Doctorat ParisTech THÈSE TELECOM ParisTech Gestion dynamique de ressources appliquée aux ...

155 Pages·2015·2.84 MB·English

2013-ENST-0054
EDITE-ED130
Doctorat ParisTech
T H È S E
pour obtenir le grade de docteur délivré par
TELECOM ParisTech
Spécialité « Wireless Communications »
présentée et soutenue publiquement par
Tania VILLA TRAPALA
le 26 Septembre 2013
Gestion dynamique de ressources
appliquée aux réseaux cellulaires
avec interférence
Directeur de thèse : Raymond Knopp
Jury
M. Angel LOZANO, Prof.,UniversitatPompeuFabra Rapporteur
M. Tommy SVENSSON, Prof.,ChalmersUniversityofTechnology Rapporteur
M. David GESBERT, Prof.,EURECOM Examinateur
M. Ruben MERZ, Dr.,Swisscom Examinateur
M. Antonio CIPRIANO, Dr.,ThalesCommunications&Security Examinateur
TELECOM ParisTech
écoledel’InstitutTélécom-membredeParisTech
DISSERTATION
In Partial Fulfillment of the Requirements
for the Degree of Doctor of Philosophy
from TELECOM ParisTech
Specialization: Wireless Communications
Tania Villa Trapala
Dynamic resource allocation for cellular networks
with interference
Defense scheduled on the 26th of September 2013 before a committee
composed of:
Reviewers Prof. Angel Lozano, Universitat Pompeu Fabra
Prof. Tommy Svensson, Chalmers University of Technology
Examiner Prof. David Gesbert, EURECOM
Dr. Ruben Merz, Swisscom
Dr. Antonio Cipriano, Thales Communications & Security
Thesis Supervisor Prof. Raymond Knopp, EURECOM

THESE
présentée pour obtenir le grade de
Docteur de TELECOM ParisTech
Spécialité: Wireless Communications
Tania Villa Trapala
Gestion dynamique de ressources appliquée aux
réseaux cellulaires avec interférence
Soutenance de thèse prévue le 26 Septembre 2013 devant le jury
composé de :
Rapporteurs Prof. Angel Lozano, Universitat Pompeu Fabra
Prof. Tommy Svensson, Chalmers University of Technology
Examinateur Prof. David Gesbert, EURECOM
Dr. Ruben Merz, Swisscom
Dr. Antonio Cipriano, Thales Communications & Security
Directeur de thèse Prof. Raymond Knopp, EURECOM

Abstract
Mobile networks have experienced dramatic growth during the past decades.
Modern communication systems require high data rates and better quality
of service control for services such as voice telephony, online gaming, web
browsing, etc. The main obstacle found in wireless communication networks
is the time-varying nature of the physical channel. Taking this into account,
the goal of a system designer is to simplify the overall network design and
optimize the performance.
Theaimofthisthesisistodesign,implementandevaluatepracticalcross-
layer algorithms to handle interference and allocate the radio resources in
an efficient way for LTE and post-LTE uncoordinated networks. We develop
mathematicalandcomputationalinterferencemodelsthatallowustounder-
stand the behavior of such networks and we apply an information-theoretic
approach to different interference scenarios and traffic characteristics. We
have tried to remain as close as possible to practical systems to be able to
test the feasibility of the proposed techniques.
As a part of the evolution to 4G systems, the introduction of small-cells
that overlay the existing cellular network has been envisioned to fill in the
coverage white spots or serve mobile and outdoor users where the cellular
network is not deployed.
This thesis deals with performance evaluation of interference scenarios
in 4G networks, in particular those arising from small-cell deployments.
The work in this thesis also deals with analysis of resource-allocation and
incremental-redundancy based hybrid automatic repeat request (HARQ)
with bursty interference (or more general time-varying channels) which al-
lows for only partial channel state information at the transmitter. The work
is then applied to practical scheduler design for LTE base stations and in-
cludes performance analysis for real LTE modems.
We showed that, in general, by adapting the number of physical dimen-
sions across rounds, we can exploit the interference mitigation effects of
HARQ using it not only to recover from errors but for interference cancel-
lation. We proposed efficient resource allocation algorithms to increase the
throughput, which can potentially come very close to optimal performance.
i
ii Abstract
Table of Contents
Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii
Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii
Notations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv
1 Introduction 1
1.1 Contributions and Thesis Outline . . . . . . . . . . . . . . . . 2
2 Background 7
2.1 Evolution of Wireless Communication Systems . . . . . . . . 7
2.2 Interference Scenarios in 4G Networks . . . . . . . . . . . . . 8
2.2.1 Heterogeneous Networks and Interference . . . . . . . 9
2.2.2 Femtocells . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.2.3 Machine-to-Machine Communications . . . . . . . . . 10
2.3 Scheduling and Link Adaptation in LTE . . . . . . . . . . . . 11
2.3.1 Resource Allocation in LTE . . . . . . . . . . . . . . . 12
2.3.2 Discontinuous Reception (DRX) . . . . . . . . . . . . 14
3 Performance Evaluation of Small-cell Deployments 15
3.1 Interference in Femtocell Deployments . . . . . . . . . . . . . 16
3.1.1 System Model and Assumptions. . . . . . . . . . . . . 16
3.1.2 Average Throughput Analysis of HARQ with Interfer-
ence Cancellation . . . . . . . . . . . . . . . . . . . . . 17
3.1.3 Performance of the HARQ Protocol in Femtocell De-
ployments with Interference . . . . . . . . . . . . . . . 20
4 Mutual Information Analysis of Interference Networks 27
4.1 Key Challenging Applications . . . . . . . . . . . . . . . . . . 27
4.1.1 Heterogeneous Networks . . . . . . . . . . . . . . . . . 28
4.1.2 M2M and Sparse Latency-Constrained Traffic . . . . . 28
4.2 Related Work . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.3 Initial Analysis for Interference-free Networks . . . . . . . . . 32
4.3.1 Signal Model and Assumptions . . . . . . . . . . . . . 32
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iv Table of Contents
4.3.2 Modeling and Optimization of a Resource Scheduling
Policy . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
4.3.3 Numerical Results . . . . . . . . . . . . . . . . . . . . 37
4.4 Interference Networks Analysis . . . . . . . . . . . . . . . . . 39
4.4.1 Modeling and Assumptions . . . . . . . . . . . . . . . 40
4.4.2 Simple Interference Analysis in Zero-outage . . . . . . 43
4.5 Practical Interference Networks Analysis . . . . . . . . . . . . 48
4.5.1 Rate Optimization (fixed across rounds) . . . . . . . . 52
4.5.2 Rate Optimization with an Outage Constraint. . . . . 52
4.6 MethodologyforResourceAllocationinPracticalInterference
Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
4.6.1 Manhattan-topology for Small-cells . . . . . . . . . . . 60
4.6.2 Macro/Small-cell Scenario . . . . . . . . . . . . . . . . 63
4.6.3 Physical layer Abstraction Models . . . . . . . . . . . 64
5 Practical Scheduler Design for LTE Base Stations 67
5.1 Handling Interference in LTE Networks with HARQ and AMC 68
5.2 OpenAirInterface Implementation . . . . . . . . . . . . . . . . 69
5.2.1 Physical Layer and Resource Allocation . . . . . . . . 70
5.3 Application of the Scheduling Policies in LTE . . . . . . . . . 71
5.4 Performance Analysis of the Scheduler . . . . . . . . . . . . . 74
5.4.1 Results without interference . . . . . . . . . . . . . . . 77
5.4.2 Results with one interferer . . . . . . . . . . . . . . . . 84
5.5 Scheduler under the Full LTE PHY/MAC Protocol Stack . . 94
5.5.1 Feasibility Evaluation . . . . . . . . . . . . . . . . . . 95
5.5.2 Interference Scenario Description . . . . . . . . . . . . 95
6 Conclusions and Areas for Further Research 99
6.1 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
6.2 Areas for further research . . . . . . . . . . . . . . . . . . . . 101
Appendix A Summary of the thesis in French 105
A.1 Abstract en français . . . . . . . . . . . . . . . . . . . . . . . 105
A.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
A.2.1 Contributions et cadre de cette thèse . . . . . . . . . . 107
A.3 Résumé du Chapitre 2 . . . . . . . . . . . . . . . . . . . . . . 110
A.3.1 Evolution des systemes san fils . . . . . . . . . . . . . 110
A.3.2 Interférence dans les reseaux 4G . . . . . . . . . . . . 111
A.3.3 Gestion et adaptation de liaison pour LTE . . . . . . . 111
A.4 Résumé du Chapitre 3 . . . . . . . . . . . . . . . . . . . . . . 114
A.4.1 Interférence dans les reseaux small cells . . . . . . . . 115
A.4.2 Modèle du system . . . . . . . . . . . . . . . . . . . . 115
A.5 Résumé du Chapitre 4 . . . . . . . . . . . . . . . . . . . . . . 116
A.5.1 Applications clés . . . . . . . . . . . . . . . . . . . . . 117
Table of Contents v
A.5.2 Analysis pour les réseaux avec interférence . . . . . . . 119
A.6 Résumé du Chapitre 5 . . . . . . . . . . . . . . . . . . . . . . 121
A.6.1 Implémentation sur OpenAirInterface . . . . . . . . . 122
A.6.2 Application des techniques pour les modems LTE . . . 124
A.7 Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Bibliography 129