Adaptive Acquisition Schemes for Photon-Limited Free-Space Optical Communications

Muhammad Salman Bashir, Mohamed Slim Alouini

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)

Abstract

Acquisition and tracking systems form an important component of free-space optical communications due to directional nature of the optical signal. Acquisition subsystems are needed in order to search and locate the receiver terminal in an uncertainty/search region with very narrow laser beams. In this paper, we have proposed and analyzed two adaptive search schemes for acquisition systems that perform better-for the low probability of detection-than the spiral scanning approach. The first of these schemes, the adaptive spiral search, provides a better acquisition time performance by dividing the search region into a number of smaller subregions, and prioritizing search in regions of higher probability mass. The second technique-The shotgun approach-searches the region in a random manner by sampling the search region according to a Gaussian distribution. The adaptive spiral scheme outperforms the shotgun approach in terms of acquisition time, especially if the number of search subregions is large enough. However, a higher pointing accuracy is required by the adaptive spiral search in order to search the region precisely. On the other hand, the shotgun scanning approach does not require such stringent pointing accuracy.

Original languageEnglish
Article number9210018
Pages (from-to)416-428
Number of pages13
JournalIEEE Transactions on Communications
Volume69
Issue number1
Early online date30 Sep 2020
DOIs
Publication statusPublished - 1 Jan 2021
Externally publishedYes

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