System for tag estimation and anti-collision, and method thereof

A system and a method for estimating the number of tags and preventing tag collision are provided to recognize an RFID(Radio Frequency IDentification) tag quickly by estimating the number of RFID tags correctly in an RFID system, transmitting an RF signal in an FSA(Framed-Slotted ALOHA) mode based on the estimated number of RFID tags, and separating the colliding RFID tags in a binary tree mode. A recognizer(10) transmits an instruction message to RFID tags and receives information from the RFID tags, and a collision manager(11) recognizes collision among the RFID tags and calculates a collision probability of the RFID tags. A tag quantity estimator(12) estimates the number of RFID tags by using the collision probability. A reader controller(13) generates the instruction message, sets the size of a frame used for a recognition process depending on the number of RFID tags, and enables an RFID reader(100) to recognize the RFID tag. The RFID performing an RFID recognition process by dividing the process into a tag quantity estimation process and a recognition process, recognizes the RFID tags in a FSA mode by using the estimated number of RFID tags, and recognizes the colliding tag in a binary tree mode when collision occurs.