An optimum demodulator for poisson processes: Photon source detectors

The optimum demodulator for time-varying Poisson processes is derived from consideration of the likelihood ratio. In the case of high background level radiation, it has been found that the optimum signal processing is cross-correlation. Under an average energy constraint and conditions of high background radiation, an optimum binary signaling method is "on-off" modulation. For both binary signaling and radar purposes, the "on" waveform should be a narrow pulse in order to maximize the "signal-to-noise" ratio.