Performance analysis of 1.28 terabit/s transmission system for dense wavelength division multiplexing free-space optical communications

This paper investigates the implementation of a dense wavelength division multiplexing (DWDM) 32 × 40 Gb/s (1.28 Tb/s) free-space optical (FSO) communication system. The analysis is performed for return-to-zero (RZ) and non-return-to-zero (NRZ) line codes over a 1 km free-space optic distance. The motivation for the current analysis is to compare RZ and NRZ line codes in the DWDM-FSO communication system, and it is found that the NRZ line code performs better than the RZ code. A 1.28 Tb/s DWDM communication system for free-space optic channels has been explored, where 32 channels, each carrying 40 Gb/s data streams, are combined using DWDM-FSO system. The study includes the attenuation caused by atmospheric effects and beam divergence. Bit-error rate, quality factor, and eye diagram are used as indicators of performance evaluation. The results suggest a promising system for high-capacity access networks with more bandwidth, cost-effectiveness, and good flexibility.