改进型帧时隙ALOHA防碰撞算法研究

Study on the Improved Framed Slotted ALOHA Anti-collision Algorithm

为进一步提高RFID系统中电子标签防碰撞算法的识别效率,对帧时隙ALOHA防碰撞算法的性能进行分析,提出一种结合精确标签估计和二进制搜索的改进型帧时隙ALOHA算法。将识别过程分为标签估计和标签识别两个阶段,在标签估计算法中引入碰撞概率上、下限参数,并精确估计标签数量对初始帧时隙大小进行优化;在标签识别阶段,利用二进制搜索算法对时隙内的碰撞标签进行快速识别。通过对识别过程进行仿真结果表明:改进的算法改善了防碰撞性能,提高了RFID系统的标签识别效率。

In order to improve the identification efficiency of tag anti-collision algorithm in RFID system further, analyzing the performance of framed slotted ALOHA anti-collision algorithm, the improved framed slotted ALOHA algorithm is proposed with accurate tag estimation and binary search. the whole identification process is divided into two phases including tag estimation and tag identification, in tag estimation algorithm, the collision probability threshold parameter is used to estimate the number of tags accurately for the optimization of the number of time slots in the initial frame ; in tag identification phase, the binary search algorithm is used to identify the tags fleetly that collide with other tags in time slots. The identification process of the algorithm is simulated and the result indi- cates that the improved algorithm can improve the performance of tag anti - collision algorithm and the tag identification efficiency in RFID system.