Performance of 120 Gbps single channel coherent DP-16-QAM in terrestrial FSO link under different weather conditions

摘要

The performance of a 120 Gbps single-carrier coherent transceiver system is evaluated in a terrestrial Free Space Optical Link (FSOL) under the haze, rain, and fog weather conditions. In-phase and Quadrature (IQ) based Dual Polarization 16 Quadrature Amplitude Modulation (DP-16-QAM) is implemented in OptiSystem v.13 simulation platform with homodyne detection and Digital Signal Processing (DSP) at the receiver. The IQ based optical modulator and the DSP unit can be fabricated in the form of Integrated Circuits (ICs) help to keep the system cost low. The system performance is evaluated in terms of Optical Signal to Noise Ratio (OSNR) requirements at an acceptable Bit Error Rate (BER = 2 x 10(-3), i.e., below the FEC limit) under low turbulence environment. Simulation results show that the system maintains good OSNR performance under severe weather conditions. This transceiver system shall be useful in short-reach, low-cost, high capacity, robust communication link with dynamic environmental conditions.