射频识别系统中自适应反碰撞法的实现

提出了一种基于射频识别系统的改进的自适应时隙Aloha（IDFSA, improved dynamic framed slotted Aloha algorithm）算法．在RFID系统的设计阶段完成了对应答器的分组，并对分频后的实时时隙数进行了优化．介绍了此算法在实际超高频射频识别系统中的应用．取代了传统的估算和实时分组方法，提高了系统效率，使碰撞率下降了2.67倍，从而有效地提高了信道的利用率,解决了时隙数随应答器数增加而指数增长的问题．通过实际系统433/868/915的实现，验证IDFSA算法的简单有效性．

Realization of the Adaptive Anti-Collision Method used in Radio Frequency Identification System

An improved dynamic framed slotted Aloha algorithm (IDFSA) based on the radio frequency identification system is presented. IDFSA divides the tags into different frequency channels in the design period and saves the communication time. In the meantime, and IDFSA optimizes the real-time slots accounts obtained after frequency division, reducing the colliding efficiency up to 2.67 times, and improves the system efficiency. IDFSA dissolves the problem that the slots amount increases exponentially with an increasing of the identified tags amount. IDFSA has been used in the 433/868/915MHz system, verifying this method easy and efficiency.