Enhancing Spectrum Efficiency in Quasi-Constant Envelope OFDM for Improved Performance

Abstract

Constant envelope OFDM (CE-OFDM) is a potential technology in coherent optical communication because it benefits from having a low peak-to-average power ratio (PAPR).  However, the applicability of CE-OFDM is constrained since Its spectrum efficiency is just 50% as efficient as conventional coherent optical OFDM. A novel in-phase/quadrature (I/Q) modulator, quasi-constant envelope OFDM (Quasi-CE-OFDM) arrangement was put forth. To further minimise computation complexity and eliminate phase ambiguity, a phase demodulation approach relied upon Taylor series expansion is implemented. According to simulation findings, the suggested system may effectively increase spectrum efficiency without sacrificing the benefit of high nonlinearity tolerance. Comparing Quasi-CE-OFDM's performance in the context of nonlinearity to PM-CE-OFDM, RF-CE-OFDM, also Con-CO-OFDM. Every OFDM systems employ the same number of subcarriers for data transmission, the length of an OFDM symbol, the overhead and the data rate to allow one to compare performance in an honest and equitable manner.