Scj Jeffrey Lee

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.

47.4 Gb/s Transmission Over 100 m Graded-Index Plastic Optical Fiber Based on Rate-Adaptive Discrete Multitone Modulation

We experimentally demonstrate a bit-rate of 47.4 Gb/s over 100 m of perfluorinated multimode graded-index plastic optical fiber (GI-POF) by exploiting discrete multitone (DMT) modulation with rate-adaptive bit-loading. The maximum achieved aggregate bit rate is 51.8 Gb/s including DMT transmission overhead (cyclic prefix and preambles) and the standard of 7% of forward-error-correction (FEC) overhead. This is achieved over an intensity-modulated direct-detection (IM-DD) link using a directly-modulated DFB laser (1300-nm) and a multimode fiber-coupled photodetector with a large diameter of 25-¿m. The bandwidth requirement is only 12 GHz due to the use of spectral-efficient modulation formats of up to 64-QAM.

Discrete multitone modulation for high-speed data transmission over multimode fibers using 850-nm VCSEL

30-Gb/s transmission over 500 m and 28-Gb/s over 1 km of multimode fiber (with 850-nm multimode VCSEL and large-area photodetector) is experimentally demonstrated by use of discrete multitone modulation (DMT) combined with bit-loading algorithm.

40-Gb/s transmission over 100m graded-index plastic optical fiber based on discrete multitone modulation

Spectral-efficient 40-Gb/s discrete multitone transmission over 100m of graded-index plastic optical fiber is experimentally demonstrated by intensity-modulation of a 10-GHz DFB-laser (1302nm) and direct-detection with a 25-µm large diameter photodetector.

Discrete Multi-Tone Modulation for Low-Cost and Robust 10-Gb/s Transmission over Polymer Optical Fibre

Utilizing a transmission bandwidth of 2 GHz, we demonstrate 10.6-Gb/s transmission (11.9-Gb/s including overhead) over 100 m of 120-micrometer core-diameter graded-index polymer optical fibre with discrete multi-tone modulation, achieving a spectral efficiency of 5.3 bit/s/Hz.

Discrete multitone for novel application areas of optical communications

Discrete multitone (DMT) is a spectral-efficient multicarrier modulation technique, derived from the more general orthogonal frequency division multiplexing. In this paper, the use of DMT in novel optical communication applications such as wireless visible light communication and plastic optical fiber links is presented and discussed.

Low-cost and high-capacity short-range optical interconnects using graded-index plastic optical fiber

We demonstrate a transmission rate of 51.8 Gb/s over 100-meters of perfluorinated multimode graded-index plastic optical fiber using discrete multitone modulation. The results prove suitability of plastic fibers for low-cost high-capacity optical interconnects.

Optical in-building network techniques

By deploying optical fiber, versatile in-building networks which integrate wired and wireless services can be realized. Advanced signal modulation techniques enable high-capacity services over multimode fiber, and dynamic wavelength routing can improve the systems efficiency.

Research trends in optical in-building networks

By using optical fibre, a single in-building network can offer many broadband services to both wired and wireless terminals. Multi-level modulation and dispersion-robust radio-over-fibre techniques allow the use of cost-effective multimode silica or plastic fibre.