Gaussian-Shaped Free-Space Optical Beam Intensity Estimation in Detector Arrays

Abstract

Photon counting detector arrays are commonly used for deep space optical communication receivers operating on the principle of intensity modulation/direct detection (IM/DD). In scenarios where beam parameters can vary at the receiver due to scattering, it is important to estimate beam parameters in order to minimize the probability of error. The use of array of detectors increases the sensitivity of the receiver as compared to single photo-detector of the same size. In this paper, we present the derivation of a maximum likelihood estimator (ML) for peak optical intensity, providing both numerical and closed form expressions for the estimator. Performance of both forms of ML estimator are compared using the mean squared error (MSE) criterion and Cramer–Rao Lower Bound (CRLB) is also derived to assess the proposed estimator’s efficiency. This research contributed to the advancement of estimation techniques and has practical implications for optimizing deep space optical communication systems.