基于时隙冲突预判的RFID防碰撞算法

摘要

射频识别技术的应用场景中,由于存在大量标签同时响应阅读器的情况,导致ALOHA协议中标签长时间无法被识别,为提高ALOHA协议的识别效率,提出一种基于时隙冲突预判的防碰撞算法.在时隙开始前判断碰撞探测码是否冲突,以此为依据消除空闲时隙,当发生探测码碰撞时,结合冲突位置和时隙冲突规避机制识别标签,有效降低碰撞时隙的发生概率.仿真结果表明,相比于同样基于时隙ALOHA的经典Q值算法、FBBS和BIS算法,该算法的最高吞吐率可以提高至86.4%,高于对比算法系统效率,碰撞时隙数平均降低了89%、84%和55.1%,在标签数小于500时通信复杂度平均减少了39.6%、38%和14.2%.%In the application scenarios of RFID technology,many tags response to the reader at the same time,which leads to the tags in the ALOHA algorithm cannot be identified for a long time.To improve the identify efficiency of ALOHA algorithm,an anti-collision algorithm that based on slotted conflict prediction was proposed.By analyzing whether the detection codes conflict exists,idle slots were eliminated before the start of slot.When detection codes conflicting,tags were identified according to the locations of collision and the mechanism of slot collision avoidance,the probability of collision was reduced successfully.According to the simulation results,compared to classical Q algorithm,FBBS algorithm and BIS algorithm that all based on slotted ALOHA algorithm,the best throughput rate of this algorithm can reach 86.4%,the recognition efficiency is higher than the contrast algorithms,the average number of collision slots is reduced by 89%,84% and 55.1% compared to the contrast algorithms,and the communication complexity is reduced by 39.6%,38% and 14.2% on average respectively when the number of tags is less than 500.