)".
[i.21] TTAS.KO-06.0094: "Physical layer - measurements (Release A) (TTAE-3G-SAT-25.215)".
ETSI
8 ETSI TR 102 278 V1.1.1 (2008-08)
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
SW-CDMA: satellite radio interface referenced as SRI-A of IMT-2000 satellite component at
ITU-R Recommendation M.1457 [i.13]
NOTE: The SW-CDMA radio interface was produced by the ETSI SES Technical Committee as S-UMTS
A-family standard.
W-CDMA: satellite radio interface referenced at SRI-G of IMT-2000 satellite component at
ITU-R Recommendation M.1457 [i.13]
NOTE: The W-CDMA radio interface was produced by the ETSI SES Technical Committee as S-UMTS
G-family standard.
SAT-CDMA: satellite radio interface referenced at SRI-C of IMT-2000 satellite component at
ITU-R Recommendation M.1457 [i.13]
NOTE 1: The SAT-CDMA was produced by TTA of Korea.
NOTE 2: These radio interfaces are based on the FDD mode of UTRA defined by 3GPP Technical Specifications
and adapted for operation over satellite transponders.
3.2 Symbols
For the purposes of the present document, the following symbols apply:
r code rate
K constraint length
R number of rows for a block interleaver
C number of columns for a block interleaver
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AI Acquisition Indicator
AICH Acquisition Indicator Channel
AP Access Preamble
APA aAccess Preamble Acquisition
APA/CD/CA-ICH Access Preamble Acquisition/Collision Detection/Channel Assignment-Indicator Channel
API Access Preamble acquisition Indicator
BCH Broadcast CHannel
BSDT Beam Selection Diversity Transmission
CA Channel Assignment
CAI Channel Assignment Indicator
CCC CPCH Control Command
CCTrCH Coded Composite Transport CHannel
CD Collision Detection
CDI Collision Detection Indicator
CDP Collision Detection Preamble
CLPC Closed Loop Power Control
CPCH Common Packet CHannel
CPCH-CCPCH CPCH-Common Control Physical CHannel
CPICH Common Pilot Channel
CRC Cyclic Redundancy Check
CSICH CPCH Status Indicator Channel
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9 ETSI TR 102 278 V1.1.1 (2008-08)
DL Downlink
DPCCH Dedicated Physical Control Channel
DPCH Dedicated Physical Channel
DPDCH Dedicated Physical Data Channel
DS Direct Spread
DTX Discontinuous Transmission
FACH Forward Access Channel
FBI FeedBack Information
FSW Frame Synchronization Word
GEO Geostationary Earth Orbit
GNSS Global Navigation Satelliite System
I I-branch
LC Long Code
LEO Low Earth Orbit
MAC Medium Access Control
MUD MultiUser Detection
MSS Mobile Satellite Service
NACK Negative ACKnowledgment
NI Notification Indicator
OLPC Open Loop Power Control
OVSF Orthogonal Variable Spreading Factor
P-CCPCH Primary Common Control Physical Channel
PCH Paging Channel
PCPCH Physical Common Packet Channel
PDSCH Physical Downlink Shared Channel
PG Processing Gain
PhCH Physical Channel
PHPPCH Physical High Penetration Paging Channel
PI Paging Indicator
PICH Paging Indicator Channel
PRACH Physical Random Access Channel
PSC Primary Synchronization Code
RAN Radio Access Network
RLC Radio Link Control
RRC Radio Resource Control
RSSI Received Signal Strength Indicator
RTD Round Trip Delay
SC Short Code
S-CCPCH Secondary Common Control Physical Channel
SCH Synchronization Channel
SF Spreading Factor
SFN System Frame Number
SI CPSH Status Indicator
SIR Signal to Interference Ratio
SSC Secondary Synchronization Code
SSDT Site Selection Diversity Transmission
TF Transport Format
TFC Transport Format Combination
TFCI Transport-Format Combination Indicator
TG Transmission Gap
TPC Transmit Power Control
TrBk Transport Block
TrCH Transport Channel
TTI Transmission Time Interval
UE User Equipment
UL Uplink
ETSI
10 ETSI TR 102 278 V1.1.1 (2008-08)
4 Presentation of (S)W-CDMA and SAT-CDMA
4.1 SW-CDMA
SW-CDMA is a satellite radio interface designed to meet the requirements of the satellite component of the third
generation (3G) wireless communication systems. The SW-CDMA radio interface was produced by TS 101 851.
SW-CDMA is based on the adaptation to the satellite environment of the IMT-2000 CDMA Direct Spread terrestrial
radio interface (UTRA FDD or WCDMA). The intention is to reuse the same core network and reuse the radio interface
specifications for the Iu and Cu interface. Only the Uu interface will be adapted to the satellite environment.
SW-CDMA operates in FDD mode with RF channel bandwidth of either 2,350 MHz or 4,700 MHz for each
transmission direction.
SW-CDMA provides a wide range of bearer services from 1,2 kbit/s up to 144 kbit/s. High-quality telecommunication
service can be supported including voice quality telephony and data services in a global coverage satellite environment.
SW-CDMA deviation from the above-mentioned terrestrial radio interface are summarized hereafter:
• Maximum bit rate supported limited to 144 kbit/s.
• Permanent softer handover forward link operations for constellations providing satellite diversity.
• Permanent reverse link satellite diversity combining for constellations providing satellite diversity.
• Feeder link (gateway-satellite) and satellite to user link beam centre Doppler pre-compensation.
• Two-steps (instead of three-steps as terrestrial) forward link acquisition procedure.
• Introduction of a high-power paging channel for in-building penetration.
• Optional (not standard) use of pilot symbols in the communication channels.
• Reduced power control rate with multi-level predictive power control loop to cope with longer propagation
delay.
• Shorter scrambling sequence length (2 560 chips) in the forward link.
• Optional use in the forward link of a short scrambling sequence (256 chips) to allow CDMA interference
mitigation.
• Single user terminal level.
• Longer random access preamble sequence.
SW-CDMA offers a great degree of commonality with the terrestrial radio interface making the interoperability
between the IMT-2000 terrestrial and the satellite components easier.
For the comparison, the present document refers to Technical Specification (TS) describing the SRI as follows:
• ETSI TS 101 851-1-2 [i.1].
• ETSI TS 101 851-2-2 [i.2].
• ETSI TS 101 851-3-2 [i.3].
• ETSI TS 101 851-4-2 [i.4].
4.2 W-CDMA
This satellite radio interface is also based on the W-CDMA UTRA FDD radio interface already standardized in 3GPP.
Mobile satellite systems intending to use this interface will address user equipment fully compatible with 3GPP UTRA
FDD W-CDMA, with adaptation for agility to the Mobile Satellite Service (MSS) frequency band.
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11 ETSI TR 102 278 V1.1.1 (2008-08)
The use of a 3GPP standardized technology as well as a satellite IMT-2000 frequency band adjacent to a terrestrial
IMT-2000 frequency band allows to accommodate these MSS system's features in 3G handsets with no waveform
modification and consequently low cost impact. This optimizes considerably the market entry and penetration.
The key service and operational features of the W-CDMA radio interface are following:
• Support for low data rate services (e.g. 1,2 kbps) up to high data rate transmission (384 kbps) with wide area
coverage.
• High service flexibility with support of multiple parallel variable-rate services on each connection.
• Efficient packet access.
• Built-in Support for future capacity/coverage-enhancing technologies, such as adaptive antennas, advanced
receiver structures, and transmitter diversity.
• Support of inter-frequency handover for operation with hierarchical cell structures and handover to other
systems, including handover to GSM.
For the comparison, the present document refers to Technical Specification (TS) describing the SRI as followed:
• ETSI TS 101 851-1-1 [i.5].
• ETSI TS 101 851-2-1 [i.6].
• ETSI TS 101 851-3-1 [i.7].
• ETSI TS 101 851-4-1 [i.8].
4.3 SAT-CDMA
The SAT-CDMA is a satellite radio interface to provide the various advanced mobile telecommunications services
defined for the IMT-2000 satellite environment with maximum data rate, 384 kbit/s. This system could be applied for
LEO and GEO satellite for the global international communications.
The major technical scheme in SAT-CDMA is also wideband code division multiple access (W-CDMA) whose chip
rate is 3.84 Mchip/s.
The system has a high degree of commonality with the terrestrial ratio specification, IMT-2000 Direct Spread (DS), but
it also has a number of different features. Those features, which are necessary to reflect the satellite-specific
characteristics, such as long round trip delay and high Doppler shift, are implemented in the form of downlink
synchronization, uplink packet access, and closed loop power control.
For the comparison, the present document refers to Technical Specification (TS) describing the SRI as followed:
• TTAS.KO-06.0090 [i.9].
• TTAS.KO-06.0091 [i.10].
• TTAS.KO-06.0092 [i.11].
• TTAS.KO-06.0093 [i.12].
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12 ETSI TR 102 278 V1.1.1 (2008-08)
5 Commonalties and differences
5.1 Introduction
This clause provides a short list with all the points of divergence identified in the analysis of the (S)W-CDMA and
SAT-CDMA specifications. This list is intended as a guide to the more detailed comments provided in clauses 2 and 3.
This means practically that in many cases an item covers several points of clauses 2 and 3. Additionally, this list is a
pure description of the differences; where appropriate, a short technical discussion and a possible way of harmonization,
are included in the comments of clause 2.
The following tables show the differences and commonalties between the draft specifications of (S)W-CDMA and
SAT-CDMA, item-by-item.
ETSI
13 ETSI TR 102 278 V1.1.1 (2008-08)
5.2 Commonalties and differences between SW-CDMA and SAT-CDMA
5.2.1 Physical channel structure
Table 1-1: Commonality in radio frame structure
Item ref. Item SW-CDMA SAT-CDMA Difference Commonality
1.1.1 Radio frame 10 ms = 15 slots = 38 400 chips 10 ms = 15 slots = 38 400 chips There is no difference. High
1.1.2 Time slot 2 560 chips 2 560 chips There is no difference. High
Abbreviations
Table 1-2: Commonality in the type of physical channels
Item ref. Item SW-CDMA SAT-CDMA Difference Commonality
1.2.1 Uplink DPDCH DPDCH There is no difference. High
dedicated DPCCH DPCCH
1.2.2 Uplink common PRACH PRACH  SAT-CDMA offers the PCPCH for Medium
PCPCH fast uplink packet-mode
transmission.
1.2.3 Downlink DPCH - DPDCH and DPCCH DPCH - DPDCH and DPCCH There is no difference High
dedicated
1.2.4 Downlink SCH SCH  SAT-CDMA offers secondary SCH Medium
common CPICH CPICH and AICH to assist mobile's beam
P-CCPCH P-CCPCH search and uplink RACH
S-CCPCH S-CCPCH transmission, respectively
CPCH-CCPCH SW-CDMA defines HPPICH for
PDSCH PDSCH high penetration paging.
PICH PICH SAT-CDMA defines the indicator
HPPICH AICH channels and the CPCH-CCPCH
APA/CD/CA-ICH for supporting the uplink PCPCH.
CSICH
Abbreviations
AICH - Acquisition Indicator Channel PCPCH - Physical Common Packet Channel
APA/CD/CA-ICH - Access Preamble Acquisition/Collision Detection/Channel PDSCH - Physical Downlink Shared Channel
Assignment - Indicator Channel PICH - Paging Indicator Channel
CPCH-CCPCH - CPCH - Common Control Physical Channel PHPPCH - Physical High Penetration Paging Channel
CPICH - Common Pilot Channel PRACH - Physical Random Access Channel
CSICH - CPCH Status Indicator Channel P-CCPCH - Primary Common Control Physical Channel
DPCH - Dedicated Physical Channel SCH - Synchronization Channel
DPCCH - Dedicated Physical Control Channel S-CCPCH - Secondary Common Control Physical Channel
DPDCH - Dedicated Physical Data Channel

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14 ETSI TR 102 278 V1.1.1 (2008-08)
Comment 1.2.2 and 1.2.4-1: In SAT-CDMA, the AICH can reduce the retransmission delay of the PRACH preamble and message because a quick acknowledgement is
possible at physical layer by transmitting an acquisition indicator corresponding to the PRACH preamble signature. Although the preamble is successfully acquired it is possible
that the message part may not be received successfully. However, generally, message detection probability is high if the preamble is detected.
Comment 1.2.2 and 1.2.4-1: There are some potential problems in the use of AICH, and, generally, Slotted transmission; this can be however modified if an analysis shows
there are no problems.
Comment 1.2.2 and 1.2.4-2: The PCPCH is required for uplink packet-mode transmission with medium length (e.g. several or several tens of frames). CPCH-CCPCH for
CPCH transmission control and power control is suggested in SAT-CDMA. In 3GPP specifications, each PCPCH is associated with a DL DPCCH for CPCH which is a
downlink dedicated channel, while in the SAT-CDMA all of PCPCHs in a CPCH set are associated with a CPCH-CCPCH which is a downlink common control channel. In
satellite environment, the common control channel is more efficient because the deviation of the propagation loss to each user is relatively little in a beam coverage, compared
to the terrestrial case. This implies that power control is not mandatory for the associated common control channel.
Comment 1.2.2 and 1.2.4-2: The PCPCH and the downlink indicator channels might be deleted in SAT-CDMA because PCPCH have not been used in a real implementation,
as close as possible to those in the 3GPP. PCPCH as applied in 3GPP specifications is not viable for satellite systems.
Comment 1.2.4-1: In SAT-CDMA, a hierarchical search procedure should be necessary for fast acquisition of the downlink primary scrambling code as in the 3GPP cell search
procedure. Even if the synchronization codes are not differentially encoded at the transmitter, the differential detection can be employed in order to overcome the large
frequency offset of the downlink carrier at the receiver.
Comment 1.2.4-1: An issue is the maximum timing uncertainty resolution, that may not be sufficient for satellite. A slightly modified three-step approach can be agreed,
keeping the UW for time ambiguity resolution in SW-CDMA.
Comment 1.2.4-2: In SW-CDMA, an additional paging channel is required for the users whose positions are out of normal coverage area. The power of user terminals will be
saved if the high-penetration paging channel could support the sleep-mode operation as the PICH.
ETSI
15 ETSI TR 102 278 V1.1.1 (2008-08)
Table 1-3: Commonality in dedicated uplink physical channel
Item ref. Item SW-CDMA SAT-CDMA Difference Commonality
1.3.1 Multiplexing DPDCH and DPCCH are I-Q/code DPDCH and DPCCH are I-Q/code There is no difference. High
multiplexed multiplexed
1.3.2 DPDCH Slot = Data field Slot = Data field There is no difference. High
k k
SF = 256/2 = 256~4 (k=0…6) SF = 256/2 = 256~4 (k=0…6)
1.3.3 DPCCH Slot = Pilot + TFCI/TPC  Slot = Pilot + TPC + TFCI + FBI  SAT-CDMA defines the FBI field Medium
SF = 256  SF = 256 for the support of BSDT.
SW-CDMA uses the combined
TFCI/TPC field, while SAT-CDMA
uses them separately.
1.3.4 Pilot field 8 bits per slot 3, 4, 5, 6, 7 or 8 bits per slot SAT-CDMA defines the several Medium
FSW used FSW used pilot bit patterns as well as 8-bit
pattern.
1.3.5 TFCI / TPC field  TFCI and TPC bits: encoded TFCI and TPC bits: encoded In SW-CDMA, the TFCI and TPC Medium
together separately bits are encoded together.
TPC/TFCI field: 2 bits per slot TPC field: 2 bits per slot In SAT-CDMA, the TFIC and TPC
TFCI field: 2, 3 or 4 bits per slot bits are independently encoded
1 TPC command per frame 1 TPC command per frame and mapped to the separated
fields
1.3.6 FBI field Not defined 0 or 1 bit per slot SAT-CDMA uses 1 bit per slot as Low
the FBI field for BSDT
1.3.7 DPCCH Power control preamble Initial transmission preamble The length of the DCPCCH Medium
preamble - ength: Npcp slots - Length: Nitp frames preamble is N slots in SW-
pcp
- Slot format: identical to the - Slot format: identical to the
CDMA, while N frames in SAT-
itp
DPCCH slot DPCCH slot
CDMA.
Abbreviations
SF: Spreading Factor FSW: Frame synchronization word
TFCI: Transport-format combination indicator BSDT: Beam Selection Diversity Transmission
TPC: Transmit power control
Comment 1.3.3 and 1.3.5: For the case when the TFCI bits and the TPC command bits are encoded together by the (32,10) RM code, the number of bits allocated for TFCI in
10 input bits to RM encoder is restricted to be smaller than 10 due to the portion of TPC command bits. This results in the limitation of TFC types come from higher layers. The
detection performances of both, moreover, will be correlated mutually. Therefore, the TFCI bits and the TPC command in SAT-CDMA are separately encoded and distributed
into the slots of the radio frame without modifying the 10-bit space reserved for TFCI bits. In this case, the same slot formats as in 3GPP can be used.
Comment 1.3.3 and 1.3.5: The idea in SW-CDMA is to reduce overhead related to unnecessary for slot power control. The proposed approach in SW-CDMA is expected to be
sufficient to support the required flexibility.
Comment 1.3.6: In SAT-CDMA, BSDT can reduce additional downlink interference and power consumption in soft handover mode as with the terrestrial site selection
diversity transmission (SSDT). Furthermore, the update period to select the primary satellite beam does not need to be as short as that in terrestrial case. In SAT-CDMA, one
primary beam ID is transmitted to Satellite-RAN via the FBI fields in a radio frame regardless of non-compressed mode or compressed mode.
ETSI
16 ETSI TR 102 278 V1.1.1 (2008-08)
Comment 1.3.6: SW-CDMA is open to accept the points of SAT-CDMA, and the matter needs further work.
Comment 1.3.7: In SW-CDMA, the power control preamble with the length of Npcp slots is transmitted before DPCCH transmission and the preamble has the same slot format
as the DPCCH. This is not consistent with the description in [i.4] due to the different 3GPP version used for the specification. This can be changed for the future release.
Table 1-4: Commonality in physical random access channel (PRACH)
Item ref. Item SW-CDMA SAT-CDMA Difference Commonality
1.4.1 Random-access ALOHA approach ALOHA approach with fast In SAT-CDMA, DL AICH is used for Medium
transmission Transmission = 1 PRACH acquisition indication fast acquisition indication of the
preamble (9 * 4 096 = 36 864 Transmission = 1 PRACH preamble PRACH transmission.
chips) + 1 PRACH message (Np * 4 096) + 1 PRACH message
(10/20 ms) (10/20 ms)
1.4.2 Access slot or Not defined Access frame = 2 radio frames SAT-CDMA defines a timing Low
frame structure consisted of the access
frames.
1.4.3 PRACH Preamble: 8 * 256 repetitions of a Preamble: Np repetitions of sub- In S-UMTS, the number of repetition Medium
preamble part signature of length of 16 chips + preambles is fixed, while in SAT-CDMA it is
an unique word of length 16 QPSK Sub-preamble = 256 repetitions of a signalled by higher layers.
symbols (SF=256) differentially signature of length of 16 chips. S-UMTS defines a unique word,
encoded. Unique word Invert the sign of the last sub- while SAT-CDMA uses the last sub-
Value=0x78DB) preamble preamble with inverse sign.
Length = 9 * 4 096 = 36 864 Length = Np * 4 096 chips
chips
1.4.4 PRACH Data and Control are I-Q/code Data and Control are I-Q/code There is no difference High
message part multiplexed multiplexed
Length = 10 ms or 20 ms Length = 10 or 20 ms
1.4.5 Data part of the Slot = Data field Slot = Data field There is no difference. High
RACH message k k
SF = 256/2 = 256~32 (k=0…3) SF = 256/2 = 256~32 (k=0…3)
1.4.6 Control part of Slot = Pilot (8 bits) + TFCI (2 bits) Slot = Pilot (8 bits) + TFCI (2 bits) There is no difference. High
the RACH SF = 256  SF = 256
message
Abbreviations
Comment 1.4.2: In SAT-CDMA, random-access transmission starts at the beginning of access frames. Each access frame has a length of two radio frames. Considering typical
beam sizes and satellite altitude for LEO, MEO and GEO systems, the deviation of delays among users in a beam ranges within 20 ms. In the downlink AICH, the access frame
of length 20 ms is also defined as the period of acquisition indicator transmission as well as the AICH frame.
Comment 1.4.2: This difference is related to the access procedure for RACH. SW-CDMA does not define access slots, as it has doubts on their suitability for satellite.
ETSI
17 ETSI TR 102 278 V1.1.1 (2008-08)
Comment 1.4.3: In SAT-CDMA, the number of sub-preamble repetitions is not fixed and signalled by higher layers. Generally, the repetition number depends on the detection
scheme and the amount of the Doppler shift. Thus in specification it should not be optimized for a specific detection scheme and a satellite constellation. The last sub-preamble
with the inverted sign and the same structure can inform the detector of the end time of the preamble or the beginning time of the message part, instead of the insertion of
symbols modulated by a method different from the modulation method used for the preamble. The structure of signature repetition makes differential detection possible
although the symbols are not differentially encoded. If the receiver has already detected and acquired the preamble using a matched filter with a differential detection scheme,
the timing of the preamble scrambling code has been acquired and thus it is not required to detect the UW for a bit and/or a message packet synchronization.
Comment 1.4.3: The change in the place where the number of repetition is fixed can be accepted in SW-CDMA. Concerning the unique word/sub-preamble, SW-CDMA would
like to have some quantitative analysis.
Comment 1.4.4: This difference is due to a change in 3GPP specifications. This will be changed in SW-CDMA for the future release.
Table 1-5: Commonality in physical common packet channel (PCPCH)
Item ref. Item SW-CDMA SAT-CDMA Difference Commonality
1.5.1 Random-access Not defined DSMA-CD approach SAT-CDMA defines the PCPCH for Low
transmission Transmission = 1 AP/CDP part + 1 fast packet transmission on uplink.
message part
1.5.2 Access slot or Not defined Access frame = 2 radio frames The timing of the PCPCH Low
frame transmission is aligned to the access
frame, as with the PRACH
transmission
1.5.3 PCPCH Not defined Preamble = 1 AP + 1 CD The PCPCH preamble consists of a Low
preamble part AP =N * 256 repetitions of a pair of the access preamble and the
p
collision detection preamble.
signature of length of 16 chips.
The access preamble has the same
CD = 256 repetitions of a signature
structure as with the PRACH
of length of 16 chips
preamble
Length = (N +1) * 4 096 chips
p
1.5.4 PCPCH initial Not defined CPCH Initial Transmission Preamble To help the detection at Satellite- Low
transmission - Length: L slots RAN, the initial transmission
itp
preamble preamble can be transmitted prior to
- Slot format: identical to the slot
the message part.
format of PCPCH message
control part
1.5.5 PCPCH Not defined Data and Control are I-Q/code  Low
message part multiplexed
Length = N frames
max_frames
1.5.6 Data part of the Not defined Slot = Data field The PCPCH message part is Low
message k transmitted after the successful
SF = 256/2 = 256 ~ 4 (k=0…6)
preamble acquisition indication.
ETSI
18 ETSI TR 102 278 V1.1.1 (2008-08)
Item ref. Item SW-CDMA SAT-CDMA Difference Commonality
1.5.7 Control part of Not defined Slot = Pilot (8 bits) + TFCI (2 bits) The control part does not have any Low
the message SF = 256 TPC field because the power of the
corresponding downlink channel is
not controlled by an inner-loop power
control procedure.
Abbreviations
AP - Access Preamble CDP - Collision Detection Preamble

Comment 1.5: SAT-CDMA defines the PCPCH for fast packet transmission on uplink. The PCPCH and the downlink indicator channels are designed as close as possible to
those in the 3GPP. However, in PCPCH transmission in SAT-CDMA, the access preamble and the collision detection preamble are successively transmitted as a pair in order to
reduce the access delay.
Table 1-6: Commonality in downlink dedicated physical channel (downlink DPCH)
Item ref. Item SW-CDMA SAT-CDMA Difference Commonality
1.6.1 Characteristics DPDCH and DPCCH DPDCH and DPCCH SAT-CDMA defines one or two data Medium
are time multiplexed are time multiplexed fields as the DPDCH portion.
Slot = TFCI/TPC + Data + Pilot  Slot = Data1 +TFCI +TPC + Data2 + SW-CDMA uses the combined
k Pilot TFCI/TPC field
SF = 512/2 = 512 ~ 4 (k=0…7)
k
SF = 512/2 = 512 ~ 4 (k=0…7)
1.6.2 DPDCH One data field per slot One or two data fields per slot In SAT-CDMA, there are one or two Medium
data fields per slot according to slot
format.
1.6.3 DPCCH TFCI/TPC and Pilot fields TPC, TFCI and Pilot fields SW-CDMA uses the combined Medium
TFCI/TPC field.
1.6.4 TFCI / TPC field  TFCI and TPC bits: encoded TFCI and TPC bits: encoded In SW-CDMA, the TFCI and TPC bits Medium
together separately are coded together.
TPC/TFCI field: 2 bits per slot TPC field: 2 bits per slot In SAT-CDMA, the TFIC and TPC
1 TPC command per frame TFCI field: 2, 3 or 4 bits per slot bits are independently encoded and
1 TPC command per frame mapped to the separated fields
1.6.5 Pilot field 0, 2, 4, 8, 16 bits per slot 2, 4, 8, 16 bits per slot In SW-CDMA, the slot format without High
FSW used FSW used dedicated pilot bits is also defined.
Abbreviations
TFCI: Transport-form
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