Lee, I. E.Ghassemlooy, Z.Ng, W. P.Khalighi, M. A.Uysal, Murat2016-02-152016-02-152013978-1-4673-5821-7http://hdl.handle.net/10679/2410https://doi.org/10.1109/NOC-OCI.2013.6582900Due to copyright restrictions, the access to the full text of this article is only available via subscription.In this paper, we investigate the joint effects of beam width and the spatial coherence length in a partially coherent free-space optical (FSO) link from the information theory perspective, taking into account the combined influence of atmospheric turbulence and pointing errors. In addition, the effects of aperture-averaging on the average capacity of FSO links employing partially coherent beams (PCBs) are examined. Results show that PCBs are desirable in the weak-to-moderate turbulence regime, whereas highly coherent laser sources are preferred under strong fluctuations conditions; and there exist optimality in the optical beam parameters for different atmospheric channel conditions. Near-optimal average capacity is best achieved through the introduction of a larger receiver aperture and the joint beam width and spatial coherence length optimization technique, which effectively mitigates the effects of scintillation and pointing errors.enginfo:eu-repo/semantics/restrictedAccessConference paper28128600036029300004210.1109/NOC-OCI.2013.6582900Free-space optical (FSO) communicationsPartially coherent beam (PCB)Atmospheric turbulencePointing errorsAverage channel capacity2-s2.0-84883772727