基于车联网的RFID读写器接收机研究

发布时间：2018-03-22 20:42

本文选题：车联网　切入点：射频识别　出处：《吉林大学》2014年硕士论文　论文类型：学位论文

【摘要】：车联网是新兴产业物联网和智能汽车两个领域的结合。把物联网中的对象都变成车辆和道路上的设施时，就是车联网。在最近的几年，随着物联网的发展使得信息产业得到了巨大的发展，这使得车联网也收到了各界的关注和支持。很多发达国家都已经投入了巨大的金额用于研发车联网通信。在中国，政府以及各个行业都很关注和支持车联网。车载通信是车联网最核心的技术，它具有如下关键的技术：射频识别(RFID)技术，卫星定位技术，云计算技术，智能技术等。在车联网的主要关键技术中，本文重点研究了其中的RFID技术。RFID技术是近年来发展极为迅速的一种通过无线方式传递信息的非接触式自动识别技术，它是利用射频信号通过空间耦合(交变磁场或电磁场)实现无接触信息传递并通过所传递的信息达到识别目的的一项新技术，现阶段对RFID技术无论是在理论还是实践方面都发展的迅速。目前在理论和实际应用方面都十分引人注目，比如：利用RFID的智能停车场引导系统和自动泊车系统等。其中超高频段(UHF)的RFID技术是国际上最先进的自动识别技术，它具有识别距离远、识别速度快、使用寿命长等特点，广泛应用于电子路牌、高速公路收费、物流管理、产品跟踪等。而随着CMOS集成电路工艺的不断成熟，，RFID读写器技术正朝着低成本、低功耗和高集成度的方向快速发展。阅读器系统普遍采用零中频结构，成本低，易于集成，但是阅读器在读取标签时，所发射的连续载波信号被下混频到零频而转变为直流信号，优势可能会干扰有用信号，这样的话，会使滤波器的截止频率产生偏差，造成RFID运行的不稳定性。本文主要针对零中频接收机系统的改进研究，在对超高频RFID系统相关理论和技术进行深入分析的基础上，根据ISO/IEC18000-6Type C型协议，对工作在UHF频段的RFID系统的读写器进行详细分析。研究了系统的基本原理及其各个组成部分，并针对180006C标准协议的编码和调制技术进行了深入研究。然后，结合车联网的现状和车联网对RFID系统的需求。根据射频识别技术的理论的实现技术，讨论了UHF RFID读写器的发送、接收电路的实现，并进行了部分发送和接收电路的信号仿真分析，重点讨论了一种射频前端电路，讨论了电路的基本原理和各个组成部分电路，对连续载波信号反馈通到接收链路，使后级模块出现饱和的原因进行了分析。然后研究了零中频接收系统的直流偏移消除电路和频率校准的可行性方案，研究了对零中频接收机的优化方法。这些优化方法可以有效地将有用信号筛选出来，并能在一定程度上抵制在室外电路工作环境的变化时滤波器截止频率产生的偏差。
[Abstract]:Car networking is a combination of the emerging industry, the Internet of things, and the smart car. When you turn the object of the Internet of things into a vehicle and a facility on the road, it's a network of cars. In recent years, With the development of the Internet of things, the information industry has been greatly developed, which makes the car networking also receive attention and support from all walks of life. Many developed countries have already invested a huge amount of money in the development of vehicle networking communications. In China, The government and various industries pay close attention to and support vehicle networking. Vehicle communication is the core technology of vehicle networking. It has the following key technologies: radio frequency identification (RFID) technology, satellite positioning technology, cloud computing technology, etc. Among the key technologies of vehicle networking, this paper focuses on the research of RFID technology, which is a kind of non-contact automatic identification technology, which has been developing rapidly in recent years. It is a new technology that uses radio frequency signals to transmit contactless information through space coupling (alternating magnetic field or electromagnetic field) and to achieve the purpose of identification through the information transmitted. At present, RFID technology is developing rapidly in both theory and practice. For example, using the intelligent parking system and automatic parking system of RFID, the RFID technology of UHF is the most advanced automatic recognition technology in the world. It has the characteristics of long recognition distance, fast recognition speed, long service life, etc. Widely used in electronic road signs, highway charges, logistics management, product tracking, etc. With the continuous maturity of CMOS integrated circuit technology, RFID reader technology is moving towards low cost. Low power consumption and high integration are developing rapidly. Reader systems generally adopt zero-if structure, low cost, easy integration, but when reading tags, The transmitted continuous carrier signal is converted into a DC signal by submixing to zero frequency. The advantage may interfere with the useful signal, in which case, the cut-off frequency of the filter will be deviated. This paper focuses on the improvement of zero-intermediate frequency receiver system, based on the in-depth analysis of UHF RFID system theory and technology, according to the ISO/IEC18000-6Type C protocol, The reader of RFID system working in UHF band is analyzed in detail. The basic principle and components of the system are studied, and the coding and modulation techniques of 180006C standard protocol are deeply studied. Then, according to the current situation of vehicle networking and the requirement of vehicle networking to RFID system, according to the realization technology of RFID theory, the realization of UHF RFID reader and receiver circuit is discussed. A RF front-end circuit is discussed in detail. The basic principle of the circuit and each component circuit are discussed. The continuous carrier signal is fed back to the receiving link. The reason of saturation in the later stage module is analyzed. Then, the feasibility scheme of DC offset elimination circuit and frequency calibration of zero-intermediate frequency receiving system is studied. The optimization methods of zero if receiver are studied. These optimization methods can effectively filter out useful signals and to some extent resist the deviation of filter cutoff frequency when the operating environment of outdoor circuits changes.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U495;TP391.44

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