High-efficiency multi-tag anti-collision radio frequency identification (RFID) method

Abstract

The invention discloses a high-efficiency multi-tag anti-collision radio frequency identification (RFID) method, which mainly comprises a tag division process and a tag searching process. An ALOHA frame or other signal frames are established in the tag division process; and in the tag division process, time slots are randomly selected for tags to transmit IDs, and function in dividing a tag group consisting of all the tags in the range of a reader-writer into a plurality of independent small tag groups. In the tag searching process, a plurality of message frames are involved; and each frame corresponds to a specific collision time slot in the tag division process, and in the frame, the tags can be identified one by one by a backtracking binary-tree searching method and the like. The method can greatly reduce collision phenomena in a multi-tag identification process and reduce times of information interaction between the tags and the reader-writer, and ensures high efficiency and security.

Description

technical field [0001] The invention relates to a collision avoidance technology in a wireless communication process, in particular to a radio frequency identification (RFID) multi-label anti-collision and rapid identification technology. Background technique [0002] The collision problem of radio frequency identification (Radio Frequency Identification, RFID) system is divided into reader-writer collision and tag collision. If the effective working areas of multiple adjacent readers overlap, when two or more readers simultaneously identify a tag or read and write data, it may cause the tag to fail to correctly identify the reader’s command, thus failing to make a correct response. The phenomenon of response is called reader collision. There are multiple tags in the working area of ​​a certain reader, and two or more tags respond to the command of the reader in the same time slot, so signal superposition occurs at the receiving end of the reader, causing the reader to The...

AI Technical Summary

Problems solved by technology

[0005] The main disadvantage of the existing RFID multi-tag anti-collision algorithm is that the efficiency of the ALOHA algorithm is very dependent on the prediction of the number of tags. When the length of the recognition frame is equal to the number of tags to be recognized, the theoretical maximum work efficiency can be close to 1 / e( ≈36.8%) label / slot

In addition, the ALOHA algorithm is very unstable, and there will be large fluctuations in the multiple recognition results of the same number of tags, especially when the number of tags is large and the reader cannot accurately predict the number of tags, the performance of the algorithm will drop significantly

Among the evolutionary algorithms of the binary tree class, the return-type query tree algorithm is the most efficient one. The algorithm recognizes M tags for (2M-1) times, and when the number of tags is large, it can approach 50% tags / time slot. However, in the case of many tags, in order to deal with a large number of tag collisions, the reader has to send the tag ID number multiple times to split the tag group, which causes the potential danger of tag information leakage

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