OFDMA上行链路中基于博弈论的子载波和功率分配算法

传统OFDMA上行链路资源分配算法中一般以最大化各用户速率或最小化发射功率为依据对子载波和功率进行分配,而对于各用户的功率效率问题并没有加以考虑。针对这一问题,该文提出了一种基于功率效率最优的联合子载波功率分配算法。首先给出了在各用户峰值功率约束条件下达到收益函数最优的必要条件并证明了算法纳什均衡的存在及唯一性,然后给出了子载波功率分配算法。仿真表明：相比最大边界速率子载波和功率分配算法(MaxRt+WF)和固定子载波和功率分配算法(MaxFA+WF),该文算法能大幅度提高各用户的功率效率。同时如果合理地选择代价参数,算法获得的和功率效率能够达到更大。     

OFDMA系统下行链路自适应带宽与子载波分配方案

该文分析了OFDMA系统下行链路自适应资源分配问题,在系统总功率约束下提出了最小化系统中断概率的次最佳两步子载波分配算法。首先分析用户带宽分配与子载波功率分配特点,在此基础上提出了根据系统可用资源、用户QoS要求及信道状态为用户分配带宽和子载波的两步分配算法。仿真结果表明,该文提出的算法能在极小化系统中断概率的同时满足总功率约束。     

应用于OFDMA中继网络的子载波分配方案

在OFDMA中继网络中,针对目前的子载波分配方案不能很好的解决速率和公平性有效结合的问题,提出了以传输速率、公平性为优化目标的子载波分配方案以及一种自适应的子载波分配方案,三种方案分别适用于用户数长时间较少、用户数长时间较多以及用户数目变化较频繁三种场景。通过仿真可以看出,所提方案可以有效地兼顾速率和公平性两方面因素,能够解决实际系统中存在的一些问题,有效提升用户的服务质量。     

OFDMA系统中子载波分配算法分析

分析和研究了OFDMA系统中总功率约束条件下的子载波分配算法,利用系统吞吐量增益和用户吞吐量公平比率两个评价参数,对几种典型的子载波分配算法进行了仿真和分析,并给出了分析结论,为实际系统中的资源调度算法设计提供了有益的参考。     

子载波交织分配的OFDMA系统

近年来，正交频分多址接入系统做为一种新的多址接入技术受到了极大关注。在OFDMA中，相临的多个子载波被分配给不同的用户来为用户并行低速传输数据。子载波是相互间重叠且正交的，所以避免了载波间干扰的产生。文中介绍了向上链接子载波交织分配的OFDMA系统。     

一种OFDMA实时子载波分配算法及仿真

正交频分多址(OFDMA)是以OFDM调制为基础的新一代无线接入技术,在这种方式中,多址是通过给每个用户分配可用子载波总数的一部分来实现的。介绍了一种OFDMA下行链路的实时动态子载波分配算法,算法根据各个子载波对各个用户的瞬时信道增益,在使系统总的发送功率最小的准则下,为各用户分配最优的子载波组。最后用MATLAB语言仿真实现了该算法.仿真结果表明该算法性能要优于传统的静态子信道方案。     

多用户OFDM系统中改进的动态子载波与功率分配算法

提出了一种对于多用户OFDM（Orthogonal Frequency Division Multiple）系统改进的动态子载波和功率分配算法.算法采用分步的思想对系统资源进行动态分配,在已知系统总功率和用户最小速率请求的条件下,使系统总的比特速率最大,资源得到了有效利用.此算法简单易于理解,复杂度较低,仿真结果表明,其性能接近于联合的分配算法.     

OFDMA系统中线性注水功率分配算法

功率分配是OFDMA系统资源调度中的一个重要研究问题。该文通过寻求快速确定不需分配功率的子载波方法,提出了一种线性注水功率分配算法,运算中不需多次迭代,就可完成功率注水过程。仿真结果表明,该算法的吞吐量逼近迭代注水功率分配算法。     

OFDMA系统中功率分配新算法研究

通过对迭代注水算法的分析,提出了一种功率分配的新算法,该算法不需要多次迭代,并且能在一定功率约束的条件下,有效地提高系统吞吐量。给出了具体的算法实现步骤和复杂度分析,表明该算法复杂度明显低于迭代注水算法。最后,对该算法进行了仿真分析,并以信噪比为8 dB时为例,分析了两算法的吞吐量性能。仿真结果表明,在低信噪比环境中该算法对系统容量的改善更为显著,且所提算法的吞吐量性能完全逼近迭代注水算法。     

基于OFDMA系统联合资源分配方案

针对多用户OFDMA系统,提出一种改进的比例公平资源分配算法。该算法采用分步法联合资源分配方案,分为子载波分配和功率分配两步进行,改进算法基于Wong算法,引入比例限制因子,在子载波分配环节,对剩余子载波的分配采用比例公平和最大化系统容量的算法,在用户中的功率分配环节,采用线性等式,大大降低了算法复杂度。仿真分析表明,改进算法不仅提高了系统吞吐量,而且降低了算法复杂度。     

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.     

基于合作博弈的CPS通信资源分配算法

为了提高信息物理融合系统的通信速率,同时保证各用户的QoS需求,提出了一种基于合作博弈的CPS通信资源分配算法。将CPS中OFDMA网络下行链路的资源分配过程建模为多用户间的合作博弈,通过求解纳什议价解,实现用户间的Pareto最优性。仿真结果表明,该算法在系统速率最大化和用户公平性上获得了很好的折中,与最大化系统速率算法相比更具有公平性,与最大化最小公平性算法相比速率提高了34%,在一定程度上提高了CPS通信网络的性能。     

Resource allocation scheme for orthogonal frequency division multiple access networks based on cooperative game theory

Cooperative game theory can be applied to orthogonal frequency division multiple access (OFDMA) networks for fair resource allocation. In this work, we consider a comprehensive cross‐layer framework including physical and medium access control layer requirements. We apply two cooperative games, nontransferable utility (NTU) game and transferable utility (TU) game, to provide fairness in OFDMA networks. In NTU game, fairness is achieved by defining appropriate objective function, whereas in TU game, fairness is provided by forming the appropriate network structure. For NTU game, we analyze the Nash bargaining solution as a solution of NTU game taking into account channel state information and queue state information. In a TU game, we show that coalition among subcarriers to jointly provide rate requirements leads to better performance in terms of power consumption. The subcarrier's payoff is determined according to the amount of payoff which that subcarrier brings to the coalition by its participation. We show that although NTU and TU games are modeled as rate adaptive and margin adaptive problems, respectively, both solutions provide a fair distribution of resources with minimum fairness index of 0.8. Copyright © 2012 John Wiley & Sons, Ltd.     

Fairness based resource allocation for uplink OFDMA systems

This article investigates two fairness criteria with regard to adaptive resource allocation for uplink orthogonal frequency division multiple access （OFDMA） systems. Nash bargaining solution （NBS） fairness and proportional fairness （PF） are two suitable candidates for fairness consideration, and both can provide attractive trade-offs between total throughput and each user＇s capacity. Utilizing Karush-Kuhn- Tucker （KKT） condition and iterative method, two effective algorithms are designed, to achieve NBS fairness and proportional fairness, respectively. Simulation results show that the proposed resource allocation algorithms achieve good tradeoff between the overall rate and fairness, with little performance loss from the total capacity.     

Research on the low complexity adaptive power allocation algorithm in cooperative systems

Cooperative diversity is a new technology to improve bit error rate(BER)performance in wireless communications.A new power allocation algorithm to improve BER performance in cellular uplink has been proposed in this paper.Some existing power allocation schemes were proposed for the purpose of maximizing the channel capacity or minimizing the outage probability.Different from these schemes,the proposed algorithm aims at minimizing the BER of the systems under the constraint of total transmission power.Besides this characteristic,the proposed algorithm can realize a low complexity real-time power allocation according to the fluctuation of channels.Simulation results show that the proposed algorithm can decrease the BER performance of the systems effectively.     

基于中断概率的协作通信中继选择与功率分配算法

研究了功率受限情况下多中继协作通信网络的中继选择和功率优化问题。在AF网络中,提出了一种低复杂度中继选择与功率分配算法,其目标是在总功率一定的条件下使系统的中断概率最小。本算法对源节点和所有潜在中继节点进行功率分配,结合当前信噪比选择最优的中继集合,通过最速下降法求出使系统中断概率最低的功率分配因子。该算法不需要知道大量瞬时信道信息、不需要系统在等功率条件下进行中继选择,只需求得中继节点排列矩阵便可根据当前信噪比自适应获得最优中继节点集合。仿真结果表明,在相同条件下,该算法明显优于不同中继节点集合下几种算法的中断性能,并且与传统的SAF及AAF算法相比,有效降低了中断概率,提升了系统性能和功率效率。     

协作通信系统的功率分配策略研究

在无线通信中,为了对抗信道衰落,人们提出了分集技术。协作分集通过共享资源达到改善通信质量、提高通信性能的目的。研究了放大转发协作通信系统中的功率分配策略。对于协作通信系统的功率分配研究了3种方法:迭代法,直接计算法,理想的穷搜索法。研究表明,迭代法是最佳方案,因为这种方法的迭代次数可以人为控制,而且性能与理想的穷搜索法相差不大。     

协作D2D异构网络的联合资源分配和功率控制

针对下行协作D2D(Device-to-Device)异构网络中复用蜂窝用户的联合资源分配和功率控制问题,提出了一种量子珊瑚礁优化算法(Quantum Coral Reef Optimization Algorithm,QCROA).首先,构建异构网络模型并推导得到整个网络总吞吐量的数学表达式;其次,基于QCROA算法...     

双中继协作通信的功率分配改进方案

为克服信息处于深度衰落情况下单中继协作困难,减少多中继协作目的端信号处理的复杂度,给出了双中继节点参与协作通信的功率分配方案。两个中继节点分别采用放大转发(AF)、译码转发(DF)以及混合译码放大转发(HDAF)3种协作方式进行通信。在满足一定的中断概率和节点功率限制情况下,利用MATLAB软件中的Fmincon优化函数,得到了各节点的最小发射功率。数值分析表明,在相同条件下,两个中继节点采用HDAF协作方式比采用AF协作方式、DF协作方式消耗的系统总功率分别少4~9 dBm、0.5~1 dBm,最大限度地节约了系统功率的消耗。     

Optimal power allocation to minimize SER for multinode amplify-and-forward cooperative communication systems

An optimal power allocation （OPA） method with mean channel gains is proposed for a multinode amplify-and-forward cooperative communication system. By making use of M-PSK modulation, a closed-form symbol-error-rate （SER） formulation and corresponding upper bound are first derived. Subsequently the OPA method is utilized to minimize the SER. Comparison of the SER of the proposed OPA method with that of the equal power allocation （EPA） method, shows that the SER of both methods, which is approximately optimal performance, is almost the same when relays are near the source. OPA outperforms the EPA when the relays are near the middle between the source and destination or near the destination. The proposed OPA method depends only on the ratio of mean channel gains of the source-to-relay to those of the relay-to-destination. Extensive simulations are performed to validate the theoretical results.