A space-time-frequency target identification technique for chipless RFID applications

Based on the Singularity Expansion Method (SEM) the late time scattered signal from an object consists of a summation of damped sinusoidals. Each damped sinusoidal represents a pair of complex conjugate natural frequencies (poles) which are tied to the scatterer's structure. The classical Matrix Pencil method has been used extensively to extract poles and residues from the late time scattered signal. Multiple objects break the matrix pencil method due to existence of different groups of poles and residues with different time windows in the same received signal. The technique presented in this paper attempts to separate poles based on their times and directions of arrival. This helps to analyze the scattered signal in presence of multiple objects.