An Adaptive Multi-tree Anti-collision Method Based on Collision Tree

Abstract

The invention relates to a self-adaptive multi-way tree anti-collision method based on a collision tree and belongs to the technical field of radio frequency identification. The method is characterized by selecting an eight-way collision tree or a two-way collision tree for search according to the number of collision tags and the number of collision bits, selecting the eight-way collision tree forsearch when the number of the collision tags is greater than or equal to four and determining a new query prefix by sending a query command to obtain the information of the first three collision bitsof a collision sequence, selecting the two-way collision tree for search when the number of collision tags is less than four. The method achieves non-free timeslot eight-way tree query by optimizinga query prefix, and thus effectively solves the problem of low search efficiency of a two-way tree under the condition that tags are too many and the problem that multi-way tree search causes increaseof free timeslots. Compared with the prior art, the method guarantees that a search process is free of free timeslots, effectively reduces the total number of timeslots of systems while greatly reducing collision timeslots, and thus increases the identification rate and the throughput rate of systems.

Description

technical field [0001] The invention relates to an adaptive multi-tree anti-collision method based on a collision tree, which belongs to the technical field of radio frequency identification. Background technique [0002] Radio Frequency Identification (RFID) technology emerged in the 1980s and 1990s. Due to its quickness and convenience, no need for human intervention in identification, and high reliability, it is widely used in automatic identification systems. The general RFID system consists of three parts: reader, electronic tag and background data processing system. The RFID system requires the reader to identify tags quickly and accurately, but when multiple tags send information to the reader at the same time, collisions will occur, resulting in failure of identification. [0003] In order to solve the problem that multiple tags respond to the reader at the same time, many tag anti-collision algorithms have emerged as the times require. Tag anti-collision algorithm...

AI Technical Summary

Problems solved by technology

[0004] However, the anti-collision algorithm based on the tree is generally more complicated, the recognition time is long, and the search efficiency is low.

In order to solve this problem, a Collision Tree (collision tree, CT) algorithm can completely eliminate the idle time slot in the algorithm, but because it is based on the characteristics of the binary tree, the recognition efficiency is lower than that of the multi-fork tree

However, although simply using a multi-fork tree can reduce the number of collision time slots, it will increase the number of free time slots. The higher the number of forks, the higher the proportion of free time slots.

There is also a mixed multi-fork tree method that combines binary tree, quad-tree and octree search, but it still does not solve the problem of a large number of idle time slots when using multi-fork tree search

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