A Comparative Study of Optimum and Suboptimum Direct-Detection Laser Ranging Receivers

摘要

A summary of previously proposed receiver strategies for direct-detection laser ranging receivers is presented. Computer simulations are used to compare performance of candidate implemen¬tation strategies in the 1- to 100-photoelectron region. Under the condition of no background radiation, the maximum-likelihood (ML) and minimum mean-square error (MMSE) estimators were found to give the same performance for both bell-shaped and rectangular optical-pulse shapes. For signal energies greater than 10 photoelectrons, the root-mean-square (rms) range error is shown to decrease as Q-2/1for bell-shaped pulses and Q-1 for rectangular pulses, where Q represents the average pulse energy. Of several receiver implementations presented, the matched-filter peak detector was found to be preferable. A similar configuration, using a constant-fraction discriminator, exhibited a signal-level dependent time bias. Suggestions for future study are also included.