QPSK-Subcarrier Intensity modulated FSO System

The effect of Subcarrier intensity modulation with QPSK is discussed in this paper. QPSK is chosen as the best modulation scheme among BPSK, OOK and PSK. This work simulates PSK-SIM, BPSK-SIM and QPSK-SIM applied to FSO system at spectral efficiency (SE) of 4bps/HZ and the analysis is performed in weak and strong turbulence conditions. The investigation shows that QPSK-SIM-FSO system shows BER of the order of 10
⁻⁸
as compared to PSK and BPSK-SIM-FSO system in different turbulence conditions.