Pulse Detection by Gated Synchronous Demodulation

Synchronous demodulation (SD) is the signal recovery method of choice when the input envelope signal is modulated by either a pure sine wave or a square wave. SD is less efficient for pulsed periodic signals with a low duty factor. For the latter signals, we introduce data processing that applies gating on a part of the signal period to achieve optimum conditions for recovering the pulse amplitude by quadrature SD. The proposed method is evaluated for signal-to-noise performance against Boxcar-type gated integrators in simulated data, as well as data acquired from physical measurements, in the presence of $1/f$ and Gaussian noise. It is shown that by combining the gating and SD principles, our suggested gated SD outperforms other routine signal processing methods under typical $1/f$ noise conditions.