MIM0-0FDMA系统中理想信道估计

该文对基于802．16d／e实现的MIMO-OFDMA系统模型的信道估计算法进行了研究,提出了已知信道估计设计的一种基于时-频域分析法的实现方案。在该方案下的性能可以作为衡量其它信道估计算法性能的一个参考基准,并根据OFDMA系统上行链路的导频分布特点,利用导频进行线性插值信道估计的LSE信道估计,测试结果表明无论对于何种情况,已知信道估计的都优干线性插值信道估计,SUI-1情况中当SNR大于7dB后,线性插值信道估计与已知信道估计的性能差距超过2dB,其它SUI情况性能差距不超过2dB。     

基于多用户OFDM和分布式天线的认知无线电中最优子载波分配方案

分别在平坦衰落和频率选择性衰落的无线信道模型中建立了基于多用户正交频分复用技术（OFDM）和分布式天线的认知无线电系统中子载波分配模型.该模型不再用＂干扰温度＂限制认知用户来保护主用户,而是规定主用户在其所有子载波上的吞吐量之和需要高于一定的门限.然后,根据不同信道模型的特点提出了最优子载波分配方案,该方案利用分支定界法和隐枚举法最大化系统的吞吐量.最后,利用Pegging算法提出了效率与公平折中的子载波分配方案.仿真证明,在不同场景中所提出的子载波分配方案与现有方案相比在吞吐量和公平性方面均具有较大的优势.     

下行多用户MC-CDMA系统中的自适应资源分配

研究了多用户场景下多载波码分多址系统（MC—CDMA）的下行信道和功率分配,并将吞吐最大化问题建模成一个混合整数优化问题．为了简化分析,将问题分成2个低复杂度的子问题：功率分配和信道分配．这2个子问题可分别被一个次最优自适应功率分配算法（APA）和一个最优自适应信道分配算法（ACA）解决．通过联合APA和ACA算法,进一步提出了一个自适应信道和功率的分配方案．仿真结果表明：与传统的均匀功率分配算法相比,提出的APA算法更加适用于MC—CDMA系统;此外,提出的自适应信道和功率分配方案可以显著地提高系统吞吐量性能．     

Optimal distributed resource allocation in a wireless sensor network for control systems

INTRODUCTION With the rapid development of wireless com-munication technology, the combination of wireless communication and control systems becomes a new trend of networked control systems. Among the kinds of wireless technologies, wireless sensor network (WSN) has attracted a lot of interest and visibility due to its huge application space. WSN is a kind of wire-less ad-hoc network which connects embedded sen-sors, actuators, and processors and in which each node consists of a wireles…     

运用匈牙利法求解分配问题

文中针对于运筹学基础及应用的教材上运用匈牙利法求解分配问题的过程做了改进,并举例说明了矩阵中没有独立零元素情况的具体处理办法.     

基于最大独立集的多信道无线网络信道分配方法(英文)

提出了一种基于最大独立集的信道分配方法,以减少网络冲突提高网络性能.首先,建立信道分配模型,并通过所提出的低复杂度近似算法求取冲突图中的最大独立集序列;然后,以独立集间的冲突顶点数作为加权值,获得加权冲突图,通过加权冲突图,以最小化独立集间冲突为目标将链路分配至各信道;最后,每个节点根据本节点网卡中队列长度为已分配信道的链路分配网卡.仿真结果表明,该方法有效地提高了网络吞吐量,降低了端到端延时.     

Joint channel and power allocation scheme for cognitive wireless networks

Cognitive radio (CR) is a promising technology deemed to improve the efficiency of spectrum utilization. This paper considers a spectrum underlay cognitive radio network, in which the cognitive users (CUs) are allowed to use the radio spectrum concurrently with the primary users (PUs) under the interference temperature constraint. We investigate the system performance by using the proposed joint channel and power allocation scheme under two transmit strategies to achieve higher data rates and performance diversity gain respectively. Simulation results show that the proposed scheme provides a significant improvement on the bit error rate (BER) performance and spectrum efficiency of a cognitive wireless network.     

Media-specific rate allocation in heterogeneous wireless networks

INTRODUCTION With the development of novel wireless tech- nologies and increasing available bandwidth, multi- media applications over wireless networks become attractive for both businesses and end users. Fast de- ployment of Wi-Fi HotSpots, increase in wireless coverage of remote habitable areas (Wi-Max, or wireless mesh networks), improved data services over the 2G cellular systems and the long awaited debut of 3G wireless services offer many potential and inter- operable communicatio…     

Joint routing and rate allocation for multiple video streams in ad-hoc wireless networks

INTRODUCTION Ad-hoc networks are attractive owing to their self-organizing nature and absence of a fixed infra- structure. They are particularly suited for communi- cation in disaster-affected areas, coordinating military operations, and sensing environmental conditions With the growing availability of supporting hardware and decreasing equipment cost, ad-hoc networking based applications are proliferating. Meshes of wire- less nodes are being deployed in cities and housing communities to…     

Adaptive resource allocation algorithm for internet of things with bandwidth constraint

In order to improve the transmission accuracy and efficiency of sensing and actuating signals in Internet of Things(IoT) and ensure the system stability,an adaptive resource allocation algorithm is proposed,which dynamically assigns the network bandwidth and priority among components according to their signals’ frequency domain characteristics.A remote sensed and controlled unmanned ground vehicle(UGV) path tracking test-bed was developed and multiple UGV’s tracking error signals were measured in the simulation for performance evaluation.Results show that with the same network bandwidth constraints,the proposed algorithm can reduce the accumulated and maximum errors of UGV path tracking by over 60% compared with the conventional static algorithm.     

一种基于结构相似度的多视点码率分配方法

多视点视频编码是当前视频编码领域的研究热点之一。在有限的网络带宽下,合理的码率分配可以提高视频主观视觉质量。本文提出一种基于结构相似度的码率分配方法,首先对视频帧提取基于结构相似度的显著图,然后结合显著图对重要宏块和非重要宏块分配不同的QP值,以达到码率分配的目的。实验结果表明,本文方法在有限的带宽下能有效的提高多视点视频的视觉主观质量。     

一种蜂窝网络中支持D2D通信的资源分配方法

基于冲突图模型形成的二进制整数规划,提出了一种蜂窝网络中支持D2D通信的无线资源分配方法．首先,提出一种频率资源分配算法,即为每个D2D链路都分配一个频率资源块．分配频率资源时将尽可能地利用蜂窝网络中的无线频率资源空间重用机会．然后,提出一种时隙调度算法,即为所有分配同一频率资源块的D2D链路进行时隙资源调度．调度时隙资源时将保证使用同一频率资源块的D2D链路之间达到长期平均吞吐率的比例公平．通过计算机仿真对所提出方法的性能进行了验证,结果表明该方法能够在蜂窝网络中实现D2D通信功能．     

多载波系统中低复杂度的改进比特和功率分配算法

基于迭代的比特和功率分配机制,提出了一种低复杂度的比特和功率分配算法.与传统的迭代分配算法不同,该算法在每次迭代中只需要比较几个特定的子载波.该方法在保持传统迭代算法性能的前提下极大地减小了迭代分配算法的复杂度.此外,通过选择等功率分配方案作为初始方案加快了算法的收敛速度,进一步降低了算法复杂度.仿真结果表明,提出的改进算法在基本不牺牲系统性能的前提下有效地降低了算法复杂度.     

多输入多输出无线光通信系统中的自适应调制技术

在基于强度调制、直接检测的多输入多输出无线光通信系统中,为了保证发射信号非负特性,提出一种基于直流偏置的自适应调制技术,并且利用奇异值分解将多输入多输出信道转换为并行信道。此外,提出一种基于 QR 分解、逐次干扰消除的自适应调制技术。在目标误比特率性能条件下,利用 QR 分解、逐次干扰消除的特性将多输入多输出信道等效为并行信道。根据最大化可达速率的优化目标,最优地给各个子信道分配功率。仿真结果表明所提出的2种自适应调制方法在保证误比特率性能和平均发射光功率恒定的前提下,有效地提高了系统的传输速率。这2种自适应调制技术在利用多输入多输出技术空分复用增益的同时,进一步提高了无线光通信系统的频谱利用率。     

凹资源配置问题的混合动态规划方法

Concave resource allocation problem is an integer programming problem of minimizing a nonincreasing concave function subject to a convex nondecreasing constraint and bounded integer variables. This class of problems are encountered in optimization models involving economies of scale. In this paper, a new hybrid dynamic programming method was proposed for solving concave resource allocation problems. A convex underestimating function was used to approximate the objective function and the resulting convex subproblem was solved with dynamic programming technique after transforming it into a 0-1 linear knapsack problem. To ensure the convergence, monotonicity and domain cut technique was employed to remove certain integer boxes and partition the revised domain into a union of integer boxes. Computational results were given to show the efficiency of the algorithm.     

Dynamic bandwidth allocation scheme for MCNS DOCSIS

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一种新的HDR无线网络吞吐率容量计算方法

基于一种新的非参数方法计算了HDR (high data rate)无线网络的吞吐率容量区域. 首先把HDR吞吐率容量区域的计算问题转化为一个不带参数的数学优化问题, 然后通过贪婪算法求解得到该优化问题的解, 从而最终给出了HDR吞吐率容量区域的非参数解析刻划. 与传统的参数化方法的庞大计算量相比, 该方法的计算复杂度降低很多, 最多只需要计算N(M2-M 1)N-1个线性约束即可, 其中N为用户数, M为系统支持速率数. 数值计算例子验证了这种非参数方法的正确性.     

Adaptive finite element-element-free Galerkin coupling method for bulk metal forming processes

An adaptive finite element-element-free Galerkin （FE-EFG） coupling method is proposed and developed for the numerical simulation of bulk metal forming processes. This approach is able to adaptively convert distorted FE elements to EFG domain in analysis. A new scheme to implement adaptive conversion and coupling is presented. The coupling method takes both advantages of finite element method （FEM） and meshless methods. It is capable of handling large deformations with no need of remeshing procedures, while it is computationally more efficient than those full meshless methods. The effectiveness of the proposed method is demonstrated with the numerical simulations of the bulk metal forming processes including forging and extrusion.     

一种二进制/十进制相互转换的创新思路与方法——"抓药式配数法"

数制的相互转换是学习计算机的重要基础内客.根据教学实践经验,分析了计算机教学中传统的数制进位原理和转换方法,创立了一种新的方法--"抓药式配数法",它不仅能够为我们推介一种新颗的、极其有效的分析计算方法,更可以为我们提供解决类似或相关问题的一种思路.     

Power auction and allocation for network-coded cooperation

Optimal resource allocation is critical to the efficiency of cooperative communications. In this paper, we develop an auction-based power allocation mechanism for network-coded cooperation in wireless networks, in which the sources compete for the relay power for maximum utility, while the relay node assigns the resource in accordance with the bids from the sources. Moreover, to improve the resource utilization, the relay node is allowed to perform network coding across the received information for the same destination. Finally, numerical results validate the performance of the proposed algorithm, and show that there exists a tradeoff between the system outage probability and the power consumed at the relay node.