Dissertations / Theses on the topic 'Throughput allocation'
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PUNYALA, SRINIVASA REDDY. "THROUGHPUT OPTIMIZATION AND RESOURCE ALLOCATION ON GPUS UNDER MULTI-APPLICATION EXECUTION." OpenSIUC, 2017. https://opensiuc.lib.siu.edu/theses/2255.
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Platform heterogeneity prevails as a solution to the throughput and computational chal- lenges imposed by parallel applications and technology scaling. Specifically, Graphics Processing Units (GPUs) are based on the Single Instruction Multiple Thread (SIMT) paradigm and they can offer tremendous speed-up for parallel applications. However, GPUs were designed to execute a single application at a time. In case of simultaneous multi-application execution, due to the GPUs’ massive multi-threading paradigm, ap- plications compete against each other using destructively the shared resources (caches and memory controllers) resulting in significant throughput degradation. In this thesis, a methodology for minimizing interference in shared resources and provide efficient con- current execution of multiple applications on GPUs is presented. Particularly, the pro- posed methodology (i) performs application classification; (ii) analyzes the per-class in- terference; (iii) finds the best matching between classes; and (iv) employs an efficient re- source allocation. Experimental results showed that the proposed approach increases the throughput of the system for two concurrent applications by an average of 36% compared to other optimization techniques, while for three concurrent applications the proposed approach achieved an average gain of 23%.
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Srinivasan, Ramya. "Throughput optimization in MIMO networks." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42735.
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Enabling multi-hop wireless mesh networks with multi-input multi-output (MIMO) functionality boosts network throughput by transmitting over multiple orthogonal
spatial channels (spatial multiplexing) and by performing interference cancellation,
to allow links within interference range to be concurrently active. Furthermore,
if the channel is in a deep fade, then multiple antenna elements at the
transmitter and/or receiver can be used to transmit a single stream, thereby improving
signal quality (diversity gain).
However, there is a fundamental trade-off between boosting individual link performance
and reducing interference, which must be modeled in the process of optimizing
network throughput. This is called the diversity-multiplexing-interference suppression
trade-off. Optimizing network throughput therefore, requires optimizing the trade-off
between the amounts of diversity employed on each link, the number of streams multiplexed
on each link and the number of interfering links allowed to be simultaneously
active in the network.
We present a set of efficient heuristics for one-shot link scheduling and stream
allocation that approximately solve the problem of optimizing network throughput
in a single time slot. We identify the fundamental problem of verifying the feasibility
of a given stream allocation. The problems of general link scheduling and stream
allocation are very closely related to the problem of verifying feasibility.
We present a set of efficient heuristic feasibility tests which can be easily incorporated
into practical scheduling schemes. We show for some special MIMO network
scenarios that feasibility is of polynomial complexity. However, we conjecture that in
general, this problem, which is a variation of Boolean Satisablility, is NP-Complete.
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Cardany, John Paul. "Node to processor allocation for large grain data flow graphs in throughput-critical applications." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1994. http://handle.dtic.mil/100.2/ADA283607.
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Garau, Luis Juan Jose. "A Comparison of artificial intelligence algorithms for dynamic power allocation in flexible high throughput satellites." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/127074.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, May, 2020Cataloged from the official PDF of thesis.
Includes bibliographical references (pages 117-123).
The Dynamic Resource Management (DRM) problem in the context of multibeam satellite communications is becoming more relevant than ever. The future landscape of the industry will be defined by a substantial increase in demand alongside the introduction of digital and highly flexible payloads able to operate and reconfigure hundreds or even thousands of beams in real time. This increase in complexity and dimensionality puts the spotlight on new resource allocation strategies that use autonomous algorithms at the core of their decision-making systems. These algorithms must be able to find optimal resource allocations in real or near-real time. Traditional optimization approaches no longer meet all these DRM requirements and the research community is studying the application of Artificial Intelligence (AI) algorithms to the problem as a potential alternative that satisfies the operational constraints.
Although multiple AI approaches have been proposed in the recent years, most of the analyses have been conducted under assumptions that do not entirely reflect the new operation scenarios' requirements, such as near-real time performance or high-dimensionality. Furthermore, little work has been done in thoroughly comparing the performance of different algorithms and characterizing them. This Thesis considers the Dynamic Power Allocation problem, a DRM subproblem, as a use case and compares nine different AI algorithms under the same near-real time operational assumptions, using the same satellite and link budget models, and four different demand datasets. The study focuses on Genetic Algorithms (GA), Simulated Annealing (SA), Particle Swarm Optimization (PSO), Deep Reinforcement Learning (DRL), and hybrid approaches, including a novel DRL-GA hybrid. The comparison considers the following characteristics: time convergence, continuous operability, scalability, and robustness.
After evaluating the algorithms' performance on the different test scenarios, three algorithms are identified as potential candidates to be used during real satellite operations. The novel DRL-GA implementation shows the best overall performance, being also the most robust. When the update frequency is in the order of seconds, DRL is identified as the best algorithm, since it is the fastest. Finally, when the online data substantially diverges from the training dataset of the DRL algorithm, both DRL and DRL-GA hybrid might not perform adequately and an individual GA might be the best option instead.
by Juan Jose Garau Luis.
S.M.
S.M. Massachusetts Institute of Technology, Department of Aeronautics and Astronautics
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Ji, Bo. "Design of Efficient Resource Allocation Algorithms for Wireless Networks: High Throughput, Small Delay, and Low Complexity." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1354641556.
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Toktas, Engin. "Subcarrier Allocation In Ofdma Systems With Time Varying Channel And Packet Arrivals." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12610029/index.pdf.
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This study considers the average system throughput and the average delay performances of subcarrier allocation algorithms in OFDMA systems. The effects of varying the number of users, the number of subcarriers, and the statistical characteristics of incoming packets are investigated on the throughput and delay performances of the algorithms. Moreover, a new subcarrier allocation algorithm with low-order computational complexity, which performs very well almost all cases, is proposed. With the aid of the simulations, the significance of channel v.s. queue state information varying with the statistical characteristic of incoming packets is examined and reached some results which can be very valuable for channel estimation and feedback systems. Finally, the stability issue is considered in OFDMA systems and a new heuristic simulation-based method for obtaining the stability region of an OFDMA subcarrier allocation algorithm is proposed.
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Cao, Fei. "Efficient Scientific Workflow Scheduling in Cloud Environment." OpenSIUC, 2014. https://opensiuc.lib.siu.edu/dissertations/802.
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Cloud computing enables the delivery of remote computing, software and storage services through web browsers following pay-as-you-go model. In addition to successful commercial applications, many research efforts including DOE Magellan Cloud project focus on discovering the opportunities and challenges arising from the computing and data-intensive scientific applications that are not well addressed by the current supercomputers, Linux clusters and Grid technologies. The elastic resource provision, noninterfering resource sharing and flexible customized configuration provided by the Cloud infrastructure has shed light on efficient execution of many scientific applications modeled as Directed Acyclic Graph (DAG) structured workflows to enforce the intricate dependency among a large number of different processing tasks. Meanwhile, the Cloud environment poses various challenges. Cloud providers and Cloud users pursue different goals. Providers aim to maximize profit by achieving higher resource utilization and users want to minimize expenses while meeting their performance requirements. Moreover, due to the expanding Cloud services and emerging newer technologies, the ever-increasing heterogeneity of the Cloud environment complicates the challenges for both parties. In this thesis, we address the workflow scheduling problem from different applications and various objectives. For batch applications, due to the increasing deployment of many data centers and computer servers around the globe escalated by the higher electricity price, the energy cost on running the computing, communication and cooling together with the amount of CO2 emissions have skyrocketed. In order to maintain sustainable Cloud computing facing with ever-increasing problem complexity and big data size in the next decades, we design and develop energy-aware scientific workflow scheduling algorithm to minimize energy consumption and CO2 emission while still satisfying certain Quality of Service (QoS) such as response time specified in Service Level Agreement (SLA). Furthermore, the underlying Cloud hardware/Virtual Machine (VM) resource availability is time-dependent because of the dual operation modes namely on-demand and reservation instances at various Cloud data centers. We also apply techniques such as Dynamic Voltage and Frequency Scaling (DVFS) and DNS scheme to further reduce energy consumption within acceptable performance bounds. Our multiple-step resource provision and allocation algorithm achieves the response time requirement in the step of forward task scheduling and minimizes the VM overhead for reduced energy consumption and higher resource utilization rate in the backward task scheduling step. We also evaluate the candidacy of multiple data centers from the energy and performance efficiency perspectives as different data centers have various energy and cost related parameters. For streaming applications, we formulate scheduling problems with two different objectives, namely one is to maximize the throughput under a budget constraint while another is to minimize execution cost under a minimum throughput constraint. Two different algorithms named as Budget constrained RATE (B-RATE) and Budget constrained SWAP (B-SWAP) are designed under the first objective; Another two algorithms, namely Throughput constrained RATE (TP-RATE) and Throughput constrained SWAP (TP-SWAP) are developed under the second objective.
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Maaz, Mohamad. "Allocation de ressource et analyse des critères de performance dans les réseaux cellulaires coopératifs." Thesis, Rennes, INSA, 2013. http://www.theses.fr/2013ISAR0036/document.
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Dans les systèmes de communications sans fil, la transmission de grandes quantités d'information et à faible coût énergétique sont les deux principales questions qui n'ont jamais cessé d'attirer l'attention de la communauté scientifique au cours de la dernière décennie. Récemment, il a été démontré que la communication coopérative est une technique intéressante notamment parce qu'elle permet d'exploiter la diversité spatiale dans le canal sans fil. Cette technique assure une communication robuste et fiable, une meilleure qualité de service (QoS) et rend le concept de coopération prometteur pour les futurs générations de systèmes cellulaires. Typiquement, les QoS sont le taux d'erreurs paquet, le débit et le délai. Ces métriques sont impactées par le délai, induit par les mécanismes de retransmission Hybrid-Automatic Repeat-Request (HARQ) inhérents à la réception d'un paquet erroné et qui a un retard sur la QoS demandée. En revanche, les mécanismes HARQ créent une diversité temporelle. Par conséquent, l'adoption conjointe de la communication coopérative et des protocoles HARQ pourrait s'avérer avantageux pour la conception de schémas cross-layer. Nous proposons tout d'abord une stratégie de maximisation de débit total dans un réseau cellulaire hétérogène. Nous introduisons un algorithme qui alloue la puissance optimale à la station de base (BS) et aux relais, qui à chaque utilisateur attribue de manière optimale les sous-porteuses et les relais. Nous calculons le débit maximal atteignable ainsi que le taux d'utilisateurs sans ressources dans le réseau lorsque le nombre d'utilisateurs actifs varie. Nous comparons les performances de notre algorithme à ceux de la littérature existante, et montrons qu'un gain significatif est atteint sur la capacité globale. Dans un second temps, nous analysons théoriquement le taux d'erreurs paquet, le délai ainsi que l'efficacité de débit des réseaux HARQ coopératifs, dans le canal à évanouissements par blocs. Dans le cas des canaux à évanouissement lents, le délai moyen du mécanisme HARQ n'est pas pertinent à cause de la non-ergodicité du processus. Ainsi, nous nous intéressons plutôt à la probabilité de coupure de délai en présence d'évanouissements lents. La probabilité de coupure de délai est de première importance pour les applications sensibles au délai. Nous proposons une forme analytique de la probabilité de coupure permettant de se passer de longues simulations. Dans la suite de notre travail, nous analysons théoriquement l'efficacité énergétique (bits/joule) dans les réseaux HARQ coopératifs. Nous résolvons ensuite un problème de minimisation de l'énergie dans les réseaux coopératifs en liaison descendante. Dans ce problème, chaque utilisateur possède une contrainte de délai moyen à satisfaire de telle sorte que la contrainte sur la puissance totale du système soit respectée. L'algorithme de minimisation permet d'attribuer à chaque utilisateur la station-relai optimale et sa puissance ainsi que la puissance optimale de la BS afin de satisfaire les contraintes de délai. Les simulations montrent qu'en termes de consommation d'énergie, les techniques assistées par relais prédominent nettement les transmissions directes, dans tout système limité en délai. En conclusion, les travaux proposés dans cette thèse peuvent promettre d'établir des règles fiables pour l'ingénierie et la conception des futures générations de systèmes cellulaires énergétiquement efficacesIn wireless systems, transmitting large amounts of information with low energetic cost are two main issues that have never stopped drawing the attention of the scientific community during the past decade. Later, it has been shown that cooperative communication is an appealing technique that exploits spatial diversity in wireless channel. Therefore, this technique certainly promises a robust and reliable communications, higher quality-of-service (QoS) and makes the cooperation concept attractive for future cellular systems. Typically, the QoS requirements are the packet error rate, throughput and delay. These metrics are affected by the delay, where each erroneous packet is retransmitted several times according to Hybrid-Automatic Repeat-Request (HARQ) mechanism inducing a delay on the demanded QoS but a temporal diversity is created. Therefore, adopting jointly cooperative communications and HARQ mechanisms could be beneficial for designing cross-layer schemes. First, a new rate maximization strategy, under heterogeneous data rate constraints among users is proposed. We propose an algorithm that allocates the optimal power at the base station (BS) and relays, assigns subcarriers and selects relays. The achievable data rate is investigated as well as the average starvation rate in the network when the load, i.e. the number of active users in the network, is increasing. It showed a significant gain in terms of global capacity compared to literature. Second, in block fading channel, theoretical analyses of the packet error rate, delay and throughput efficiency in relayassisted HARQ networks are provided. In slow fading channels, the average delay of HARQ mechanisms w.r.t. the fading states is not relevant due to the non-ergodic process of the fading channel. The delay outage is hence invoked to deal with the slow fading channel and is defined as the probability that the average delay w.r.t. AWGN channel exceeds a predefined threshold. This criterion has never been studied in literature, although being of importance for delay sensitive applications in slow fading channels. Then, an analytical form of the delay outage probability is proposed which might be useful to avoid lengthy simulations. These analyses consider a finite packet length and a given modulation and coding scheme (MCS) which leads to study the performance of practical systems. Third, a theoretical analysis of the energy efficiency (bits/joule) in relay-assisted HARQ networks is provided. Based on this analysis, an energy minimization problem in multiuser relayassisted downlink cellular networks is investigated. Each user has an average delay constraint to be satisfied such that a total power constraint in the system is respected. The BS is assumed to have only knowledge about the average channel statistics but no instantaneous channel state information (CSI). Finally, an algorithm that jointly allocates the optimal power at BS, the relay stations and selects the optimal relay in order to satisfy the delay constrains of users is proposed. The simulations show the improvement in terms of energy consumption of relay-assisted techniques compared to nonaided transmission in delay-constrained systems. Hence, the work proposed in this thesis can give useful insights for engineering rules in the design of the next generation energyefficient cellular systems
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Yassin, Mohamad. "Inter-cell interference coordination in wireless networks." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1S106/document.
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Grâce aux avancées technologiques dans le domaine des réseaux cellulaires et des équipements mobiles, le nombre d'applications multimédia à haut débit dans les réseaux mobiles ne cesse d'augmenter. On prévoit que le trafic de données dans les réseaux mobiles en 2017 sera 13 fois plus important que celui en 2012. Pour satisfaire aux besoins des équipements mobiles, de nouvelles approches pour la gestion des ressources radio et des puissances de transmission sont requises.Dans le cadre de cette thèse, on s'intéresse à proposer des solutions pour remédier aux problèmes des interférences intercellulaires dans les réseaux mobiles de dernière génération. Nous enquêtons d'une manière exhaustive les différentes techniques de coordination des interférences intercellulaires existantes. Ces techniques sont qualitativement comparées, puis classées selon le taux de coopération requis entre les différentes stations de base, mais aussi selon leurs principes de fonctionnement. Nous abordons également le problème multicellulaire d'allocation des ressources et des puissances de transmission d'une manière centralisée. Nous formulons ce problème d'optimisation centralisé, puis nous le décomposons en deux sous-problèmes indépendants : l'allocation de ressources et l'allocation des puissances de transmission. De plus, une approche distribuée basée sur la théorie des jeux est proposée pour l'allocation des puissances de transmission. Les techniques centralisées de minimisation des interférences intercellulaires offrent la solution optimale au prix d'une grande charge de signalisation. Par contre, les solutions décentralisées réduisent le trafic de signalisation sans garantir l'optimalité de la solution obtenue. Nous proposons ensuite une heuristique de contrôle de puissance qui modifie localement l'allocation des puissances de transmission de manière à éviter le gaspillage d'énergie et pour réduire les interférences ressenties par les utilisateurs des stations de base voisines. Nous proposons également une technique autonome qui gère la distribution des ressources radio entre les différentes zones de chaque cellule. Cette technique répond aux besoins des utilisateurs dans chaque zone en adaptant la distribution des ressources d'une manière dynamique. Nous abordons aussi le compromis entre les techniques de gestion d'interférences intercellulaires centralisées et décentralisées. Nous proposons une approche hybride où l'allocation des ressources radio et des puissances de transmission est faite d'une manière coopérative entre les différentes cellules. Dans un premier lieu, les cellules voisines collaborent afin d'ajuster les puissances de transmission allouées aux ressources radio. Ensuite, la distribution des ressources entre les différentes zones de chaque cellule est modifiée localement, selon les besoins des utilisateurs dans chaque zoneThe exponentially increasing demand for mobile broadband communications have led to the dense deployment of cellular networks with aggressive frequency reuse patterns. The future Fifth Generation (5G) networks are expected to overcome capacity and throughput challenges by adopting a multi-tier architecture where several low-power Base Stations (BSs) are deployed within the coverage area of the macro cell. However, Inter-Cell Interference (ICI) caused by the simultaneous usage of the same spectrum in different cells, creates severe problems. ICI reduces system throughput and network capacity, and has a negative impact on cell-edge User Equipment (UE) performance. Therefore, Inter-Cell Interference Coordination (ICIC) techniques are required to mitigate the impact of ICI on system performance. In this thesis, we address the resource and power allocation problem in multiuser Orthogonal Frequency Division Multiple Access (OFDMA) networks such as LTE/LTE-A networks and dense small cell networks. We start by overviewing the state-of-the-art schemes, and provide an exhaustive classification of the existing ICIC approaches. This qualitative classification is followed by a quantitative investigation of several interference mitigation techniques. Then, we formulate a centralized multi-cell joint resource and power allocation problem, and prove that this problem is separable into two independent convex optimization problems. The objective function of the formulated problem consists in maximizing system throughput while guaranteeing throughput fairness between UEs. ICI is taken into account, and resource and power allocation is managed accordingly in a centralized manner. Furthermore, we introduce a decentralized game-theoretical method to solve the power allocation problem without the need to exchange signaling messages between the different cells. We also propose a decentralized heuristic power control algorithm based on the received Channel Quality Indication (CQI) feedbacks. The intuition behind this algorithm is to avoid power wastage for UEs that are close to the serving cell, and reducing ICI for UEs in the neighboring cells. An autonomous ICIC scheme that aims at satisfying throughput demands in each cell zone is also introduced. The obtained results show that this technique improves UE throughput fairness, and it reduces the percentage of unsatisfied UEs without generating additional signaling messages. Lastly, we provide a hybrid ICIC scheme as a compromise between the centralized and the decentralized approaches. For a cluster of adjacent cells, resource and power allocation decisions are made in a collaborative manner. First, the transmission power is adjusted after receiving the necessary information from the neighboring cells. Second, resource allocation between cell zones is locally modified, according to throughput demands in each zone
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Wu, Fei. "Ultra-Low Delay in Complex Computing and Networked Systems: Fundamental Limits and Efficient Algorithms." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu155559337777619.
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ElAzzouni, Sherif. "Algorithm Design for Low Latency Communication in Wireless Networks." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1587049831134061.
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Haj, Hmida Wafa. "Affectation de pilotes dans la liaison descendante des systèmes de télécommunication sans cellule." Thesis, Limoges, 2020. http://aurore.unilim.fr/theses/nxfile/default/0fd5c3e4-7bba-4783-9a5e-f033b34aa0e9/blobholder:0/2020LIMO0079.pdf.
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En systèmes « Cell-Free massive Multiple-Input-Multiple-Output (Cell-Free massive MIMO) » on distribue dans un territoire géographique un nombre massif de points d’accès, contrôlés par des unités centrales de processing (CPUs), afin de servir simultanément un nombre beaucoup moins inférieur au nombre d’équipements utilisateurs dans les mêmes ressources temporelles et fréquentielles. Contrairement aux systèmes MIMO massifs centralisés, « Cell-Free massive MIMO » est caractérisé par un durcissement de canal pas suffisamment accentué, c’est pourquoi il serait convenable d’inclure des pilotes envoyés en voie descendante afin d’estimer le canal descendant. Cette thèse met en exergue l’allocation de pilotes en voie descendante en systèmes « cell-free massive MIMO » moyennant une métrique qui prend en compte l’interférence inter-utilisateurs en voie descendante. Cette métrique nous donne une information sur le taux de sévérité du problème de «contamination de pilotes envoyés en voie descendante». Suite au calcul de cette métrique, un seuil d’interférence est déni pour déterminer les utilisateurs qui sont susceptibles de réutiliser le même pilote en voie descendante. Fixer un tel seuil vise à optimiser le nombre de pilotes envoyés en voie descendante, tout en maximisant le minimum du débit effectif par utilisateur en voie descendante. Cette approche donne lieu à un graphe de conflit, dans lequel chaque équipement utilisateur est considéré un nœud du graphe. C’est un problème d’optimisation combinatoire qui pourrait être résolu approximativement en utilisant un algorithme de coloriage. C’est un algorithme glouton dont les étapes sont les suivantes. En fixant un seuil adéquat, qui maximise le minimum du débit effectif en voie descendante par utilisateur, un graphe de conflit est ainsi construit. Il modélise l’interférence susceptible d’être présente parmi les équipements utilisateurs interférents, où chaque équipement utilisateur représente un noeud du graphe de conflit. Ensuite, la méthode de coloriage proposée permet de mitiger l’interférence inter-utilisateurs par l’affectation de différents pilotes en voie descendante aux équipements utilisateurs directement connectés dans le graphe de conflit, caractérisés par une interférence considérable et le même pilote aux utilisateurs, non directement connectés dans le graphe de conflit, présentent avec une interférence moins prédominante dans le graphe de conflit. Ce processus de coloriage s’effectue en accord à des règles bien déterminées. Les résultats de simulation démontrent que la méthode proposée présente des performances, en termes de débit effectif par utilisateur en voie descendante, mieux que celles des méthodes existantes à l’instar de la méthode celle qui s’appuie sur la connaissance de la statistique du canal « statistical channel state information », l’allocation orthogonale et aléatoire de pilotes en voie descendante. De surcroît, notre analyse met l’accent également sur la réduction de la charge de pilotes en voie descendante en utilisant l’allocation de pilotes en voie descendante reposant sur notre méthode proposée comparativement aux méthodes conventionnelles susmentionnésIn Cell-Free massive Multiple-Input-Multiple-Output (Cell-Free massive MIMO) systems, we distribute in a coverage area a massive number of access points, mastered by central processing units (CPUs), to simultaneously serve much smaller number of user equipments (UEs) over the same time/frequency resources. In contrast to the centralized massive MIMO, cell-free massive MIMO is characterized by a channel hardening not sufficiently accentuated, thus, it will be appropriate to include downlink (DL) pilots to estimate the DL channel. This thesis considers a DL pilot assignment for the cell-free massive MIMO systems by defining a metric, involving the inter-user interference (IUI). This metric gives insights about DL pilot contamination. A threshold is then defined to optimize the number of DL pilots, which maximizes the minimum per-user DL throughput. This approach gives a conflict graph, where each UE is regarded as a vertex of the graph. It consists in a combinatorial optimization problem that can be approximated using a graph coloring algorithm. It is a greedy algorithm whose steps are described as follows. By fixing the adequate threshold, maximizing the minimum per-user DL throughput, a conflict or interference graph is constructed. It models the potential interference among interfering UEs, the UEs between which there is an edge are in conflict, i.e., present a high IUI. Then, the proposed scheme mitigates the potential IUI by appointing different DL pilots to connected UEs with high IUI and same DL pilots to UEs with low IUI in the conflict graph in accordance with some coloring rules. The simulation results validate that the minimum per-user DL throughput based on the proposed approach outperforms the conventional methods, i.e., statistical channel state information, the orthogonal and the random pilot assignment in the DL training. Our analysis underlines also the reduction of the DL pilot overhead ratio using the DL pilot assignment based on our proposed scheme, compared to the conventional methods aforementioned
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Bircan, Anil. "Resource allocation for CDMA downlink to achieve maximum throughput." Thesis, 2001. http://library1.njit.edu/etd/fromwebvoyage.cfm?id=njit-etd2001-045.
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Lee, Ting-Wei, and 李亭葦. "Throughput Optimization in LoRa by Proper Transmission Parameter Allocation." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/zc27kk.
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碩士國立臺灣科技大學
資訊工程系
107
As the Internet of things (IoT) is gradually realized, the focus on IoT lies in the design of low-power wide-area networks (LPWANs) nowadays. LPWAN arises for power saving and long-range data transmission in IoT. It enables the long-range communication at a low bitrate. Despite the technology of LoRa is developed maturely, how to allocate radio resources efficiently among many end devices in the wide area is still an open issue. Target at this goal, this paper will propose an algorithm for LoRa to better system performance. First, end devices are clustered. Then, the fact that a different transmission ratio causes a different bitrate serves as the principle of allocation. By using this fact and the results of clustering, the system performance is optimized. Via simulations, we successfully show that our proposed algorithm outperforms the closely related algorithms in the literature in terms of the data extraction rate and throughput when more end devices are involved.
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Ho, Yi-Lun, and 何宜倫. "A Thermal-Driven Task Allocation for 3D MCP Throughput Optimization." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/70423367915036175273.
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碩士國立清華大學
資訊工程學系
98
Three-dimensional integrated circuits (3D ICs) have become an emerging technology because of advantages of higher packaging density and more flexible in heterogeneous integration. However, due to the heat dissipation problem in 3D ICs, thermal issues must be considered when maximizing the throughput of 3D Multi-Core Processors (MCPs). Furthermore, since the thermal behavior of a core in 3D MCPs strongly depends on its location, a proper task allocation can reduce potential thermal problems and improve the throughput. In this thesis, to enable the possibility of on-line scheduling, we present a very high performance task allocation algorithm to solve the problem of throughput optimization under thermal constraints for 3D MCPs. The experimental results show our fast algorithm can finish in less than 1ms for 128 cores. Compared to solutions obtained from LINGO, our algorithm only has 0.85% throughput loss on average.
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Chang, Ching-Hsu, and 張景旭. "Resource Allocation with Sum Throughput Improvement for LTE Uplink Transmission." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/16693203077150046648.
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碩士國立交通大學
網路工程研究所
99
Long Term Evolution (LTE), one of most promising technology for 4G mobile networks, is the latest standard of 3rd Generation Partnership Project (3GPP). The goal of LTE is to provide high data rate transmission, flexible frequency usage, smaller latency, and supportable transmission in high mobility. To achieve this, LTE employs the modulation technique by OFDMA in downlink and SC-FDMA in uplink, breaking the technical limitations of traditional wireless, and makes itself be the one of members of 4G mobile networks. To increase the cell throughput and multi-user diversity gain, channel dependent scheduling (CDS) is implemented for the OFDMA-based multi-user scenario to allocate resource blocks (RBs) to users experiencing better channel conditions. Nevertheless, CDS may not perform well in SC-FDMA due to its two inherent constraints－one is contiguous RB assignment and the other is robust modulation and coding mode. In this paper, the formulation of resource allocation for a SC-FDMA system upon considering two inherent constraints is proposed. Since the optimization problem of resource allocation in SC-FDMA is NP-hard, we further propose two heuristic algorithms to find feasible solutions. We evaluate the proposed formulation and heuristic algorithms by conducting simulation. The simulation results show that our methods achieve significant performance improvement in not only system sum throughput, but also transmission delay and outage ratio.
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Huang, Meitian. "Efficient Resource Allocation for Throughput Maximization in Next-Generation Networks." Phd thesis, 2021. http://hdl.handle.net/1885/219207.
Full textAbstract:
Software-Defined Networking (SDN) and Network Function Virtualization (NFV) have emerged as the foundation of the next-generation network architecture by introducing great flexibility and network automation capabilities, including automatic response to faults and load changes and programmatic provision of network resources and connections. It has been envisioned that the SDN- and NFV-based next-generation network architecture will play a critical role in providing network services to users, where the desired network services, including data transfer and policy enforcement, are fulfilled by allocating network resources using virtualization technologies. However, the disparity between ever-growing user demands and scarce network resources makes resource allocation exceptionally central to the performance of a network service, because only by effectively allocating these scarce resources can a network service provider satisfy users and maximize the gain from running the service.
In this thesis, we study efficient resource allocation for network throughput maximization in next-generation networks, while meeting user resource demands and Quality of Service (QoS) requirements, subject to network resource capacities. This however poses great challenges, namely, (1) how to maximize network throughput, considering that both SDN-enabled switches and links are capacitated, (2) how to maximize the network throughput while taking into account network function and QoS requirements of users, (3) how to dynamically scale and readjust resource allocation for user requests, and (4) how to provision a network service that can satisfy user reliability requirements.
To address these challenges, we provide a thorough study of network throughput maximization problems in the context of the next-generation network architecture, by formulating the problems as optimizations problems and developing novel optimization frameworks and algorithms for the problems. Specifically, this thesis makes the following contributions.
Firstly, we consider dynamic user request admissions where user requests arrive one by one and the knowledge of future request arrivals is not given as a priori. We develop a novel cost model that accurately captures the usage costs of network resources and propose online algorithms with provable performance guarantees.
Secondly, we study the problem of realizing user requests with network function requirements, with the objective of maximizing network throughput, while meeting user QoS requirements, subject to resource capacity constraints. For this problem, we develop two algorithms that strive for the trade-off between the accuracy/quality of a solution and the running time of obtaining the solution.
Thirdly, we investigate maximization of network throughput by dynamically scaling network resources while minimizing the overall operational cost of a network. We propose a unified framework for two types of resource scaling {--} vertical scaling and horizontal scaling. Through non-trivial reductions of the problem of concern into several classic problems, we propose an algorithm that has been empirically demonstrated to deliver near-optimal solutions.
Fourthly, we deal with the problem of reliability-aware provisioning of network resources for users, with the aim of maximizing network throughput. We devise an approximation algorithm with a logarithmic approximation ratio for the general case of this problem. We also develop constant-factor approximation and exact algorithm for two special cases of the problem, respectively. The formulated problem is a generalization of several classic optimization problems.
Finally, in addition to extensive theoretical analyses, we also evaluate the performance of proposed algorithms empirically through experimental simulations based on real and synthetic datasets. Experimental results show that the proposed algorithms significantly outperform existing algorithms.
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"Resource allocation and throughput analysis for multi-radio multi-channel networks." 2007. http://library.cuhk.edu.hk/record=b5893479.
Full textAbstract:
Xu, Ceng.Thesis (M.Phil.)--Chinese University of Hong Kong, 2007.
Includes bibliographical references (p. 68-71).
Abstracts in English and Chinese.
Abstract --- p.i
Acknowledgement --- p.iii
Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- Motivation --- p.3
Chapter 1.2 --- Contributions --- p.5
Chapter 1.3 --- Thesis Scope --- p.5
Chapter 2 --- Background Study --- p.6
Chapter 2.1 --- Wireless Mesh Networks --- p.6
Chapter 2.1.1 --- Overview of Wireless Mesh Networks --- p.6
Chapter 2.1.2 --- Challenges of Wireless Mesh Networks --- p.9
Chapter 2.1.3 --- Capacity Analysis of Wireless Mesh Net- works --- p.11
Chapter 2.2 --- Network Coding --- p.13
Chapter 2.2.1 --- Overview of Network Coding --- p.13
Chapter 2.2.2 --- Network Coding in Wireless Networks --- p.17
Chapter 3 --- Throughput Analysis --- p.19
Chapter 3.1 --- Introduction --- p.19
Chapter 3.2 --- Preliminaries --- p.20
Chapter 3.3 --- Proof of Theorem 3.2.1 when n = m --- p.23
Chapter 3.4 --- Proof of Theorem 3.2.1 when n≠ m --- p.36
Chapter 3.4.1 --- Proof of Theorem 3.2.1 when m
Chapter 3.5 --- Applying network coding into multi-radio multichannel networks --- p.37
Chapter 3.6 --- Some simulation results --- p.40
Chapter 3.6.1 --- String Topology --- p.40
Chapter 3.6.2 --- Grid Topology --- p.41
Chapter 3.6.3 --- Random Topology --- p.42
Chapter 4 --- Interface Reduction in Wireless Mesh Networks --- p.43
Chapter 4.1 --- Introduction --- p.43
Chapter 4.2 --- Preliminaries --- p.44
Chapter 4.2.1 --- Assumptions and Objectives of the Algorithm --- p.44
Chapter 4.2.2 --- Definitions --- p.45
Chapter 4.3 --- Steps of the Algorithm and an Example --- p.49
Chapter 4.4 --- Simulation Results and Discussions --- p.53
Chapter 4.5 --- Generalization --- p.54
Chapter 5 --- Conclusion --- p.66
Bibliography --- p.68
19
Jhang, Jia-Hong, and 張珈弘. "The throughput-based sub-carrier allocation for multi-user OFDM system." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/27440630320526361929.
Full textAbstract:
碩士國立東華大學
電機工程學系
96
In recent years, Orthogonal Frequency Division Multiple Access (OFDMA) becomes one of the high speed data rate wireless communication systems, and is a multi-user technique derived from Orthogonal Frequency Division Multiplexing (OFDM). By different channel responses due to the propagation paths for every user, each user uses the proper modulation and allocation on sub-carriers to get higher transmission rate. Sub-carrier allocation and adaptive modulation techniques are subject to multi-user diversity and feedback channel state information. In this thesis, we propose a throughput-based sub-carrier allocation, and compare three referred algorithms with the proposed method to those without the proposed method, in different channel states. We propose two algorithms to compare with those algorithms, and the simulation results express that the proposed method achieves the better performance than that of the referred algorithms with the maximum data rate.
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Kuo, Kuo-Shiang, and 郭國祥. "The double-criterion throughput-based sub-carrier allocation for multi-user OFDM system." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/64668287524553292246.
Full textAbstract:
碩士國立東華大學
電機工程學系
97
In recent years, Orthogonal Frequency Division Multiplexing (OFDM) technology has been widely used in many wireless communication systems, including LTE and WiMAX. Bandwidth is always precious over wireless channel, so it is important to have an effective bandwidth arrangement. On a multi-user system, each user needs to share entire bandwidth with others. In order to enhance the transmission rate, how to perform a proper arrangement on wireless channel becomes essential. In this thesis, we propose a method which utilizes the estimated Channel State Information (CSI) to achieve this goal. We allocate sub-carrier to each user by double criteria with throughput-based sub-carrier allocation, and use adaptive modulation to maximize data rate. The simulation results express that the proposed method achieves better performance than that of the referred algorithms with the single criterion.
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Dai, Chang-Yong, and 戴昌滽. "An Efficient Burst Allocation Algorithm to Enhance Downlink Throughput in IEEE 802.16e Networks." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/31746828244291319801.
Full textAbstract:
碩士國立雲林科技大學
電機工程系碩士班
101
An orthogonal frequency division multiple access (OFDMA) frame of IEEE 802.16e network can be described as a two-dimensional matrix. The burst allocation problem of the IEEE 802.16e network is to explore how to allocate a burst in rectangular shape in an OFDMA frame efficiently. In this thesis, if different subchannels may adopt different modulation coding schemes (MCSs) and the MCS that a burst adopts must be the lowest MCS of all subchannels that the burst allocates, we call such a burst allocation problem the burst allocation problem of different MCSs. When the height of a rectangle becomes lower, the probability of it meeting up with lower MCS gets lower. Therefore, the rectangle height that every burst forms should be as low as possible. In addition, a burst will associate different throughputs when it is allocated in different positions of a frame, so each burst should be allocated on the positions that can generate higher throughputs. Based on these two ideas, we propose a high-performance algorithm for the burst allocation problem of different MCSs in this thesis. Through our algorithm, it is more efficient for a downlink subframe to deliver bursts to every user. In other words, our algorithm may enhance downlink throughput. In fact, computer simulation results show that compared with other existing algorithms for the burst allocation problem of different MCSs, our algorithm may generate higher total throughput.
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Xia, Qiufen. "Cost-Effective Resource Allocation and Throughput Maximization in Mobile Cloudlets and Distributed Clouds." Phd thesis, 2017. http://hdl.handle.net/1885/117056.
Full textAbstract:
With the advance in communication networks and the use explosion of mobile devices, distributed clouds consisting of many small and medium datacenters in geographical locations and cloudlets defined as "mini" datacenters are envisioned as the next-generation cloud computing platform. In particular, distributed clouds enable disaster-resilient and scalable services by scaling the services into multiple datacenters, while cloudlets allow pervasive and continuous services with low access delay by further enabling mobile users to access the services within their proximity. To realize the promises provided by distributed clouds and mobile cloudlets, it is urgently to optimize various system performance of distributed clouds and cloudlets, such as system throughput and operational cost by developing efficient solutions. In this thesis, we aim to devise novel solutions to maximize the system throughput of mobile cloudlets, and minimize the operational costs of distributed clouds, while meeting the resource capacity constraints and users' resource demands. This however poses great challenges, that is, (1) how to maximize the system throughput of a mobile cloudlet, considering that a mobile cloudlet has limited resources to serve energy-constrained mobile devices, (2) how to efficiently and effectively manage and evaluate big data in distributed clouds, and (3) how to efficiently allocate the resources of a distributed cloud to meet the resource demands of various users. Existing studies mainly focused on implementing systems and lacked systematic optimization methods to optimize the performance of distributed clouds and mobile cloudlets. Novel techniques and approaches for performance optimization of distributed clouds and mobile cloudlets are desperately needed.
To address these challenges, this thesis makes the following contributions. We firstly study online request admissions in a cloudlet with the aim of maximizing the system throughput, assuming that future user requests are not known in advance. We propose a novel admission cost model to accurately model dynamic resource consumption, and devise efficient algorithms for online request admissions. We secondly study a novel collaboration- and fairness-aware big data management problem in a distributed cloud to maximize the system throughput, while minimizing the operational cost of service providers, subject to resource capacities and users' fairness constraints, for which, we propose a novel optimization framework and devise a fast yet scalable approximation algorithm with an approximation ratio. We thirdly investigate online query evaluation for big data analysis in a distributed cloud to maximize the query acceptance ratio, while minimizing the query evaluation cost. For this problem, we propose a novel metric to model the costs of different resource consumptions in datacenters, and devise efficient online algorithms under both unsplittable and splittable source data assumptions. We fourthly address the problem of community-aware data placement of online social networks into a distributed cloud, with the aim of minimizing the operational cost of the cloud service provider, and devise a fast yet scalable algorithm for the problem, by leveraging the close community concept that considers both user read rates and update rates. We also deal with social network evolutions, by developing a dynamic evaluation algorithm for the problem. We finally evaluate the performance of all proposed algorithms in this thesis through experimental simulations, using real and/or synthetic datasets. Simulation results show that the proposed algorithms significantly outperform existing algorithms.
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(7026389), Seth A. Tolley. "Biomass Allocation Variation Under Different Nitrogen and Water Treatments in Wheat." Thesis, 2019.
Find full textAbstract:
Wheat is among the most important cereal crops in the world today with respect to the area harvested (219 million ha), production (772 million tonnes), and productivity (3.53 tons/ha). However, global wheat production goals for the coming decades are falling short of needed increases. Among the leading factors hindering yields is abiotic stress which is present in nearly 38% of wheat acres globally. Nevertheless, many standard wheat breeding programs focus on yield and yield related traits (i.e. grain yield, plant height, and test weight) in ideal environments rather than evaluating traits that could lead to enhanced abiotic stress tolerance. In this thesis, we explore the use of root and high-throughput phenotyping strategies to aid in further development of abiotic stress tolerant varieties.
In the first three experiments, root phenotypes were evaluated in two nitrogen (N) treatments. Over a series of seedling, adult, and multiple-growth-stage destructive plant biomass measurements, above-ground and below-ground traits were analyzed in seven geographically diverse wheat accessions. Root and shoot biomass allocation in fourteen-day-old seedlings were analyzed using paper-roll-supported hydroponic culture in two Hoagland solutions containing 0.5 (low) and 4.0 (high) mM of N. Root traits were digitized using a WINRhizo platform. For biomass analysis at maturity, plants were grown in 7.5-liter pots filled with soil mix using the same concentrations of N. Traits were measured as plants reached maturity. In the third N experiment, above- and below-ground traits were measured at four-leaf stage, stem elongation, heading, post-anthesis, and maturity. At maturity, there was a ~15-fold difference between lines with the largest and smallest root dry matter. However, only ~5-fold difference was observed between genotypes for above-ground biomass. In the third experiment, root growth did not significantly change from stem elongation to maturity.
In the final experiment, two of these lines were selected for further evaluation under well-watered and drought treatments. This experiment was implemented in a completely randomized design in the Controlled Environment Phenotyping Facility (CEPF) at Purdue University. The differential water treatments were imposed at stem elongation and continued until post-anthesis, when all plants were destructively phenotyped. Image-based height and side-projected area were associated with height and shoot dry matter with correlations of r=1 and r=0.98, respectively. Additionally, 81% of the variation in tiller number was explained using convex hull and side-projected area. Image-based phenotypes were used to model crop growth temporally, through which one of the lines was identified as being relatively more drought tolerant. Finally, the use of the Munsell Color System was explored to investigate drought response.
These experiments illustrate the value of phenotyping and the use of novel phenotyping strategies in wheat breeding to increase adaptation and development of lines with enhanced abiotic tolerance.
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Wang, Chao-hung, and 王朝宏. "Using Channel Allocation Mechanism and Collision Avoidance Method to Improve the Throughput of WiMax." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/30523468006634917226.
Full textAbstract:
碩士朝陽科技大學
資訊管理系碩士班
97
In recent year, the rapid growth of wireless communication technology improves the transmission data rate and communication distance. Although the transmission rate of wireless network still cannot catch up with the cable one, there are still increasingly applications on wireless network due to its features of mobility and low setup cost. WiMax is the one of new broadband wireless technologies. It can solve the last mile problem of the metropolitan network because of the features of high bandwidth and long distance.Owing to the features of WiMax, it can be extensively applied to various related fields. However, if large amount of users use these applications, it may occur transmission collision and broadcast storm. The most important factor to cause this problem is the competition of communication bandwidth by different service requests.In this research, two methods are proposed which are channel allocation mechanism and interference aware method to solve the problem. The interference aware method will assist to channel allocation mechanism enhances the utilization of resource and shortens the time of transmission.
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Karim, Shafiqul. "Throughput Management for CSMA/CA Networks : IEEE 802.11e Wireless LAN." Thesis, 2012. http://hdl.handle.net/2440/80596.
Full textAbstract:
This thesis investigates the design and development considerations to introduce through- put differentiation and management capabilities into the Medium Access Control (MAC) layer of IEEE 802.11 Wireless Local Area Network (WLAN) systems, while also maximizing overall throughput performance. The final control mechanism highlighted in this thesis requires only an initial user configuration to specify the required throughput differentiation and management rules prior to it operating in a fully autonomous manner. In order to maximize throughput performance the control mechanism is designed to seamlessly adjust the throughput differentiation and management rules to reflect the current network traffic load. Throughout this thesis, we discovered and identified the great difficultly that is inherent in trying to create a control mechanism that is capable of operating autonomously in a broad range of possible traffic load conditions. The difficulties faced stemmed primarily from the design philosophy of a fully self-contained control mechanism within the MAC layer of the AP alone, and employing a completely passive/non-intrusive decision making procedure. Furthermore the idiosyncrasies of TCP-based traffic required special attention which could have otherwise been avoided if cross layer interaction was permitted. The IEEE 802.11e MAC layer standard [1] is chosen to be the foundation for providing throughput management capabilities in a WLAN. In particular, the throughput management capability is provided using the IEEE 802.11e Enhanced Distributed Channel Access (EDCA). The EDCA mechanism supports service differentiation across 4 different Access Categories (AC). Each AC has specific tunable parameters associated to it, which affects the level of probabilistic medium access it obtains against other ACs. The implementation and control objective of tuning parameters within EDCA are left open in the IEEE 802.11e standard [1]. We describe the process of selecting appropriate settings for the tunable parameters associated with each AC such that a specified throughput proportion allocation can be achieved between each AC. The selection process is aided by an analytical model of IEEE 802.11e EDCA under saturation load conditions [2]. The model allows us to identify, when under saturation load conditions, the parameter combinations that achieves a required throughput proportion allocation amongst ACs and at the same time maximizes overall throughput performance. Based on this information, we define Control Scheme-1 that resides within the access point (AP) and, as required, notifies all stations in the WLAN what required parameters should be associated with each AC. Through this process, regardless of dynamically changing active station counts transmitting a particular AC traffic, we demonstrate the control scheme's ability to maintain a required throughput proportion allocation regime between ACs. We then proceed to specify throughput proportion allocations between Downlink (DL) and Uplink (UL) paths in a WLAN under saturation load. EDCA allows for differentiating the AP and wireless client stations through the use of independent tunable parameters specifically associated to the AP. We make use of this feature directly by describing an updated parameter selection process. Therefore based on the new selection of parameters, we describe the new Control Scheme-2 and demonstrate its ability to manage the WLAN. We then investigate a new objective of developing a control that can also operate in non-saturation load conditions. In doing this, we still aim to maintain, wherever possible, the requirements of managing the throughput proportion allocation between the DL and UL and its respective ACs, and all the while focussing on maximizing throughput performance. In order to achieve this goal, we divided the modification of Control Scheme-2 into two parts. The first being modifications required to handle non-saturation load conditions in DL and subsequently modifications required to handle non-saturation load conditions in UL. With both DL and UL modifications in place we verify that the completed control mechanism Control Scheme-3 is able to achieve the required performance results across a wide range of test case scenarios. In addition, we compare these performance results to that obtained when employing the standard reference implementation of IEEE 802.11e EDCA [1].Thesis (Ph.D.) -- University of Adelaide, School of Electrical and Electronic Engineering, 2012
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Ho, Danh Huu. "Power allocation and cell association in cellular networks." Thesis, 2019. http://hdl.handle.net/1828/11065.
Full textAbstract:
In this dissertation, power allocation approaches considering path loss, shadowing,
and Rayleigh and Nakagami-m fading are proposed. The goal is to improve power
consumption, and energy and throughput efficiency based on user target signal to interference plus noise ratio (SINR) requirements and an outage probability threshold.
First, using the moment generating function (MGF), the exact outage probability
over Rayleigh and Nakagami-m fading channels is derived. Then upper and lower
bounds on the outage probability are derived using the Weierstrass, Bernoulli and
exponential inequalities. Second, the problem of minimizing the user power subject
to outage probability and user target SINR constraints is considered. The corresponding power allocation problems are solved using Perron-Frobenius theory and
geometric programming (GP). A GP problem can be transformed into a nonlinear
convex optimization problem using variable substitution and then solved globally and
efficiently by interior point methods. Then, power allocation problems for throughput
maximization and energy efficiency are proposed. As these problems are in a convex
fractional programming form, parametric transformation is used to convert the original problems into subtractive optimization problems which can be solved iteratively.
Simulation results are presented which show that the proposed approaches are better
than existing schemes in terms of power consumption, throughput, energy efficiency
and outage probability.
Prioritized cell association and power allocation (CAPA) to solve the load balancing issue in heterogeneous networks (HetNets) is also considered in this dissertation.
A Hetnet is a group of macrocell base stations (MBSs) underlaid by a diverse set
of small cell base stations (SBSs) such as microcells, picocells and femtocells. These
networks are considered to be a good solution to enhance network capacity, improve
network coverage, and reduce power consumption. However, HetNets are limited
by the disparity of power levels in the different tiers. Conventional cell association
approaches cause MBS overloading, SBS underutilization, excessive user interference
and wasted resources. Satisfying priority user (PU) requirements while maximizing
the number of normal users (NUs) has not been considered in existing power allocation algorithms. Two stage CAPA optimization is proposed to address the prioritized
cell association and power allocation problem. The first stage is employed by PUs
and NUs and the second stage is employed by BSs. First, the product of the channel
access likelihood (CAL) and channel gain to interference plus noise ratio (GINR) is considered for PU cell association while network utility is considered for NU cell association. Here, CAL is defined as the reciprocal of the BS load. In CAL and GINR
cell association, PUs are associated with the BSs that provide the maximum product
of CAL and GINR. This implies that PUs connect to BSs with a low number of users
and good channel conditions. NUs are connected to BSs so that the network utility
is maximized, and this is achieved using an iterative algorithm. Second, prioritized
power allocation is used to reduce power consumption and satisfy as many NUs with
their target SINRs as possible while ensuring that PU requirements are satisfied.
Performance results are presented which show that the proposed schemes provide fair
and efficient solutions which reduce power consumption and have faster convergence
than conventional CAPA schemes.Graduate
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Ho, Nan-Chin, and 何南瑾. "A New Power Allocation Scheme for D2D Communication with Enhanced Throughput in Massive MIMO Multicasting Networks." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/09526954463654676949.
Full textAbstract:
碩士國立臺北大學
資訊工程學系
103
Device-to-Device (D2D) communication has become more and more important for mobile wireless communication in recent years. D2D is an emerging technology intention to improve the performance of traditional wireless communication systems. D2D communication allows two user equipments to communicate directly without passing through the Base Station (BS). Existing results just only consider problem of interference management between D2D communication and cellular User Equipment (UEs). The management of interference when calculating the adjustment of D2D transmission power does not consider the interference to all the other D2D pairs in the same channel. The thesis applies to overcome the interference between D2D communicating devices. The main contribution of this work is to propose a new power allocation algorithm to investigate the dispose of D2D communication in a single base station network. The BS provides huge numbers of antennas, labeled as massive Multiple-Input-Multiple-Output (MIMO). The proposed scheme ensures that UE maintains some Quality of Sevice (QoS) constraints over the Signal to Interference plus Noise Ratio (SINR) threshold and maximizes the totally achievable data rate of the D2D pairs. Mathematical analysis and simulations results have shown that the new power allocation algorithm can reduce the interference between D2D pairs and UE, and improve the system throughput.
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Chang, Wen-Chieh, and 張紊傑. "Throughput-Oriented Power Allocation Policies for Parallel Gaussian Channels Under Finite-Length and Fixed-Rate Coding Constraints." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/15489412930609265328.
Full textAbstract:
碩士國立交通大學
電信工程研究所
99
The common criterion used in the power allocation problem for parallel memoryless Gaussian channels is to maximize overall mutual information (namely, to achieve the ca- pacity), resulting in the well-known water-filling policy. Such a capacity-achieving power allocation, although theoretically interesting and beneficial in conceptually elucidating the behavior of coding systems, does not match well with practical situations as capacity is an asymptotic rate requiring the codeword length to grow to infinity. In addition, the overall system capacity can only be achieved when the coding scheme of each channel is optimally and continuously adapted to the allotted power. However in a practical system, the adopted codes are by no means optimal in terms of achieving capacity and have only a finite number of rate choices. Furthermore, a common quantity of interest is the effective system through- put. In light of these observations, we study in this paper the problem of determining the power allocation strategy for a system of coded parallel Gaussian channels with the objective of maximizing effective throughput under finite-length and fixed-rate coding constraints. An approximating formula of the system’s effective throughput is proposed for the case of con- volutional codes and used to identify the optimal power allocation for each parallel channel. Our results show that the proposed power allocation policies can be graphically represented as a variation of the water-filling principle and achieves a near-optimal throughput.
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Chuang, Cheng-Ming, and 莊烝銘. "System throughput maximization with user allocation in the dual-band IEEE 802.11ac and IEEE 802.11ad wireless networks." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/tewwxq.
Full textAbstract:
碩士國立交通大學
網路工程研究所
107
In the existing APs, there are already existing APs supporting the dual-band architecture. In response to different needs of users, the AP can simultaneously support transmissions in the 5 GHz and 60 GHz bands. Therefore, in this paper, we analyze the dual-band network that IEEE 802.11ac has MU-MIMO (Multi-User Multiple-Input Multiple-Output) but no beamforming and IEEE 802.11ad has SU-SISO (Single-User Single-Input Single-Output) and beamforming. We will analyze it in two cases. In the first case, the queue to be transmitted by the user is saturated, we estimate the number of users through the derived IEEE 802.11ac and IEEE 802.11ad saturation throughput formulas to maximize the system throughput. In the second case, the queue to be transmitted by the user is unsaturated, the difference from the saturation case is that each user's packet arrival rate and the session duration are different, so the amount of data to be transmitted by each user is different. We estimate the amount of data and the number of users to be configured in IEEE 802.11ad and IEEE 802.11ac networks through the derived IEEE 802.11ac and IEEE 802.11ad unsaturated throughput formulas to maximize the system throughput.
30
Hoppe, Sandra. "High-Throughput Air-to-Ground Connectivity for Aircraft." 2020. https://tud.qucosa.de/id/qucosa%3A75165.
Full textAbstract:
Permanent connectivity to the Internet has become the defacto standard in the second decade of the 21st century. However, on-board aircraft connectivity is still limited. While the number of airlines offering in-flight connectivity increases, the current performance is insufficient to satisfy several hundreds of passengers simultaneously. There are several options to connect aircraft to the ground, i.e. direct air-to-ground, satellites and relaying via air-to-air links. However, each single solution is insufficient. The direct air-to-ground coverage is limited to the continent and coastal regions, while the satellite links are limited in the minimum size of the spot beams and air-to-air links need to be combined with a link to the ground. Moreover, even if a direct air-to-ground or satellite link is available, the peak throughput offered on each link is rarely achieved, as the capacity needs to be shared with other aircraft flying in the same coverage area. The main challenge in achieving a high throughput per aircraft lies in the throughput allocation. All aircraft should receive a fair share of the available throughput. More specifically, as an aircraft contains a network itself, a weighted share according to the aircraft size should be provided. To address this problem, an integrated air-to-ground network, which is able to provide a high throughput to aircraft, is proposed here. Therefore, this work introduces a weighted-fair throughput allocation scheme to provide such a desired allocation. While various aspects of aircraft connectivity are studied in literature, this work is the first to address an integrated air-to-ground network to provide high-throughput connectivity to aircraft.
This work models the problem of throughput allocation as a mixed integer linear program. Two throughput allocation schemes are proposed, a centralized optimal solution and a distributed heuristic solution. For the optimal solution, two different objectives are introduced, a max-min-based and a threshold-based objective. The optimal solution is utilized as a benchmark for the achievable throughput for small scenarios, while the heuristic solution offers a distributed approach and can process scenarios with a higher number of aircraft. Additionally, an option for weighted-fair throughput allocation is included. Hence, large aircraft obtain a larger share of the throughput than smaller ones. This leads to fair throughput allocation with respect to the size of the aircraft. To analyze the performance of throughput allocation in the air-to-ground network, this work introduces an air-to-ground network model. It models the network realistically, but independent from specific network implementations, such as 5G or WiFi. It is also adaptable to different scenarios. The aircraft network is studied based on captured flight traces. Extensive and representative parameter studies are conducted, including, among others, different link setups, geographic scenarios, aircraft capabilities, link distances and link capacities. The results show that the throughput can be distributed optimally during high-aircraft-density times using the optimal solution and close to optimal using the heuristic solution. The mean throughput during these times in the optimal reference scenario with low Earth orbit satellites is 20 Mbps via direct air-to-ground links and 4 Mbps via satellite links, which corresponds to 10.7% and 1.9% of the maximum link throughput, respectively. Nevertheless, during low-aircraft-density times, which are less challenging, the throughput can reach more than 200 Mbps. Therefore, the challenge is on providing a high throughput during high-aircraft-density times. In the larger central European scenario, using the heuristic scheme, a minimum of 22.9 Mbps, i.e. 3.2% of the maximum capacity, can be provided to all aircraft during high-aircraft-density times. Moreover, the critical parameters to obtain a high throughput are presented. For instance, this work shows that multi-hop air-to-air links are dispensable for aircraft within direct air-to-ground coverage. While the computation time of the optimal solution limits the number of aircraft in the scenario, larger scenarios can be studied using the heuristic scheme. The results using the weighted-fair throughput allocation show that the introduction of weights enables a user-fair throughput allocation instead of an aircraft-fair throughput allocation. As a conclusion, using the air-to-ground model and the two introduced throughput allocation schemes, the achievable weighted-fair throughput per aircraft and the respective link choices can be quantified.
31
Tien, Fengyu, and 田豐瑜. "Improving the Throughput Performance by Adaptive Power Allocation to Femto BS Channels in Next-Generation Hybrid Macrocell/Femtocell Networks." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/36270299636880398958.
Full textAbstract:
碩士國立中正大學
通訊工程研究所
99
Due to the increase of smart mobile phone users and more and more multimedia streaming and new Internet services, the 3rd-generation mobile communication system is running out of gas, which triggers the development of the higher-speed 4th -generation (4G) mobile communication system . The International Tele- communication Union (ITU) is actively working on finalizing the technical standards for 4G. The standards require 4th-generation service to support data rate at 100 Mbit/s for high mobility communication and 1 Gbit/s for stationary communication. WiMAX (802.16m) and LTE Advanced are two 4G standards that are being developed now. In them,the femto base stations are defined as small low-power cellular base stations, deployed by the user at home, without complicated configuration and using DSL or cable modem of different telecommunications operators to connect to the Internet. The 4G system improves signal coverage and dead area problem of indoor users by provisioning a large number of femto base stations. It also improves the total system throughput. In the thesis, we consider some drawbacks of average power allocation to femto BS channels in the fourth-generation system, and then utilize the multi-carrier characteristic of the orthogonal frequency-division multiple access (OFDMA) to improve the throughput performance by adaptive power allocation to femto BS channels in next-generation hybrid macrocell/femtocell networks. We will compare the performances of average power allocation and adaptive power allocation in different channel assignment and femtocell density settings. Keyword: fourth-generation, femto base stations, adaptive power allocation
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Fang, Ching-Hong, and 方清宏. "An Efficient Strategy of Improving Throughput with Multiple Data Channels over Optimal Data and Control Bandwidth Allocation for Ad Hoc Networks." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/gew5fe.
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碩士朝陽科技大學
資訊工程系碩士班
93
In the Ad Hoc Wireless Networks, when the MAC Layer is a single channel, it is subject to collision in case of network transmission load saturation, which might further lead to Hidden/Exposed Terminal problem to influence the channel transmission throughput. Most people take the multiple channels as the solution without an appropriate bandwidth allocation for the control channel and the data channel, resulting in the overload of control messages to disable the improvement of the throughput. We proposes the optimal bandwidth allocation strategy for the data channel and the control channel by means of the multiple channels, and makes a profound research on the relationship between the division and the latency time based on the bandwidth proportion between the data channel and the control channel. Firstly, it adopts the multiple channel technology to divide the channel into the control channel and the data channel to solve the problem on single channel. Secondly, it takes an analysis of the ideal proportion of channel bandwidth for the data channel and control channel to enable the optimal transmission throughput and thus to solve the control message overload problem. Furthermore, based on this optimal bandwidth proportion, considering the data transmission latency time, it adopts the asymmetrical bandwidth allocation to subdivide the data bandwidth, so as to decrease the collision. After that, based on IEEE 802.11 (DCF) , it readjusts the number of data channels properly to enable a maximum availability of the data channel and minimum collision probability, so as to improve the total throughput, which also helps solve the Hidden/Exposed Terminal problem. According to the statistics from the emulation, the above-mentioned method can help to greatly increase the general throughput based on the proper division of the data channel.
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Li, Yi-Wei, and 李怡緯. "Joint Flow Control, Capacity Allocation and Routing Strategy to Achieve End-to-end Delay and Throughput Fairness in Wireless Mesh Networks." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/39875693085230980600.
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碩士國立臺灣大學
資訊管理學研究所
98
Wireless mesh networks provide connectivity to communities and act as a solution for last-mile broadband Internet access. By improvements of routers and gateways, service region expands much broader than before. Fairness, which is an important issue since Internet has been researched, is our objective subject to the capacity of equipments. The hop count from client to gateway influences the performance. A more hop count may experience lower quality of service (QoS) and even starvation. In this thesis, we focus on capacity allocation, flow control and routing to achieve end-to-end fairness. This end-to-end fairness problem is formulated as a mathematical programming model and then deal with by an optimization-based algorithm. In this thesis, two important performance metrics, end-to-end delay and throughput are discussed. Several decision variables need to be determined where a certain level of QoS requirements is satisfied. We purpose a two-phased heuristic to ensure end-to-end delay and throughput fairness. To solve this problem, the Lagrangean Relaxation method is introduced to decompose the primal problem into several subproblems and we also adopt the subgradient method to obtain a reasonable lower bound. Further, we show the efficiency and effectiveness of the purposed algorithm by computational experiments.
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Lin, Li-Yi, and 林岦毅. "A Near-Optimal Time Slot Allocation Algorithm for Wireless Communication Networks under Throughput and Delay Constraints for Multiple Classes of Traffic." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/49621848169299863093.
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碩士國立臺灣大學
資訊管理學研究所
95
Wireless communication networks provide convenience, however, also challenges to multimedia services due to typically limited bandwidth and various QoS (Quality-of-Service) requirements. For a wireless communication network service provider/administrator, it is then essential to develop an effective resource allocation policy so as to fully satisfy possibly different QoS requirements by different classes of traffic, while in the meantime, for example, the overall long-term system revenue rate can be maximized. In this thesis, the problem of time slot allocation in wireless communication networks under throughput and delay constraints for multiple classes of traffic is considered. The basic approach to the algorithm development is a novel combination of MDP (Markovian Decision Process) and Lagrangean relaxation. The problem is first formulated as a standard linear-programming form of an MDP problem, however, with additional QoS constraints. Lagrangean relaxation is then applied to relax such QoS constraints. This Lagrangean relaxation problem, after proper regrouping of the terms involved in the objective function, becomes a standard MDP problem (with a new revenue matrix compared with the original problem) and can be solved by standard liner programming techniques or the policy enhancement algorithm. Another primal heuristic based upon the policy enhancement algorithm is also developed for comparison purposed. It is expected that efficient and effective algorithms be developed by the proposed approach.
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Lin, Li-Yi. "A Near-Optimal Time Slot Allocation Algorithm for Wireless Communication Networks under Throughput and Delay Constraints for Multiple Classes of Traffic." 2007. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2207200715295500.
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Wang, Chun-chieh, and 王俊傑. "Cooperative CoMP Adaptive QoS-based Scheduling and Min-Max Radio RB Allocation for Maximizing Reliability and Throughput in 4G LTE-A Networks." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/84194657153484091797.
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碩士國立雲林科技大學
資訊工程系碩士班
101
The Long Term Evolution-Advanced (LTE-A) specifications have been specified by 3GPP as the 4-th generation cellular communication. LTE-A proposes several key features, including increasing data rate by using 8x8 MIMO, improving signal quality for edge users, increasing service range while not increasing much deployment cost of eNBs, etc. Although the supreme mechanisms have been depicted in related studies, some critical issues need to be addressed efficiently: 1) requiring a cooperative cross-layer scheduling for intra- and inter-eNB, 2) requiring an efficient CoMP-based scheduling for inter-eNB and inter-eNB-Relays, 3) needing an efficient RB resource allocation, etc. Thus, this paper proposes the Cooperative CoMP adaptive QoS-based scheduling and the Min-Max radio resource block(RB) allocation for 4G LTE-A, namely CCMM. CCMM consists of three key phases: 1) Adaptive CoMP JT Initiation/Termination rules(ACJT), 2) Dynamic Division of RBs(DDRB), and 3) Hierarchical Scheduling with Min-Max RB allocation(HSMM). Numerical results demonstrate that the proposed CCMM approach outperforms the compared approaches in system capacity, network throughput, average packet delay and average dropping probability. Additionally, the computation complexity of CCMM is analyzed and it shows that CCMM needs (K‧C) or (K‧B)of running time, where K is number of UEs, C is number of traffic classes and B is number of RBs within a TTI.
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Bilan, Georges. "A comparative review of risk based portfolio allocations: An empirical study throughout rising yields." Master's thesis, 2016. http://hdl.handle.net/10362/16857.
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Since the financial crisis, risk based portfolio allocations have gained a great deal in popularity. This increase in popularity is primarily due to the fact that they make no assumptions as to the expected return of the assets in the portfolio. These portfolios implicitly put risk management at the heart of asset allocation and thus their recent appeal. This paper will serve as a comparison of four well-known risk based portfolio allocation methods; minimum variance, maximum diversification, inverse volatility and equally weighted risk contribution. Empirical backtests will be performed throughout rising interest rate periods from 1953 to 2015. Additionally, I will compare these portfolios to more simple allocation methods, such as equally weighted and a 60/40 asset-allocation mix. This paper will help to answer the question if these portfolios can survive in a rising interest rate environment.
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Φραίμης, Ιωάννης. "Τεχνικές βελτιστοποίησης της ποιότητας των παρεχομένων υπηρεσιών (QoS) με έλεγχο κρίσιμων ηλεκτρικών και ηλεκτρομαγνητικών παραμέτρων στα σύγχρονα ασύρματα τηλεπικοινωνιακά συστήματα." Thesis, 2012. http://hdl.handle.net/10889/5546.
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Στην παρούσα διδακτορική διατριβή προτείνονται τεχνικές για την βελτιστοποίηση της ποιότητας των παρεχομένων υπηρεσιών στους χρήστες σύγχρονων ασύρματων τηλεπικοινωνιακών συστημάτων που ως τεχνολογίες πρόσβασης έχουν την πολλαπλή πρόσβαση ορθογωνικής διαίρεσης συχνότητας και την πολλαπλή πρόσβαση διαίρεσης κώδικα. Οι τεχνικές που αναπτύχθηκαν αφορούν επαναληπτικούς αλγόριθμους κατανομής των διαθέσιμων ραδιοπόρων και εφαρμόζοναι κυρίως στην κατερχόμενη των ασύρματων συστημάτων. Ως παράμετροι της ποιότητας των παρεχόμενων υπηρεσιών θεωρούνται: το ελάχιστο απαιτούμενο επίπεδο ρυθμού μετάδοσης των δεδομέων, ο ρυθμός των λανθασμέων bit, και η ελάχιστη απαιτούμενη ποσότητα ραδιοπόρων σε κάθε χρήστη. Η αξιολόγηση των τεχνικών που προτείνονται γίνεται μέσω δεικτών της απόδοσής τους, οι οποίοι είναι: η πιθανότητα παραβίασης της ποιότητας της υπηρεσίας, ο δείκτης δικαιοσύνης του συστήματος, ο ρυθμός μετάδοσης δεδομένων στα άκρα της κυψέλης και η χωρητικότητα της κυψέλης. Για την εξαγωγή των δεικτών αυτών είναι απαραίτητα στατιστικά δεδομένα, τα οποία συλλέγονται μέσα από μεγάλο αριθμό προσομοιώσεων.This doctoral thesis proposes QoS optimization techniques in modern wireless telecommunication systems, whereby orthogonal frequency division multiple access and code division are used. The proposed techniques are iterative resource allocation algorithms which are mainly suitable for the downlink of wireless networks. The minimum required level of data rate, the bit error rate and the minimum number of resources per user are considered as quality of service parameters. The validation of the proposed techniques is done through the performance of performance metrics like the : the quality of service violation probability, the system fairness index, the cell-edge data rate and the cell capacity. Statistical data are required which are collected through extensive simulation