A slot detection anti-collision algorithm with Hamming Weight Re-selection in RFID

In this paper, an anti-collision algorithm based on Hamming Weight Re-selection (HWEA) in Radio Frequency Identification (RFID) system is proposed. Tags are identified in two situations: the unique selection of conventional random number and the Hamming weight of each tag. These two parameters are returned to the reader after coded. According to the received information of reader, the selection conditions of slots can be detected and the corresponding processing can be made. Reader skip all the idle slots and collided tags which have different Hamming weight from other tags in a collision slot. So there are more tags can be identified successfully in a frame. Analysis and simulation results illustrate that the identification efficiency of all unrecognized tags can be increased to above 80%, and it also outperforms existing algorithms on number of needed frames and transmission data.