CDMA RoFSO Links With Nonzero Boresight Pointing Errors Over <italic>M</italic> Turbulence Channels

Abstract

Radio-on-Free-Space Optical systems constitute a very attractive option for interconnecting central base stations with remote antenna units. Nonetheless, the optical signal propagation through the atmosphere is tremendously affected by turbulence- and misalignment-induced fading. In the present study, we investigate the transmission of code division multiple access signals over a free-space optical (FSO) link. The atmospheric turbulence is modeled by the M (Malaga) distribution, which acts as a unifying statistical model encompassing all the well-known distributions that have been proposed in the FSO area. In addition, nonzero boresight pointing errors (PEs) are employed, which are described by an accurate approximation of the Beckmann distribution. Novel mathematical expressions are extracted regarding the average bit error rate and the outage probability of the forward and the reverse link. Moreover, appropriate numerical results are depicted for various turbulence and PE scenarios, along with their associated corroborative outcomes.

Keywords

• Radio on FSO (RoFSO)
• code division multiple access (CDMA)
• atmospheric turbulence
• nonzero boresight pointing errors (PEs).