Optimal Power Allocation between Beam Tracking and Symbol Detection Channels in a Free-Space Optical Communications Receiver

Muhammad Salman Bashir, Mohamed Slim Alouini

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)

Abstract

Free-space optical (FSO) communications will play an important role in the backhaul of future generation of wireless networks in order to support high data rates. Because of narrow beamwidth inherent to an optical signal, acquisition and tracking form an important component of any FSO communication system. In this study, we have analyzed the optimization of received power allocation between tracking and data channels in an FSO receiver. In this regard, we have carried out a detailed analysis of the error statistics of the centroid estimator that is used for tracking the beam with the help of an array. The objective function that is optimized (minimized) are the probability of error and the probability of outage, and the optimization of power allocation is carried out as a function of parameters such as noise power, pointing error variance, pointing error correlation coefficient, and the threshold of outage. We have analyzed the optimization concerning the lognormal and exponentiated Weibull fading scenarios as well. We learn that the optimal power allocation is a function of the received signal-to-noise ratio: a lower signal-to-noise ratio dictates that a higher fraction of received power should be diverted to the tracking channel and vice versa.

Original languageEnglish
Article number9495783
Pages (from-to)7631-7646
Number of pages16
JournalIEEE Transactions on Communications
Volume69
Issue number11
Early online date26 Jul 2021
DOIs
Publication statusPublished - 1 Nov 2021
Externally publishedYes

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