29 research outputs found
Comparison of Digital Signal Processing Approaches for Subcarrier Multiplexed 5G and Beyond Analog Fronthaul
Analog fronthaul transport architectures with digital signal processing at the end stations are promising as they have the potential to achieve high spectral efficiencies, increased flexibility and reduced latency. In this paper, two digital techniques for frequency domain multiplexing/de-multiplexing large numbers of channels are contrasted: one operates on the pre-Inverse Fast Fourier Transform (IFFT) “frequency-domain” samples while the other does so on the post-IFFT “time-domain” samples. Performance criteria including computational complexity and sampling rate requirements are used in the comparison. Following modeling and simulation of the techniques, implemented within a radio-over-fiber transport architecture, error vector magnitude performance estimates are obtained. These results show that each technique has performance advantages under specific channel transport scenarios
Flexible and Efficient DSP-assisted Subcarrier Multiplexing for an Analog Mobile Fronthaul
The digital formation of an analog subcarrier multiplex employing in combination both a technique using pre-IFFT frequency-domain samples and one using post-IFFT time-domain samples is proposed and demonstrated. This combined technique enables a compromise for sampling rate requirements, while maintaining low complexity and good performance
Study of the potentialities of multicarrier modulation techniques for future WDM and TDM passive optical access networks
Malgré son succès dans le domaine des radio-fréquences, l OFDM n a que récemment commencé à attirer l attention de la communauté optique grâce à une remarquable évolution de l électronique et aux demandes de débit de plus en plus élévées dans les réseaux d accès. OFDM apparaît comme un très fort candidat pour fournir la flexibilité tant attendue dans les réseaux d accès optiques "rigides" d aujourd hui ayant aussi le potentiel de permettre une évolution vers des débits, portées et nombre d abonnés plus élévés. Dans cette thèse, nous nous concentrons sur une approche de modulation en intensité et détection directe (IMDD) qui permet de conserver la simplicité sur le plan optique en transférant la complexité de la transmission au domaine du traitement numérique du signal. Ce travail se base sur deux axes principaux. Dans le premier, nous étudions l influence de la réponse fréquentielle du canal, caracterisée par l interaction entre la dispersion chromatique de la fibre optique et la modulation parasite en phase provenant de la source optique et les moyens d optimiser le débit du système avec des algorithmes d allocation de puissance et modulation. Deuxièmement, nous évaluons l approche IMDD OFDM sous différentes architectures et techniques de partage des ressources du réseau entre les abonnées, à savoir les multiplexages en temps, longueur d onde et fréquence.Despite its success in radio-frequency applications, OFDM has only recently started to draw the attention of the optical community owing principally to the outstanding advancements in electronics and the increasing demands in terms of bit-rates in the last miles of the network. OFDM appears as one possible solution to cost-effectively provide the long-awaited flexibility that lacks on today s somewhat "rigid" passive optical networks (PON). It may also allow their evolution towards higher bit-rates, longer transmission distances and increased number of subscribers per PON tree. Here, we focus on the IMDD approach, which can manage to keep the simplicity and cost-effectiveness at the optical plane by transferring the "hard work" to the digital signal processing domain. We focus this work on two main axes. In the first one, we study the influence of the dispersive IMDD channel frequency response characterized by the interplay between fiber chromatic dispersion and the parasite phase modulation of the light source (chirp) and the ways of optimizing the system s throughput by means of bit and power loading algorithms. Secondly, we evaluate the IMDD OFDM approach under different architectures. Those architectures characterize distinct solutions to share the network ressources between the subscribers, namely time, wavelength and frequency multiplexing.LIMOGES-BU Sciences (870852109) / SudocSudocFranceF
INFLUENCE DES PROPRIETES FREQUENTIELLES DE DIFFERENTS LASERS DML SUR LES PERFORMANCES D'UNE EMISSION DUO-BINAIRE A 20 GBIT/S
International audienceLa réponse fréquentielle de lasers DML est analysée afin d'évaluer la limitation de leur usage dans les transmissions optiques multi-niveaux tels que le duo-binaire
An analysis of linear digital equalization in 50Gbit/s HS-PONs to compensate the combined effect of chirp and chromatic dispersion
International audienc
Study of minimum mean square error optimal equalizers for 50Gbit/s high speed passive optical networks
International audienc
Transmission Performance of Chirp-Controlled Signal Emitted by Electroabsorption Modulator Laser Integrated with a Semiconductor Optical Amplifier
International audienc
Up to 10 Gbit/s transmission in WDM-PON architecture using External Cavity Laser based on Self-Tuning ONU
International audience<p>An external cavity laser is demonstrated with a RSOA at ONU and a mirror at the RN which can be 5km away. A record transmission of 10Gbits/s is shown and compared with performance at 1.25, 2.5, 5Gbit/s.</p
Pre-coded NRZ and Electrical Duo-Binary Transmission in C and O-band at Data Bit Rate up to 25Gbit/s
International audienc
10 Gb/s Continuous Clock and Data Recovery for BurstMode Transmissions with Externally Modulated Laser
International audienceWe present the performance of a newly developed receiver with embedded CDR for 10 Gb/s burst data transmission. A 30dB loss budget with 6dB extinction ratio, 1024 bits preamble and 12.5 ÎĽs bursts is demonstrated