室内无线传感网络位置指纹法的研究

近年来，基于位置的定位服务技术被普遍应用，依据其使用的不同技术,可以分为室内、室外两种定位服务。其中，卫星定位及基站定位是眼下应用最广泛的室外定位技术，卫星定位利用卫星反馈的信息，如经纬度的坐标参数等进行定位，常见的卫星定位系统如美国全球定位系(GPS)、俄罗斯格洛纳斯(GLONASS)、欧洲伽利略(GALILEO)系统、中国北斗卫星导航系统等。室外定位服务技术已经实现了规模化和体系化，随着互联网时代的高速发展及大数据时代的到来，人们足不出户就可以办理很多事情。在这样的前提下，室内定位的需求越来越强烈，精度要求越来越高，由于室内环境复杂及空间相对狭小，技术难度也日益增大。当下，WiFi、蓝牙、UWB等是应用最广泛的室内定位技术，而不断发展的无线传感网络(WirelessSensorNetwork，WSN)也为室内定位提供了新的应用方案——无线室内定位。     

一种基于iBeacon技术在室内定位上的应用

众所周知,目前国内定位技术主要以室外定位为主,依靠于北斗/GPS定位技术来实现;针对GPS定位技术在室内无法获取精确位置信息的问题,文章提出了一种基于低功耗蓝牙技术的室内定位方案。在该方案中,基站iBeacon配合接收机将与位置有关RSSI(Received Signal Strength Indicator)值,通过信号衰减模型室内定位算法计算其位置。实验表明,该系统方案使室内定位精度保持在3m以内,基本满足大多数室内定位的场合;且该套方案成本较低,具有一定的市场应用价值。     

基于GPS与WiFi的室内外无缝定位技术研究

随着信息技术的突飞猛进,人们对于基于位置的服务的需求日益增加。在室外,GPS技术已经日趋成熟,已经可以满足人们在室外的位置需求。室内Wi Fi定位技术具有信息传输速度快,成本低,定位精度高的优点,受到研究者的青睐。结合两者优势,本文研究了一种结合GPS与Wi Fi的室内外无缝定位技术。     

基于ZigBee的城市公交车定位系统设计

利用无线传感器单片机CC2431和CC2430设计了一个基于ZigBee的公交车无线定位系统。传统的定位都是采用GPS或者GPRS的定位。GPS定位系统设计简单,可以使用免费的定位卫星资源,但是移动台到控制中心的数据传送需要借助其它网络资源;GPRS定位是基于移动蜂窝式通信的定位,使用现有的移动网络,但是带宽低,不利于突发事件的快速处理。本文设计的Zigbee的无线定位系统基于无线单片机CC2431[1],利用CC2431自带的RSSI定位引擎[2],再运用无线自组网[3]进行定位并向控制中心传送定位信息。该系统设计简单,定位精确度高,设备成本低廉,适合现代化城市的公交车系统智能管理。     

蜂窝网与GPS相结合的手机混合定位技术-gpsOne

介绍了手机定位技术，分析了目前两种主要无线定位技术即基于GPS和基于蜂窝移动通信网络定位的优缺点，接着介绍了结合以上两种无线定位技术的手机混合定位技术-gpsOne技术以及它的应用现状，表明gpsOne技术改善了定位的可用性、灵敏性、精确度和定位耗时，已逐渐成为世界上被广泛使用的移动电话个人定位技术。     

基于ZIGBEE技术的室内定位算法研究及应用

近年来,随着无线传感器网络技术的发展,人们对基于无线传感器网络的室内定位需求越来越多。本文对现有的几种室内定位技术进行了研究,分析了它们的原理及特点,并针对ZigBee网络着重介绍了RSSI在室内定位方面的应用。     

5G NR定位技术及其部署方案

提出了5G新空口(NR)在不同场景下的定位网络部署方案和定位技术部署方案。其中,定位网络部署包括基于核心网部署的架构和基于本地计算部署的架构。5G不同场景下的定位技术部署包括室外单站的往返时间(RTT)+到达角(AOA)方案部署、室外多站的RTT方案部署、室内室分环境的上行信号到达时间差(UL-TDOA)部署,以及室内室分+融合定位的QCell+X无线定位等。这些技术和方案能为5G时代的定位部署带来重要参考价值。     

混合无线定位技术的应用研究

无线定位技术在现代社会中发挥着重要的作用。文中首先描述基于GPS、蜂窝网络和RFID的3种典型无线定位技术的原理,分析了各自的特点,并介绍了混合无线定位技术在手机定位和智能交通管理中的应用实例。研究表明,混合无线定位技术,综合了多种无线定位技术的优点,能有效提高定位准确性和可靠性,是无线定位技术发展的趋势。     

基于圆形可重构智能超表面阵列的单基站定位方法

无线定位技术在物联网时代至关重要,在室外开阔场景下,GPS可以提供米级精度的定位;而在室内等特殊应用场景,其精确的位置信息则依赖于额外部署的基站来提供。通常而言,一个终端设备的位置信息至少需要3个定位基站同时工作,并通过几何解算的方式来提供。近些年,随着RIS的发展,其灵活性为单基站的高精度定位提供了新思路。基于RIS的单基站定位技术,通过同时估计目标方位和目标距离,来提供定位终端的位置信息。该系统具备低复杂度、高精度、和低成本的特点,有望在室内定位、自动驾驶、工业互联等领域发挥重要作用。     

基于RSSI的室内定位算法

随着生活水平的不断提高,智能设备越来越普及,人们对室内定位的需求越来越高,室内定位技术是指在室内环境下,通过无线终端设备和无线传感器网络来确定用户位置信息的相关技术,文章对基本的RSSI的室内定位进行了分析。     

一种基于多天线簇的新型LTE室内定位系统

随着移动互联网业务的迅速发展,位置服务需求越来越多样化,定位技术也变得越来越重要.LTE(long term evolution)室内蜂窝网络可以解决GPS(global positioning system)信号无法进入室内的问题,从而提供高精度的位置服务.LTE室内定位需要不同基站之间进行精确同步,这给室内网络部署带来了新的挑战.针对上述问题,提出了一种基于多天线簇的LTE新型无线定位系统,通过上行探测参考信号(sounding referencesignal,SRS)获取信号到达时间差(time difference of arrival,TDOA).该方法不需要簇间同步,可有效降低网络部署难度.其次,针对此系统设计了一种新的TDOA定位算法,可支持灵活的天线簇配置.最后,通过仿真及实验验证了该定位系统及算法的有效性,实验结果表明可实现米级室内定位精度.     

基于反向学习策略的自适应花授粉接收信号强度指示室内可见光定位

为提高大型室内场所的定位精度,提出一种基于改进自适应花授粉算法的接收信号强度指示(RSSI)可见光定位方案。利用固定在屋顶呈网格型排布的LED发送位置信息,接收端采用基于反向学习策略和自适应花授粉算法的RSSI定位方法实现精确定位。传统花授粉算法具有易陷入局部最优、缺乏变异机制等缺点,利用反向学习策略可使初始种群分布更加均匀,通过提高种群多样性可使算法跳出局部最优;采用有利于全局广泛搜索的自适应移动因子提高收敛速度。在100 m×100 m×100 m大型室内场所的一层100 m×100 m×10 m的空间中,考虑热噪声和散射噪声干扰的情况,经过多次仿真可得,相比于传统定位算法,随机灯排布下采用改进花授粉的RSSI算法的定位误差小于±1 cm;采用网格型灯排布结合改进定位算法的室内可见光定位系统时,定位精度得到明显提升,定位时间大幅缩短。该方案具有定位精度更高、计算速度更快、工作稳定等优点。     

Multipath Mitigation Technique Based on Partial Autocorrelation Function

GPS positioning accuracy in indoor and urban canyons environments is greatly affected by multipaths due to distortions in its autocorrelation function. In this paper, the first sidelobe of Pseudorandom Noise (PN) code autocorrelation is studied and a new multipath mitigation technique based on PN code autocorrelation function is presented. This new technique relies on the detection of the partial autocorrelation function that is affected by multipath signals. The increase in fractional delay of the line-of-sight (LOS) signal is calculated. Simulation results indicate that the proposed technique has superior performance compared with the 0.1-chip-spacing narrow correlator on mitigating multipath signals, especially the short-delay multipath signals. Zhang Zhen obtained his Bachelor’s Degree from Beijing Information and Technology Institute in 1999, Master’s Degree from Tsinghua University, Beijing China, in 2002. He now is a Ph.D. student in Nanyang Technological University. Currently he also works as a Research Associate in the Positioning and Wireless Technology Center (PWTC), NTU. His research interest includes multipath mitigation for GPS, software GPS receiver design, indoor GPS as well as Ultra Wide Band (UWB) based ranging systems. C. L. Law is an Associate Professor in School of EEE, NTU and the Director of PWTC. Dr. Law’s current research area is in Wireless Networks. His research topics are in microwave integrated circuits, indoor wireless channel modeling, analysis of indoor wireless LAN performances and in techniques for overcoming the time-dispersion distortions in high speed wireless LAN. E. Gunawan is an Associate Professor in School of EEE, NTU and his research interest includes Error Correction Codings, Modeling of Cellular Communications Systems, Power Control for CDMA Cellular Systems, MAC Protocols, Multicarrier Modulations, Multiuser Detections, Space-time Coding, Radio-location Systems, UWB and its applications for Human Body Vital Signs Detection, and Powerline Communications.     

位置指纹定位技术

在室内利用无线网络对移动目标定位,可用的技术有基于波达时间(TOA/TDOA)、基于波达角度(AOA)、以及基于接收信号强度(RSS)的技术等。比较而言,基于接收信号强度(RSS)的位置指纹(LF)技术更适合于复杂的室内环境。对该技术目前的研究情况进行比较全面和详细的介绍。     

基于GPS／GPRS的智能公交系统的设计与实现

针对国内外公共交通管理的实际情况及GPS技术的发展现状,以及目前国内没有将GPS,GPRS和GIS相融合以实现车辆定位信息的采集、收发和显示的成熟智能公交系统。文中设计一种基于GPS,GPRS和GIS技术的智能公交系统,并详细介绍了其组成结构和工作原理。该系统实现了基于GPS的车辆实时信息采集、基于GPRS的信息无线传输、基于GIS的车辆远程监控调度。     

Performance Analysis of Tags Collection Time on A New Architecture of 2.4 GHz Embedded Active RFID System for Indoor and Outdoor Tracking and Monitoring Applications Based on IEEE 802.15.4 Standard

This paper focuses on the analysis of tags collection time of 2.4 GHz embedded active Radio Frequency Identification (RFID) system for indoor and outdoor real-time tracking and monitoring applications based on IEEE 802.15.4 standard. The main novelty of the system is the implementation of the communication method in order to provide Machine to Machine (M2M) communication and automated switching mechanism between indoor and outdoor location by utilizing active RFID, Wireless Sensor Network (WSN), Global Positioning System (GPS) and mobile communication on a single platform. In this work, GPS receiver covers outdoor location tracking, while active RFID provides identification and Receive Signal Strength Indicator (RSSI) reading for each tag holder to cover indoor location tracking especially near or inside building where location information is not detected by GPS. Several experiments were conducted on three different RFID tags which were active RFID tag embedded with GPS and GSM (ERFIDG2), active RFID tag embedded with GPS (ERFIDG) and standalone RFID tag communicating with the same active RFID reader. The experiment was done to evaluate the communication performance of the active RFID in terms of tags collection time using Transparent (AT) and Application Programming Interface (API) mode. The experiment was extended to measure tags collection time in single hop and multi hops communication for Tag Talk First (TTF) and Reader Talk First (RTF) protocols. The results show that the proposed active RFID system (ERFIDG2) is better than the standalone and ERFIDG systems. The in-depth research done in this work is to study the experience and identify the challenges that will be faced in the development and implementation of a wireless RFID-based system for tracking and monitoring applications.     

A Novel Wireless Positioning System for Seamless Internet Connectivity based on the WLAN Infrastructure

Nowadays, several positioning systems are available for outdoor localization, such as the global positioning system (GPS), assisted GPS (A-GPS), and other systems working on cellular networks, for example, time difference of arrival (TDOA), angle of arrival (AOA) and enhanced observed time difference of arrival (E-OTD). However, with the increasing use of mobile computing devices and an expansion of wireless local area networks (WLANs), there is a growing interest in indoor wireless positioning systems based on the WLAN infrastructure. Wireless positioning systems (WPS) based on this infrastructure can be used for indoor localization to determine the position of mobile users. In this paper, we present a novel wireless positioning system, based on the IEEE 802.11b standard, using a novel access point (AP) with two transceivers to improve the performance of WPS in terms of accuracy of the location estimation and to avoid service connectivity interruption. In our proposed system, the novel AP uses the second transceiver to find information from neighboring mobile stations (STAs) in the transmission range and then sends information in advance to associated APs, which estimate the location of the STA based on an internal database. We also use a TDOA technique to estimate the location of the STA when there is not enough information in the database (in this case, the STA moves into a new area where the system has not run the calibration phase). Using TDOA, the database can be generated and updated automatically. The initial results from our simulations show that the proposed system provides higher accuracy of location estimation than other related work and does not interrupt the Internet connection for end users in contrast with other proposed schemes.

基于DMT/QAM和STBC的室内MIMO光无线通信

针对室内漫射光无线通信问题,提出一种采用离散多音/正交幅度调制和空时块编码的多输入多输出(MIMO)光无线通信技术.基于离散多音/正交幅度调制技术,并通过考虑室内全光无线信道的脉冲响应和其噪声特性,建立起室内红外光无线链路的信道模型;再采用空时块编码技术,提出一种实现室内漫射光无线通信的MIMO无线通信系统,并通过分析...     

粒子群算法优化的智能机器人无线充电方法

目前机器人传统直插式充电方式存有布线复杂、灵活性差,且不适用于易燃、易爆等特殊环境等问题,无线充电技术的应用有利于促进机器人智能化方向发展。为提高机器人无线充电效率,设计了一种基于无线通信技术、定位技术、无线充电技术的机器人智能无线充电系统;为提高粒子群算法全局寻优能力,引入鸽群优化算法地图、指南针算子和地标算子,提出了一种粒子群-鸽群融合定位算法对机器人充电位置进行定位优化;实验数据表明,设计算法具有较高的定位精度,较快的收敛速度,有利于机器人获取最佳充电位置,提高充电效率。