共查询到19条相似文献,搜索用时 187 毫秒
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对多用户MIMO-OFDM系统下行链路的资源分配问题进行了研究.依据实时(RT,real-time)和非实时(NRT,non real-time)业务的不同特点分别设计了QoE效用函数,并提出一种基于RT &NRT QoE效用函数的跨层资源分配算法.该算法利用所设计的效用函数计算用户分得资源所贡献的QoE增量,并根据由QoE增量确定的用户优先级完成时频资源块的分配,进而通过“拟注水”方式对功率分配进行优化.仿真结果表明,该算法相比已有算法在用户平均QoE、实时业务平均分组时延、非实时业务平均分组丢失率以及系统和吞吐量方面的性能均得到了明显改善. 相似文献
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目前已提出的HSDPA调度算法仅是基于用户的优先级进行数据分组的调度.文章考虑了3G系统的业务多样性,综合考虑用户的优先级和业务的级别,创新性地提出将两类分组调度算法,即基于业务类别的分组调度算法--加权公平排队算法,与基于用户优先级的调度算法--最短队列算法或者最长队列算法相结合后的调度算法.仿真的结果显示,提出的调度算法能满足不同业务要求的QoS.从吞吐量和延时来看,最短队列算法与加权公平排队算法结合方案优于最长队列算法与加权公平排队算法结合的方案. 相似文献
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对多业务MIMO-OFDMA/SDMA 系统下行链路跨层调度与动态资源分配问题进行了研究.首先,在满足各种约束条件的前提下,以最大化系统吞吐量为目标建立了相应的优化模型;然后,提出了一种基于业务类型和子空间距离的用户分组算法,该算法采用聚类分析的方法在每个子载波上对配置有多根接收天线的用户进行分组,从而降低了调度时所需搜索的用户空间的维数;接着,基于所提出的用户分组算法并结合不同业务的优先级提出了一种新的跨层调度和资源分配算法,该算法充分利用跨层信息为每个子载波调度相应的用户组,并为调度到的用户分配相应的系统资源,从而通过最大化每个子载波的吞吐量近似实现了系统整体吞吐量的最大化.仿真结果表明,与现有的方案相比,所提算法更好地满足了不同业务用户的QoS要求,并获得了更好的吞吐量性能. 相似文献
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符合3GPP多业务处理原则的子信道调度方案是影响E-UTRA系统性能的关键技术。为减少填充和提高多用户分集效应,提出了一种多业务两步比率公平调度算法。在不区分用户业务优先级的情况下,先采用实际缓存量替代传统比率公平算法中的传输速率来分配子信道;业务优先级高的未分配用户再按比率公平算法确认的优先权重从低到高来挤占业务优先级低的用户所分配的子信道,从而确保符合3GPP提出的服务完高优先级业务后再服务低优先级业务的多业务处理原则。仿真结果表明,该算法能在保证用户公平的基础上提高系统吞吐量。 相似文献
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(余翔马广浩郭垸汝朱嘉羲) 《广东通信技术》2014,(2):43-48
WiMAX(IEEE802.16)为每个节点提供实时业务和非实时业务,并对不同的业务提出了QoS保证服务。调度算法是WiMAX为分类业务提供QoS保证的重要技术。本文提出一种用于WiMAX系统PMP模式下的动态调整优先级的分层调度算法DAPQ,DAPQ算法由基站(BS)和用户站(SS)共同实现,为不同优先级的业务流动态分配带宽,可以为系统提供更好的公平性,并有效的减少时延。仿真结果表明,本文提出的算法在一定程度上降低了rtPS业务的时延和丢包率。 相似文献
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为了提高LTE实时业务调度的公平性,在M-LWDF资源调度算法的优先级判断机制中引入了平均传输速率和保证比特速率,将经济学中的效用思想和效用函数引入M-LWDF调度算法,提出了一种基于时延效用函数和速率效用函数的M-LWDF改进算法,更好地体现了调度算法的时延特性和速率特性。仿真结果表明基于时延和速率效用函数的M-LWDF调度算法具有更高的公平性,能够更好地满足对实时业务的调度要求。 相似文献
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In this paper, a novel scheduling scheme is proposed for multiple traffic classes to exploit multiuser diversity of the non-real-time (NRT) traffic. The proposed scheduling algorithm consists of two stages, i.e. at the first scheduling stage, the inter-traffic scheduler dynamically allocates the bandwidth resources to each traffic class by a periodic and triggered way with the objective of maximizing a room for NRT traffic while guaranteeing the quality of service (QoS) requirements of real-time (RT) traffics; at the second scheduling stage, the intra-traffic scheduler is used to schedule different users' packets within each traffic class simultaneously. The proposed algorithm not only enhances the system throughput but also satisfies the QoS requirements of RT traffic. Simulation results validate the effectiveness and good performance of the proposed scheme. 相似文献
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A novel cross layer scheduling algorithm is proposed for real-time (RT) traffic in multiuser downlink multiple-input multiple-output orthogonal frequency division multiple access (MIMO-OFDMA) wireless systems. The algorithm dynamically allocates resources in space, time and frequency domain based on channel state information (CSI), users' quality of service (QoS) requirements and queue state information (QSI). To provide higher data rate and spectrum efficiency, adaptive modulation and coding (AMC) is employed. The proposed algorithm can improve cell throughput and increase the number of users that can be supported while guaranteeing users' QoS requirements and fairness among all users. Simulation results indicate that the proposed algorithm can achieve superior performance. 相似文献
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A low-complexity beamforming-based scheduling to downlink OFDMA/SDMA systems with multimedia traffic
In this paper, we propose a low-complexity beamforming-based scheduling scheme utilizing a semi-orthogonal user selection
(SUS) algorithm in downlink orthogonal frequency division multiple access (OFDMA)/space division multiple access (SDMA) systems
to support multimedia traffic. One of the challenges in the multi-dimensional (space, time, and frequency) radio resource
allocation problem for OFDMA/SDMA systems is its high complexity, especially to simultaneously satisfy the quality of services
(QoS) requirements for various traffic classes. In the literature, the SUS algorithm is usually applied to the single-class
traffic environment, but extending the SUS algorithm to the multimedia environment is not straightforward because of the need
to prioritize the real-time (RT) users and the non-real-time (NRT) users. To solve this problem, we propose the concept of
urgency value to guarantee the fairness of the NRT as well as the best effort (BE) users while satisfying the delay requirement
for the RT users. Simulation results show that, when traffic load is greater than 0.5, the proposed scheduling algorithm can
improve the fairness performance by more than 100% over the most recently proposed algorithms. 相似文献
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Managing Resources and Quality of Service in Heterogeneous Wireless Systems Exploiting Opportunism 总被引:1,自引:0,他引:1
We propose a novel class of opportunistic scheduling disciplines to handle mixes of real-time and best-effort traffic at a wireless access point. The objective is to support probabilistic service rate guarantees to real-time sessions while still achieving opportunistic throughput gains across users and traffic types. We are able to show a ldquotightrdquo stochastic lower bound on the service a real-time session would receive assuming that the users possibly heterogeneous capacity variations are known or estimated, and are fast fading across slots. Such bounds are critical to enabling predictable quality of service and thus the development of complementary resource management and admission control strategies. Idealized simulation results show that the scheme can achieve 80%-90% of the maximum system throughput capacity while satisfying the quality of service (QoS) requirements for real-time traffic, and that the degradation in system throughput is slow in the number of real-time users, i.e., inter- and intra-class opportunism are being properly exploited. We note however, that there is a tradeoff between strictness of QoS requirements and the overall system throughput one can achieve. Thus if QoS requirements on real-time traffic are very tight, one would need to simply give priority to real-time traffic, and in the process lose the throughput gains of opportunism. 相似文献
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该文给出了无线通信系统中MAC层可实现的评价用户VoIP业务和实时视频业务满意度的方法,该方法根据MAC层统计的丢包率及丢包模式等信息计算当前业务的用户满意度。基于文中的业务满意度评价准则,该文进一步提出一种在WiMax系统中基于满意度的包调度和资源分配算法。仿真结果表明,该方法在保证系统获得较高吞吐率的同时,能够更好的保证实时业务的满意度。 相似文献
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Jeong Hwan Lee Sungkyung Kim Chung G. Kang Seong-Choon Lee Yongjoo Tcha 《Telecommunication Systems》2008,39(1):15-24
In this paper, we present a packet scheduling algorithm for a non-real-time service, with soft QoS requirements, which allows
for degrading the QoS level, e.g., typically the packet delay, whenever necessary, in mobile broadband wireless Internet access
systems. This algorithm is designed to properly trade off system throughput and delay performance, which can improve the system
capacity by relaxing the delay constraint with respect to the underlying soft QoS requirement. This is as opposed to most
of the existing packet scheduling algorithms for non-real-time service which are simply designed to maximize the system throughput
without a delay constraint. The proposed adaptive exponential scheduling algorithm intentionally introduces additional delay
to some users, especially under bad channel conditions, opportunistically allowing for serving users only under good channel
conditions, as long as the resulting QoS degradation is acceptable for non-real-time service users. The results from a system-level
simulation demonstrate that the system capacity can be significantly increased over existing algorithms, by as much as 65%,
using the adaptive exponential scheduling algorithm while satisfying the given QoS-level requirements. 相似文献
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Efficient Traffic Scheduling for Real Time VBR MPEG Video Transmission Over DOCSIS-Based HFC Networks 总被引:1,自引:0,他引:1
Wen-Kuang Kuo 《Lightwave Technology, Journal of》2009,27(6):639-654
Data-over-cable service interface specifications (DOCSIS), the de facto standard in the cable industry, defines a scheduling service called real-time polling service (rtPS) to provision quality of service (QoS) transmission of real-time variable bit rate (VBR) videos. However, the rtPS service intrinsically has high latency, which makes it not applicable to real-time traffic transport. In this paper, we present a novel traffic scheduling algorithm for hybrid fiber coax (HFC) networks based on DOCSIS that aims to provide QoS for real-time VBR video transmissions. The novel characteristics of this algorithm, as compared to those described in published literatures, include 1) it predicts the bandwidth requirements for future traffic using a novel traffic predictor designed to provide simple yet accurate online prediction; and 2) it takes the attributes of physical (PHY) layer, media access control (MAC) layer and application layer into consideration. In addition, the proposed traffic scheduling algorithm is completely compatible with the DOCSIS specification and does not require any protocol changes. We analyze the performance of the proposed traffic predictor and traffic scheduling algorithm using real-life MPEG video traces. Simulation results indicate that 1) the proposed traffic predictor significantly outperforms previously published techniques with respect to the prediction error and 2) Compared with several existing scheduling algorithms, the proposed traffic scheduling algorithm surpasses other mechanisms in terms of channel utilization, buffer usage, packet delay, and packet loss rate. 相似文献
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Cheng-Han Lin Ce-Kuen Shieh Wen-Shyang Hwang Wei-Tsang Huang 《Wireless Networks》2018,24(5):1575-1592
Wireless mesh networks (WMNs) extend the limited transmission coverage of wireless LANs by enabling users to connect to the Internet via a multi-hop relay service provided by wireless mesh routers. In such networks the quality of experience (QoE) depends on both the user location relative to the Internet gateway and the traffic load. Various channel access or queue management schemes have been proposed for achieving throughput fairness among WMN users. However, delay and bandwidth utilization efficiency of such schemes may be unacceptable for real-time applications. Accordingly, the present study proposes a proportional bandwidth allocation scheme with a delay constraint consideration for enhancing the QoE of users of WMNs based on the IEEE 802.11e standard. An analytical model of the proposed scheme is provided. Moreover, the performance of the proposed scheme is systematically compared with that of existing bandwidth allocation methods. The simulation results show that the proposed scheme outperforms previously proposed schemes in terms of both an improved throughput fairness among the WMN users and a smaller end-to-end transmission delay. 相似文献
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The effective radio resource allocation algorithms, which satisfy diversiform requirements of mobile multimedia services in wireless cellular networks, have recently attracted more and more attention. This paper proposes a service-aware scheduling algorithm, in which the Mean Opinion Score (MOS) is chosen as the unified metric of the Quality of Experience (QoE). As the network needs to provide satisfactory services to all the users, the fairness of QoE should be considered. The Proportional Fair (PF) principle is adopted to achieve the trade-off between the network performance and user fairness. Then, an integer programming problem is formed and the QoE-aware PF scheduling principle is derived by solving the relaxed problem. Simulation results show that the proposed scheduling principle can perform better in terms of user fairness than the previous principle maximizing the sum of MOS. It also outperforms the max-min scheduling principle in terms of average MOS. 相似文献