Research And Performance Analysis Of New RFID Tag Anti-collision Algorithm

Compared with traditional identification methods, RFID(Radio Frequency Identification, RFID) can quickly identify target objects without manual intervention in a complex environment. In RFID system, the collision problem of tags’ response signals is often happened, and it will also reduce the efficiency of RFID system. Especially for the inexpensive passive RFID tags, tag collision problem is more seriously. Tag collision algorithm can ensure normal communication between multiple tags and readers and is mainly used to handle tag collision problem in RFID system. For the above problems, a systematic research is carried out in the paper. The main work includes:(1) A new type of RFID tag anti-collision algorithm combined with a universal hashing function was proposed. Combined with a universal hashing function, through regarding the tags of RFID system and the reader hash table as two dynamic gather, the algorithm designed a hash function that can make tag key to the readable slots of the hash table correspondence and proved its correctness, then the reader search slots in sequence to make the tags respond which meet the condition, so as to identify tags quickly. Simulation results show that the proposed algorithm has a great improvement in throughput, the number of queries and the amount of data transmission aspects.(2) A blind separation and framed-slot anti-collision algorithm for RFID system was proposed. Firstly, the algorithm establishes a model of blind source separation antenna system of reader and verifies the reasonability of using blind source separation for tag identification and analyses the relationship between slot number and tag collision. By selecting reasonable frame time slot number, the algorithm make tags’ number in each slot less than or equal to its antennas’ number and then several tags can be identified simultaneously by using Fast ICA algorithm. Simulation results show that the tags identification rate of the proposed algorithm is obviously better than that of traditional anti-algorithms and BSDBG algorithm. And with the increasing number of antennas, the tags identification time of the proposed algorithm is less than that of BSDBG algorithm. The algorithm adds a growing body of evidence about the feasibility an efficiency of identification tags based on blind sources separation technology.(3). An adaptive tree grouping and blind separation anti-collision algorithm for RFID system was proposed. Combined with multi-antenna technology and the grouping of binary tree slots based on tags ID sequence, by adjusting query code length of reader according to the number of antennas in RFID system and sending a query signal, eligible response tags are assigned to the appropriate slots so that the number of tags in each slot is less than or equal to the number of antennas and meets blind source separation system conditions which can identify tags, so the algorithm can achieve the purpose of identifying tags simultaneously and quickly. Compared with BSDBG algorithm using the same multi-antenna technology, simulation results show that the tag identification speed of the presented algorithm increased from 20% to 69% and the tag identification rate improved from 60% to 88% when the number of antennas is from 4 to 32, while it has low complexity, low hardware overhead and it is relatively simple to implement and conducive to use.With fast-developing of RFID technology today, the tradition algorithm which is used to handle tag collision problem gradually can not satisfy the requirement of people for efficiency, the three new algorithms proposed provides a certain theoretical basis for the development of tag anti-collision algorithm, and form experiments the article justifies the above algorithms have a better performance.