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针对OFMDA解码-转发中继系统的资源分配问题,提出了一种以系统总功率和用户间的数据速率比例公平为约束条件,以最大化系统总速率为目标的资源分配算法。该资源分配问题为非线性最优化问题,联合求解所有变量复杂度很高,通过次优化的方法降低计算复杂度。算法包括:子载波分配和功率分配。子载波分配是以功率平均分配为前提,对基站-中继站和中继站-用户链路的子载波按照信道条件进行配对,并根据比例公平约束将配对的子载波分配给相应的用户。功率分配是对每个用户利用Lagrange方法调整每个子载波的功率,进一步提高系统的数据速率。算法仿真分析表明,该算法既能同时满足多用户不同数据速率的要求,又能提高系统的数据速率。 相似文献
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基于比例公平的多用户MIMO-OFDM系统自适应资源分配算法* 总被引:2,自引:1,他引:1
针对传统多用户MIMO-OFDM系统中自适应资源分配算法计算复杂度较高、实时性不强、无法保证用户间公平性等问题,提出了一种低复杂度的自适应子载波、比特及功率分配算法。在子载波分配上,该算法能够在兼顾比例速率约束的前提下使系统发射功率达到最小化;在比特及功率分配上,该算法将非线性优化问题转换为线性优化问题,在保证系统性能的同时显著降低计算量。仿真结果表明,该算法具有良好的性能,能够有效降低计算量,并使系统容量在用户间分配得更加公平和合理。 相似文献
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资源分配是OFDMA系统中保证用户QoS和提高系统容量的一种重要手段.在传统的OFDMA资源分配算法中,分组调度和子载波分配两部分是独立进行优化的.为了进一步提高系统的整体性能,提出一种基于遗传算法的分组调度和子载波分配联合优化的资源分配算法.资源分配算法中,利用随机逼近的方法来更新调度算法中的控制参数,在保证用户公平性的前提下最大化系统吞吐量;利用遗传算法来求解联合优化中的子载波分配.仿真结果表明,无论是在系统的吞吐量、丢包率,数据包等待时延还是用户公平性方面,都具有良好的性能. 相似文献
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针对多用户OFDMA系统资源分配中已有算法对系统容量和公平性兼顾较差的情况,提出了一种满足比例公平性的系统容量最大化资源分配算法。首先选择合适的公平度门限范围,在子载波分配中,先将各个子载波分配给信道增益最大的用户,再在公平度门限约束下重新分配最大速率用户的信道增益最小的子载波,可以实现子载波利用率和公平度的折中。然后采用注水线法分配功率来调整用户间的比例公平性,最终找到使系统容量最大的公平度门限。仿真结果表明,该算法在保证了用户间比例公平性为1的同时提高了系统容量。 相似文献
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针对电力线通信自适应OFDM系统的限制条件,探讨在每OFDM符号内各RT用户要求的约束下,研究系统总功率地窖注水分配后多子载波上的速率自适应子载波分配模型,提出一种新的动态子载波组分配算法。在典型电力线信道环境下对其仿真,并与另外两种分配算法进行比较,结果表明,本文动态子载波组分配算法的复杂度大大减小,能满足多用户资源分配的多目标要求。 相似文献
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针对非正交多址接入(NOMA)系统的最优用户分组和功率分配方案的高复杂度问题,提出一种改进的用户分组和功率分配策略。首先,对用户进行分组,由信道增益值确定每个子信道的第一个用户,再由贪婪匹配方法分配剩余用户;然后,对用户的功率进行分配,将该功率分配问题分成子信道间和子信道内两部分,对于子信道间采用线性注水算法分配功率,对于子信道内则采用所提的迭代功率分配算法分配功率;最后,构造拉格朗日函数以实现在最大发射功率以及保证每个用户最低数据速率的约束下系统吞吐量的最大化。仿真结果表明,在多用户的情况下,与线性注水的分数阶功率分配(LWF-FTPA)算法和等分数阶功率分配(EQ-FTPA)算法相比,系统吞吐量分别提高了8%和20%,所提策略优于传统算法。 相似文献
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基于分布式网络资源的网络带宽分配方法 总被引:1,自引:0,他引:1
本文针对计算机网络资源的带宽分配问题提出一种分配求解方法,该方法根据用户提出的带宽资源需求和系统可用资源的状况,按用户满意度最佳和系统效率最佳的原则制订价格,并通过用户的价格参数进行带宽资源的协商与分配.分析表明,该方法可以达到优化系统效率和提高用户满意度的目标. 相似文献
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Oscar Ardaiz Pau Artigas Torsten Eymann Felix Freitag Leandro Navarro Michael Reinicke 《Applied Intelligence》2006,25(2):131-145
Efficient resource allocation in dynamic large-scale environments is one of the challenges of Grids. In centralized economic-based
allocation approaches, the user requests can be matched to the fastest, cheapest or most available resource. This approach,
however, shows limitations in scalability and in dynamic environments. In this paper, we explore a decentralized economic
approach for resource allocation in Grid markets based on the Catallaxy paradigm. Catallactic agents discover selling nodes
in the resource and service Grid markets, and negotiate with each other maximizing their utility by following a strategy.
By means of simulations, we evaluate the behavior of the approach, its resource allocation efficiency and its performance
with different demand loads in a number of Grid density and dynamic environments. Our results indicate that while the decentralized
economic approach based on Catallaxy applied to Grid markets shows similar efficiency to a centralized system, its decentralized
operation provides greater advantages: scalability to demand and offer, and robustness in dynamic environments. 相似文献
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We deal with a buffer allocation problem of assembly/disassembly (AD) systems with a finite buffer capacity. The problem is to determine capacities of individual buffers for a given total available capacity of buffers with the objective of maximizing throughput rate. We first present an algorithm (BA-G) in which a conventional gradient search is used for finding an initial solution and a two-optimization procedure is used for improving the initial solution. Since this algorithm may require an excessive computation time, especially when a procedure for performance evaluation employed in the algorithm takes a long computation time, a new algorithm (BA-P) is developed in which a sophisticated procedure is used for finding an initial solution. In this procedure, capacities of individual buffers are determined based on the efficiency of their upstream and downstream machines. Results of computational experiments show that the latter algorithm gives the same solutions as those obtained by the former algorithm in much shorter time. 相似文献
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本文提出了一种多载波系统中自适应功率和比特分配算法。该算法在低信噪比时基于最大化信道容量分配比特,基于最小化误码率分配功率;在高信噪比时采用Fischer算法进行比特功率分配。仿真结果表明,低信噪比时所提算法比Fisher算法性能好,高信噪比时和Fisher算法的性能一样好。因此,文中所提算法比Fisher算法更具有实际应用价值。仿真结果也表明了子载波数对系统性能的影响。 相似文献
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Wei Li Flávia C. Delicato Paulo F. Pires Young Choon Lee Albert Y. Zomaya Claudio Miceli Luci Pirmez 《Journal of Parallel and Distributed Computing》2014
Wireless Sensor Networks (WSNs) are useful for a wide range of applications, from different domains. Recently, new features and design trends have emerged in the WSN field, making those networks appealing not only to the scientific community but also to the industry. One such trend is the running different applications on heterogeneous sensor nodes deployed in multiple WSNs in order to better exploit the expensive physical network infrastructure. Another trend deals with the capability of accessing sensor generated data from the Web, fitting WSNs in novel paradigms of Internet of Things (IoT) and Web of Things (WoT). Using well-known and broadly accepted Web standards and protocols enables the interoperation of heterogeneous WSNs and the integration of their data with other Web resources, in order to provide the final user with value-added information and applications. Such emergent scenarios where multiple networks and applications interoperate to meet high level requirements of the user will pose several changes in the design and execution of WSN systems. One of these challenges regards the fact that applications will probably compete for the resources offered by the underlying sensor nodes through the Web. Thus, it is crucial to design mechanisms that effectively and dynamically coordinate the sharing of the available resources to optimize resource utilization while meeting application requirements. However, it is likely that Quality of Service (QoS) requirements of different applications cannot be simultaneously met, while efficiently sharing the scarce networks resources, thus bringing the need of managing an inherent tradeoff. In this paper, we argue that a middleware platform is required to manage heterogeneous WSNs and efficiently share their resources while satisfying user needs in the emergent scenarios of WoT. Such middleware should provide several services to control running application as well as to distribute and coordinate nodes in the execution of submitted sensing tasks in an energy-efficient and QoS-enabled way. As part of the middleware provided services we present the Resource Allocation in Heterogeneous WSNs (SACHSEN) algorithm. SACHSEN is a new resource allocation heuristic for systems composed of heterogeneous WSNs that effectively deals with the tradeoff between possibly conflicting QoS requirements and exploits heterogeneity of multiple WSNs. 相似文献
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网络环境下高校自动排课系统中教室安排算法的设计与分析 总被引:6,自引:0,他引:6
自动排课系统在高校教学管理中处于重要位置,也是一个难题。本文设计了一种高校自动排课系统中教室安排算法,对算法中四类不同的教室安排方式结果的合理性和效率进行了详细地比较和分析,设计并实现了高校教室安排与管理系统。 相似文献