A digitally implemented demodulator. A frequency-modulated signal is applied
to
a limiting amplifier such that the signal amplitude is fixed at a constant level.
The signal is undersampled and quadrature demodulated. The demodulator generates
the cross-product of the baseband complex envelope to recover the original modulating
signal. A digital Frequency Shift Keyed signal can be further recovered by applying
the recovered signal to a data slicer to square-up the signal, and a matched filter
for improved error resistance.
