Tag detection in RFID system based on RSSI technique for LF and HF passive tags

Radio-Frequency Identification (RFID) is the use of radio waves to read and capture information stored on a tag attached to an object. RFID can be used to solve localization problems effectively. A number of novel methods have been proposed in the recent years for tag detection. In some cases it is not possible for the reader to identify all the tags which results in missing of those tags. One of the reasons may be increase in read range between tag and the reader. Read range depends on a number of factors like the frequency of the radio waves used for reader — tag communication, the size of the tag antenna, the signal strength of the receiver antenna, transmitting power output of the reader and the type of tags that is deployed in the system. To determine the tags effectively without any loss the proposed method uses Received signal strength indicator (RSSI) method to calculate the distance between the reader and all the tags in the RFID environment. The transmitter power of the Readers' antenna is adjusted based upon the RSSI value. Hence through this proposed framework the tags which are out of vicinity from the reader's coverage area could be tracked and identified efficiently.