In order to solve the problem of tag collision in Radio Frequency Identification (RFID) system, the paper proposes a Multi-Bit Identification Collision Tree (MICT) algorithm based on a collision tree. The algorithm uses an array scheme to mark the collision bits in the identification process, and determines the collision information according to the first few bits of the tag, which can effectively reduce the number of recognitions and the amount of communication data. The testing results show that the proposed algorithm reduces the time complexity by about 38% and the communication complexity by about 27% compared to existing collision-tree-based algorithms. Through theoretical analysis and experimental evaluation, the MICT algorithm has obvious advantages in terms of time and communication complexity compared to the other typical algorithms. The algorithm can be applied to the field of RFID-related systems to significantly improve the system efficiency.
IntroductionRFID technology is a non-contact intelligent identification technology. Compared to traditional automatic identification technology, it has the advantages of small volume, low cost, large storage, high security, and reusability. As a result, RFID is rapidly replacing outdated barcode systems and various smartcard systems. RFID systems have great application value in the fields of industrial production, logistics, cargo and health management, safety inspection, and intelligent transportation [1][2][3][4]. However, in the process of RFID identification of multiple tags simultaneously, the collision between tags is a key issue affecting the efficiency of RFID identification.Several classical algorithms have been presented, such as the ALOHA algorithm [5,6], the Query Tree (QT) [7-10] algorithm, the Collision Tree (CT) algorithm [11], etc. These anti-collision algorithms can be divided into two categories: probabilistic methods based on ALOHA, and deterministic methods based on tree structure [12][13][14][15]. The probabilistic identification algorithms are simple to design and the identification time is short, but there will be a "tag hunger" problem. The deterministic algorithms ensure that all tags in the identified range are identified, but often do not perform well in communication efficiency. Recently, several algorithms such as tag grouping [16,17], bit tracking [18,19], and multi-bit identification have been proposed to improve the performance of RFID identification. Jung has proposed an Optimized Binary Search with Multiple Collision Bits Resolution Anti-Collision Algorithm (OBS-MCBR) [20]. In this algorithm, the collision bits are extracted and coded, and the collision location information is restored according to the collision situation. The performance of the algorithm is 30% higher than that of the CT algorithm. Wang has put forward an anti-collision algorithm based on multi-bit identification (MBI) [21]. The algorithm makes full use of the collision information of a certain length, and uses a distinguishable grouping scheme to group the spec...