Performance evaluation of 64-QAM OFDM based FSO transmission for millimeter wave 5G applications

Abstract This article presents a simulation architecture to investigate the performance of high dynamic range orthogonal frequency division multiplexing (OFDM) as a modulation technique to transmit the quadrature amplitude modulation (QAM) basebands signal over free space optics (FSO) for the fifth generation/new radio (5G/NR) signals for millimeter wave (mm-wave) applications that broadcasting at 28 GHz. The evaluation study of this FSO system is carried out using the opti-system software (2024). The combination of FSO and 64QAM-OFDM systems has led to a high data rate at lower cost of wireless networks. The performance of the system has been analysed and compared with different values of the CW laser power, FSO range under different weather condition. Moreover, the FSO channel was modeled using both log-normal and gamma–gamma turbulence distributions. The performance analysis is based on bit error rate (BER),Q-factor, signal to noise ratio (SNR), error vector magnitude (EVM),optical spectrum analyses and cancellation diagram. According to the results obtained, the presented system can be considered as a good candidate for 5G and beyond mobile communication systems.