Notch identification is a major challenge in Frequency Coded (FC) chipless RFID. The main objective of this contribution is to introduce three signal processing techniques for notch identification and detection. The three algorithms are Matched Filter(MF), Window Based- Singular Value Decomposition (WB-SVD) and Dynamic Time Warping (DTW). The algorithms should be able to detect both notch bandwidth and shift in a real environment, where the notch is likely to be highly distorted. In this work both a simulation model and a testbed is performed to analyze and verify each algorithm using fabricated tags.