基于终端干扰和链路稳定性的多终端协同维护机制

在泛在末梢环境中,为了减少协同方案维护代价,满足一定的业务质量需求,提出了一种基于终端干扰和链路稳定性的多终端协同维护机制(MDCMM)。该机制建立了协同方案维护模型,结合终端干扰和链路稳定性确定了维护指标,并使用动态规划思想优先选择可靠的协同方案,减少方案切换对用户的干扰,满足用户多样化的业务质量需求。经OPNET和MATLAB仿真实验,该机制具有较低的维护代价,并且协同方案切换更平滑,证明该机制能更好地保障用户体验。     

泛在网络下的群组移动模型研究现状及展望

群组移动模型的研究对泛在网络下通信协议的设计、算法性能的评价等问题具有重要意义。泛在网络涉及多种终端同时为移动用户服务的场景,有效地整合终端能力需要有效的群组移动模型进行指导。总结了以往Ad Hoc网络下各种群组移动模型的特点和适用场景,结合泛在网络下多终端多网络的环境特点,以用户和业务为中心,对个人服务场景中的群组移动模型的构建方案进行了探讨和展望,提出了关键的技术要求。     

基于多终端协同的业务流控制

文章基于IP多媒体子系统(IMS)分层网络架构模型,设计了一种基于多终端的业务流控制系统构架。根据该系统架构和多终端协同的特征,文章提炼出基于多终端协同的业务流控制所面临的关键技术需求。满足这些需求可充分发挥网络与终端融合协同所带来的个人化、智能化业务能力,改善信息传输服务质量,为用户提供智能化业务体验。文章通过阐述两种典型的多终端协同应用场景——多网协作传输和移动性管理,说明了基于多终端协同的业务流控制所具有的重要意义。     

基于多目标进化的终端聚合选择算法研究

当单一终端业务能力受限时,如何根据终端能力对异构终端进行有效聚合,以支持内容丰富的业务应用成为一个非常重要的问题。该文提出一种基于多目标进化的终端聚合选择算法,给出终端聚合的描述框架,构建基于个体和协同能力的0-1规划模型,包括多指标权重自动生成法,减轻用户负担,避免用户直接指定权重的困难。仿真结果表明,算法能得到一个Pareto最优解集,用户根据其对个体和协同表现的个人偏好或实际业务应用需要选择最满意的方案聚合终端,同时算法具有良好的可行性和有效性。     

泛在融合网络下的个性化业务动态合成技术研究

在融合多种异构网络的泛在网络中,网络需要实时地发布、发现、聚合和适配多样的个性化业务。个性化业务动态合成能快速搜索合适业务组件进行协同工作以满足丰富多彩的用户体验。本文首先基于SOA架构对业务合成进行建模．然后引入由调用监控器、业务路由器、业务发现器和接口适配器四部分组成的基于用户活动的动态业务融合管理器,并对其内部的各个功能模块进行了具体的说明分析,最后设计场景描述了个性化业务动态合成的工作流程。     

面向业务的多终端动态协同构造机制

在MANET组成的泛在末梢环境中,网络的时变性和终端能力的有限性无法保证持续性的高质量异构业务。该文首先定义了通用的泛在个性化业务模型,并提出了综合业务上下文信息的多终端协同问题;在此基础上,提出了基于启发式的多终端协同构造机制,实现执行业务终端集合的构造,包括业务发起、多终端协同构造和质量监测3部分;最后,通过OPNET和MATLAB仿真,在支持差异性业务的同时,丢包率较动态嵌入式任务任播(DTA)提高了3%～17%,达到了面向业务的终端任播(SDA)相同的水平,并且在能耗方面相对于前两者节约了0%～20%,同时缩短了业务重启过程的时间,由此证明该机制具有较优的效率。     

M2M业务泛在支撑平台的设计与实现

为了解决物联网三层架构中业务支撑层的应用需求、实现物联网的"4A"终极目标,对M2M业务泛在支撑平台的需求分析、系统设计、软件开发等进行研究;实现了跨行业、跨网络、松耦合的M2M软件中间件系统,简化了传感采集终端的业务接入。该平台具备对M2M业务的泛在支撑能力,并在架构设计、跨网络接入及支撑、电信增值能力的封装、第三方能力的发现调用和终端协议的适配解析等方面取得了很好的效果。     

一种泛在网络的安全认证协议

泛在网络是标准的异质异构网络,保证用户在网络间的切换安全是当前泛在网的一个研究热点。该文对适用于异构网络间切换的认证协议EAP-AKA进行分析,指出该协议有着高认证时延,且面临着用户身份泄露、中间人攻击、DoS攻击等安全威胁,此外接入网络接入点的有效性在EAP-AKA协议中也没有得到验证,使得用户终端即使经过了复杂的认证过程也不能避免多种攻击。针对以上安全漏洞,该文提出一种改进的安全认证协议,将传统EAP-AKA的适用性从3G系统扩展到泛在网络中。新协议对传播时延和效率进行完善,为用户和接入点的身份信息提供有效性保护,避免主会话密钥泄露,采用椭圆曲线Diffie Hellman算法生成对称密钥,在每次认证会话时生成随机的共享密钥,并实现用户终端与家乡域网络的相互认证。通过开展实验,对协议进行比较分析,验证了新协议的有效性及高效率。     

泛在网络发展现状分析

通过对泛在网络的概要分析,归纳出泛在网络的抽象模型,即网络融合层、业务汇聚层和应用汇聚层;分析了泛在网络的研究概况,并借助典型案例论述了泛在网络的发展趋势和重要性。     

移动泛在融合的通信业务发展趋势

融合作为下一代通信系统发展潮流,将发生在多个方面。从业务体验角度出发,“泛在”将被引入,与移动发生融合,成为一个活跃业务发展方向。本文从业务提供模式以用户需求角度出发,对移动泛在业务环境进行展望,并着重分析了周边泛在环境的特点及其在协同方面的功能需求。最后,对泛在系统的体系结构设计中的自组织特征进行简单分析。     

Dynamic computation offloading in time-varying environment forultra-dense networks: a stochastic game approach

To meet the demands of large-scale user access with computation-intensive and delay-sensitive applications, combining ultra-dense networks (UDNs) and mobile edge computing (MEC)are considered as important solutions. In the MEC enabled UDNs, one of the most important issues is computation offloading. Although a number of work have been done toward this issue, the problem of dynamic computation offloading in time-varying environment, especially the dynamic computation offloading problem for multi-user, has not been fully considered. Therefore, in order to fill this gap, the dynamic computation offloading problem in time-varying environment for multi-user is considered in this paper. By considering the dynamic changes of channel state and users queue state, the dynamic computation offloading problem for multi-user is formulated as a stochastic game, which aims to optimize the delay and packet loss rate of users. To find the optimal solution of the formulated optimization problem, Nash Q-learning (NQLN) algorithm is proposed which can be quickly converged to a Nash equilibrium solution. Finally, extensive simulation results are presented to demonstrate the superiority of NQLN algorithm. It is shown that NQLN algorithm has better optimization performance than the benchmark schemes.     

Competitive flow control in general multi-node multi-link communication networks

In this paper, we consider the flow control in a general multi-node multi-link communication network with competing users. Each user has a source node, a destination node, and an existing route for its data flow over any set of links in the network from its source to its destination node. The flow rate for each user is a control variable that is determined by optimizing a user-specific utility function which combines maximizing the flow rate and minimizing the network congestion for that user. A preference parameter in the utility function allows each user to adjust the trade-off between these two objectives. Since all users share the same network resources and are only interested in optimizing their own utility functions, the Nash equilibrium of game theory represents a reasonable solution concept for this multi-user general network. The existence and uniqueness of such an equilibrium is therefore very important for the network to admit an enforceable flow configuration. In this paper, we derive an expression for the Nash equilibrium and prove its uniqueness. We illustrate the results with an example and discuss some properties and observations related to the network performance when in the Nash equilibrium. Copyright © 2007 John Wiley & Sons, Ltd.     

Theil Utility Based Multi-Device Cooperation Mechanism for Service Quality Equilibrium in Ubiquitous Stub Environments

An approach to make heterogeneous devices cooperate with each other to provide ubiquitous service remains a longstanding challenge in ubiquitous environments. In addition, when multi-user request ubiquitous services simultaneously, the arbitrariness in resource allocation process easily leads to non-equilibrium of qualities of multi- user＇s services. Thus, How to design an effective heterogeneous devices cooperation mechanism that meet the QoS requirements and also equilibrate QoS among multi-user＇s services becomes a very tough problem. In the paper, Equilibrium Index and Theil Utility function are imported to establish a multi- device equilibrium cooperation model, which is benefit for resource allocation in ubiquitous environments. Then a Theil-Equilibrium based Cooperation Mechanism for multi-service is proposed. Firstly, in order to simplify calculating, a dimensionless processing is introduced. After that, a cooperation approach with Theil-Utility Heuristic algorithm is designed to choose the best solution for the simplified model. At last, the mechanism is simulated in a smart home scenario. The simulation results show that this mechanism outperforms non-equilibrium method by improving almost 40% in internal equilibrium with just reducing 0-2% in the total utility of all the requested ubiquitous services. These data show that the proposed mechanism performs well in equilibrating qualities of multi-user＇s ubiquitous services.     

基于量子特性的多用户检测技术

多用户检测技术的最优解在常规条件下是一个NP难解问题,利用量子态的并行计算特性以及量子态检测等理论,量子多用户检测技术能够有效地获得多用户检测的最优解。本文介绍利用量子态特性进行多用户检测的几种方案,并分析和比较这些方案的性能特点和发展趋势。     

Joint transmit beamforming and power control in multi-user MIMO downlink using a game theoretic approach

This study addresses the problem of jointly optimizing the transmit beamformers and power control in multi-user multiple-input multiple-output (MIMO) downlink. The objective is minimizing the total transmission power while satisfying the signal-to-noise plus interference ratio (SINR) requirement of each user. Before power control, it uses the maximum ratio transmission (MRT) scheme to determine the beamformers due to its attractive properties and the simplicity of handling. For power control it introduces a supermodular game approach and proposes an iterated strict dominance elimination algorithm. The algorithm is proved to converge to the Nash equilibrium. Simulation results indicate that this joint optimization method assures the improvement of performance.     

基于非均衡求解的D2D多复用通信资源块分配算法研究

针对小区内D2D多复用的通信资源块分配问题,该文以一个D2D用户分别复用2个和3个蜂窝为基础,提出基于非均衡求解的D2D多复用模式下的资源块分配方案。利用博弈论将资源块划分问题转化为求解被复用蜂窝用户收益联合最大问题。当纳什均衡解不存在时,分析目标函数特性,在可行域内求解“最优解”,保证对不均衡解处理的最优性;对于均衡解存在的情况,将其取整后作为资源分配方案依据,保持其最优性。通过理论分析及仿真实验表明该算法可以提升系统吞吐率,提高小区通信性能。     

Neural Network Implementation of the Optimum CDMA Multi-user Detector

lintroductionCDMA,owingtoitshighcapacitypotentialandotherdesirablefeatures,suchasanti-mutipath,fadingandantljammingcapabilities,isaimatprovidingamuchhighercapacitythanthepreviousgenerationsofmobilecommunicationsystems.ThistechniquepermitSalltheuserin...     

多用户MIMO-OFDM系统基于QoE效用函数的跨层资源分配

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.     

基于并行遗传算法的CDMA优化多用户检测方法

多用户检测技术是第三代移动通信系统CDMA中的一项关键技术。在多用户检测中求解最佳矢量问题可以转化为在遗传算法中求解具有最高适应度函数的问题。本文提出了一种基于并行遗传算法的CDMA多用户检测器,并与最佳多用户检测和传统检测器进行比较,实验结果表明本方法可获得接近最佳检测的性能。由于采用并行遗传算法,这种多用户检测器更易于实时应用和硬件实现。     

最佳量子多用户检测技术

多用户检测的最优解在经典条件下是一个NP难解问题.利用量子态物理特性,通过量子检测能够有效地解决这一难题.本文给出在量子贝叶斯最小代价准则下量子最优解的实现过程,与经典多用户检测最优解相比,基于量子检测的最佳多用户检测技术的性能得到了极大的提高.