共查询到20条相似文献,搜索用时 78 毫秒
1.
2.
针对认知无线网络中存在的干扰问题和功率消耗过大问题,提出了一种新的基于斯坦克尔伯格(Stackelberg)博弈的功率控制算法。建立了主次用户双层网络模型,将主用户设置为领导者,次用户设置为追随者,并对次用户产生的总干扰进行定量分析。在次用户多次博弈的过程中,动态地调整主用户单位干扰价格,在保证主用户自身正常通信前提下,尽量使得收益最大化,提高主用户的参与积极性。仿真实验表明,该算法在保证主次用户的服务质量(QoS)前提下,有效地减小了次用户的发射功率,而且能获得更高的系统容量。 相似文献
3.
带有接入阈值和超时隙的认知无线网络频谱分配策略 总被引:1,自引:0,他引:1
为了提高认知用户的响应性能,并降低传输中断的概率,通过限制进入系统的认知用户数据包数量,并令授权用户以超时隙为单位优先使用信道,提出一种带有接入阈值和超时隙的集中式认知无线网络频谱分配策略。结合时隙序号及系统中认知用户数据包的数量建立2维离散时间Markov链模型,给出认知用户数据包的平均延迟、吞吐量及信道切换率等性能指标的表达式。建立系统收益函数,针对不同的超时隙大小给出接入阈值的优化设置方案,并利用优化结果,进行系统实验。实验结果显示:合理的接入阈值和超时隙大小可以有效提高认知用户的传输质量。 相似文献
4.
认知无线网络中基于主用户行为的联合路由和信道分配算法 总被引:1,自引:0,他引:1
针对认知无线网络中主用户行为将导致频谱瞬时变化而影响路由稳定性的问题,提出了一种基于主用户行为的路由和信道联合分配算法。该算法通过采用呼叫模型对主用户行为建模,并根据动态源路由协议的路由寻找机制,在目的节点等待多个路由请求分组后选择受主用户行为影响最小的路由,然后沿着所选定路径的反方向传送路由回复分组并完成信道分配。理论分析证明了算法中的链路平均持续时间期望与主用户活动概率成反比且具有与网络节点数成正比的计算复杂度。仿真结果表明,该算法具有比Gymkhana路由方案更高的分组投递率和更低的平均分组时延。 相似文献
5.
6.
7.
8.
9.
无线网络虚拟化中资源共享的功率分配算法 总被引:1,自引:0,他引:1
针对传统无线网络中功率不能动态分配共享的问题,采用无线网络虚拟化,设计了一种基于博弈的两阶段功率分配方法(G2SPA, game theory based two steps power allocation scheme for wireless network virtualization),首先利用买卖博弈模拟了服务提供商(SP, service provide)和移动用户(MUE, mobile user equipment)之间的相互影响,提出了基于斯坦博格均衡(SE, stackelberg equilibrium)的报价策略。然后,利用拍卖理论对空闲下行功率资源进行再分配,采取McAfee机制保证拍卖的诚实性。通过仿真实验证明G2SPA算法的正确性和有效性。 相似文献
10.
11.
针对认知用户的功率控制在实现用户效用的最大化时牺牲网络收益进行了研究,联合网络和用户两端对用户进行功率控制可以实现网络收益和用户效用的平衡。联合算法的实现可以采用认知用户单位价格的多维搜索方式,但是该方式计算量大,为了减少计算的复杂度,文章提出一种渐进分析法求解最优单位价格。首先确定使得网络收益最大化的单位价格,并基于该单位价格,采用博弈论分析方法,对认知用户进行功率控制。该算法表明在实现网络收益最大化的同时,用户的收益达到最优化。通过仿真分析,验证了联合算法的有效性。 相似文献
12.
13.
Seyyed Mohammad Javad Asgari Tabatabaee Mohsen Abbasi‐Jannatabad 《International Journal of Communication Systems》2020,33(5)
In this paper, power allocation and beamforming are considered in a multiple input multiple output (MIMO) downlink cognitive radio (CR) communication system, which a base station (BS) serves one primary user (PU) and one secondary user (SU). In order to design the CR system, a constrained multiobjective optimization problem is presented. Two objectives are the signal to noise plus interference ratios (SINRs) of PU and SU. Since PU has a spectrum license for data communication, a constraint in the optimization problem is that the SINR of PU must be greater than a predefined threshold based on the PU demand requirement. Another constraint is a limitation on power in BS. By considering the mentioned model, three iterative algorithms are proposed. At each iteration of all algorithms, the receiver beamforming vectors are derived based on the maximization of PU and SU SINRs, by assuming that the allocated powers and BS beamforming vectors are known. Also, power is assigned to users such that the constraint of power limitation is satisfied. The difference between the algorithms is in the obtaining of transmitter beamforming parameters. We evaluate the performance of the proposed algorithms in terms of bit error rate (BER) in simulations. Also, the computational complexity of the proposed algorithms is obtained. 相似文献
14.
Various cognitive network technologies are developed rapidly. In the article, the power and spectrum allocation in multi-hop cognitive radio network (CRN) with linear topology is investigated. The overall goal is to minimize outage probability and promote spectrum utility, including total reward and fairness, while meeting the limits of total transmit power and interference threshold to primary user simultaneously. The problem is solved with convex optimization and artificial bee colony (ABC) algorithm jointly. Simulation shows that the proposed scheme not only minimizes outage probability, but also realizes a better use of spectrum. 相似文献
15.
Optimal power allocation for cognitive radio networks with relay‐assisted directional transmission 下载免费PDF全文
In this paper, the problem of power allocation in a cooperative cognitive radio (CR) network is investigated. An optimal power allocation is proposed to maximize efficiency of the secondary network in which secondary users transmit simultaneously over a spectral band assigned to the primary users. The CR network employs directional relays to improve efficiency of the communication links and minimize interference introduced to the primary users. Unlike the conventional cooperative relay‐assisted network, the directional relays are grouped in clusters. This clustering technique along with directional transmission can significantly reduce interference to the primary links and improve the system performance. Two algorithms are also developed on the basis of the penalty method to determine unknown transmission powers. Some corroborant numerical examples are provided to illustrate quick convergence behavior of the proposed algorithms and great superiority of employing clustered directional relays in cooperative CR networks. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
16.
A novel adaptive power control and beam-forming joint optimization algorithm is proposed in cognitive radio(CR) underlay networks,where cognitive network share spectrum with primary network which spectrum is licensed.In this paper,both primary base station(PBS) and cognitive base station(CBS) are all equipped with multi antennas,while each primary user(PU) and cognitive user(CU) has only one antenna.Different from traditional algorithms,an adaptive weight factor generating solution is supplied to different access users(both PUs and CUs) in this paper,and the different priority of users is also considered,because PUs have higher priority,the weight factor of PUs is fixed as constant and signal-to-interference and noise ratio(SINR) threshold is unchanged,while for CUs,it is set adaptively and SINR threshold is also changed accordingly.Using this algorithm,the transmit power is decreased,which relax the strict requirements for power amplifier in communication systems.And moreover,owing to PUS has fixed SINR threshold,the calculated SINR at receiver is nearly unchanged,but for CUs,the SINR is changing with the adaptive weight factor.Under the assurance of quality of service(QoS) of PUs,the solution in this paper can enable CRs access to the CR network according to adaptive SINR threshold,therefore which supplies higher spectrum utilization efficiency. 相似文献
17.
典型部署策略下认知无线传感网的机会频谱接入方法 总被引:1,自引:0,他引:1
在典型规则拓扑模式及覆盖部署方式的传感网中探讨无冲突的认知频谱接入方法(包括频谱和时隙分配、协作频谱感知和感知结果汇报方案),为数据采集提供高效的传输手段。提出对应网络环境下的次级用户的阻塞率和掉话率、各拓扑模式下的网络有效接收带宽和最大传输时延的分析模型。通过对几种拓扑模式的比较,表明Triangle的协作频谱感知效果最佳,而Square的有效接收带宽最佳;在完全覆盖部署方式下,Square和Triangle的传输时延较小,而多重覆盖部署方式下Square的时延最小。指出单个节点上的虚警概率对传输时延的影响不大,授权用户出现概率则对时延有明显影响,而选择较大的传输时隙/感知时隙比能显著降低时延。 相似文献
18.
认知无线电网络被认为是实现动态频谱共享、缓解频谱资源紧缺的重要途径。喷泉码能有效抵抗认知无线电网络中来自主用户的突发干扰,且无需反馈重传,从而为认知无线电网络提供了一种有效的信道编码方案。首先简介了数字喷泉码以及认知无线电网络基础知识,然后综述了数字喷泉码在认知无线电网络的链路建立、认知通信以及在资源分配中的应用现状,最后指出了在这一研究领域中需要解决的问题,并展望了发展前景。 相似文献
19.