A 500 km Long Transmission with Coherent Optical OFDM Using Dual Polarization Quadrature Phase Shift Keying (QPSK) and Double Sideband Suppressed‐Enhanced Carrier (DSS‐EC).

Coherent optical orthogonal frequency division multiplexing (CO‐OFDM) systems are chosen for this task because of their high spectral efficiency, low inter‐symbol interference (ISI), low intercarrier interference (ICI), robustness against chromatic dispersion (CD), and high nonlinearity interference tolerance (HNIT). The DSS‐EC technique is utilized in this study to investigate a high‐speed 100 Gbps CO‐OFDM with a QPSK encoder over a 500 km uncompensated connection distance. The proposed system is compared to CO‐OFDM‐QPSK and CO‐OFDM‐16QAM systems in terms of log BER at various input optical signal to noise ratios (OSNRs). Results reveal that due to enhanced available bandwidth use of communication channels, the proposed CO‐OFDM‐DSS‐EC‐QPSK system provides minimum log BER at lower input OSNRs while the rest two systems show identical log BER performance at high input OSNRs. Therefore, proposed technique is a prominent solution for future generations high data demands and for a cost‐effective solution due to an uncompensated transmission channel. [ABSTRACT FROM AUTHOR]