Abstract
Free space optical (FSO) communication systems experience atmospheric turbulence-induced fading, which is typically modelled by lognormal distribution. Since the decreasing rate of error probability over lognormal fading channels does not converge to a finite value, the conventional definition of diversity order yields infinity and does not provide any insight into system design. In this letter, we propose the so-called incremental diversity order (IDO), which is defined as the incremental change in the decreasing rate of bit error rate (BER) on a log-log scale. As an example, we consider multiple-input multiple-output (MIMO) FSO system over lognormal turbulence channels. We derive a novel closed-form BER expression in terms of Lambert-W function and obtain IDO as a function of the number of laser sources, the number of photodetectors and the variance of the log-amplitude coefficient. We further present numerical results to validate the derived BER expression and associated IDO.
Original language | English (US) |
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Article number | 8959173 |
Pages (from-to) | 825-829 |
Number of pages | 5 |
Journal | IEEE Communications Letters |
Volume | 24 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2020 |
Keywords
- Asymptotic analysis
- Free space optical communication
- Incremental diversity order
- Lognormal fading
ASJC Scopus subject areas
- Modeling and Simulation
- Computer Science Applications
- Electrical and Electronic Engineering