The main objective of this contribution is to introduce novel techniques for reducing the time taken from the reader to identify the frequency coded chipless radio frequency identification tags existed in the reader's interrogation region, system latency. The frequency scanning methodology, number of averaging for clutter removal, and hop duration are the 3 main parameters that significantly affect the overall system latency. Consequently, the adaptive frequency hopping (AFH) and adaptive sliding window (ASW) methodologies are proposed and proofed to be efficient for the chipless radio frequency identification systems from the latency and accuracy perspectives. Likewise, the performance of the designed AFH and ASW techniques are compared with the classical fixed frequency hopping methodology with a fine frequency step to validate the accuracy of the proposed methods. Moreover, 4 different coded frequency coded chipless tags are manufactured and used in the measurements. A real-world testbed is designed including a software-defined radio platform by which the proposed adaptive algorithms and traditional fixed frequency hopping methodology are implemented. All the measurements are performed in an indoor realized scenario, including the environmental effects. The experiments show that the proposed AFH combined with ASW algorithms significantly reduce the system latency by 58%. |
