On the extension of the discrete model for optical detection

Previous work on a "natural" set of observables for time-varying Poisson point processes and its usefulness in analyzing continuous models of optical communication systems is briefly reviewed. The result on the variance of the maximum likelihood estimator of delay is used to derive an approximate lower bound to the information rate of continuously position modulated laser pulses. It appears that the continuous PPM system has a potentially superior performance as compared to a discrete PPM system recently analyzed.