Channel Estimation Errors in FSO Systems Over High Turbulence Channels: A Negative Exponential Model Perspective

This study conducts a detailed performance analysis of free-space optical (FSO) communication systems in high atmospheric turbulence, where a negative exponential model charac-terizes channel conditions. The research focuses on understanding how inaccuracies in channel estimation critically affect FSO system performance in such turbulent settings. We present novel analytical expressions for the probability density function (PDF) and cumulative distribution function (CDF) of signal-to-noise ratio (SNR) under channel estimation errors. The derived expressions provide insights into key performance metrics such as outage probability, average bit error rate (BER), and ergodic capacity. Through numerical simulations, we demonstrate the extent of performance deterioration due to imperfect channel knowledge as compared to ideal estimates. Finally, Monte Carlo simulations validate our findings, highlighting the essential role of precise channel estimation for dependable FSO performance under severe turbulence conditions.