Free-space optical communications with peak and average constraints: High SNR capacity approximation

Anas Chaaban, Jean-Marie Morvan, Mohamed-Slim Alouini

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations


The capacity of the intensity-modulation direct-detection (IM-DD) free-space optical channel with both average and peak intensity constraints is studied. A new capacity lower bound is derived by using a truncated-Gaussian input distribution. Numerical evaluation shows that this capacity lower bound is nearly tight at high signal-to-noise ratio (SNR), while it is shown analytically that the gap to capacity upper bounds is a small constant at high SNR. In particular, the gap to the high-SNR asymptotic capacity of the channel under either a peak or an average constraint is small. This leads to a simple approximation of the high SNR capacity. Additionally, a new capacity upper bound is derived using sphere-packing arguments. This bound is tight at high SNR for a channel with a dominant peak constraint.
Original languageEnglish (US)
Title of host publication2015 4th International Workshop on Optical Wireless Communications (IWOW)
PublisherInstitute of Electrical and Electronics Engineers (IEEE)
Number of pages5
ISBN (Print)9781467377263
StatePublished - Dec 3 2015

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01


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