GT-800数字集群通信系统信息传输机制

GT-800数字集群通信系统具有自主知识产权,是行业内性能优良的集群通信系统。文章以GT-800数字集群通信系统标准为依据,介绍了GT-800的接口信令扩充机制、数据帧结构和信道共享机制等信息传输关键技术,对GT-800系统的推广运用具有实践指导意义。     

ZigBee Mesh网络在有源RFID系统中的应用

有源射频识别(RFID)系统广泛应用于人和物品的低功耗无线追踪,而ZigBee是一种基于IEEE802.15.4标准的低功耗、低成本、高性能的局域网协议。这里介绍了一种将ZigBee Mesh网络应用于有源RFID系统的方法,设计了系统节点,并进行了单跳通信和多跳通信实验,实验结果显示两者结合增强了系统灵活性,降低了系统功耗。     

基于FPGA的E1/Ethernet互联方案的研究与实现

作为电信网与计算机Internet网基础——E1链路和以太网传输链路,它们之间的互连互通对实现两网的融合通信和优势互补具有很强的应用价值和现实意义。对此提出了一种基于FPGA的E1_以太网适配器的设计,主要包括HDLC帧与MAC数据帧格式的转换、系统同步机制的实现、数据缓存机制和流量控制的实现。适配器的主要功能是采用FPGA硬件编程实现的,具有系统处理速度快、设计灵活、控制方便等优点,在应用中取得了较好的效果。     

RFID 有源电子标签节能技术研究

在对RFID有源电子标签节能常规解决方法中存在的弊端进行分析的基础上,提出了利用感应器切换RFID有源电子标签的工作模式和对RFID有源电子标签根据不同应用场景设置不同休眠策略的办法,有效减少RFID有源电子标签射频发送次数,达到节约能量的一种新的节能技术。以典型应用详细说明了电子标签进出出入口方向的准确判定和休眠时间策略设置方法,并介绍了在重要物品管控系统中利用新节能技术研发的感应器、RFID有源电子标签的功能、组成、软件设计,从而验证新的节能技术能应用于RFID有源电子标签系统中。     

基于RFID和微功率技术的落水人员搜救系统

本搜救系统将RFID技术和微功率无线通信技术相结合,使RFID技术如同插上了“翅膀”,将其信息通信距离增大;系统将RFID与传感器（温度传感器、时间传感器）技术相结合,实现了RFID在无线传感网中的应用。系统通过应用RFID、微功率通信、无线定位、通信加密、数据统计等多项技术,形成了不依赖于人眼视觉和声音进行搜索的独特优势。     

一种时间高效的易于实现的多标签射频识别技术

多标签碰撞问题严重影响射频识别RFID系统的识别效率.在研究子帧观测机制的基础上,针对常规动态帧时隙Aloha多标签防碰撞算法存在的复杂度高、时间效率低等问题,提出了一种基于子帧的动态帧时隙Aloha算法,其在识别过程中采取设定的子帧观测,运用空闲与碰撞时隙数的关系估计剩余标签数,再依据预估的结果优化设置新的帧长,显著提升了大容量多标签RFID系统的识别效率.该算法的运算复杂度低、计算量小,易于在常规RFID读写器中实现,工程应用前景广阔.仿真结果表明：同传统的Aloha类防碰撞算法相比,提出的算法具有复杂度低、稳定好、识别效率高等优势.     

有源RFID的LF无线唤醒技术研究

文章根据有源RFID具备在特定的环境下发射功率是很低的;它根据两边点对点的传输,通信传输的距离很长;在传输的过程中,根据传输的介质的特性使得传输数据量很大;在传输的过程中传输的数据不容易被丢失,其可靠性很高;传输中的不同的数据彼此间不会排斥,兼容性好且稳定等特点,现阶段研究最多的就是有源RFID的LF无线唤醒技术,这种技术取得了新的突破,并得到了广泛的应用。有源RFID标签设计领域关键技术是如何提高电池使用寿命以及降低功耗。LF无线唤醒技术的开发将大大降低功耗,延长电池使用寿命,它被广泛地应用到公路收费、港口货运管理等应用中,使我国在现代物流等若干领域缩短与世界先进国家的差距。     

一种事件驱动的RFID中间件研究

RFID（射频识别）中间件在设备和应用软件之间起到数据传输和处理的重要作用。针对当前RFID中间件过滤规则简单、缺少复杂事件处理等缺点,在分析消息传输机制和企业应用需求的基础上,引入一种具有复杂事件计算能力的RFID中间件,该中间件具有过滤方式丰富、可以有效降低系统之间通信复杂度等优点。     

基于OPNET的RFID系统信道研究

在RFID系统数据通信的过程中,所有的信息都在信道中传输,因此通信质量的好坏受信道性能的影响。为了分析信道的性能,在基于OPNET建立RFID软件平台的基础上仿真了瑞利信道和高斯白噪声信道对RFID系统通信质量的影响,并得出了瑞利信道对RFID通信质量的影响更大的结论。     

基于OpenGL的载体姿态实时显示系统设计

针对目前实时姿态显示系统在数据通信和数据显示等方面的不足,设计并完成SINS实时姿态测量系统。在介绍该系统原理和组成的基础上,着重阐述了系统上位机软件的设计方法和流程。通过多缓存、数据连接等手段解决了数据实时通信过程中产生的数据错帧、丢帧等问题。同时利用OpenGL较好实现了数据的实时显示和三维姿态显示。通过功能测试实验,验证了系统的预期功能,且实时数据显示直观、流畅。     

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.     

Analysis of energy consumption for multiple object identification system with active RFID tags

Radio frequency identification (RFID) systems are very effective for identifying objects. Existing published works focus on designing efficient collision resolution protocols for the tag identification problem in RFID systems with passive RFID tags. However, advances in low‐cost and low‐power sensing technologies will make active RFID tags more popular and affordable in the near future. In multiple object identification systems with active tags, the tags are designed for extremely low‐cost large‐scale applications such that battery replacement is not feasible. This imposes a critical energy‐constraint on the communication protocols used in these systems. In this paper, we analyze energy consumption and identification times for several protocols. The objective is to decrease energy consumption of tags by reducing both the total identification time and the total active time. Copyright © 2007 John Wiley & Sons, Ltd.     

Evaluating the energy consumption of the RFID tag collision resolution protocols

RFID technology acts as a bridge to connect the physical world with the digital space, and RFID system is pervading our daily life in the last few years. The energy consumed by the reader and a tag in resolving the collisions caused by multiple tags is a key issue that affects life time of mobile reader and active tags, as well as the identification accuracy of passive tags. In this paper, the energy consumed by the reader and a tag in resolving the tag collision is examined for the commonly used RFID tag collision resolution protocols, including the frame slotted ALOHA based and the binary query tree based protocols. Numeric evaluation is also performed and the result verifies that regarding to energy consumption, the dynamic frame slotted ALOHA protocol for the Class-1 RFID system performs best among the frame slotted ALOHA protocols, and the modified binary query tree protocol also performs better than the standard binary query tree protocols.     

射频识别技术及其在交通领域的应用

射频识别（RFID）技术采用大规模集成电路技术，识别技术，计算机及通信技术，通过读写器和安装在载体（车辆或设备或人员）上的RFID卡，构成RFID系统，实现对载体的非接触的识别和数据信息交换，RFID技术已广泛应用于交通、公安，路政、物流管理等领域，本文介绍该技术在交通领域的几个主要应用。     

智能滑套内低频段RFID 标签识别率的研究

实际应用中智能滑套内低频段RFID 标签存在识别率低的问题,从射频识别技术的工作机理出发,借助MATLAB 仿真软件,对低频螺线管天线感应电压特性进行了仿真分析,讨论了读写器天线长度和内径对识别率的影响,提出了基于井下智能滑套的RFID 通信系统最佳天线部署。同时为减弱井下复杂工况环境对标签识别率的影响,设计了读写器天线自适应阻抗匹配系统,建立一套基于井下RFID 通信系统识别率的模拟试验平台,验证仿真设计结果的正确性。     

Problem of dynamic change of tags location in anticollision RFID systems

Presently the necessity of building anticollision RFID systems with dynamic location change of tags appear more often. Such solutions are used in identification of moving cars, trains (automatic identification of vehicles – AVI processes) as well as moving parts and elements in industry, commerce, science and medicine (internet of things). In the paper there were presented operation stages in the RFID anticollision system necessary to communicate with groups of tags entering and leaving read/write device interrogation zone and communication phases in conditions of dynamic location change of tags. The mentioned aspects influence RFID system reliability, which is characterized by the efficiency coefficient and the identification probability of objects in specific interrogation zone. The communication conditions of correct operation of multiple RFID system are crucial for efficient exchange of data with all tags during their dynamic location changes. Presented problem will be the base to specify new application tag parameters (such as maximum speed of tag motion) and synthesis of interrogation zone required for concrete anticollision RFID applications with dynamic location change of tags.     

Design and Performance Analysis of Emulator for Standard Conformance Test of Active RFID

An active radio frequency identification (RFID) system has the advantages of a long identification distance and a good identification rate, overcoming passive RFID drawbacks. Therefore, interest in the development of active RFID systems has been gradually increasing in areas of harbor logistics and national defense. However, some identification failures between active RFID systems developed under the same standards have been reported, presumably due to a lack of development of accurate evaluation methods and test equipment. We present a realization of the hardware and software of an emulator to evaluate the standard conformance of an active RFID system in a fully anechoic chamber. The performance levels of the designed emulator are analyzed using Matlab/Simulink simulations, and the applicability of the emulator is verified by evaluating the standard conformance of a real active RFID tag. Finally, we propose a new evaluation method by incorporating a self‐running test mode environment into the RFID tags to reduce testing time and increase testing accuracy. The application of the suggested method to actual tags improves measurement uncertainty by 0.56 dB over that obtained using existing methods.     

一种低功耗智能传感主动式标签的设计

针对普通标签不能满足一些特定的场合应用需求的问题,提出一种低功耗单片智能传感标签的设计方案。详细阐述了主动式RFID标签的设计思想、硬件结构和软件的设计方法。智能传感标签基于MSP430系列超低功耗单片机进行控制,并结合nRF2401射频芯片以及温湿度传感器SHT21S,实现传感信号的调制解调。该智能传感标签可以定时采集和存储外部温度湿度数据,能够通过无线射频识别通信上传数据并对其进行相应的分析和处理。该标签具有较高的实用性和可靠性,成本低,功耗低,具有良好的应用前景。     

A compact low-power UHF RFID tag

In this paper, the design of an ultra-low-power UHF RFID tag is introduced. The system architecture and the communication protocols are chosen to operate with the minimum requirements possible from the RFID tag. By moving most of system functionality to the RFID reader side, the circuit requirements of the RFID tag circuits are relaxed. Supply voltages for both analog and digital parts are chosen carefully for minimum power consumption. The RFID tag is designed in standard digital 0.13 μm CMOS technology. Simulations results of the main blocks are shown. The power consumption of the chip is only 1 μW, and the chip area is only 0.14 mm×0.23 mm.     

A new anti‐collision protocol based on information of collided tags in RFID systems

Radio frequency identification (RFID) technology has recently become an integral part of a wide range of applications. One of the challenges in RFID systems is the tag anti‐collision issue, for which several anti‐collision tag identification protocols have been proposed. This paper proposes a novel slotted ALOHA‐based RFID tag anti‐collision algorithm which can be employed for tag identification. The main idea of this algorithm is to use the information available in collision slots, called collided data, to identify tags uniquely. For this purpose, the collision slots that include only two tags are selected. Then, the non‐conflict bits in these slots are used to possibly identifying the tags. Because in the proposed algorithm readers use both single slots and also the collision slots for tag identification, the performance is increased significantly compared with other protocols. Results of the study indicate that in the proposed algorithm, the optimal frame size for an individual tag number is equal to the half of tags number and the efficiency of the proposed protocol is improved to about 73%. Copyright © 2015 John Wiley & Sons, Ltd.