Spatial Diversity for CDMA RoFSO Links over <i>M</i> Turbulence Channels with Nonzero Boresight Pointing Errors

• Main Authors: Michalis P. Ninos, Hector E. Nistazakis
• Format: Article
• Language: English
• Published: MDPI AG 2018-10-01
• Series: Computation
• Subjects: free-space optical communications; spatial diversity; RoFSO; CDMA; malaga distribution; nonzero boresight pointing errors
• Online Access: https://www.mdpi.com/2079-3197/6/4/55

A CDMA RoFSO link with receivers&#8217; spatial diversity is studied. Turbulence-induced fading, modeled by the <i>M</i>(alaga) distribution, is considered that hamper the FSO link performance along with the nonzero boresight pointing errors effect. Novel, analytical closed-form expressions are extracted for the estimation of the average bit-error-rate and the outage probability of the CDMA RoFSO system for both directions of the forward and the reverse link. The numerical results show clearly the performance improvement of using spatial diversity, even in the most adverse atmospheric conditions with strong and saturated atmospheric turbulence with enhanced misalignment. Also, the effects of nonlinear distortion, multiple access interference and clipping noise aggravate the performance of the link, where cases with large number of users are taken into account.