Cramér-Rao Bounds for Beam Tracking With Photon Counting Detector Arrays in Free-Space Optical Communications

Muhammad Salman Bashir, Ming-Cheng Tsai, Mohamed-Slim Alouini

Research output: Contribution to journalArticlepeer-review

7 Scopus citations


Optical beam center position on an array of detectors is an important parameter that is essential for estimating the angle-of-arrival of the incoming signal beam. In this paper, we have examined the beam position estimation problem for photon-counting detector arrays, and to this end, we have derived and analyzed the Cramir-Rao lower bounds on the mean-square error of unbiased estimators of beam position. Furthermore, we have also derived the Cramir-Rao lower bounds of other system parameters such as signal peak intensity, and dark current noise power, on the array. In this sense, we have considered robust estimation of beam position in which none of the parameters are assumed to be known beforehand. Additionally, we have derived the Cramir-Rao lower bounds of beam and noise parameters for observations based on both pilot and data symbols of a pulse position modulation (PPM) scheme. Finally, we have considered a two-step estimation problem in which the signal peak and dark current noise intensities are estimated using a method of moments estimator, and the beam center position is estimated with the help of a maximum likelihood estimato.
Original languageEnglish (US)
Pages (from-to)1-1
Number of pages1
JournalIEEE Open Journal of the Communications Society
StatePublished - 2021

Bibliographical note

KAUST Repository Item: Exported on 2021-05-12
Acknowledgements: This work is supported by Office of Sponsored Research (OSR) at King Abdullah University of Science and Technology (KAUST).


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