High-speed transmission over multimode fiber using discrete multitone modulation

Focus Issue: Orthogonal-Frequency-Division Multiplexed Communications Systems and Networks Discrete multitone (DMT) modulation is a subclass of the more general orthogonal-frequency-division multiplexing, where the output of the inverse fast Fourier transform modulator is real instead of complex-valued. Therefore, no in-phase and quadrature modulation onto an RF carrier is required. As a result, broadband, high-frequency, analog RF components are omitted, reducing system complexity and costs. We give an overview of important issues such as synchronization and peak-to-average power that should be considered when DMT is employed in an intensity-modulated direct-detection multimode fiber (MMF) link. Experimental results showing 24Gbits/s transmission over silica MMF and 8Gbits/s transmission over the standard step-index polymer optical fiber (SI-POF) are presented, demonstrating the potential of DMT to enable high-speed transmission over MMF using only low-bandwidth transceivers.