Effects of atmospheric turbulence and misalignment fading on performance of serial‐relaying M‐ary pulse‐position modulation free‐space optical systems with partially coherent Gaussian beam

• DOI: 10.1049/iet-com.2013.0721
• Publication Date: 2014-06-25T18:03:00Z
• Authors: Hien T.T. Pham; Ngoc T. Dang; Anh T. Pham
• Keywords: Pulse-position modulation; Position (finance); Modulation (music); Free space; Free-Space Optical Communication; Gaussian beam

A novel method is presented to analyse the effects of atmospheric turbulence and misalignment fading (or pointing error) on performance serial‐relaying M ‐ary pulse‐position modulation (PPM) free‐space optical (FSO) systems. This study more comprehensive than previous ones, since effect beam size variation due by using partially coherent Gaussian model taken into account. In addition, a closed‐form expression formulated for bit error rate PPM FSO systems over Gamma–Gamma channel, taking account attenuation, extinction ratio signal‐dependent noise. The authors find that laser source's parameter, which governs at receiver, plays an important role in system design. If this parameter not chosen properly, impairment will be either dominated or geometric spreading loss. Thanks use PPM, mitigated; hence ability combating transmission distance are significantly improved. useful information design, such as required number relays specific strength distance, could obtained from numerical results.