关键词: ALOHA算法, 随机数, 标签碰撞, 防碰撞, 动态帧时隙

Abstract: According to the problem that the highest tag identification efficiency can only reach 36.8% using those existing dynamic frame slotted ALOHA algorithm in the radio frequency identification system, this paper proposes a new selecting the time slots method based on collision sequence of tag symbol and the uniqueness of the tags symbol sequence instead of random selecting the time slots method using in classical dynamic frame slotted ALOHA anti-collision algorithm. This new algorithm effectively reduces the probability of tag collision so as to improve the efficiency of system identification. The simulation results show that the lowest identity efficiency is 37.5% for the new ALOHA tag anti-collision algorithm, what is more important, as the actual number of tags is closer to the tags number that collision bit sequences can determine, the higher the recognition efficiency. The highest identity efficiency can reach 100%. The new ALOHA tag anti-collision algorithm is significantly better than those existing dynamic frame ALOHA algorithms.

Key words: ALOHA algorithm, random number, tag collision, anti-collision, dynamic frame timeslots