共查询到20条相似文献,搜索用时 337 毫秒
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线性令牌传递网络在严格实时条件下的带宽分配方法 总被引:3,自引:0,他引:3
本文对线性令牌传递网络(LTPB)的实时特性进行了研究,提出了与节点负载匹配的网络带宽分配方法,导出了在该方法下网络消息集严格实时的充要条件,导出并证明了即使在最坏情况下消息集严格实时的网络可达负载率不小于50%。 相似文献
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在集群系统中,负载均衡算法是影响系统性能的关键因素之一.为了进一步提高集群系统的性能,有必要对负载均衡算法进行优化.通过对最小连接算法和DFB(Dynamic Feed-Back)算法的详细分析,提出了一种改进的动态反馈负载均衡算法.该算法通过收集每台服务器的实时性能参数,动态地计算出各服务节点的分配概率,并由此决定用户请求分配给哪一个服务节点.通过对上述三种算法性能的测试,得出了该算法能够有效提高集群系统性能的结论. 相似文献
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一种混合WDM网络的实时传输策略 总被引:2,自引:2,他引:0
波分复用(Wavelength Division Multiplexing,WDM)网络应用于实时性网络环境的关键因素是实时传输策略。在混合式WDM网络结构中,研究了子网内的实时调度和子网间的路由策略。其中子网内为星形耦合式WDM网络,分析了区分丢弃-最早时限优先调度法(DDS-EATS)的不足,针对多消息多次调度的问题提出了改进方案。子网间网络采用洗牌型WDM波长路由网,消息路由采用轻载固定路由,重载流量疏导的方法。最后在OPNET仿真平台上,验证了该传输策略下消息的实时传输性能和多次消息调度中改进算法的网络延迟和网络利用率的网络性能。 相似文献
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In this paper, we present an approach to hardware-software partitioning for real-time embedded systems. Hardware and software components are modeled at the system level, so that cost and performance tradeoffs can be studied early in the design process and a large design space can be explored. Feasibility factor is introduced to measure the possibility of a real-time system being feasible, and is used as both a constraint and an attribute during the optimization process. An imprecise value function is employed to model the tradeoffs among multiple performance attributes. Optimal partitioning is achieved through the use of an existing computer-aided design tool. We demonstrate the application of our approach through the design of an example embedded system. 相似文献
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Jrg-Peter Elbers Christoph Glingener 《AEUE-International Journal of Electronics and Communications》2001,55(5):295-304
An efficient design methodology for high-capacity dense wavelength-division multiplexed systems is presented. In contrast to complex and time-consuming numerical simulations, analytical equations and heuristicapproximations are used to model the system performance. They facilitate first-order performance estimates and the identification of limiting effects even for multi-Tb/s systems within a few seconds.Taking into account local and accumulated group velocity dispersion, impairments due to fibre nonlinearities are described as a function of the average optical input power per channel. In combination with thedegradation of the optical signal-to-noise ratio caused by optical amplifier noise the maximum transmission distance versus optical input power can bedetermined.The validity of the models is verified by means of numerical simulations and system experiments. The dependence on data rate, modulation format, fibre type and dispersion compensation scheme is determined. Practical examples illustrate the usefulness of our design approach. 相似文献
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Gemmeke T. Gansen M. Stockmanns H.J. Noll T.G. 《Solid-State Circuits, IEEE Journal of》2004,39(7):1131-1139
In recent years, power dissipation along with silicon area has become the key figure in chip design. The increasing demands on system performance require high-performance digital signal processing (DSP) systems to include dedicated number-crunching units as individually optimized building blocks. The various design methodologies in use stress one of the following figures: power dissipation, throughput, or silicon area. This paper presents a design methodology reducing any combination of cost drivers subject to a specified throughput. As a basic principle, the underlying optimization regards the existing interactions within the design space of a building block. Crucial in such optimization is the proper dimensioning of device sizes in contrast to the common use of minimal dimensions in low-power implementations. Taking the design space of an FIR filter as an example, the different steps of the design process are highlighted resulting in a low-power high-throughput filter implementation. It is part of an industrial read-write channel chip for hard disks with a worst case throughput of 1.6 GSamples/s at 23 mW in a 0.13-/spl mu/m CMOS technology. This filter requires less silicon area than other state-of-the-art filter implementations, and it disrupts the average trend of power dissipation by a factor of 6. 相似文献
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针对现有利用阵列单通道系统对机动目标跟踪精度不高,实时性差等不足,提出了一种新的基于改进粒子滤波算法的阵列单通道机动目标波达方向(direction of arrival, DOA)跟踪方法。该方法首先在利用接收机轮流采样建立数学模型的基础上,建立跟踪模型。然后,利用粒子群优化算法对马尔科夫链蒙特卡罗(Markov Chain Monte Carlo, MCMC)粒子滤波算法的重采样环节进行优化处理,给出了一种交互MCMC粒子滤波算法,该算法克服了传统粒子滤波算法粒子退化及样本贫化的固有缺陷。最后利用该算法求解跟踪方程,实现了实时DOA估计。理论分析与仿真结果表明,本文方法可实现基于阵列单通道的DOA跟踪与波束形成一体化,且能够处理相干信号,与标准粒子滤波和子空间类算法相比,收敛速度快,跟踪精度高。 相似文献
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Qi Hao Boon-Hee Soong Gunawan E. Jin-Teong Ong Cheong-Boon Soh Zheng Li 《Selected Areas in Communications, IEEE Journal on》1997,15(7):1315-1326
This paper deals with the optimization of the design and radio network resource planning for cellular mobile communication systems. The key element to be considered for mobile network planning is cost. A hierarchical optimization planning method (HOP) is utilized since there are so many factors like system performance, terrain features, base station parameters, and cost factors which are involved in the large-scale system design. We present a three-level optimization approach for designing a cellular mobile system. It determines the cell number, cell site allocation, and the specific base station parameters in order to minimize the total system cost and to comply with the required system performance. The problem is formulated as a large combinatorial optimization model which can determine the optimal number of cells and select the best base stations' locations. The simulated annealing approach is developed to solve the hard combinatorial problem. Simulation results demonstrate the feasibility and effectiveness of the HOP approach for radio network planning 相似文献
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本文提出的多服务器轮询系统分析模型考虑了故障对系统性能的影响,特别适应于在任务级或传输子系统级评估分布式实时系统的响应特性,对容错分布式系统设计及系统重组策略的优化、选择具有指导意义。 相似文献