基于议价博弈论的无线协作中继网络性能改进算法

针对自私性无线协作中继(CR)网络中的放大再中继(AF)和解码再中继(DF)协议,分别给出 公平且有效率的协作中继功率分配方案。两种方案虽然具体研究内容有差别,但有着共同 的研究策略。首先,将节点间的协作功率选择问题建模为纳什议价博弈问题(NBP);然后, 通过求取其纳什议价解(NBS)获得协作节点的共赢策略;最后,针对AF和DF协议分别给出计 算机仿真。仿真结果表明,所提出协作中继性能改进算法的效率性体现在所有协作节点在AF 和DF协议中均获得信号接收质量的提高,其公平性则体现在任意节点为其协作伙伴所贡献的 转发功率大小仅取决于对方为其带来的性能增益大小。     

双层分级蜂窝网最优频谱分配与定价

针对异频组网的双层分级蜂窝网,提出了一种基于纳什谈判解法的最优频谱分配与定价策略,该策略能激励家庭基站采用开放用户组模式,最大化频谱效益。通过Stackelberg博弈建模,分析了频谱定价与用户需求的关系。通过纳什谈判解法,获得了最佳的频谱分配与定价策略,按需地为宏基站与家庭基站分配了带宽资源,定量地分析了家庭基站所提高的频谱效益。仿真结果表明,该策略相比非合作博弈方法,可有效提高运营商以及家庭基站拥有者所能获得的频谱效益,部署家庭基站将提高蜂窝网络的总效益。      

P2P流媒体网络中基于博弈理论的带宽请求分配策略

基于对等网(P2P)技术的视频流媒体系统以其较低的服务器开销和良好的可扩展性被广泛应用。但由于在这类系统中普遍存在节点的资源及视频播放位置的异构性,使得节点负载不均衡的问题极易发生,进而严重影响到节点的视频播放质量。该文重点研究面向节点负载均衡的节点带宽请求分配策略,将服务请求节点竞争服务提供节点带宽的行为建模为一个非协作博弈,通过寻求该博弈问题的 Nash 均衡解的方法确定优化的带宽请求分配(GBRA)策略。通过和典型的带宽请求分配策略进行实验对比,数值结果表明该文提出的GBRA 策略能有效改善P2P流媒体网络节点负载不均的问题并降低节点获取所需视频数据的平均延迟。     

基于纳什议价的认知无线电合作感知算法

认知无线电技术是建立在授权空闲频谱或非授权频谱基础上,主用户(Licensed user)享有优先频谱使用权,为保护主用户的正常需求,提高探测数据的可靠性,提出了一种新型两人纳什议价合作感知NBS算法,利用两个用户的合作感知信息,根据认知用户(secondary users)与主用户基站的距离和能量的差异,自适应的调节能量检测门限.并将多用户合作感知指派分组为两人纳什合作议价问题,结合"AND"规格融合每组感知数据,在保障主用户通信基础上,提高频谱利用率.仿真结果表明,NBS算法可有效的提高数据可信度,该算法与"AND"数据融合规则相比,感知数据的探测概率显著提高.     

对协作系统自适应角色选择策略的思考

在传统协作系统基础上提出了一种新颖的自适应协作方式——机会角色选择协作.为进一步说明该策略,构建了一种最基本的两用户机会协作框架,其中两个用户相互竞争将各自信息发送给同一目的端.根据瞬时信道条件,两用户均可以机会地充当信息源角色,而另一用户将作为放大转发中继来为信源服务.同时,在此基础上提出并简要描述了一种最优的中心化角色选择策略(C-ROSE).该策略能够最大化目的端接收信噪比(SNR),进而提高系统传输性能.研究表明,通过这种动态、灵活、高效的节点角色分配方式,协作系统的传输可靠性可得到进一步增强,从而为构建稳固、高效、互惠的协作传输体系开辟了新道路.     

基于多维资源自适应分配的协作认知传输机制

该文针对协作认知无线电网络提出一种时域、频域和空域资源联合分配的传输机制,在改善授权用户传输性能的前提下使参与协作的认知用户获得合理的回报。所提机制利用多天线认知节点担任中继,通过自适应的时隙划分与带宽分配,对两跳传输链路中的瓶颈予以消除;并在包含多个协作认知用户的场景中,给出一种考虑公平性的中继选择算法。该方法一方面采用比例公平的思想实现认知用户间的公平性,另一方面通过调整奖励因子,使中继获得合理的回报。仿真结果表明,所提算法能够改善授权与认知系统的数据速率,同时给予认知中继公平的回报。     

分布式Alamouti空时码的信道容量及最优资源分配方案

该文针对基于译码转发协议的分布式Alamouti空时码(DF-DASTC)系统的信道容量以及最优资源分配策略问题。利用退化中继信道模型,推导得到了DF-DASTC系统在衰落信道下的信道容量闭式解。以DF-DASTC信道容量最大化为目标,对该系统在固定带宽分配时,中继及信源节点的最优功率分配方案进行了研究,推导得到了DF-DASTC系统的最优功率分配方案的闭式解。利用凸优化理论,将以DF-DASTC信道容量最大化为目标函数的多目标优化问题转换为非线性不等式约束的单目标凸优化问题,进一步得到了可变带宽分配时的DF-DASTC系统的最优带宽和功率分配策略。理论分析和系统仿真表明,该文所提出的资源分配策略,比平均分配的资源方案具有更大的信道容量。另外,该文的最优资源分配策略适用于具有多个中继节点的无线中继网络,具有普适性。     

无线视频通信中带宽分配策略

本文针对无线网络中多用户传输视频时带宽分配问题,提出了一种基于微观经济学中供需平衡的带宽分配策略。该方法充分考虑了运营商的收益,在运营商和用户收益同时最大且供需平衡时,所求得的频谱价格即为运营商的出售价格。同时给出了针对不同用户等级有不同的用户优先级因子,据运营商提出的带宽价格,彼此相互博弈,最终使得自身效用最大。仿真结果表明:本文提出的博弈论方法存在纳什均衡解和均衡单价;用户等级因子能按照用户的不同等级来分配带宽;系统传输质量相比以往方法有所提高。      

基于加权协商对策论异构网络快速无线传输的速率分配算法

本文研究异构无线网络合作传输的速率分配问题.作为合作传输的理性参与者,异构网络可通过反复协商得到彼此都满意的最优分配方案,即协商对策.因此,本文在速率需求和可用带宽这两个约束条件下,考虑网络传输能力的异构性,用加权协商对策论对异构网络合作传输的速率分配进行了数学建模;以最小传输时间作为优化目标构造了效用函数,证明了该函数是一个凸函数,并利用拉格朗日乘数法推导出最优显式解;提出了一种在终端上可实现的速率分配算法,进行了性能仿真实验.本文算法特别适合于应急通信等快速传输场景.     

多天线系统中多中继传输的时间分配和功率分配优化方法

本文考虑单小区内的两个中继使用解码转发的方法为两个用户提供下行数据的场景,基站和中继配置多根天线,用户配置单天线。两中继使用相同的频率资源同时为两个用户提供服务。为减小两中继同时向两用户传输时产生的干扰,中继到用户的传输采用协作干扰避免的策略;相应的基站到中继的传输采用多用户空分复用的传输策略。本文在时间分配和功率分配两个方面对上述两跳传输过程进行了优化,提出了两跳传输最优的时间分配策略。由于功率分配最优化问题难以求解,本文提出了一种匹配链路容量的次优功率分配方法,并对其进行简化以降低复杂度。通过仿真可以看出,简化的功率分配方法与匹配链路容量的功率分配性能很接近;所提出的时间分配和功率分配方案可以获得有效的性能提升。      

Bandwidth allocation and admission control scheme based on Nash bargaining solution for WiMAX systems

Development of fair and efficient bandwidth allocation and admission control schemes is one of the key issues in the design of IEEE 802.16 broadband wireless access systems in time division multiple access (TDMA) mode. In this article, the problem of bandwidth allocation and admission control is formulated as a Nash bargaining model. The nash bargaining solution (NBS) derived from the cooperative game is adopted to maximize the spectrum utilization. Analysis and simulation results show that there is a unique Pareto optimal bandwidth allocation solution by using NBS among various flows. Furthermore, maximum utility of the system can also be maintained by using the admission control policy with different number of connections and variable channel qualities. The total throughput of the proposed scheme is close to the maximal one, while significantly improving fairness compared to the existing solutions.     

Game-theoretic solutions through intelligent optimization for efficient resource management in wireless visual sensor networks

We propose a quality-driven cross-layer optimization scheme for wireless direct sequence code division multiple access (DS-CDMA) visual sensor networks (VSNs). The scheme takes into account the fact that different nodes image videos with varying amounts of motion and determines the source coding rate, channel coding rate, and power level for each node under constraints on the available bit rate and power. The objective is to maximize the quality of the video received by the centralized control unit (CCU) from each node. However, since increasing the power level of one node will lead to increased interference with the rest of the nodes, simultaneous maximization of the video qualities of all nodes is not possible. In fact, there are an infinite number of Pareto-optimal solutions. Thus, we propose the use of the Nash bargaining solution (NBS), which pinpoints one of the infinite Pareto-optimal solutions, based on the stipulation that the solution should satisfy four fairness axioms. The NBS results in a mixed-integer optimization problem, which is solved using the particle swarm optimization (PSO) algorithm. The presented experimental results demonstrate the advantages of the NBS compared with alternative optimization criteria.     

Fair resource sharing for cooperative relay networks using nash bargaining solutions

This letter considers the problem of resource sharing between two selfish nodes in cooperative relay networks. In our system, each node can act as a source as well as a potential relay, and both nodes are willing to achieve an optimal signalto- noise ratio (SNR) increase by adjusting their power levels for cooperative relaying. We formulate this problem as a two-person bargaining game, and use the Nash bargaining solution (NBS) to achieve a win-win strategy for both nodes. Simulation results indicate the NBS resource sharing is fair in that the degree of cooperation of a node only depends on how much contribution its partner can make to its SNR increase.     

Optimal power control for wireless cooperative relay networks: a cooperative game theoretic approach

Wireless nodes operating on batteries are always assumed to be selfish to consume their energy solely to maximize their own benefits. Thus, the two network objectives, that is, system efficiency and user fairness should be considered simultaneously. To this end, we propose two game theoretic mechanisms, that is, the signal‐to‐noise ratio (SNR) game and the data‐rate game to stimulate cooperation among selfish user nodes for cooperative relaying. Considering one node could trade its transmission power for its partner's relaying directly, the strategy of a node is defined as the amount of power that it is willing to contribute for relaying purpose. In the SNR game, selfish nodes are willing to achieve SNR increases at their receivers, while in the data‐rate game the nodes are willing to achieve data‐rate gains. We prove that each of the games has a unique Nash bargaining solution. Simulation results show that the Nash bargaining solution lead to fair and efficient resource allocation for both the cooperative partner nodes in the Pareto optimal sense, that is, both the nodes could experience better performance than they work independently and the degree of cooperation of a node only depends on how much contribution its partner can make to improve its own performance. Copyright © 2012 John Wiley & Sons, Ltd.     

Dynamic subcarrier and power allocation based on cooperative game theory in symmetric cooperative OFDMA networks

In order to improve the efficiency and fairness of radio resource utilization,a scheme of dynamic cooperative subcarrier and power allocation based on Nash bargaining solution(NBS-DCSPA) is proposed in the uplink of a three-node symmetric cooperative orthogonal frequency division multiple access(OFDMA) system.In the proposed NBS-DCSPA scheme,resource allocation problem is formulated as a two-person subcarrier and power allocation bargaining game(SPABG) to maximize the system utility,under the constraints of each user’s maximal power and minimal rate,while considering the fairness between the two users.Firstly,the equivalent direct channel gain of the relay link is introduced to decide the transmission mode of each subcarrier.Then,all subcarriers can be dynamically allocated to the two users in terms of their selected transmission mode.After that,the adaptive power allocation scheme combined with dynamic subcarrier allocation is optimized according to NBS.Finally,computer simulation is conducted to show the efficiency and fairness performance of the proposed NBS-DCSPA scheme.     

Cooperative Relay‐Aware Spectrum leasing based on Nash bargaining solution in cognitive radio networks

This paper proposes a spectrum leasing strategy based on cooperative relaying for cognitive radio networks. The basic idea is to make the primary user lease a fraction of the licensed spectrum to the secondary user, which acts as a relay for the primary user in return. We formulate the spectrum leasing problem as a Nash bargaining game to avoid the ineffective solution obtained by Stackelberg game. The cooperative condition and the optimal time allocation can be obtained by solving the game. Numerical results demonstrate that both the primary user and the secondary user can obtain larger profits from the spectrum leasing based on Nash bargaining solution. Copyright © 2014 John Wiley & Sons, Ltd.     

基于合作博弈的多虚拟机实时迁移带宽分配机制

IaaS云计算平台采用虚拟机实时迁移技术进行资源动态调度和管理。在实际应用场景下,需要并行实时迁移多个虚拟机。由于实时迁移算法本身以最大利用带宽的方式进行数据传输,存在着迁移进程间竞争带宽的问题,无法保证带宽全局最优分配,影响整体迁移的性能。提出一种基于合作博弈的多虚拟机实时迁移带宽分配机制,将带宽分配问题建模为一个纳什议价,通过求解纳什议价解得到帕累托最优的带宽分配方案,并在实际的虚拟化平台上进行了实现。实验结果表明,相比标准的并行实时迁移,所提出的带宽分配机制能够公平有效地分配带宽,提高了并行实时迁移的性能。     

Bandwidth allocation for cooperative relay networks based on Nash bargaining solution

This paper is concerned with the bandwidth allocation problem for cooperative relay networks. The relay takes the roles of not only forwarding the data originated from the users but also of transmitting its own data to the access point. We focus on the interesting questions of when and how the users and the relay can both benefit from the cooperation by bandwidth allocation for relaying among the users. The bandwidth allocation problem is formulated in this paper as a Nash bargaining problem, and then the bandwidth allocation algorithm can be given on the basis of the sub‐gradient method. Simulation results illustrate that users and the relay can both obtain more profits through cooperation. Copyright ©2011 John Wiley & Sons, Ltd.     

Z number improved reference ideal method-based decision-making process for enforcing cooperation during data dissemination in mobile ad hoc networks

In mobile ad hoc networks (MANETs), cooperative communication and resource constraint are the two important core characteristics essential to guarantee trusted data dissemination. The cooperative communication between mobile nodes depends on the trust rendered by them towards the process of reliable data routing. However, stringent resource constraints of mobile nodes such as energy, memory, communications, and computations result in the introduction of selfish and malicious node that completely degrades the network performance in different dimensions. In this paper, Z number improved reference ideal method (RIM)-based decision-making process (NIRIMDMP) is proposed with the merits of maximizing deviation method (MDM) and best–worst method (BWM) to ensure reliable data routing by modeling the cooperation degree in terms of Z number. This NIRIMDMP adopted Z number to represent the information reliability and handle the problem of inherent uncertainty during the process of evaluating each mobile node in the routing process. In specific, MDM and BWM are included into the proposed NIRIMDMP to determine comprehensive attribute weights based on the calculated objective and subjective weights that could be possible derived in routing. It extended the merits of classical RIM using Z numbers to confirm reliable ranking of mobile nodes, even when the optimal solution exists amid extreme values taken into consideration for assessing the mobile nodes during decision making. Simulation investigations of the proposed NIRIMDMP confirmed improved throughput and network lifetime with reduced control overhead, energy consumptions, and delay independent of the amount of malicious and non-cooperative nodes.