130 research outputs found

    Social-sine cosine algorithm-based cross layer resource allocation in wireless network

    Get PDF
    Cross layer resource allocation in the wireless networks is approached traditionally either by communications networks or information theory. The major issue in networking is the allocation of limited resources from the users of network. In traditional layered network, the resource are allocated at medium access control (MAC) and the network layers uses the communication links in bit pipes for delivering the data at fixed rate with the occasional random errors. Hence, this paper presents the cross-layer resource allocation in wireless network based on the proposed social-sine cosine algorithm (SSCA). The proposed SSCA is designed by integrating social ski driver (SSD) and sine cosine algorithm (SCA). Also, for further refining the resource allocation scheme, the proposed SSCA uses the fitness based on energy and fairness in which max-min, hard-fairness, proportional fairness, mixed-bias and the maximum throughput is considered. Based on energy and fairness, the cross-layer optimization entity makes the decision on resource allocation to mitigate the sum rate of network. The performance of resource allocation based on proposed model is evaluated based on energy, throughput, and the fairness. The developed model achieves the maximal energy of 258213, maximal throughput of 3.703, and the maximal fairness of 0.868, respectively

    Review on Radio Resource Allocation Optimization in LTE/LTE-Advanced using Game Theory

    Get PDF
    Recently, there has been a growing trend toward ap-plying game theory (GT) to various engineering fields in order to solve optimization problems with different competing entities/con-tributors/players. Researches in the fourth generation (4G) wireless network field also exploited this advanced theory to overcome long term evolution (LTE) challenges such as resource allocation, which is one of the most important research topics. In fact, an efficient de-sign of resource allocation schemes is the key to higher performance. However, the standard does not specify the optimization approach to execute the radio resource management and therefore it was left open for studies. This paper presents a survey of the existing game theory based solution for 4G-LTE radio resource allocation problem and its optimization

    Adaptive Power Allocation and Control in Time-Varying Multi-Carrier MIMO Networks

    Full text link
    In this paper, we examine the fundamental trade-off between radiated power and achieved throughput in wireless multi-carrier, multiple-input and multiple-output (MIMO) systems that vary with time in an unpredictable fashion (e.g. due to changes in the wireless medium or the users' QoS requirements). Contrary to the static/stationary channel regime, there is no optimal power allocation profile to target (either static or in the mean), so the system's users must adapt to changes in the environment "on the fly", without being able to predict the system's evolution ahead of time. In this dynamic context, we formulate the users' power/throughput trade-off as an online optimization problem and we provide a matrix exponential learning algorithm that leads to no regret - i.e. the proposed transmit policy is asymptotically optimal in hindsight, irrespective of how the system evolves over time. Furthermore, we also examine the robustness of the proposed algorithm under imperfect channel state information (CSI) and we show that it retains its regret minimization properties under very mild conditions on the measurement noise statistics. As a result, users are able to track the evolution of their individually optimum transmit profiles remarkably well, even under rapidly changing network conditions and high uncertainty. Our theoretical analysis is validated by extensive numerical simulations corresponding to a realistic network deployment and providing further insights in the practical implementation aspects of the proposed algorithm.Comment: 25 pages, 4 figure

    Fairness adaptive resource allocation in OFDMA networks

    Get PDF
    Projecte realitzat en el marc d'un programa de mobilitat amb el Royal Institute of Technology (KTH)This thesis work reviews contributions regarding dynamic resource allocation problems in Orthogonal Frequency Division Multiplexing (OFDM) systems, where various system metrics can be improved by periodically reassigning sub-carriers and transmit power to terminals depending on their current channel state. The following three classical problems have been reviewed: a) the sum rate maximization problem, b) the max min rate problem, and c) the sum rate maximization with rate proportionalities. System capacity is maximized in (a), by providing optimal spectral efficiency, but also poor system fairness index. In (b) and (c), fairness is very high but the capacity and spectral efficiency have been limited due to the fair policy; so the system capacity versus fairness trade off has been highlighted. The novel contribution of this thesis work is the formulation of a new problem which includes a system fairness target constraint enabling operators the ability to adjust fairness level. Operators, according to their needs, can get the most of spectral efficiency while providing a certain level of fairness among users. Several novel results regarding the new problem of system capacity maximization with a system fairness target constraint and various comparisons of different sub-optimal fairness-adaptive algorithm families are presented in this work. From the simulation results, including metrics such as system capacity, user fairness, user satisfaction and computational demand, it was possible to conclude about the most efficient fairness-adaptive approach from the perspective of both the user and the operator

    Resource Allocation in Drone-Assisted Emergency Communication Systems

    Get PDF
    Due to low cost and high mobility, drones are considered important in emergency communications. In this thesis, we consider a unique drone assisted emergency communication system used in disaster scenarios, where the drone with limited power acts as a relay to improve the downlink sum rate through rational resource allocation. The wireless channel model between drones and ground users in emergency communications is different from conventional relay networks, while drones have their coverage area and data rate limits. Considering these specific characteristics, we formulate a joint power and subcarrier allocation problem to maximize data rate of users, which is limited by the transmit power budget per drone and the number of users on each subcarrier in emergency communications. However, resource allocation in a unique drone assisted emergency communication system is a nondeterministic polynomial time (NP)-hard problem requiring brute force search, which has prohibitive computational complexity. Instead, efficient algorithms that provide a good trade-off between system performance and implementation practicality are needed. The contributions of this thesis are proposing two different resource allocation schemes. Both schemes divide users into high-priority(HP) users and low-priority(LP) users and both guarantee minimum guaranteed rate for HP users. The first scheme is an adaptive algorithm with low complexity. In this scheme, a suboptimal solution is proposed by dividing users into two priority groups: HP users (rescuers) and LP users (affected people). This procedure achieves quasi-linear complexity in terms of the number of users. Finally, the data of the brute force search method and this method were collected through simulation experiments. The data shows that the data rate of the proposed scheme was very close to the optimal data rate when there was a lack of resources. The second scheme is an adaptive algorithm. In the proposed scheme, we formulate a joint power and subcarrier allocation problem to maximize data rate of users, which is limited by the transmit power budget per drone and the number of users on each subcarrier in emergency communications. Due to the intractability of the formulated problem, it is decomposed into two sub-problems: power allocation optimisation and subcarrier allocation optimization. Then a joint resource allocation algorithm is proposed. The simulation results show that the performance of the proposed method is close to that of the optimal solution but with much lower complexity

    Channel assembling and resource allocation in multichannel spectrum sharing wireless networks

    Get PDF
    Submitted in fulfilment of the academic requirements for the degree of Doctor of Philosophy (Ph.D.) in Engineering, in the School of Electrical and Information Engineering, Faculty of Engineering and the Built Environment, at the University of the Witwatersrand, Johannesburg, South Africa, 2017The continuous evolution of wireless communications technologies has increasingly imposed a burden on the use of radio spectrum. Due to the proliferation of new wireless networks applications and services, the radio spectrum is getting saturated and becoming a limited resource. To a large extent, spectrum scarcity may be a result of deficient spectrum allocation and management policies, rather than of the physical shortage of radio frequencies. The conventional static spectrum allocation has been found to be ineffective, leading to overcrowding and inefficient use. Cognitive radio (CR) has therefore emerged as an enabling technology that facilitates dynamic spectrum access (DSA), with a great potential to address the issue of spectrum scarcity and inefficient use. However, provisioning of reliable and robust communication with seamless operation in cognitive radio networks (CRNs) is a challenging task. The underlying challenges include development of non-intrusive dynamic resource allocation (DRA) and optimization techniques. The main focus of this thesis is development of adaptive channel assembling (ChA) and DRA schemes, with the aim to maximize performance of secondary user (SU) nodes in CRNs, without degrading performance of primary user (PU) nodes in a primary network (PN). The key objectives are therefore four-fold. Firstly, to optimize ChA and DRA schemes in overlay CRNs. Secondly, to develop analytical models for quantifying performance of ChA schemes over fading channels in overlay CRNs. Thirdly, to extend the overlay ChA schemes into hybrid overlay and underlay architectures, subject to power control and interference mitigation; and finally, to extend the adaptive ChA and DRA schemes for multiuser multichannel access CRNs. Performance analysis and evaluation of the developed ChA and DRA is presented, mainly through extensive simulations and analytical models. Further, the cross validation has been performed between simulations and analytical results to confirm the accuracy and preciseness of the novel analytical models developed in this thesis. In general, the presented results demonstrate improved performance of SU nodes in terms of capacity, collision probability, outage probability and forced termination probability when employing the adaptive ChA and DRA in CRNs.CK201

    Resource Allocation in Service Area based Networks

    Get PDF
    By applying joint transmission in the downlink and joint detection in the uplink, the novel service area architecture allows multiple mobile stations to be simultaneously active on the same OFDM subcarrier without causing interference to each other. Moreover, the proposed adaptive subcarrier and power allocation techniques are shown to be able to improve the spectral efficiency significantly in service area based networks. The significance of the frequency selectivity of wireless channels, the correlation among users’ spatial signatures and the presence of interferences to resource allocation is also assessed through simulations.Durch den Einsatz von Joint Detection in der Aufwärtsstrecke und Joint Transmission in der Abwärtsstrecke ermöglicht die neuartige Service Area Architektur es mehreren Mobilstationen in dem selben OFDM-Subträger gleichzeitig interferenzfrei aktiv zu sein. Darüber hinaus wrid gezeigt, dass die vorgeschlagenen adaptiven Subträger- und Leistungsallokationstechniken die spektrale Effizienz eines Service Area basierten Mobilfunksystems erheblich erhöhen können. Die Bedeutung der Frequnzselektivität der Funkkanäle, der Korrelation zwischen räumlichen Signaturen der Teinehmer und der Existenz der Interferenz für die adaptive Ressourcenallokation wird ebenfalls durch Computersimulationen bewertet

    DR9.3 Final report of the JRRM and ASM activities

    Get PDF
    Deliverable del projecte europeu NEWCOM++This deliverable provides the final report with the summary of the activities carried out in NEWCOM++ WPR9, with a particular focus on those obtained during the last year. They address on the one hand RRM and JRRM strategies in heterogeneous scenarios and, on the other hand, spectrum management and opportunistic spectrum access to achieve an efficient spectrum usage. Main outcomes of the workpackage as well as integration indicators are also summarised.Postprint (published version
    • …
    corecore