Analysis of different modulation methods for wireless optical communication systems

Abstract

Wireless optical systems are gaining popularity When the signal is received in the channel the performance may be greatly affected by the turbulent atmosphere This study aims to investigate the ideal modulation strategy for FSO systems using an FSO channel The four modulation systems are OnOff keying OOK Binary Phase Shift Keying BPSK Differential Phase Shift Keying DPSK and Quadrature Phase Shift Keying QPSK were investigated and their energy and bandwidth efficiencies bit error rates BER and signaltonoise ratios SNR were compared Numerical studies have demonstrated that BPSK and QPSK schemes perform better than other schemes in terms of BER performance and power consumption The BER results of the BPSK and QPSK systems when using the Gamma channel for intensity scintillation are essentially the same BPSK is turbulenceresistant As a result BPSK can be used in free communication systems