Interference Management for DS-CDMA Systems through Closed-Loop Power Control, Base Station Assignment, and Beamforming

In this paper, we propose a smart step closed-loop power control (SSPC) algorithm and a base station assignment method based on minimizing the transmitter power (BSA-MTP) technique in a direct sequence-code division multiple access (DS-CDMA) receiver with frequency-selective Rayleigh fading. This receiver consists of three stages. In the first stage, with constrained least mean squared (CLMS) algorithm, the desired users’ signal in an arbitrary path is passed and the inter-path interference (IPI) is reduced in other paths in each RAKE finger. Also in this stage, the multiple access interference (MAI) from other users is reduced. Thus, the matched filter (MF) can use for more reduction of the IPI and MAI in each RAKE finger in the second stage. Also in the third stage, the output signals from the matched filters are combined according to the conventional maximal ratio combining (MRC) principle and then are fed into the decision circuit of the desired user. The simulation results indicate that the SSPC algorithm and the BSA-MTP technique can significantly reduce the network bit error rate (BER) compared to the other methods. Also, we observe that significant savings in total transmit power (TTP) are possible with our methods.

Optimal Positions of Relay Stations for Cluster-Based Two-Hop Cellular Network

Multihop cellular networks is an exciting and a fledgling area of wireless communication which offers huge potential in terms of coverage enhancement, data-rates, power reduction, and various other quality of service improvements. However, resource allocation in MCN is an NP-hard problem. Hence, significant research needs to be done in this field in order to efficiently design the radio network. In this paper, optimal position of relay stations in a hierarchical cluster-based two-hop cellular network is investigated. Vector algebra has been used to derive general equation for carrier-to-interference ratio (C/I) of a mobile station. It has been observed that when the transmit power of base station (BS) and the gateway (GTW)/relay station (RS) are same, the RSs should be located close to mid-point of BS and the edge of the cell. However, significantly, when the transmit power of the BS is greater than that of the GTW, then the RSs should be placed closer to the edge of the cell, in order to maximize the minimum C/I at any point in the cell. This in turn results in higher modulation technique at the physical layer, and hence, a higher data-rate to all the users in the system.

A Trajectory Prediction Based Intelligent Handover Control Method in UAV Cellular Networks

The airborne base station(ABS) can provide wireless coverage to the ground in unmanned aerial vehicle(UAV) cellular networks.When mobile users move among adjacent ABSs,the measurement information reported by a single mobile user is used to trigger the handover mechanism.This handover mechanism lacks the consideration of movement state of mobile users and the location relationship between mobile users,which may lead to handover misjudgments and even communication interrupts.In this paper,we propose an intelligent handover control method in UAV cellular networks.Firstly,we introduce a deep learning model to predict the user trajectories.This prediction model learns the movement behavior of mobile users from the measurement information and analyzes the positional relations between mobile users such as avoiding collision and accommodating fellow pedestrians.Secondly,we propose a handover decision method,which can calculate the users' corresponding receiving power based on the predicted location and the characteristic of air-to-ground channel,to make handover decisions accurately.Finally,we use realistic data sets with thousands of non-linear trajectories to verify the basic functions and performance of our proposed intelligent handover controlmethod.The simulation results show that the handover success rate of the proposed method is 8% higher than existing methods.

Location correction technique based on mobile communication base station for earthquake population heat map

China has mobile phone penetration rate of over 96.2%.Mobile phone has become the largest Internet terminal for Chinese Internet users.Population geographic distribution in earthquake zones can be got based on mobile phone positioning and map matching.For reducing earthquake black-box stage,we propose a real-time collection,correction and schedule algorithm of population position data by four stream processing environments(Redis,Hbase,Kafka,and Spark Streaming)in this paper.For labeling precisely population geographic distribution on the network map,matching of population geographic coordinates and map coordinates are optimized by sample comparison based on location data of mobile communication base stations and prefecture level cities.The test result shows the proposed system is high efficient and can rapidly respond to any emerging parallel tasks during the earthquake.A high-precision heat map of affected population can be produced and published on-line within 2 min after the devastating earthquake happened.

Register Allocation Compilation Technique for ASIP in 5G Micro Base Stations

The currently available compilation techniques are for general computing and are not optimized for physical layer computing in 5G micro base stations.In such cases,the foreseeable data sizes and small code size are application specific opportunities for baseband algorithm optimizations.Therefore,the special attention can be paid,for example,the specific register allocation algorithm has not been studied so far.The compilation for kernel sub-routines of baseband in 5G micro base stations is our focusing point.For applications of known and fixed data size,we proposed a compilation scheme of parallel data accessing,while operands can be mainly allocated and stored in registers.Based on a small register group(48×32b),the target of our compilation scheme is the optimization of baseband algorithms based on 4×4 or smaller matrices,maximizing the utilization of register files,and eliminating the extra register data exchanging.Meanwhile,when data is allocated into register files,we used VLIW(Very Long Instruction Word)machine to hide the time of data accessing and minimize the cost of data accessing,thus the total execution time is minimum.Experiments indicate that for algorithms with small data size,the cost of data accessing and extra addressing can be minimized.

A Path-Based Approach for Data Aggregation in Grid-Based Wireless Sensor Networks

Sensor nodes in a wireless sensor network （WSN） are typically powered by batteries, thus the energy is constrained. It is our design goal to efficiently utilize the energy of each sensor node to extend its lifetime, so as to prolong the lifetime of the whole WSN. In this paper, we propose a path-based data aggregation scheme （PBDAS） for grid-based wireless sensor networks. In order to extend the lifetime of a WSN, we construct a grid infrastructure by partitioning the whole sensor field into a grid of cells. Each cell has a head responsible for aggregating its own data with the data sensed by the others in the same cell and then transmitting out. In order to efficiently and rapidly transmit the data to the base station （BS）, we link each cell head to form a chain. Each cell head on the chain takes turn becoming the chain leader responsible for transmitting data to the BS. Aggregated data moves from head to head along the chain, and finally the chain leader transmits to the BS. In PBDAS, only the cell heads need to transmit data toward the BS. Therefore, the data transmissions to the BS substantially decrease. Besides, the cell heads and chain leader are designated in turn according to the energy level so that the energy depletion of nodes is evenly distributed. Simulation results show that the proposed PBDAS extends the lifetime of sensor nodes, so as to make the lifetime of the whole network longer.

TP80共享 BCM—Ⅲ的 DBASE—Ⅱ数据库

本文讨论了TP801在局域网中共享DBASEⅡ数据库的一种方法.以提高计算机资源的利用率和单板机TP801的功能,为生产过程参数的实时打印报表提供了一个实用工具。

Topology Control and Routing in Large Scale Wireless Sensor Networks

In this paper, a two-tiered Wireless Sensor Network (WSN) where nodes are divided into clusters and nodes forward data to base stations through cluster heads is considered. To maximize the network lifetime, two energy efficient approaches are investigated. We first propose an approach that optimally locates the base stations within the network so that the distance between each cluster head and its closest base station is decreased. Then, a routing technique is developed to arrange the communication between cluster heads toward the base stations in order to guaranty that the gathered information effectively and efficiently reach the application. The overall dynamic framework that combines the above two schemes is described and evaluated. The experimental performance evaluation demonstrates the efficacy of topology control as a vital process to maximize the network lifetime of WSNs.

基于置信规则库气象站故障检测专家系统

针对气象站故障检测的需求,研制了基于置信规则库的气象站故障检测专家系统。专家系统利用前期建立起来的气象站的气象数据库,根据当前实时气象数据,通过改进的置信规则库模型结合专家经验知识自动完成数据分析和处理、是否有故障判断并对故障程度进行等级划分。工作人员在进行现场故障检测之前,只需通过气象站传感器故障专家系统对异常传感器进行辅助诊断,确定故障等级后依据故障等级携带相应检修设备或需更换的零部件进入现场实施检查和维修。实验测试表明系统对各个设备的总体平均检测准确率从69.8%提高到85.7%,极大提升了检测的效率和准确性。

基于POI数据的公共免租站点数字化检测策略探索与应用

在5G网络大规模部署和刚性成本快速增长的局势下,为了节省基站建设场地租赁费用以及制定有效的选址策略,文章提出了一种公共免租站点智能检测的方法。该方法利用中文切词算法挖掘公共免租站点关键词并建立公共免租关键词库,引入广泛的POI数据、基站数据以及合同数据进行匹配和交叉运算,实现系统化、智能化地检测现有站点是否满足公共免租条件。通过建设公共免租关键词库,辅助锁定存量租用的现网物业站点,并以公共免租谈判的手段进行推动,有效地摆脱了传统人工判断的主观性与不确定性,为基站选址决策者提供可靠的参考,从而降低基站租金成本,提高5G网络的经济效益。

面向2G~5G通信的双频双极化基站天线设计

为满足多种通信制式融合的无线通信需求,提出一款覆盖2G、3G、LTE、Sub-6 GHz波段的交叉偶极子基站天线。2对呈±45°正交的偶极子用以实现天线的双极化特性,辐射单元中的扇形内环、钻石状的外环分别对应天线要实现的低频以及高频波段,可以通过对内环以及外环结构参数的调整实现对2个频段的独立控制。天线上方的寄生贴片用以优化天线阻抗匹配。通过制作实物,测得天线在2个频段分别具有49.9%(1.70~2.80 GHz)和19.2%(3.20~3.88 GHz)的相对带宽,隔离度整体优于20 dB,主视轴的交叉极化比优于21 dB,2个波段的半功率波束宽分别为66°±5°、78°±6°。与已有研究比较,该天线结构简单,在交叉极化和增益方面具有显著优势。

基站空调在640层CT数据机房的使用效果

目的探讨基站空调在640层CT数据机房的使用效果。方法640层CT正常开机时,分别记录并比较基站空调和普通空调开启后数据机房温度由28℃降至24℃所需时间、正常运行必需后勤维护项目及次数、整体价格。结果室外温度为-5~30℃时,两种空调达到设定温度所需时间比较,差异无统计学意义(P>0.05),后勤维护项目次数相同;室外环境温度为31~42℃时,基站空调机房降温时间短于普通空调(P<0.05);普通空调需完成后勤维护项目一2次和项目二1次,基站空调需完成项目一2次;在室外环境温度为-6~-15℃时,普通空调故障停机,基站空调达到设定温度需要(12.4±1.5)min;基站空调整体价格高于普通空调;基站空调的整机性价比、操作使用、降温效率、故障报警和环境影响评分高于普通空调(P<0.05)。结论基站空调虽整体价格偏贵,但制冷速度快、可靠性高、维护简单,更适用于640层CT数据机房。

基于负荷准线的5G基站虚拟电厂优化控制方法

在新型电力系统中,亟待深度挖掘需求侧资源以提升系统灵活性和新能源消纳能力。在“新基建”背景下,5G基站作为一种新型需求侧资源正迅速发展。研究如何在保证基站备用需求的前提下,由铁塔公司组建含大规模5G基站的虚拟电厂(virtual power plant,VPP)并常态化参与需求响应。首先,提出了考虑储能动态备用容量的5G基站运行可行域构建方法,建立了5G基站VPP的聚合模型。然后,建立了5G基站VPP响应负荷准线的日前优化模型,提出了适合对大规模5G基站进行协调控制的日内解聚合方法。最后,建立了含高比例新能源的区域电网仿真算例。仿真结果表明,聚合大规模基站参与准线型需求响应,可以显著降低5G基站的运行成本,同时提高电网的新能源消纳能力。

基于AI大数据的无线基站节能系统的设计与应用

为应对2G/3G/4G无线基站在运营商日常运营中高能耗开销及不断上升的电费支出问题,文章提出了一种基于AI大数据技术的无线RAN基站节能系统。该系统旨在针对全网各种场景和不同设备,通过对现有网络配置的深入梳理与调整优化,以及节能功能的智能部署和优化,并对现网站点的建模寻找最优门限值,最后通过AI大数据的持续优化迭代,持续提升节能效益,增强系统的稳定性。在满足用户业务需求的前提下,不断优化无线基站的节能功能,从而显著降低设备功耗,大幅度降低运营商的节能支出。通过实验结果表明,该系统部署到运营商网络中的节能效果十分明显,相比部署该系统之前功耗降幅接近12%,远远高于传统节能手段的增益效果。

LNG储存设施的性能化安全设计研究

本研究重点在江苏如东LNG接收站的性能化布局设计,重点评估储罐区的防火间距。通过依据国际相关标准(NFPA59A–2009和EN1473–2007),结合事故后果分析及安全措施效率,建立了安全调节因子体系,分析了液池火灾潜在影响。结果显示,基于不同标准的储罐防火间距存在差异,并提供了安全距离建议。为满足紧急应急需求,建议储罐与边界距离至少为9m,最终形成了一个兼顾安全性与空间效率的储罐区设计方案。

基于矿用5G技术的采煤机智能化技术

通过综述当前专家学者及工矿企业对“矿用5G+煤矿智能化”技术的研究与应用,得出其进展长足但仍然存在应用场景和生态匮乏的结论。针对采煤机智能化方面存在全面感知能力较弱、远程控制时效性低、通信系统可靠性差的技术短板,构建基于采煤机的矿用5G通信系统。以单一采煤机通信系统为研究对象,分别阐述了采煤机5G通信系统架构、采煤机5G CPE安装方式、综采工作面5G基站布设方式。基于5G技术具有的大宽带、低延时、广连接的特性,展望5G技术应用于采煤机后,可拓展采煤机在煤机云端控制、海量数据传输、故障远程诊断等智能化方面的应用。

基于PROFIBUS-DP控制网络型船舶电站的控制实现

结合当前船舶电站控制所采用的现场总线组网技术介绍某三机组电站的控制实现。其控制核心是由主站可编程序控制器(PLC)与三台发电机同步保护装置(PPU)的从站构成的控制网络;主站PLC实现电站的逻辑控制,从站PPU监测三相电参数及控制发电机运行。主、从站通过PROFIBUS-DP协议实现数据共享。其中网络组态和电站控制逻辑的实现均在Step7V5.4中完成。实践证明其控制方式灵活、可靠、可移植性强,是目前船舶电站控制的主流之一。

基于RK3568的采煤机5G智能控制器硬件电路设计

随着煤矿智能化以及5G技术的快速发展,为了适应煤矿智能化的发展需要,设计了一款基于RK3568为核心处理器的采煤机5G智能控制器,以矿用5G通信技术为基础,通过该5G控制器、矿用隔爆5G路由器、矿用5G基站等组成采煤机5G通信系统,将采煤机摄像头视频、各传感器数据、采煤机工作状态数据等通过5G上传至地面调度中心,实现通信的高可靠、大带宽和低延时。

6G智简无线网络

6G网络需要满足感知与通信、AI与通信、泛在互联等多场景需求,这对6G网络能力提出更高要求。架构与功能设计作为6G网络设计的根基,成为业界研究的焦点。文章提出的6G智简无线网络,基于内生AI的设计,将多样化原子功能通过服务化的形式对外开放,通过按需组合实现网络能力的一体式供给,在接入网架构上采用控制节点与数据节点分离的组网方式,突破现有系统架构与功能的固化设计,有效提升无线系统的可扩展性、可组合性、可复用性,同时基于内生AI可实现网元的动态开关与多维资源的高效复用,由此大幅降低系统能耗和运营成本。

5G通信基站周围电磁辐射水平影响因素研究

随着5G通信基站的大规模建设,5G通信基站的电磁辐射安全成为居民日渐担忧的问题,所以了解各因素对周围电磁辐射水平的影响是环境现场监测的关键之一,该文通过现场监测所得数据进行分析和研究,以期分析结果能为相关监测工作者提供一些帮助和参考。