Research Of The Collision Problem In RFID System

Radio Frequency Identification (RFID) is a contactless automatic identification technology rose from the 1990s, which applies and develops the automatic identification technology into radio technology. There are many advantages of RFID technology such as high accuracy, strong ability to adapt to the environment, efficient operation, long service life, long reading distance, encrypted tag data, large data storage capacity, and so on. Along with the developing of RFID technology, RFID has more and more important effect on many areas such as supply chain management, logistics, automation, transportation management and control, retail, etc. RFID will become the mainstream of automatic identification technology and has broad prospects.Data integrity problem of RFID is one of the important factors that hinder the development of RFID. It is directly related to the quality of the performance of the whole system level. Collision problem is an important aspect that affects the integrity of the data. There are two kinds of collision. They are reader collision and tag collision. The way to solve the collision called the anti-collision algorithm. Comparing with the reader collision, the tag collision take place in a higher probability and the problem of tag anti-collision is considered to be an important issue to resolve. When more than one tag in the reader area and send datum to the reader at the same time, the signal of the tags will interferes each other and the tags will not be able to be identified. We call it tag collision. It belongs to the multi-target identification problems. Because RFID is the only one technology that can identifies multi object at the same time, multi-target identification is both the advantages and the challenge of RFID technology.In this thesis, we deeply study the issue of tag anti-collision on the basis of the literature search, collation, analysis and synthesis. Main works as follows:1. Apply the theory of minimum area-covering to the RFID system. Under the condition of no blind spots in the system, use the readers at least as possible.2. Presents a zoning solution to solve problems of tag collision and reader collision in the RFID system.3. For problems of tag collision and reader collision, analyzed and summarized the existing efficient algorithms.