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1 Overview of RFID System Anti-Collision Technology
non-contact automatic identification technology that emerged and developed rapidly
in the 1990s. It uses radio waves by induction or electromagnetic wave radiation.
The non-contact two-way communication achieves the purpose of automatically
identifying target objects, obtaining relevant data, and data exchange. Internationally, RFID systems have been widely used in logistics supply chains, transportation,
electronic tickets, production and assembly, anti-counterfeiting and anti-theft, smart
agriculture, environmental protection, military defense, and many other fields [2–5].
Major developed countries and regions in the world have successively carried
out research on RFID and IoT technology. The National Development and Reform
Commission of China included RFID in the first batch of national key industry
adjustment and revitalization plans in the electronic information field. In recent years,
China has successively carried out the research and development and industrialization
of RFID-related technologies, and has initially established a certain foundation in
RFID and IoT technology research and development, standard development, industry
cultivation, and industry applications. At present, although the annual scale of China’s
RFID technology market exceeds RMB 10 billion, it ranks third in the world, after
the United Kingdom and the United States. However, compared with existing foreign
technologies, China’s RFID technology foundation is relatively weak compared with
developed countries. There is still a gap, especially in the research of chips, tags, and
sensor networks compared with developed countries. After years of development,
the accuracy and performance stability of low-frequency and high-frequency RFIDrelated products in China has reached the international level, in UHF and microwave
frequency bands, many studies are still in the preliminary explorations and laboratory
research stages. Moreover, there is a big gap between indicators such as the sensitivity
and reliability of the performance and foreign products. The immaturity of these
technologies limits the pace of RFID development, and has become a hot spot and
difficulty for breakthroughs in the research of RFID technology in the frequency
bands above UHF. With the continuous rapid development of China’s economy and
the continuous upgrading of the industrial structure, in the large-scale intelligent and
information high-tech industry, there are several key technologies problems of RFID
systems above the UHF frequency band that urgently need to be solved in the field
of RFID application promotion. The obvious asymmetry phenomenon of advanced
technology and weak basic research has severely restricted the development of RFID
and IoT engineering disciplines.
Since the data transmission of the RFID system is a weak signal wireless communication, the integrity and accuracy of the data will be interfered with by the external
environment. The actual communication environment (multipath interference, noise
environment, metal structure, liquid environment, etc.) The signal performance has a
great impact [6, 7]. With the increase of the working frequency of the RFID system,
the batch reading success rate of RFID multi-tags has become the key to the improvement of the system’s automatic identification efficiency. In many practical application
scenarios of RFID, multiple tags of the same specification may be closely fitted and
overlapped. For example, batch initialization read and write operations are carried
out after stacking product tags are shipped. In file and book management applications, there are many tags on the surface of the book and these tags may overlap
1 Overview of RFID System Anti-Collision Technology
non-contact automatic identification technology that emerged and developed rapidly
in the 1990s. It uses radio waves by induction or electromagnetic wave radiation.
The non-contact two-way communication achieves the purpose of automatically
identifying target objects, obtaining relevant data, and data exchange. Internationally, RFID systems have been widely used in logistics supply chains, transportation,
electronic tickets, production and assembly, anti-counterfeiting and anti-theft, smart
agriculture, environmental protection, military defense, and many other fields [2–5].
Major developed countries and regions in the world have successively carried
out research on RFID and IoT technology. The National Development and Reform
Commission of China included RFID in the first batch of national key industry
adjustment and revitalization plans in the electronic information field. In recent years,
China has successively carried out the research and development and industrialization
of RFID-related technologies, and has initially established a certain foundation in
RFID and IoT technology research and development, standard development, industry
cultivation, and industry applications. At present, although the annual scale of China’s
RFID technology market exceeds RMB 10 billion, it ranks third in the world, after
the United Kingdom and the United States. However, compared with existing foreign
technologies, China’s RFID technology foundation is relatively weak compared with
developed countries. There is still a gap, especially in the research of chips, tags, and
sensor networks compared with developed countries. After years of development,
the accuracy and performance stability of low-frequency and high-frequency RFIDrelated products in China has reached the international level, in UHF and microwave
frequency bands, many studies are still in the preliminary explorations and laboratory
research stages. Moreover, there is a big gap between indicators such as the sensitivity
and reliability of the performance and foreign products. The immaturity of these
technologies limits the pace of RFID development, and has become a hot spot and
difficulty for breakthroughs in the research of RFID technology in the frequency
bands above UHF. With the continuous rapid development of China’s economy and
the continuous upgrading of the industrial structure, in the large-scale intelligent and
information high-tech industry, there are several key technologies problems of RFID
systems above the UHF frequency band that urgently need to be solved in the field
of RFID application promotion. The obvious asymmetry phenomenon of advanced
technology and weak basic research has severely restricted the development of RFID
and IoT engineering disciplines.
Since the data transmission of the RFID system is a weak signal wireless communication, the integrity and accuracy of the data will be interfered with by the external
environment. The actual communication environment (multipath interference, noise
environment, metal structure, liquid environment, etc.) The signal performance has a
great impact [6, 7]. With the increase of the working frequency of the RFID system,
the batch reading success rate of RFID multi-tags has become the key to the improvement of the system’s automatic identification efficiency. In many practical application
scenarios of RFID, multiple tags of the same specification may be closely fitted and
overlapped. For example, batch initialization read and write operations are carried
out after stacking product tags are shipped. In file and book management applications, there are many tags on the surface of the book and these tags may overlap