Introduction to Electromagnetic Compatibility

In this tutorial overview, the principles, advantages, challenges, and practical requirements of optical orthogonal frequency division multiplexing (OFDM)-based optical access are presented, with an emphasis on orthogonal frequency division multiple access (OFDMA) for application in next-generation passive optical networks (PON). General OFDM principles, including orthogonality, cyclic prefix use, frequency-domain equalization, and multiuser OFDMA are summarized, followed by an overview of various optical OFDM(A) transceiver architectures for next-generation PON. Functional requirements are outlined for high-speed digital signal processors (DSP) and data converters in OFDMA-PON. A techno-economic outlook for such a “software-defined,” DSP-based optical access platform is also provided.

OFDM for Next-Generation Optical Access Networks

We design and fabricate a novel multicore fiber (MCF), with seven cores arranged in a hexagonal array. The fiber properties of MCF including low crosstalk, attenuation and splice loss are described. A new tapered MCF connector (TMC), showing ultra-low crosstalk and losses, is also designed and fabricated for coupling the individual signals in-and-out of the MCF. We further propose a novel network configuration using parallel transmissions with the MCF and TMC for passive optical network (PON). To the best of our knowledge, we demonstrate the first bi-directional parallel transmissions of 1310 nm and 1490 nm signals over 11.3-km of seven-core MCF with 64-way splitter for PON.

Seven-core multicore fiber transmissions for passive optical network.

In recent decades, power line communication (PLC) has attracted considerable attention from the research community and industry, as well as from regulatory and standardization bodies. In this paper, we provide an overview of both narrowband and broadband systems, covering potential applications, regulatory and standardization efforts, and recent research advancements in channel characterization, physical layer performance, medium access, and higher layer specifications and evaluations. We also identify the areas of current and further study that will enable the continued success of PLC technology.

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State of the Art in Power Line Communications: From the Applications to the Medium

In recent decades, power line communication has attracted considerable attention from the research community and industry, as well as from regulatory and standardization bodies. In this article we provide an overview of both narrowband and broadband systems, covering potential applications, regulatory and standardization efforts and recent research advancements in channel characterization, physical layer performance, medium access and higher layer specifications and evaluations. We also identify areas of current and further study that will enable the continued success of power line communication technology.

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State-of-the-art in Power Line Communications: from the Applications to the Medium

We experimentally investigate the transmission performance of a novel modulation based on a recently proposed technique of adaptively modulated optical orthogonal frequency-division multiplexing (AMOOFDM) for next-generation passive optical network (NG-PON). This signal was generated by direct modulation of cost-effective and low-bandwidth commercially available distributed-feedback and vertical-cavity surface-emitting lasers. Using the Levin-Campello adaptive bit-loading algorithm for channel capacity optimization over AMOOFDM modulation to reach maximum transmission performance, we experimentally demonstrated that high bit rate can be transmitted in optical access network without the need for chromatic dispersion compensation and optical amplification on the link.

Adaptive Loading Algorithm Implemented in AMOOFDM for NG-PON System Integrating Cost-Effective and Low-Bandwidth Optical Devices

A significant portion of the end-to-end delay in high-rate DSL systems is due to the impulse noise protection scheme employed in order to shield those systems against random, non-stationary noise bursts of high energy that appear on the copper lines. Systems are protected from impulse noise using a combination of interleaving and Reed-Solomon codes. In order to lower the end-to-end delay without reducing the data rate that is available to the user, one needs to decrease the interleaver depth. This paper presents a way to achieve this reduction without compromising neither the robustness to noise bursts nor the data rate of the system. The proposed algorithm relies on the inner code used by many DSL systems and uses the metric provided by the inner code decoder at the receiver. A DMT-VDSL system is used as a particular example of the achieved reduction of the end-to-end delay.

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A byte-erasure method for improved impulse immunity in DSL systems using soft information from an inner code

We report the performance of a chirped laser in IMDD-based transmissions and we show that the interplay between laser chirp and fiber dispersion can be very attractive for long distance PONs if adaptive OFDM modulation is used.

On the interest of chirped lasers for AMOOFDM transmissions in long distance PON networks

DSL systems achieve high rate transmission through copper pairs traditionally used for voiceband communication In order to attain high rates, sophisticated system designs are employed to cope with both stationary and non-stationary disturbers In current DSL systems, protection against nonstationary interference, comprising impulse noise and radio frequency ingress (RFI), is achieved using a forward error correction (FEC) scheme consisting of a Reed-Solomon (RS) code and interleaving However, interleaving results in increased end-to-end delay The end-to-end delay can be reduced by taking advantage of the erasure decoding property of RS codes The paper presents a byte-erasure technique that allows erasure decoding to be employed The method locates the possibly erroneous bytes in each RS codeword by comparing the square distance between each received carrier symbol of the interleaved stream and the closest point of the constellation to which the symbol belongs Thus, the interleaving delay can be reduced by a factor up to 2 when impulse noise impairs transmission The method can also be applied to systems affected by both impulse noise and RFI, since it can distinguish between the two sources of non-stationary interference Finally, no change is required at the transmitter, and hence compatibility with currently deployed systems is guaranteed A DMT-VDSL system is used as a particular example of the achieved reduction of the interleaving delay

A square distance-based byte-erasure method for reduced-delay protection of DSL systems from non-stationary interference

A bit rate as high as 19Gbit/s transmission was experimentally demonstrated for NG-PON without chromatic dispersion compensation by direct modulation of DFB laser using DMT signal combined with adaptive power-bit loading algorithm.

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Meryem Ouzzif

Papers

Adaptive Loading Algorithm Implemented in AMOOFDM for NG-PON System Integrating Cost-Effective and Low-Bandwidth Optical Devices

A byte-erasure method for improved impulse immunity in DSL systems using soft information from an inner code

On the interest of chirped lasers for AMOOFDM transmissions in long distance PON networks

A square distance-based byte-erasure method for reduced-delay protection of DSL systems from non-stationary interference

High bit rate transmission for NG-PON by direct modulation of DFB laser using discrete multi-tone