Long-distance Transmission Experiments Research Articles

Investigation on the Electromagnetic Surface Waves for Single-Wire Power Transmission

Single-wire power transmission (SWPT) is a power transmission method that uses only one wire to realize long-distance transmission of power. For deep insight, the theory of electromagnetic surface waves in this article is applied to reveal the principle of a long-distance large-scale SWPT system. Maxwell's equations under two different media in this system are established, based on them and the boundary conditions on the interface of the media, the propagation law of electromagnetic field energy in the SWPT system is analyzed. A simulation model is built by high frequency simulator structure (HFSS). The distribution law of the Poynting vector in different situations is studied to verify the correctness of the theoretical analysis. Moreover, long-distance transmission experiments are carried in the campus. It is shown that the transmission power can reach 300 W or 135 W when the transmission distance is 100 m or 200 m, respectively.

Experimental Study of Plane Spiral OAM Mode-Group Based MIMO Communications

Spatial division multiplexing using conventional orbital angular momentum (OAM) has become a well-known physical layer transmission method over the past decade. The mode-group (MG) superposed by specific single-mode plane spiral OAM (PSOAM) waves has been proved to be a flexible beamforming method to achieve the azimuthal pattern diversity, which inherits the spiral phase distribution of conventional OAM wave. Thus, it possesses both beam directionality and vorticity. In this article, it is the first time to show and verify a novel PSOAM MG based multiple-in–multiple-out (MG-MIMO) communication link experimentally in a line-of-sight (LoS) scenario. A compact multimode PSOAM antenna is demonstrated experimentally to generate multiple-independent controllable PSOAM waves, which can be used for constructing MGs. After several proof-of-principle tests, it has been verified that the beam directionality gain of MG can improve the receiving signal-to-noise ratio (SNR) level in an actual system. Meanwhile, the vorticity can provide another degree of freedom (DoF) to reduce the spatial correlation of MIMO system. Furthermore, a tentative long-distance transmission experiment operated at 10.2 GHz has been performed successfully at a distance of 50 m with a single-way spectrum efficiency of 3.7 bits/s/Hz/stream. The proposed MG-MIMO may have potential in the long-distance LoS backhaul scenario.

Dense Space Division Multiplexed Transmission Over Multicore and Multimode Fiber for Long-haul Transport Systems

In this paper, we review recent progress on space division multiplexed (SDM) transmission and our proposal of dense SDM (DSDM) with more than 30 spatial channels toward capacities beyond petabit/s. Furthermore, we discuss the requirements for realizing long-haul DSDM transport systems using multicore and/or multimode fiber, including power and space efficient amplification schemes, the use of fibers with large effective areas and transmission lines with low intercore crosstalk, low differential mode delay (DMD), and low mode dependent loss (MDL). Graded index heterogeneous 12-core × 3-mode fiber with low crosstalk, low DMD, and low MDL, parallel multiple-input and multiple-output signal processing, low mode dependent gain Erbium-doped fiber amplifiers, and MDL equalization technologies are significant as regards extending the reach of multicore and multimode transmission. We review our long-distance transmission experiment on polarization-division multiplexed 16-quadrature amplitude modulation signaling over 12-core × 3-mode fiber.

Using Superimposed ASK Label in a 10-Gb/s Multihop All-Optical Label Swapping System

A novel optical-label-swapping technique is proposed, experimentally verified, and theoretically analyzed in this paper. The technique superimposes a low-speed amplitude-shift-keying (ASK) label on top of a high-speed dc-balanced-line-coded ASK payload. A multihop long-distance transmission experiment using a recirculating loop has been successfully demonstrated, and an experimental record is set when compared with other optical-label-swapping techniques.

32 x 40-Gb/s dense WDM transmission over 3000 km using "double-hybrid" fiber configuration

This paper reports long-distance transmission experiments of 100-GHz-spaced 32 /spl times/ 40 Gb/s dense wavelength-division-multiplexing (DWDM) signals, designed for submarine applications. A transmission distance of 3000 km was obtained with more than 11.9-dB Q value. Keys to the achievement are the use of a novel fiber configuration and a nonlinear tolerant carrier-suppressed return-to-zero signal format for effectively suppressing the self-phase-modulation group-velocity-induced waveform degradation. The advantage of this double-hybrid fiber configuration is also confirmed by a transmission performance comparison with a quadruple-hybrid fiber configuration using 40-Gb/s-based DWDM signals.

Long-distance WDM transmission experiments using the dispersion slope compensator

Recently, long-haul transmission experiments of more than 100-Gbit/s capacity were reported. Wavelength-division multiplexing (WDM) is a key technology to achieve this kind of high-capacity transmission. One technical problem of the long distance WDM transmission is the dispersion slope of the transmission fiber. It causes the difference of the chromatic dispersion accumulation upon the WDM channels, and it will lead to transmission performance degradation. In order to solve the problem, equalization of the dispersion slope should be quite effective. This paper describes the results of the long-distance transmission experiments using the dispersion slope equalization. Both IM-DD WDM and optical soliton WDM are discussed.

All-optical regenerator for 20 Gbit/s transoceanictransmission

The authors report the first demonstration of an all-optical regenerator tested in a long-distance transmission experiment, using 20 Gbit/s solitons. All-optical clock recovery from a mode-locked semiconductor ring laser and polarisation-independent all-optical phase modulation in a Kerr fibre provides in-line regeneration over a distance of 6500 km.

Two 2 × 5 Gbit/s, 9500 km transmission experimentsusing densely-spaced WDM channels and 980 nm pumped EDFA

The authors have successfully demonstrated long-distance transmission experiments using densely-spaced WDM technology. 22 signal wavelengths, each containing 5 Gbit/s of binary data, were transmitted through a recirculating loop fibre transmission line; less than a 10/sup -9/ bit error rate equivalent was achieved after 9500 km of transmission on all channels.