An advanced tag detection technique for chipless RFID systems

Chipless RFID systems have been identified as a major candidate to replace optical barcode systems in future. However, the main challenge is its less data encoding capacity. Researchers have attempted to overcome this by mainly improving the chipless tag design and the RFID reader architecture. However, they were using primitive tag detection techniques such as thresholds and moving averages. This paper presents a Maximum Likelihood (ML) based tag detection technique for chipless RFID systems. The detection technique does not require any channel knowledge and it jointly optimizes both the tag detection and the channel. The proposed technique is compatible with both frequency and time domain based chipless RFID readers. Chipless tags were designed in CST and the system model was simulated in MATLAB. The results show that the proposed tag detection technique allows to remove the guard-band used in multi-resonators permitting the tag data capacity to be doubled.