A coalitional game-based relay load balancing and power allocation scheme in decode-and-forward cellurlar relay networks

In this paper, a game theoretic relay load balancing and power allocationscheme is proposed for downlink transmission in a decode-and-forward orthogonal frequency division multiple access-based cellular relay network. A system with a base station communicating with multiple users via multiple relays is considered. The relays have limited power, which must be divided among the users they support. In traditional scheme, each relay simply divides its transmit power equally among all its users. Moreover, each user selects the relay with the highest channel gain. In this work, we do not apply the traditional relay scheme. It is because the users are distributed randomly, and by applying the traditional relay selection scheme, it may happen that some relays have more users connected to them than other relays, which results in having unbalanced load among the relays. In order to avoid performance degradation, achieve relay load balancing, and maximize the total data rate of the network, a game theoretic approach is proposed, which efficiently assigns the users to relays. The power of each relay is wisely distributed among users by the efficient power allocation scheme. Simulation results indicate that the proposed game-based scheme can considerably improve the average sum-spectral efficiency. Moreover, it shows that by applying the game, users who can connect to uncongested relays join them as opposed to connecting to congested relays.Grant from the Natural Sciences and Engineering Research Council (NSERC) IRC and Bell Canada.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1530-86772017-06-30hb2016Electrical, Electronic and Computer Engineerin

D13.2 Techniques and performance analysis on energy- and bandwidth-efficient communications and networking

Deliverable D13.2 del projecte europeu NEWCOM#The report presents the status of the research work of the various Joint Research Activities (JRA) in WP1.3 and the results that were developed up to the second year of the project. For each activity there is a description, an illustration of the adherence to and relevance with the identified fundamental open issues, a short presentation of the main results, and a roadmap for the future joint research. In the Annex, for each JRA, the main technical details on specific scientific activities are described in detail.Peer ReviewedPostprint (published version

Resource allocation in networks via coalitional games

The main goal of this dissertation is to manage resource allocation in network engineering problems and to introduce efficient cooperative algorithms to obtain high performance, ensuring fairness and stability. Specifically, this dissertation introduces new approaches for resource allocation in Orthogonal Frequency Division Multiple Access (OFDMA) wireless networks and in smart power grids by casting the problems to the coalitional game framework and by providing a constructive iterative algorithm based on dynamic learning theory.  Software Engineering (Software)Algorithms and the Foundations of Software technolog

Distributed radio resource management in LTE-advanced networks with type 1 relay

Long Term Evolution (LTE)-Advanced is proposed as a candidate of the 4th generation (4G) mobile telecommunication systems. As an evolved version of LTE, LTE- Advanced is also based on Orthogonal Frequency Division Multiplexing (OFDM) and in addition, it adopts some emerging technologies, such as relaying. Type I relay nodes, de_ned in LTE-Advanced standards, can control their cells with their own reference signals and have Radio Resource Management (RRM) functionalities. The rationale of RRM is to decide which resources are allocated to which users for optimising performance metrics, such as throughput, fairness, power consumption and Quality of Service (QoS). The RRM techniques in LTE-Advanced networks, including route selection, resource partitioning and resource scheduling, are facing new challenges brought by Type 1 relay nodes and increasingly becoming research focuses in recent years. The research work presented in this thesis has made the following contributions. A service-aware adaptive bidirectional optimisation route selection strategy is proposed to consider both uplink optimisation and downlink optimisation according to service type. The load between di_erent serving nodes, including eNBs and relay nodes, are rebalanced under the _xed resource partitioning. The simulation results show that larger uplink throughputs and bidirectional throughputs can be achieved, compared with existing route selection strategies. A distributed two-hop proportional fair resource allocation scheme is proposed in order to provide better two-hop end-to-end proportional fairness for all the User Equipments (UEs), especially for the relay UEs. The resource partitioning is based on the cases of none Frequency Reuse (FR) pattern, full FR pattern and partial FR patterns. The resource scheduling in access links and backhaul links are considered jointly. A proportional fair joint route selection and resource partitioning algorithm isproposed to obtain an improved solution to the two-hop Adaptive Partial Frequency Reusing (APFR) problem with one relay node per cell. In addition, two special situations of APFR, full FR and no FR, are utilised to narrow the iterative search range of the proposed algorithm and reduce its complexity

Game Theoretical Approaches for Wireless Networks

학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2017. 2. 김성철.In this dissertation, I introduce three algorithms, which are connectivity reconstruction game (CRG), adaptive sector coloring game (ASCG), and asymmetric transmission game (ATG), by mainly using supermodular game and exact potential game with considerations of various objectives (e.g., energy consumption and interference management) in wireless sensor and cellular networks. My main contributions are threefold: 1) connectivity relaxation (energy saving) in wireless localization2) intercell interference coordination in wireless cellular networks3) interference minimization in wireless ad-hoc relay networks. The corresponding explanations are as follows. 1) In geographically dense and energy limited wireless sensor networks, connectivity based localization with full power transmission can be inefficient in terms of energy consumption. In this work, I propose a distributed power control based connectivity reconstruction game, which takes into considerations of both energy efficiency and the quality of localization. The proposed scheme results in a better performance with an improved 61.9% reduction in energy consumption while maintaining the performance of localization at a level similar to the conventional algorithm with full power transmission. 2) Inter-cell interference coordination (ICIC) is a promising technique to improve the performance of frequency-domain packet scheduling (FDPS) in downlink LTE/LTEA networks. However, it is difficult to maximize the performance of FDPS using static ICIC schemes because of insufficient consideration of signal-to-interference-and-noise ratio (SINR) distribution and user fairness. On the other hand, dynamic ICIC schemes based on channel state information (CSI) also have difficulty presented in the excessive signaling overhead and X2 interface latency. In order to overcome these drawbacks, I introduce a new concept of ICIC problem based on geometric network information (GNI) and propose an ASCG as a decentralized solution of the GNI based ICIC problem. Furthermore, I develop an ASCG with a dominant strategy space noted as ASCGD to secure a stable solution through proving the existence of Nash equilibrium (NE). The proposed scheme provides better performance in terms of system throughput gain of up to about 44.1%, and especially of up to about 221% for the worst 10% users than static ICIC schemes. Moreover, the performance of the CSI based ICIC, which require too much computational load and signaling overhead, is only 13.0% and 5.6% higher than that of ASCG-D regarding the total user throughput and the worst 10% user throughput, respectively. The most interesting outcome is that the signaling overhead of ASCG-D is 1/144 of dynamic ICIC schemes one. 3) In this work, I introduce the new concept of temporal diversity utilization based on asymmetric transmission to minimize network interference in wireless ad-hoc networks with a two-hop half-duplex relaying (HDR) protocol. Asymmetric transmission is an interference-aware backoff technique, in which each communication session (source-relay-destination link) adaptively chooses a certain subset of spectrallyorthogonal data streaming which should be delayed by the duration of one time-slot (i.e., half of one subframe). I design the problem in the HDR scenario by applying the concept of asymmetric transmission, and evaluate the game-theoretical algorithm, called ATG, to derive the suboptimal solution. I show that ATG is an exact potential game, and derive its convergence and optimality properties. Furthermore, I develop an approximated version of ATG (termed A-ATG) in order to reduce signaling and computational complexity. Numerical results verify that two algorithms proposed showsignificant synergistic effects when collaborating with the conventional methods in terms of interference coordination. Ultimately, the energy consumption to satisfy the rate requirement is reduced by up to 17:4% compared to the conventional schemes alone.1 INTRODUCTION 1 1.1 Application of Supermodular Game for Connectivity Relaxation in Wireless Localization 2 1.2 Application of Exact Potential Game for Effective Inter-Cell Interference Coordination in Wireless Cellular Networks 3 1.3 Application of Exact Potential Game for Interference Minimization in Wireless Ad-hoc Relay Networks 7 1.4 Dissertation Outline 11 2 APPLICATION OF SUPERMODULAR GAME: Distributed Power Control based Connectivity Reconstruction Game inWireless Localization 13 2.1 Brief Introduction 13 2.2 System Model 13 2.3 Proposed Power Control Algorithm 14 2.3.1 Reliability Function 14 2.3.2 Game Formulation 15 2.3.3 Convergence Properties of CRG 17 2.4 Simulation Results 20 3 APPLICATION OF EXACT POTENTIAL GAME: Adaptive Sector Coloring Game for Geometric Network Information based Inter-Cell Interference Coordination in Wireless Cellular Networks 24 3.1 Brief Introduction 24 3.2 Network Model 26 3.2.1 System Preliminaries 26 3.2.2 Determination of Time Policy 27 3.2.3 Two-Stage Framework of RB Allocation 27 3.3 PROBLEM FORMULATION: Geometric Network Information based ICIC 28 3.3.1 Outline 28 3.3.2 What Is the GNI 28 3.3.3 Temporal Perspective: Why GNI 29 3.3.4 Spatial Perspective: How do I Design a Suitable Utility Function 29 3.3.5 GNI based ICIC Problem 33 3.4 ADAPTIVE SECTOR COLORING GAME 33 3.4.1 Design of ASCG 33 3.4.2 ASCG with a Dominant Strategy Space 35 3.4.3 Summary of System Operation 40 3.5 PERFORMANCE EVALUATION 41 3.5.1 Simulation Settings and Baselines for Comparison 41 3.5.2 SINR Distribution and Average User Throughput 43 3.5.3 Signaling Overhead for ICIC and FDPS 47 3.5.4 Reduction of Feasible ASCG Strategy Space 49 4 APPLICATION OF EXACT POTENTIAL GAME: Asymmetric Transmission Game for Interference Coordination in Wireless Ad-hoc Relay Networks 51 4.1 Brief Introduction 51 4.2 Problem Formulation 52 4.2.1 System Preliminaries 52 4.2.2 The Concept of Asymmetric Transmission for Interference Coordination: A Simple Example 53 4.2.3 Optimization Problem 54 4.3 Asymmetric Transmission Game 55 4.3.1 Game Formulation 55 4.3.2 Convergence and Optimality Properties of Asymmetric Transmission Game 55 4.3.3 Approximated Version of Asymmetric Transmission Game . . 58 4.4 Simulation Results 61 4.4.1 Parameters Settings 61 4.4.2 Network Interference in One-shot Game 62 4.4.3 Individual Power Consumption in One-shot Game 66 4.4.4 Total Energy Consumption in 1000-shot Games 70 4.4.5 Complexity Analysis for Varying K and M 71 5 CONCLUSION 74 Appendix A Derivation of number of partitions for extracting the dominant feasible strategy set 76 Appendix B Derivation of the cardinal number of the dominant feasible strategy set 78 Appendix C Existence of NE in ASCG-D 79 Appendix D The Required Signaling overhead of ASCG-D 82 Bibliography 83 Abstract (In Korean) 93Docto

RESOURCE ALLOCATION FOR WIRELESS RELAY NETWORKS

In this thesis, we propose several resource allocation strategies for relay networks in the context of joint power and bandwidth allocation and relay selection, and joint power allocation and subchannel assignment for orthogonal frequency division multiplexing (OFDM) and orthogonal frequency division multiple access (OFDMA) systems. Sharing the two best ordered relays with equal power between the two users over Rayleigh flat fading channels is proposed to establish full diversity order for both users. Closed form expressions for the outage probability, and bit error probability (BEP) performance measures for both amplify and forward (AF) and decode and forward (DF) cooperative communication schemes are developed for different scenarios. To utilize the full potentials of relay-assisted transmission in multi user systems, we propose a mixed strategy of AF relaying and direct transmission, where the user transmits part of the data using the relay, and the other part is transmitted using the direct link. The resource allocation problem is formulated to maximize the sum rate. A recursive algorithm alternating between power allocation and bandwidth allocation steps is proposed to solve the formulated resource allocation problem. Due to the conflict between limited wireless resources and the fast growing wireless demands, Stackelberg game is proposed to allocate the relay resources (power and bandwidth) between competing users, aiming to maximize the relay benefits from selling its resources. We prove the uniqueness of Stackelberg Nash Equilibrium (SNE) for the proposed game. We develop a distributed algorithm to reach SNE, and investigate the conditions for the stability of the proposed algorithm. We propose low complexity algorithms for AF-OFDMA and DF-OFDMA systems to assign the subcarriers to the users based on high SNR approximation aiming to maximize the weighted sum rate. Auction framework is proposed to devise competition based solutions for the resource allocation of AF-OFDMA aiming tomaximize either vi the sum rate or the fairness index. Two auction algorithms are proposed; sequential and one-shot auctions. In sequential auction, the users evaluate the subcarrier based on the rate marginal contribution. In the one-shot auction, the users evaluate the subcarriers based on an estimate of the Shapley value and bids on all subcarriers at once

Energy-efficient cooperative resource allocation for OFDMA

Energy is increasingly becoming an exclusive commodity in next generation wireless communication systems, where even in legacy systems, the mobile operators operational expenditure is largely attributed to the energy bill. However, as the amount of mobile traffic is expected to double over the next decade as we enter the Next Generation communications era, the need to address energy efficient protocols will be a priority. Therefore, we will need to revisit the design of the mobile network in order to adopt a proactive stance towards reducing the energy consumption of the network. Future emerging communication paradigms will evolve towards Next Generation mobile networks, that will not only consider a new air interface for high broadband connectivity, but will also integrate legacy communications (LTE/LTE-A, IEEE 802.11x, among others) networks to provide a ubiquitous communication platform, and one that can host a multitude of rich services and applications. In this context, one can say that the radio access network will predominantly be OFDMA based, providing the impetus for further research studies on how this technology can be further optimized towards energy efficiency. In fact, advanced approaches towards both energy and spectral efficient design will still dominate the research agenda. Taking a step towards this direction, LTE/LTE-A (Long Term Evolution-Advanced) have already investigated cooperative paradigms such as SON (self-Organizing Networks), Network Sharing, and CoMP (Coordinated Multipoint) transmission. Although these technologies have provided promising results, some are still in their infancy and lack an interdisciplinary design approach limiting their potential gain. In this thesis, we aim to advance these future emerging paradigms from a resource allocation perspective on two accounts. In the first scenario, we address the challenge of load balancing (LB) in OFDMA networks, that is employed to redistribute the traffic load in the network to effectively use spectral resources throughout the day. We aim to reengineer the load-balancing (LB) approach through interdisciplinary design to develop an integrated energy efficient solution based on SON and network sharing, what we refer to as SO-LB (Self-Organizing Load balancing). Obtained simulation results show that by employing SO-LB algorithm in a shared network, it is possible to achieve up to 15-20% savings in energy consumption when compared to LTE-A non-shared networks. The second approach considers CoMP transmission, that is currently used to enhance cell coverage and capacity at cell edge. Legacy approaches mainly consider fundamental scheduling policies towards assigning users for CoMP transmission. We build on these scheduling approaches towards a cross-layer design that provide enhanced resource utilization, fairness, and energy saving whilst maintaining low complexity, in particular for broadband applications