Research On RFID Anti-collision Algorithm

RFID is a non-contacting automatic identification technology. By the electromagnetic coupling technologic, it realizes data communication between reader and tag which pastes on an object.RFID’s key technology divided into application and industrialization. The former mainly includes: data interface technology and service technology, data management technology; the latter include:tag’s chip production, tag’s storage, tag’s security, anti-collision algorithm. As the tag collision RFID technology decisions recognition accuracy and recognition efficiency, therefore Tags collision problem has become research focus. This paper has research on anti-collision algorithm based on ALOHA. The main research areas are as follows:(1) The research on anti-collision algorithm about domestic and foreign, especially for anti-collision algorithm based on ALOHA, including Pure ALOHA algorithm, Slot ALOHA algorithm, Frame slot ALOHA algorithm, Dynamic frame slot ALOHA algorithm, adaptive ALOHA algorithm. Comparing application and disadvantage of these algorithms.(2) This paper proposed optimum double weight Q algorithm based on adaptive ALOHA algorithm. In this algorithm, by splitting the single parameter c into two weight parameter c1 and C2 to deal with the case of collision and idle respectively so that the number of collision slots and idle slots can be control. When idle slot or collision slot occurs, using c1 or c2 to adjust Q. Simulation results show that the proposed algorithm can not only decrease the number of identifies slots but increase the system throughput than previous work.(3)This paper proposed Q Algorithm with D-Value Threshold for Collision and Idle. In this algorithm, every reader was added two counters to calculate the number of collisions and idle slots respectively. When a collision slot was detected, the collisions counter increment. Idle slot as well. Compare the setting threshold by the subtraction of collision counter and idle counter. Experiments show that the proposed algorithm can not only shorten delay identification but improve the Identification speed than previous work.(4) Finally, software about RFID anti-collision system simulation was developed by Visual Basic, and it was used to test the proposed algorithm and to compare with the original algorithm. The simulation system includes three functions:parameter selection and optimization, optimal performance and optimal performance comparison. Users can obtain the system optimized parameters under different environmental parameters through simulation system, and verify the improved performance of the algorithm.