This demo demonstrates creation and effect of a Gabor multiplier. The multiplier performs a time-varying bandpass filtering. The band-pass filter with center frequency changing over time is explicitly created but it is treated as a "black box" system. The symbol is identified by "probing" the system with a white noise and dividing DGT of the output by DGT of the input element-wise. The symbol is smoothed out by a 5x5 median filter.