When there is more than one tag to simultaneously transmit their data to the reader of radio frequency identification ( RFID) systems,the mixing signals may collide and the reader can not identify what is received,which may significantly reduce the identification rate and the working efficiency of RFID systems. In order to solve this problem,an anti-collision algorithm for RFID systems based on the tag information grouping is proposed,in
which the tags are divided into several groups according to the information stored in them,the groups are orderly identified according to the grouping sequence,and the colliding probability is reduced by decreasing the number of tags responding to the reader's order. Moreover,the grouping efficiency and the timeslot selection of the proposed algorithm are analyzed,verified and simulated. The results show that the proposed algorithm is superior to the common binary tree algorithm and the ALOHA algorithm because it reduces the collision probability and improves the group identification efficiency.