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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 17, Iss. 15 — Jul. 20, 2009
  • pp: 12601–12611

Capacity of coherent free-space optical links using diversity-combining techniques

Aniceto Belmonte and Joseph M. Kahn  »View Author Affiliations

Optics Express, Vol. 17, Issue 15, pp. 12601-12611 (2009)

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We study the performance of diversity combining techniques applied to synchronous laser communication through the turbulent atmosphere. We assume that a single information-bearing signal is transmitted over two or more statistically independent fading channels, and that the multiple replicas are combined at the receiver to improve detection efficiency. We consider the effects of log-normal amplitude fluctuations and Gaussian phase fluctuations, in addition to local oscillator shot noise. We study the effect of various parameters, including the ratio of receiver aperture diameter to wavefront coherence diameter, the scintillation index, and the number of independent diversity branches combined at the receiver. We consider both maximal-ratio combining (MRC) and selective combining (SC) diversity schemes. We derive expressions for the outage Shannon capacity, thus placing upper bounds on the spectral efficiency achievable using these techniques.

© 2009 OSA

OCIS Codes
(010.1330) Atmospheric and oceanic optics : Atmospheric turbulence
(060.4510) Fiber optics and optical communications : Optical communications

ToC Category:
Atmospheric and Oceanic Optics

Original Manuscript: May 13, 2009
Revised Manuscript: July 3, 2009
Manuscript Accepted: July 3, 2009
Published: July 20, 2009

Aniceto Belmonte and Joseph M. Kahn, "Capacity of coherent free-space optical links using diversity-combining techniques," Opt. Express 17, 12601-12611 (2009)

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