Performance analysis for multi-hop FSO communication system over M distribution with pointing errors

Multi-hop is a promising technology that can help the free space optical (FSO) transmission to establish robust routes in atmospheric turbulence. In this work, a multi-hop FSO communication system based on decode-and-forward protocol is investigated over $M$ distribution united with path loss and pointing errors. Particularly, with the BPSK subcarrier intensity modulation and direct detection techniques, the analytical expressions of average bit error rate and ergodic capacity are obtained for an independent but not identically distributed FSO system, and corroborated through Monte Carlo simulation method. Moreover, numerical analyses are presented to evaluate the influences of atmospheric turbulence, pointing errors and hop counts on performance of the studied system.