Physical layer collision resolution for active RFID systems

射频识别（RFID）是一种用于识别、跟踪和定位物理对象的无线通信技术。RFID技术的应用有很多，从资产跟踪以优化设施利用率，到访问控制，以及设备和人员的管理，再到实时定位系统。RFID系统包括标签和读取器，其中标签附接到被识别和跟踪的对象，并且读取器部署在企业的场所中，附接到建筑物或机器基础设施或由人员操作。标签通常是小型且廉价的设备，仅具有很少的处理能力和电池资源。它们被读取器询问或周期性地发送包含其标识和附加环境或对象信息的信号。RFID系统面临的最大挑战之一，限制了其应用空间，是传输失败，这通常发生在来自多个标签的数据包在阅读器上发生冲突时。有许多防冲突协议通过基本上避免冲突来解决这个问题。这增加了标签的复杂性。在UBC，我们开发了一种完全不同的冲突问题解决方案，我们称之为RFID多用户检测（RFID-MUD）。RFID-MUD的主要特点是它能够解决冲突。RFID-MUD在阅读器上实现，不需要对标签技术进行任何更改。它适用于流行的现有RFID信号格式，可与传统的防冲突协议互操作，并对RFID应用程序透明。进入RFID市场将是完全无缝的，使RFID系统受益于RFID-MUD的改进冲突解决方案。计算机仿真证实了RFID-MUD的巨大潜力。该项目的目标是设计和建立一个RFID-MUD使能阅读器的概念验证原型，并在商用标签的现场试验中测试其碰撞分辨率能力。原型实施和现场测试对于与合作伙伴RFID公司的RFID-MUD技术商业化和/或产生投资者兴趣至关重要。

Radio-frequency identification (RFID) is a wireless communications technology used for identifying, tracking and locating a physical object. The applications for RFID technology are many, ranging from asset tracking in order to optimize facility utilization, to access control, and management of equipment and personnel, to real-time location systems. RFID systems comprise tags and readers, where tags are attached to the objects that are identified and tracked, and readers are deployed in the premises of the enterprise, either attached to a building or machine infrastructure or operated by personnel. Tags typically are small and inexpensive devices with only little processing capability and battery resources. They are interrogated by the reader or periodically transmit signals containing their identification and additional environmental or object information. One of the biggest challenges for RFID systems, limiting their application space, are failed transmissions, which usually happen when packets from multiple tags collide at the reader. There are a number of anti-collision protocols addressing this problem by essentially avoiding collisions. This adds complexity to the tags. At UBC, we have developed an entirely different solution to the collision problem, which we refer to as RFID multiuser-detection (RFID-MUD). The key feature of RFID-MUD is that it is able to resolve collisions. RFID-MUD is implemented at the reader and does not require any changes to tag technology. It is applicable to popular existing RFID signal formats, interoperable with conventional anti-collision protocols, and transparent to applications of RFID. Introduction into the RFID market would be entirely seamless, allowing RFID systems to benefit from improved collision resolution due to RFID-MUD. Computer simulations have confirmed the great potential of RFID-MUD. The objective of this project is to design and build a proof-of-concept prototype of an RFID-MUD enabled reader and test its collision-resolution capability in field trials with commercial tags. The prototype implementation and field tests will be critical for commercialization of the RFID-MUD technology with a partner RFID company and/or generating investor interest.