Asynchronous diversity receiving scheme and analysis on cooperative relay networks简

The transmission antennas of cooperative systems are spatially distributed on multiple nodes, so the received signal can be asynchronous due to propagation delays. A receiving scheme for cooperative relay networks is proposed, multiple asynchronous signals are reconstructed at the receiver by forward and backward interference cancellation, which can obtain gains of cooperative transmission diversity with obvious delay and with no requiring timing synchronization or orthogonal channelization between relays. Analysis and simulation show that the bit error rate（BER） of the proposed scheme is similar to Alamouti code, and the scheme has the diversity order of orthogonal transmission scheme accompanied by minimal BER losses. It is demonstrated that the performance can be further improved by adding an error correcting code（ECC）.     

Routing protocol based on social characteristics for opportunistic networks简

Opportunistic networks are derived from delay tolerant networks, where mobile nodes have no end-to-end connections. Nodes are represented by people, which means that opportunistic networks can be regarded as social networks. Human mobility plays an important role in affecting the performance of forwarding protocols in social networks, furthermore, the trajectory of people＇s movements are driven by social characteristics. However, current routing protocols rely on simple mobility models, and rarely consider social characteristics. Considering two heterogeneous network models, an social opportunistic networks routing（SONR） was proposed which brings an adapted discrete Markov chain into nodes＇ mobility model and calculates the transition probability between successive status. Comparison was made between Spray, Wait and Epidemic protocol. Simulation show that SONR can improve performance on delivery ratio, delivery latency and network overhead, meanwhile. SONR approaches the performance of Epidemic routing.     

Sensor data compression based on MapReduce简

A compression algorithm is proposed in this paper for reducing the size of sensor data. By using a dictionary-based lossless compression algorithm, sensor data can be compressed efficiently and interpreted without decompressing. The correlation between redundancy of sensor data and compression ratio is explored. Further, a parallel compression algorithm based on MapReduce [1] is proposed. Meanwhile, data partitioner which plays an important role in performance of MapReduce application is discussed along with performance evaluation criteria proposed in this paper. Experiments demonstrate that random sampler is suitable for highly redundant sensor data and the proposed compression algorithms can compress those highly redundant sensor data efficiently.     

CATV新技术(9)简

1前言 据日刊“卫星与CATV”连载．继续介绍CATV网络面向家庭所开展的通信业务。本文首先介绍在CATV网络上开展高速通信业务的技术。其中包括DOCSIS（有线电视数据传输业务接口规范）的概况、规格以及QoS等。其次就普及率逐年提高的IP电话业务及其发展概况与技术协议作一综述。同时也对IP电话的通话质量评价方法与质量基准作一介绍以供参考。     

Improved ant colony-based multi-constrained QoS energy-saving routing and throughput optimization in wireless Ad-hoc networks简

In order to establish a route supporting multi-constrained quality of service（QoS）, increase network throughput and reduce network energy consumption, an improved ant colony-based multi-constrained QoS energy-saving routing algorithm（IAMQER） is proposed. The ant colony algorithm, as one of the available heuristic algorithms, is used to find the optimal route from source node to destination node. The proposed IAMQER algorithm, which is based on the analysis of local node information such as node queue length, node forwarding number of data packets and node residual energy, balances the relationship between the network throughput and the energy consumption, thus improving the performance of network in multi-constrained QoS routing. Simulation results show that this IAMQER algorithm can find the QoS route that reduce average energy consumption and improves network packet delivery ratio under the end-to-end delay and packet loss ratio constraints.     

Data streams classification with ensemble model based on decision-feedback简

The main challenges of data streams classification include infinite length, concept-drifting, arrival of novel classes and lack of labeled instances. Most existing techniques address only some of them and ignore others. So an ensemble classification model based on decision-feedback（ECM-BDF） is presented in this paper to address all these challenges. Firstly, a data stream is divided into sequential chunks and a classification model is trained from each labeled data chunk. To address the infinite length and concept-drifting problem, a fixed number of such models constitute an ensemble model E and subsequent labeled chunks are used to update E. To deal with the appearance of novel classes and limited labeled instances problem, the model incorporates a novel class detection mechanism to detect the arrival of a novel class without training E with labeled instances of that class. Meanwhile, unsupervised models are trained from unlabeled instances to provide useful constraints for E. An extended ensemble model Ex can be acquired with the constraints as feedback information, and then unlabeled instances can be classified more accurately by satisfying the maximum consensus of Ex. Experimental results demonstrate that the proposed ECM-BDF outperforms traditional techniques in classifying data streams with limited labeled data.     

下一代电视技术的初步应用探讨简

1前言 下一代广播电视网NGB给与了有线网络业务发展的良好机遇,东方有线已经完成了上海500万户NGB网络的改造和整转工作,发展了百万互动高清家庭用户。随着智能终端、互联网视频等新技术的广泛应用,对现有电视业务产生了较大冲击。目前,欧美日韩以及国内都在研究下一代电视技术。对于什么是下一代电视有多种解释,东方有线从自身业务和网络特点出发,对相关技术做了部分预研工作,希望能与全国同行一起探讨,共同促进有线行业在视频传输和应用方面的持续发展。     

CR–RSS location algorithm for primary user in cognitive radio简

This article introduces the classic locating method based on the receiving signal strength in the cognitive radio and puts forward a cognitive radio-receiving signal strength（CR-RSS） localization algorithm which solves the problem of secondary users locating the primary user and succeeds in estimating the primary user＇s location and transmission power. Through the establishment of cognitive radio network, evaluating the number of secondary users,sampling and the environmental factors to the results in CR-RSS approach. The consequence shows that this approach can effectively locate the primary user and the technology of localization in cognitive radio can assist network optimization.     

浅析计算机病毒及其防范策略简

计算机的应用已经深入到社会生活的各个领域,在给人们生活和工作带来便利的同时,计算机病毒的危害也在与日俱增。只有掌握计算机病毒的有关知识,才能为计算机安全工作提供保障。现从计算机病毒的概念入手,分析了计算机病毒的特性、类型及计算机感染病毒后的症状,并给出了计算机病毒的防范策略。     

LTE时代的异网漫游需求及政策发展趋势简

分析和梳理国外异网漫游的情况以及政策发展趋势,分析我国开展异网漫游的时机和需求,并提出我国异网漫游的政策建议。     

Residual energy based multi-relay selection and power allocation scheme in two-way relay network

In this paper, we have proposed a multi-relay selection and power allocation scheme for two-way relay network which aims to maximize the sum-rate of two-way relay system. First, to prolong network lifetime, a multi-relay selection strategy is proposed in which both channel state information （CSI） and remaining energy （RE） are considered. Next, a multi-relay power allocation algorithm based on convex optimization （MRPA-CO） is presented. To reduce the computational complexity, it can be divided into two steps： terminal nodes power allocation （TNPA） and relay nodes power allocation （RNPA）. Simulation results indicate that the proposed relay selection strategy can significantly prolong network lifetime compared to other relay selection strategies which consider CSI only, and the MRPA-CO algorithm has great advantage over equal power allocation （EPA） on sum-rate in two-way relay network.     

中继蜂窝网中基于功率控制的频谱分配方案

中继蜂窝网络是近年来移动通信领域的热点,为了解决传统蜂窝网络的缺点,本文提出了在中继蜂窝网中基于功率控制的频谱分配方案,通过中继方式,解决了远近效应的问题,通过频率复用可以显著的提高系统频率资源利用率和系统性能,通过采用基站功率控制技术解决了由于资源复用带来的链路干扰过大问题。     

Multi-user selection based on particle swarm optimization and power control scheme in the uplink CoMP-MU-MIMO system

Orthogonal frequency division multiplexing （OFDM） which has been adopted in the long-term evolution （LTE） system can improve the system capacity obviously. However, it also brings about severe inter-cell interference （ICI） for cell-edge users （CEUs）. To tackle this problem, multi-user selection and power control （MuS-PC） is proposed as an efficient scheme in uplink coordinated multi-point multi-user multi-input multi-output （CoMP-MU-MIMO） transmission/reception. This paper jointly considers user＇s signal to interference plus noise ratio （S1NR） and proportional fairness （PF） to maximize the total channel capacity in multi-user selection by formulating a penalty function. To simplify the penalty function＇s computation, particle swarm optimization （PSO） algorithm is introduced. In addition, power control is adopted to maximize overall energy efficiency. Simulation results demonstrate that the MuS-PC scheme can not only obtain the optimal total channel capacity while guarantee each user＇s quality of service （QoS） and PF, but also largely reduce computational complexity and improve energy efficiency. As a result, the poor communication quality of CEUs can be enhanced.     

多业务CDMA蜂窝移动通信系统的功率控制

本文提出了多业务CDMA蜂窝移动通信系统的一种下行链路功率控制策略，系统的最优功率分配可以归结为求解归一化链路增益矩阵在有约束条件下的最大实特征值。在对系统的最优功率分配进行理论分析的基础上，给予了相应的仿真结果，并针对实际系统负载过重的情形，提出了按照业务优先级别逐步去除小区用户的功率控制策略。     

基于PLC的电源终端控制设计

终端控制是电源系统的重要组成,是实现电源各种功能控制的执行和监督单元。电源系统包括控制、驱动、终端控制,供电部分和安全保护部分。本次研究的终端控制主要任务是提高电源20%的有效利用率,采用预定程序改变主电路和控制电路的启动、调速、制动和反向的主令装置,实现对系统数据信息进行采集和反馈,针对采集信息对控制系统发出相应命令,进而达到对系统电源有效提高20%工作效率的目的。     

Joint power allocation and multi-relay selection scheme based on system outage probability

An amplify-and-forward （AF） based multi-relay network is studied. In order to minimize the system outage probability with a required transmission rate, a joint power allocation （PA） and multi-relay selection scheme is proposed under both total and individual power constraints （TIPC）. In the proposed scheme, the idea of ordering is adopted to avoid exhaustive search without losing much system performance. Besides the channel quantity, the ordering algorithm proposed in this article also takes relays＇ maximal output ability into consideration, which is usually ignored in traditional relay ordering algorithms. In addition, simple power reallocation method is provided to avoid repetitive PA operation during the process of searching all possible relay subsets. By Adopting the idea of ordering and using the proposed power reallocation method lead to remarkable decrease of the computation complexity, making the scheme easier and more feasible to implement in practical communication scenarios. Simulations show that the proposed multi-relay selection scheme provides similar performance compared to the optimal scheme with optimal PA and exhaustive search （OPAES） but with much lower complexity.     

基于状态机控制的飞机供电系统仿真

飞机供电系统是整个飞机系统的重要部分,负责向机上的所有负载提供可靠的电能。电源控制单元能够针对飞机的故障采取相应的保护措施,保证飞机的安全飞行。传统的飞机供电系统仿真采用逻辑器件完成电源控制作用,这种方法对供电系统多重故障的处理过于复杂。基于Ansoft/Simplorer软件,本文提出了一种基于状态机控制的飞机供电系统仿真新方法。通过状态变量和状态转换条件的设置,实现电源控制单元功能,完成飞机供电系统仿真。结果表明,状态机控制方法能够准确快捷地实现飞机供电系统的仿真。     

基于不确定非线性智能电网感知网络控制系统方法研究

针对传统的不确定时滞的鲁棒控制系统不能满足现代电力系统发展的需求,提出一种基于不确定非线性智能电网感知云网络化控制识别方法。使用传统的数据值和基于电力网络到网络系统模型作为电力感知网络到网络模型的电力云网络,控制数据优化使用电源感知网络,而不是利用控制节点的预测值,突破了鲁棒控制的不确定时滞系统的控制效果。运用感知模型中的正向云算法修正加权系数,仿真实验证明,该识别方法能够很好地优化传统的不确定时滞鲁棒控制电力系统,具有良好的适应性和鲁棒控制性,进一步提高了智能电网传感云网络控制的各项性能指标。     

基于STC单片机的电源管理模块的设计

在土木工程建设领域,一些工程监测项目中使用的监测设备采用的是太阳能电池板、蓄电池供电方式.为了保证整套监测系统长期可靠运行,文中详细介绍了基于STC单片机的远程电源管理模块的设计方法,该模块以STC11F02E单片机为核心,具有无线通讯的功能,可以灵活设定继电器固定的开启关闭时间,现场测试结果表明该模块实现了对监测设备的电源管理功能,具有一定的实用价值.     

Optimal energy-efficient scheme for two-way relay channel using physical layer network coding

Systems are always designed and optimized based on full traffic load in the current literatures.However,practical systems are seldom operating at full load,even at peak traffic hours.Instead of maximizing system rate to achieve the full load,an optimal energy-efficient scheme to minimize the transmit power with required rates is investigated in this article.The considered scenario is a two-way relay channel using amplify-and-forward protocol of physical layer network coding,where two end nodes exchange mess...