ETSI TR 145 903 V13.0.0 (2016-01)

ETSI TR 145 903 V13.0.0 (2016-01)






TECHNICAL REPORT
Digital cellular telecommunications system (Phase 2+);
Feasibility study on Single Antenna Interference
Cancellation (SAIC) for GSM networks
(3GPP TR 45.903 version 13.0.0 Release 13)

R
GLOBAL SYSTEM FOR
MOBILE COMMUNICATIONS

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3GPP TR 45.903 version 13.0.0 Release 13 1 ETSI TR 145 903 V13.0.0 (2016-01)



Reference
RTR/TSGG-0145903vd00
Keywords
GSM
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3GPP TR 45.903 version 13.0.0 Release 13 2 ETSI TR 145 903 V13.0.0 (2016-01)
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 (https://ipr.etsi.org/).
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 3rd Generation Partnership Project (3GPP).
The present document may refer to technical specifications or reports using their 3GPP identities, UMTS identities or
GSM identities. These should be interpreted as being references to the corresponding ETSI deliverables.
The cross reference between GSM, UMTS, 3GPP and ETSI identities can be found under
http://webapp.etsi.org/key/queryform.asp.
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
ETSI

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Contents
Intellectual Property Rights . 2
Foreword . 2
Modal verbs terminology . 2
Foreword . 5
Introduction . 5
1 Scope / objectives . 7
2 References . 7
3 Abbreviations . 7
4 Network scenarios for SAIC evaluation . 8
5 Interference modelling . 11
5.1 Introduction . 11
5.2 Interference statistics . 11
5.3 Synchronous link level models . 14
5.3.1 Interferer levels . 14
5.3.2 Delay distributions . 16
5.3.3 Frequency offset distributions. 17
5.4 Asynchronous link level models . 17
5.4.1 Burst structure . 18
5.4.2 Time-offset modelling . 18
5.4.3 Power control . 19
5.4.4 Phase transition . 20
5.4.5 Guard period and power ramping . 20
5.4.6 DTX . 21
5.5 Summary . 21
6 SAIC Link Level Characterisation . 21
6.1 Introduction . 21
6.2 Link level performance . 22
6.2.1 Results for exemplary link models . 22
6.2.2 Additional results . 24
6.3 Link-to-system interface . 24
7 SAIC system level characterization . 25
7.1 Introduction . 25
7.2 Link-to-system mapping . 26
7.3 System level simulator . 26
7.3.1 Satisfied user definition . 27
7.4 System level simulation results . 28
7.4.1 System capacity for 100% SAIC mobile penetration . 28
7.4.1.1 Configuration 1 – unsynchronized network . 28
7.4.1.2 Configuration 2 – synchronized network . 28
7.4.1.3 Configuration 2 – unsynchronized network . 29
7.4.1.4 Configuration 3 – synchronized network . 30
7.4.1.5 Configuration 3 – unsynchronized network . 31
7.4.1.6 Configuration 4 – unsynchronized network . 32
7.4.2 Impact of SAIC Mobile Penetration . 33
7.4.3 Additional results . 37
7.4.3.1 Effect of antenna patterns and Quality of Service (QoS) on system capacity . 37
7.4.3.2 System performance for Configuration 1, another perspective . 39
7.4.3.3 Impact of 8-PSK interference on GMSK SAIC performance . 40
7.5 The effect of SAIC on GPRS performance . 40
7.6 Summary and conclusions . 44
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8 SAIC field trials . 45
8.1 Asynchronous network field trial . 46
8.2 Synchronous network field trial . 46
9 Test considerations . 47
9.1 Introduction . 47
9.2 Discussion . 48
9.3 Summary . 51
10 Signalling considerations . 51
10.1 Logical binding of receiver performance to protocol version . 52
10.2 Release-independent indication of receiver performance: Classmark 3 IE . 52
10.3 Release-independent indication of receiver performance: MS Radio Access Capability IE . 53
10.4 Summary . 55
10.5 References . 55
11 Conclusions . 55
11.1 Specification impacts . 56
11.1.1 Core specifications . 57
11.1.2 Testing specifications . 57
Annex A: Change history . 58
History . 59

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Foreword
rd
This Technical Report has been produced by the 3 Generation Partnership Project (3GPP).
The contents of the present document are subject to continuing work within the TSG and may change following formal
TSG approval. Should the TSG modify the contents of the present document, it will be re-released by the TSG with an
identifying change of release date and an increase in version number as follows:
Version x.y.z
Where:
x the first digit:
1 presented to TSG for information;
2 presented to TSG for approval;
3 or greater indicates TSG approved document under change control.
y the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections,
updates, etc.
z the third digit is incremented when editorial only changes have been incorporated in the document.
Introduction
This document studies the feasibility of utilising Single Antenna Interference Cancellation (SAIC) as a means of
increasing the downlink spectral efficiency of GSM networks.
SAIC is a generic name for techniques, which attempt to cancel or suppress interference by means of signal processing
without the use of multiple antennas. The primary application is the downlink, where terminal space and aesthetics
typically preclude the use of multiple antennas.
Clause 1 of this document defines the scope and objectives of this feasibility study. Clause 4 defines the network
scenarios that have been defined to evaluate SAIC performance in GSM networks. These scenarios are representative
of typical GSM deployments worldwide today. Clause 5 presents the interference statistics associated with the network
scenarios defined in Clause 4. These interference statistics are developed via system simulations, and are defined in
terms of the distributions of the parameters which are critical to understanding SAIC performance. These critical
parameters include;
• The Carrier to Interference plus noise Ratio (CIR)
• The Dominant to rest of Interferer Ratio (DIR)
• The other interferer ratios, which define the relative power of the dominant co-channel interferer to each of the
other considered interferers
• The delay between the desired signal and each of the interferers.
It is important to understand the network statistics of these key parameters since most SAIC algorithms can only cancel
one interferer, and their effectiveness in doing this is affected by the 'remaining' interference, and delays between the
desired signal and the interferers.
In Clause 6, candidate SAIC algorithms are evaluated at the link level based on the interference statistics defined in
Clause 5. Both 'long-term average' and per burst results are generated. The long-term average results represent the
classical way of looking at link performance via link simulations, defining the Bit Error Rate (BER) and Frame Error
Rate (FER) averaged over the entire simulation run as a function of the CIR. This is the type of performance that is
typically specified in the GSM standards. However, to develop a system capacity estimate, it is necessary to define the
link performance on a per burst basis. To this end, Clause 6 also defines the average BER over the burst as a function
of the burst CIR and burst DIR. This burst performance is used to develop a link-to-system level mapping. This
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mapping is used in Clause 7 to develop voice capacity and data throughput estimates for both conventional and SAIC
receivers. The voice capacity gain and data throughput gain for SAIC is then deduced from these estimates.
Clause 8 describes the field trials that have been conducted using an SAIC prototype Mobile Station (MS). Clause 9
addresses testing considerations for SAIC capable MSs, while Clause 10 defines a couple of signalling options for
identifying an MS as being SAIC capable. Finally, Clause 11 provides the relevant conclusions that can be drawn from
this feasibility study, the most important of which is the conclusion that SAIC is a viable and feasible technology, which
will support significant voice capacity gains for both synchronous and asynchronous networks when applied to GMSK
modulation. In addition, modest increases in GPRS data throughput are also supported for the types of data traffic
considered. Clause 11 also identifies those clauses of the core and testing specifications that will be impacted by the
inclusion of an SAIC capability.

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1 Scope / objectives
The objective of this document, as defined in the work item [2], is to determine the potential of SAIC in typical network
layouts. This includes study of the following aspects:
a) Determine the feasibility of SAIC for GMSK and 8PSK scenarios under realistic synchronized and non-
synchronized network conditions. Using a single Feasibility Study, both GMSK and 8PSK scenarios will be
evaluated individually.
b) Realistic interference statistics including CIR (Carrier to Interference plus noise Ratio) and DIR (Dominant-to-
rest of Interference Ratio) levels and distributions based on network simulations and measurements, where
possible.
c) Robustness against different training sequences.
d) Determine method to detect/indicate SAIC capability.
2 References
The following documents contain provisions, which, through reference in this text, constitute provisions of the present
document.
• References are either specific (identified by date of publication, edition number, version number, etc.) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including
a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same
Release as the present document.
[1] ETSI TR 101 112 v3.2.0 (1998-04), "Universal Mobile Telecommunications System (UMTS);
Selection procedures for the choice of radio transmission technologies of the UMTS".
[2] 3GPP TSG-GERAN TDOC GP-022891: "Work Item Description, Single Antenna Interference
Cancellation", Sophia Antipolis, France, 18-22 November 2002.
[3] 3GPP TSG-GERAN SAIC Workshop TDOC GAHS-030009: "Network level simulation scenarios
and assumptions for SAIC", Atlanta, USA, 8-9 January 2003.
[4] 3GPP TSG-GERAN SAIC Workshop TDOC GAHS-030005: "Scenarios and Modelling
Assumptions for SAIC in GERAN", Atlanta, USA, 8-9 January 2003.
[5] 3GPP TSG-GERAN SAIC Workshop TDOC GAHS-030002: "Single antenna interference
cancellation - evaluation principles and scenarios", Atlanta, USA, 8-9 January 2003.
[6] 3GPP TSG-GERAN SAIC Workshop TDOC GAHS-030020: "Interference Characterization for
SAIC Link Level Evaluation", Seattle, USA, 4-5 March 2003.
[7] 3GPP TSG-GERAN SAIC Workshop TDOC GAHS-030022: "Link Level model for SAIC",
Seattle, USA, 4-5 March 2003.
Additional references are noted in the individual clauses of this document
3 Abbreviations
ACI Adjacent Channel Interference
AMR Adaptive Multi Rate
BEP Bit Error Probability
BER Bit Error Rate
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BLER Block Error Rate
BTS Base Transceiver Station
CDF Cumulative Distribution Function
C/I Carrier-to-Interference Power Ratio
cdfs cumulative distribution functions
CINR Carrier to Interference-plus-Noise Ratio
DIR Dominant-to-rest Interference Ratio
DPC Downlink Power Control
DTX Discontinuous Transmission
EFL Effective Frequency Load
FEP Frame Error Probability
FER Frame Error Rate
FL Frequency Load
FR Full Rate
FTP File Transfer Protocol
GMSK Gaussian Minimum Shift Keying
GPRS General Packet Radio Service
HR Half Rate
IE Information Element
MMS Multimedia Messaging Service
MS Mobile Station
PDF Probability Distribution Function
PSK Phase-Shift Keying
QoS Quality of Service
SAIC Single Antenna Interference Cancellation
TSC Training Sequence

4 Network scenarios for SAIC evaluation
A multi-step approach was taken to evaluate SAIC performance in realistic network scenarios. This approach consisted
of first determining relevant interference statistics based on the network scenarios described in this clause. These
interference statistics were then used to determine the link level performance at the GSM burst level. From this link
level characterization, link-to-system mapping tables were developed, which were then used in system level simulations
to determine the voice and data capacity gains provided by SAIC capable MSs. The network scenarios used in these
simulations were discussed and agreed to as part of SAIC Workshop #1.
It was agreed that the network scenarios, also referred to as configurations in this document, should represent typical
GERAN networks at the time frame when operators would be deploying SAIC capable MSs. The goal was to try to
make the interference statistics as realistic as possible, while trying to keep the overall complexity of the simulations
reasonable. As a result of [3], [4], and [5], the following parameters are considered to be the major issues which affect
the interference statistics:
• Frequency Hopping scheme
• Reuse (also adjacent channel reuse) and cell radius
• Regularity of the network (different cell sizes, different number of TRXs per cell, hotspots)
• Propagation conditions, including network topology (street corner effects, shadowing from buildings/hills
etc.)
• Downlink Power Control (DPC) scheme
• Channel coding, mainly if quality-based DPC is used; schemes with less coding requires higher
transmission powers
• Penetration of different MSs/bearers in the network
• SAIC MS penetration: power levels, higher tolerated load/interference for SAIC MSs, but the non-SAIC
MS must not be negatively impacted
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• Packet-switched connections to support GPRS and EGPRS, which are characterized by short connection
times, asymmetry, bursty traffic, multiplexing of several users on the same time slot, and often lack of DPC
• Legacy non-AMR (mainly EFR) mobiles: higher transmit powers, less robustness
• Level of synchronization in the network
• Mobility: speed distribution of the mobiles affects the interference pattern
Going into the study, it was believed that SAIC would support larger gains in tighter reuse networks, as the interference
becomes more and more limiting to system performance. Similarly, the higher the load, the more interference to cancel.
However, interference scenarios are more complex with a higher load, so the interference cancellation algorithms may
be less efficient. Finally, SAIC techniques generally give the largest gains in synchronized networks. These initial
observations were found to be true, for the most part as is shown in clause 7, which provides a characterization of the
system level performance of SAIC.
Two tables define the network scenario assumptions. Table 4-1 defines operator or configuration specific assumptions,
while table 4-2 defines parameters common to all of the configurations.  Both tables were derived from [3], [4], [5],
and discussed as part of the SAIC Workshop #1. The four configurations defined in Table 4-1, and the common
parameters defined in Table 4.2 are described in detail in clause 7.
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3GPP TR 45.903 version 13.0.0 Release 13 10 ETSI TR 145 903 V13.0.0 (2016-01)
Table 4-1
Configuration specific network scenario assumptions
Parameter Value Unit Comment
Configuration 1 - Asynchronous
Frequency 900 MHz
Bandwidth 7.8 MHz
Reuse 4/12 (BCCH)
3/9 (TCH)
Hopping Baseband
Voice Codec AMR 12.2 FR
Blocking 2 %
Modulation Source/Interferer
GMSK/GMSK
GMSK/8PSK
Cell Radius 500 m

Configuration 2 – Sync & Async
Frequency 1900 MHz
Bandwidth 1.2 MHz
Reuse 1/1 (TCH)
Hopping Random RF
Voice Codec AMR 5.9 FR/HR
Frequency Load 20, 40 (FR) %
10, 20 (HR) %
Modulations Source/Interferer
GMSK/GMSK
GMSK/8PSK
8PSK/GMSK
8PSK/8PSK
Cell Radius 1000 m

Configuration 3 – Sync & Async
(Optional)
Frequency 900 MHz
Bandwidth 2.4 MHz
Reuse 1/1 (TCH)
Hopping Random RF
Voice Codec AMR 5.9 FR/HR
Frequency Load 40, 70 (FR) %
25, 40 (HR) %
Modulation Source/Interferer
GMSK/GMSK
Cell Radius 750 m
Configuration 4 - Asynchronous
Frequency 900 MHz
Bandwidth 7.2 MHz
Reuse 1/3 (TCH)
Hopping Random RF
Voice Codec AMR 12.2 FR
Blocking 2 %
Frequency Load 30 %
Modulation Source/Interferer
GMSK/GMSK
GMSK/8PSK m
Cell Radius 300


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3GPP TR 45.903 version 13.0.0 Release 13 11 ETSI TR 145 903 V13.0.0 (2016-01)
Table 4-2
Common network scenario assumptions
Parameter Value Unit Comment
3
Sectors (cells) per site
Sector antenna pattern UMTS 30.03

Propagation model UMTS 30.03  Pathloss
exponent, MCL
Per 30.03
Log-normal fading standard deviation 6 (900) dB
8 (1900) dB
Correlation distance 110 m
Adjacent channel interference attenuation 18 dB Carrier +/- 200
KHz
Handover margin 3 dB
Mobile speed TU3 and TU50 km/h
Mean Call length 90 sec.
Minimum Call Length 5 sec.
Voice activity 60% Includes SID
signalling.
DTX Enabled
Link adaptation Disabled
BTS output power 20 W
Power control RxQual/RxLev
Dynamic Range 14 dB
Step Size 2 dB
Noise figure 10 dB Reference
temperature
25c
Inter-site Lognormal Correlation Coefficient 0
Channel Allocation Random
See clause 7.5 Web-browsing
Traffic data models for GPRS
& FTP/MMS

5 Interference modelling
5.1 Introduction
When assessing the link and system level performance it is important to base the performance investigations on realistic
link level models. Especially for SAIC receivers previous studies ha
...