基于比例速率保证的信道误差OFDMA中继系统资源分配

针对存在有信道估计误差的正交频分多址( OFDMA)中继系统,在考虑用户传输中断概率的同时,提出了满足不同用户最小服务质量( QoS)需求和比例公平性约束条件下的中继选择、子载波分配和功率分配的联合优化问题,建立了以最大化系统总容量为目标的优化模型。在此基础上以速率最大化为目标进行最佳中继选择,并通过动态子载波分配来满足用户的最小QoS需求和比例公平性,最后采用拉格朗日乘子法来得到最优功率分配方案。仿真结果表明,此算法在降低用户中断概率的同时,提高了系统吞吐量并保证了用户速率的比例公平性。     

基于应用时间窗多用户MIMO-OFDM系统中的比例公平算法

该文针对基于延时信道状态信息的多用户MIMO-OFDM系统,在用户比例速率要求和功率限制的情况下,以最大化时间窗内系统吞吐量为目标,提出了一种基于应用时间窗比例公平算法。该算法首先设计各子载波上满足用户误比特率要求的星座距离,然后把系统中每个用户按照其比例映射为相应数目的虚拟用户,最后根据影子价格把子载波最优地分配给虚拟用户。仿真结果表明,该算法在保证用户公平性的基础上,有效地提高了系统吞吐量。     

LTE无线网络下行链路的动态资源分配算法研究

LTE无线网络下行链路系统中的可用带宽被分为成千上百个正交子频带,在给定的时隙,一个给定的子频带（子信道）只能分配给一个用户。由于信道的衰落,子信道的分配是时变的,在每个时隙子信道的分配取决于其和用户的连接状态和用户队列的数据积压。对这种系统中n个用户竞争单个子信道的问题进行了研究。由于分配政策不但要提高系统的吞吐量,还要降低单个用户的延迟,因此本文采用李雅普诺夫最优化的方法设计了一种资源分配算法。理论分析和仿真结果表明,该方法不但提高了系统的吞吐量,同时还在在吞吐量和延迟之间提供了一个很好的均衡。     

一种新型的OFDMA比例公平资源分配算法

针对已有算法对系统容量和高公平性兼顾较差的情况,提出了一种满足公平性的系统容量最大化资源分配算法。在子载波分配中通过建立信道效率控制模型,给当前用户分配信道效率最高的子载波,将信道增益低于门限值的子载波重新分配,改进了最大化最小(max-min)用户速率模型。在功率分配中将系统模型转化成用注水线表示的数学模型,首先求解各用户的注水线,再求解各用户的功率分配,保证了用户间比例公平性。两种信噪比情形下的仿真和分析表明,整个方案计算复杂度稍低,系统容量获得较大提升,并且用户间的公平性始终为1。     

基于比例公平原则的多用户MIMO-OFDM系统资源分配

提出了一种基于比例公平原则提高MIMO-OFDM系统吞吐量的子载波和功率分配算法.它在总功率和误比特率的约束下,以获取最大系统吞吐量为目标,同时为兼顾用户间资源享用的公平性,根据用户速率成比例推导出了子载波分配限制准则.仿真结果表明,本算法不仅可满足不同用户的速率要求,而且平衡了容量最大化和用户间公平性的矛盾,同时计算...     

基于用户公平性的MIMO-OFDM空间子信道分配算法

对多用户"多入多出-正交频分复用"(MIMO-OFDM)系统的空间子信道分配算法进行了研究,提出了使系统吞吐量最大化并且满足用户速率最小要求的多用户无线资源调度算法.仿真结果表明,与波束形成相比.所提算法具有更好的性能,既充分利用空间子信道,提高了系统容量,又采取有效措施保障了用户的公平性.     

协作系统中基于比例公平的资源分配方法

针对多用户协作中继系统中的资源分配问题,提出了一种在满足用户速率比例公平约束条件下的新算法。该算法先将由2个时隙组成的中继用户传输链路转换为一个等效信道链路,将涉及子载波分配、中继选择和功率分配的组合优化问题转化为分步的次优化问题。该算法在等功率分配情况下,根据各用户速率比例公平系数进行初步子载波数目分配;以瞬时信道增益最佳原则,进行剩余子载波数目分配及具体子载波分配,同时完成中继选择;在速率比例公平约束条件下推导出次优化功率分配的闭式表达式,从而完成各子载波上的功率分配。仿真结果表明,该算法在有效提高系统容量的同时,保证了各用户速率之间的比例公平性。     

高速无线个域网中一种基于效用公平的机会调度算法

基于对无线高速个域网中机会调度的研究,提出了一种适用于WPAN的机会主义时隙调度算法FPTS。该算法充分考虑了信道状态的波动和用户间的公平性,由参数更新模块和调度分配模块组成。参数更新模块根据调度结果更新控制参数,维护用户的公平性和自适应的跟踪信道的变化;调度分配模块负责计算每个用户的公平效用权值,并按照权值向各用户比例分配信道资源。仿真结果表明：所提调度方案能够在保证系统高吞吐量的前提下,获得LLPTS算法更好的公平性和信道使用效率。     

OFDM中基于信道变化载波分配算法

OFDM系统利用用户的多样性,根据信道状态对系统中的子载波资源进行动态的分配,有效的提高了系统的容量。最大化系统容量的子载波分配算法,忽略了用户之间的公平性。使某些信道状态不好的用户由于没有被分配子载波,不能进行数据的传送。针对这一问题提出一种新的子载波的分配方法,在有效保证系统容量的前提下,通过确保每个用户分配到的子载波数目,兼顾了用户之间资源分配的公平性。     

MIMO-MC-CDMA中基于拉氏算子的资源分配算法

提出一种应用于多输入多输出MC-CDMA系统的功率、码道自适应分配算法。基于接收端的信道反馈信息,发送端在总发射功率受限的条件下通过多用户间功率和码道的分配最大化系统吞吐量。算法通过限制用户的最大和最小码道数来实现用户之间的带宽公平性。算法最终归结为一个约束优化问题并利用拉格朗日乘子法进行求解。提出一种用于加快拉格朗日乘子收敛速度的搜索算法,计算机仿真验证了算法的有效性。     

A Novel Bandwidth Allocation Algorithm for IEEE 802.16 TDD Mode Wireless Access Networks

In this paper, we propose a novel bandwidth allocation algorithm for a two-tier hierarchy in IEEE 802.16 time division duplex mode wireless access networks under symmetric and/or asymmetric uplink and downlink traffic input. We demonstrate the performance of the new bandwidth allocation algorithm in terms of accumulated throughput (cumulative bandwidth) and fairness in both infinite and finite buffer cases compared with others by simulations. The simulation results show that the proposed algorithm not only can provide much better fairness and maintain satisfactory QoS support and high cumulative bandwidth but also in the case of finite buffer depth is less buffer-consuming than the others, meaning that the hardware cost can be reduced by employing the proposed algorithm.     

Enhanced Dynamic Bandwidth Allocation Algorithm in Ethernet Passive Optical Networks

As broadband access is evolving from digital subscriber lines to optical access networks, Ethernet passive optical networks (EPONs) are considered a promising solution for next generation broadband access. The point‐to‐multipoint topology of EPONs requires a time‐division multiple access MAC protocol for upstream transmission. In this paper, we propose a new enhanced dynamic bandwidth allocation algorithm with fairness called EFDBA for multiple services over EPONs. The proposed algorithm is composed of a fairness counter controller and a fairness system buffer in the optical line terminal. The EFDBA algorithm with fairness can provide increased capability and efficient resource allocation in an EPON system. In the proposed EFDBA algorithm, the optical line termination allocates bandwidth to the optical network units in proportion to the fairness weighting counter number associated with their class and queue length. The proposed algorithm provides efficient resource utilization by reducing the unused remaining bandwidth made by idle state optical network units.     

Link scheduling with power control for throughput enhancement in multihop wireless networks

Joint scheduling and power control schemes have previously been proposed to reduce power dissipation in wireless ad hoc networks. However, instead of power consumption, throughput is a more important performance concern for some emerging multihop wireless networks, such as wireless mesh networks. This paper examines joint link scheduling and power control with the objective of throughput improvement. The MAximum THroughput link Scheduling with Power Control (MATH-SPC) problem is first formulated and then a mixed integer linear programming (MILP) formulation is presented to provide optimal solutions. However, simply maximizing the throughput may lead to a severe bias on bandwidth allocation among links. To achieve a good tradeoff between throughput and fairness, a new parameter called the demand satisfaction factor (DSF) to characterize the fairness of bandwidth allocation and formulate the MAximum Throughput fAir link Scheduling with Power Control (MATA-SPC) problem is defined. An MILP formulation and an effective polynomial-time heuristic algorithm, namely, the serial linear programming rounding (SLPR) heuristic, to solve the MATA-SPC problem are also presented. Numerical results show that bandwidth can be fairly allocated among all links/flows by solving the MILP formulation or by using the heuristic algorithm at the cost of a minor reduction of network throughput. In addition, extensions to end-to-end throughput and fairness and multiradio wireless multihop networks are discussed.     

A local fairness algorithm for gigabit LAN's/MAN's with spatialreuse

The authors present an algorithm to provide local fairness for ring and bus networks with spatial bandwidth reuse. Spatial bandwidth reuse can significantly increase the effective throughput delivered by the network. The proposed algorithm can be applied to any dual ring or bus architecture such as MetaRing. In the dual bus configuration, when transporting ATM cells, the local fairness algorithm can be implemented using two generic flow control (GFC) bits in the ATM cell header. In the performance it is shown that this local fairness algorithm can exploit the throughput advantage offered by spatial bandwidth reuse better than a global fairness algorithm. This is accomplished because it ensures fair use of network resources among nodes that are competing for the same subset of links, while permitting free access to noncongested parts of the network. The performance advantage of the local fairness scheme is demonstrated by simulating the system under various traffic scenarios and comparing the results to that of the MetaRing SAT-based global fairness algorithm. It is also shown that under certain traffic patterns, the performance of this algorithm achieves the optimal throughput result predicted by the known Max-Min fairness definition     

脏纸编码的多用户MIMO-OFDM系统中基于纳什公平的资源分配算法

MIMO-OFDM技术是实现大容量无线数据传输的一项关键技术。多用户系统中,在最大化系统资源利用率的同时保证用户间资源分配的公平性是系统设计的一个重要问题。该文首先分析了MIMO系统中最大化吞吐量的一种实现方式脏纸编码(DPC),然后基于纳什公平性准则提出了一种用于DPC的多用户MIMO-OFDM系统中的自适应资源分配算法。仿真结果表明,该算法在损失较小系统吞吐量的前提下,很好地保证了用户间资源分配的公平性。     

Dynamic Channel Allocation in Wireless Networks Using Adaptive Learning Automata

Single-channel based wireless networks have limited bandwidth and throughput and the bandwidth utilization decreases with increased number of users. To mitigate this problem, simultaneous transmission on multiple channels is considered as an option. In this paper, we propose a distributed dynamic channel allocation scheme using adaptive learning automata for wireless networks whose nodes are equipped with single-radio interfaces. The proposed scheme, Adaptive Pursuit learning automata runs periodically on the nodes, and adaptively finds the suitable channel allocation in order to attain a desired performance. A novel performance index, which takes into account the throughput and the energy consumption, is considered. The proposed learning scheme adapts the probabilities of selecting each channel as a function of the error in the performance index at each step. The extensive simulation results in static and mobile environments provide that the proposed channel allocation schemes in the multiple channel wireless networks significantly improves the throughput, drop rate, energy consumption per packet and fairness index—compared to the 802.11 single-channel, and 802.11 with randomly allocated multiple channels. Also, it was demonstrated that the Adaptive Pursuit Reward-Only (PRO) scheme guarantees updating the probability of the channel selection for all the links—even the links whose current channel allocations do not provide a satisfactory performance—thereby reducing the frequent channel switching of the links that cannot achieve the desired performance.     

一种新型认知无线电资源分配跨层技术

为有效利用频谱资源,提高频谱效率,文中利用环境感知技术,设计出认知无线电跨层结构框架,提出一种新的功率控制博弈BPCG（Bandwidth and Power Control Game Algorithm）算法。研究不同用户的频谱带宽分配和功率控制,该算法在确保频谱带宽有效分配前提下,通过对用户功率的有效控制,实现网络总吞吐量的提高。仿真结果表明该算法在相同的功率消耗前提下,网络吞吐量显著提高,并随频谱带宽的增加,实现网络吞吐量的最大化。     

一种基于多小区OFDMA系统用户公平性约束的分布式资源分配算法

针对多小区OFDMA系统下行链路,研究了用户公平性约束下的资源分配问题,提出了一种多基站协作的迭代优化的分布式资源分配算法。每个小区根据干扰状况及用户公平性,迭代地进行子载波和功率的资源优化;而每次迭代中,根据用户公平性准则分配子载波,并将非凸的小区功率优化问题转化为其下界的凸问题,通过一个分布式算法来求解。通过仿真验证了算法的有效性;仿真结果表明,与传统网络的固定功率分配的情形相比,所提算法保证了用户之间的公平性并显著提高了系统吞吐量。     

LTE-Advanced中继系统中一种公平的下行资源分配机制

LTE-Advanced(LTE-A)系统引入中继后,带来了如提高频谱效率、拓展网络覆盖等优点,但是也给资源分配带来了更多的挑战。针对LTE-A中继系统的下行资源分配问题,在资源足够使用的情况下,提出一种在eNB和中继功率受限且用户数据速率限制的条件下,以权衡系统吞吐量和用户公平性为目标的资源分配机制。通过仿真验证表明,该算法较好地权衡了系统吞吐量和用户公平性,并且能满足用户速率要求。     

多用户OFDM系统中一种新颖的自适应功率分配方案

针对多用户正交频分复用(OFDM)系统自适应资源分配的问题,提出了一种新的自适应子载波分配方案。子载波分配中首先通过松弛用户速率比例约束条件确定每个用户的子载波数量,然后对总功率在所有子载波间均等分配的前提下,按照最小比例速率用户优先选择子载波的方式实现子载波的分配;在功率分配中提出了一种基于人工蜂群算法和模拟退火算法(ABC-SA)相结合的新功率分配方案,并且通过ABC-SA算法的全局搜索实现了在所有用户之间的功率寻优,同时利用等功率的分配方式在每个用户下进行子载波间的功率分配,最终实现系统容量的最大化。仿真结果表明,与其他方案相比,所提方案在兼顾用户公平性的同时还能有效地提高系统的吞吐量,进而证明了所提方案的有效性。