IMD Mitigation Using Orthogonal-Time-Set OFDM in Multi-IF Over Fiber Optical Transmission System

This study proposes orthogonal- time-set orthogonal frequency-division-multiplexing (OTS OFDM) optical transmission technique to mitigate the intermodulation distortion (IMD) effect in multiband IF over fiber (multi-IFoF) transmission systems. Multi-band OFDM signals are modulated with each band's signal using an orthogonal time set to minimize the effects of IMD caused by beating between different band signals. The correlation between signal and IMD was analyzed, and it was mathematically proven that IMD production is suppressed through orthogonality of OTS. IMD caused by interband beating is suppressed through OTS OFDM, which results in a reduction of signal distortion caused by IMD. The proposed technique is verified theoretically and experimentally through BER performance.