Simulation and measurement of collision signal in passive UHF RFID system and edge transition anti-collision algorithm

Radio-Frequency IDentification (RFID) is an enabling and emergent technology. Nowadays it still remains several challenging research issues before its widespread implementation, especially in dense environment. One of the main problems that limits the efficiency of passive UHF RFID system is the collision between tags. Current solutions are based on collision avoidance using Media Access Control (MAC) Protocols (e.g. Frame Slotted Aloha, Binary Tree algorithms), which can be time consuming process because when a collision is detected, the retransmission of RN16 frame is required and all the signals in the physical layer are discarded. This paper presents an experimental and simulation study of collision signal in passive UHF RFID system. We take into consideration physical layer parameters of passive UHF RFID system to give correct model of collision signal. Based on FM0 encoded properties and other physical parameters, we proposed Edge transition algorithm to solve the tags collision problem.