Multiple RFID tags identification with M-ary query tree scheme

An anti-collision scheme in RFID systems is required to identify all the tags in the reader field. Deterministic tree search algorithms are mostly used to guarantee that all the tags in the field are identified, and achieve the best performance. Such tree search algorithms are based on the binary tree, and single bit arbitration is made at a time. In this letter, a novel tag anti-collision algorithm called M-ary query tree scheme (MQT) is proposed. An analytic model is developed for the response time to complete identifying all tags and then derive optimal M-ary tree for the minimum average response time. Our theoretical analysis and simulation results verify that MQT outperforms other tree-based protocols in terms of time complexity and communication overhead.