1,721,018 research outputs found
Modeling and Optimization of Experimental S+C+L WDM Coherent Transmission System
No full textUsing accurate ISRS GN modeling and the fast-converging ASE-NL optimization algorithm, we demonstrate 6.2 Tbit/s throughput improvement in a 2-span ultra-wide-band system thanks to the use of the predicted total and per channel power. (c) 2022 The Author(s
S+C+L High-Capacity Transmission Systems: Challenges and Opportunities
No full textMore than two decades after the first terabit transmission using the C+L band, and recent advancements in ultra-wideband (UWB) technology have demonstrated remarkably high-throughput achievements in S+C+L demonstrations. The development of fast and reliable closed-form propagation models accounting for wavelength-dependent impairments has paved the way for effective equalization techniques that contribute to this capacity boost. In this work, we compare the capacity of S+C+L systems to C+L and C systems, highlighting the importance of model-based power control strategies. Additionally, we explore different power pre-emphasis to either maximize capacity or achieve a uniform signal-to-noise ratio (SNR), the latter being of interest for actual networks in which the bit rate options of a transceiver are typically limited. Furthermore, we use the model-based performance prediction to analyze the impact of the amplifier's failure, highlighting the complex challenges this process leads to in terms of inter-channel stimulated Raman scattering (ISRS) power variations and transmission performance. Overall, this work aims to study through model-based simulations, the benefits and challenges of UWB systems while considering the feasibility of its deployment
Experimental analysis of degenerate vector phase-sensitive amplification
No full textWe comprehensively investigate a degenerate vector phase-sensitive amplifier (PSA). We determine the gain dependence on the relative phase and polarization angle between the pumps and the degenerate signal wave. The vector PSA is experimentally shown to be sensitive to the pump states of polarization (SOP) due to polarization mode dispersion in the fiber. However, the scheme performance agrees well with theory under specific pump SOPs and we achieve an on-off gain over 10 dB with a small deviation from the theoretically expected results. In comparison to the scalar scheme, the proposed vector scheme has larger tolerance for pump depletion due to four-wave mixing between pumps and generation of higher-order idlers
67.2 Tbit/s Real-Time DCI Transmission Demonstration Using Single Seamless SOA
No full textNew effective amplification solutions are required to extend existing network architectures for data center interconnect (DCI) beyond the C band. We implement a new multiband amplification solution for DCI application by employing a single seamless ultra-wideband SOA to amplify both C and L bands. We evaluate its transmission performance, including system nonlinear impairments, by testing three different input power spectra and three distinct span losses. We demonstrate a total real-time throughput of 67.2 Tbit/s over a transmission span of 100 km standard single-mode fiber with a total span loss of 25 dB
Reducing ROADM Filtering Penalties Using Subcarrier Multiplexing with Offline Bit and Power Loading
No full textWe experimentally demonstrate that the impact of cascaded ROADMs on subcarrier multiplexing can be efficiently predicted and near-optimally counteracted by simple offline bit and/or power loading. At 200G, we show SNR gains of ~3 dB when passing through 7 ROADMs
Impact of WDM-Band Drop on Multi-Band Optical Transmission Systems
No full textWe experimentally assess the impact of different band drops on the performance of S+C+L multi-band optical transmission systems. We also present the digital twin of our
experiment that quantifies the different noise contributions affecting the system performance in detail. Our results highlight how the L band is largely affected due to the lack of ISRS induced power transfer when the S band is missing
Digital Pre-Distortion for Drivers and SOAs Nonlinearities Enabling Power Budget Extension
No full textWe experimentally show that DPD nonlinear compensation can improve the power budget from 13.5 dB to 16.9 dB with an 800 Gbps 90 Gbaud signal thanks to enabling larger transmitted power while reducing nonlinear SNR degradation
Optical nonlinearity mitigation of 6×10GBd polarization-division multiplexing 16-QAM signals in a field-installed transmission link
No full textWe report nonlinear impairment mitigation of PDM 16-QAM WDM signals through mid-link optical phase conjugation in an 834km-long installed fiber link. Efficient reuse of signal bandwidth and Q-factor improvements of up to 3dB are demonstrated
Implementação de um rádio defnido por software LTE para a infraestrutura ORCIP
Get PDFThe constant evolution in communications has lead to the development of
new technologies such as LTE and SDR systems. This dissertation presents
the development of a LTE-based SDR system for the ORCIP testbed. A
detailed study of LTE technologies and standards is firstly presented, in order to ensure a complete understanding of the topic. Subsequently, using
MATLAB, a configurable LTE transmitter and receiver are designed while
taking into the corresponding standarts. The functionally of the transmitter
and receiver include generating and decoding LTE waveforms with multiple parameter choices such as bandwidth, modulation order, number of
subframes, among others. With these modules a carrier aggregation implementation is also performed. To complete the SDR system, an oscilloscope
and an arbitrary waveform generator were connected to verify the implemented LTE modules. The generated LTE signals are loaded to the AWG
and the waveforms captured by the oscilloscope are processed with the developed LTE receiver. Test based on EVM measurements are performed for
both single carrier and carrier aggregation scenarios. The obtained results
confirms a good performance for both single carrier and carrier aggregation,
which proves that the system implementation can be applied to testbed systems; e.g. ORCIP testbed.A constante evolução das comunicações levou ao desenvolvimento de novas tecnologias como o LTE e sistemas SDR. Esta dissertação apresenta o desenvolvimento de um sistema SDR baseado em LTE para o banco de testes do ORCIP. Um estudo detalhado das tecnologias e normas do LTE é primeiramente apresentado para garantir uma completa interpretação do tópico. Subsequentemente, usando MATLAB, um transmissor e recetor LTE configuráveis são projetados tendo em conta as normas correspondentes. A funcionalidade do transmissor e recetor inclui a geração e descodificação de formas de onda LTE com a escolha de múltiplos parâmetros como largura de banda, ordem de modulação, número de subframes, entre outros. Com estes módulos é também realizada uma implementação de agregação de portadoras. Para completar o sistema SDR, um osciloscópio e um gerador de sinais arbitrário foram conectados para verificar os módulos LTE implementados. Os sinais LTE gerados são carregados para o AWG e as formas de onda capturadas pelo osciloscópio são processadas com o recetor LTE desenvolvido. E realizado um teste baseado em medições de EVM para ambos os cenários de portadora única e agregação de portadoras. Os resultados obtidos confirmam um bom desempenho para ambos os cenários de portadora única e agregação de portadoras, provando assim que o sistema implementado pode ser aplicado para sistemas de banco de testes; p. ex. banco de testes do ORCIP.Mestrado em Engenharia Eletrónica e Telecomunicaçõe
Desenvolvimento de uma unidade de rádio remota e rede ótica de acesso para a infraestrutura ORCIP C-RAN
Get PDFThe new generations of mobile communications bring new challenges for
their transport. The support for multiple services, the high bandwidth and
the low latency are the most important requirements.
This dissertation explores the use of analog radio-over-fibre transmission
in the ORCIP testbed. Low cost SFP optical transceivers modified for
analogue signal transmission, are studied and characterised. Additionally, a
remote radio unit that contains an RF frontend and the optical transceivers
is designed. The RF frontend is designed for operation over band 7 of
4G-LTE. The performance of both RF frontend and optical link is assessed
using a real 4G-LTE signal.As novas gerações de comunicações móveis trazem novos desafios para o
seu transporte. O suporte a múltiplos serviços, a grande largura de banda
e baixa latência, são os requisitos mais importantes.
Esta dissertação aborda a possibilidade do uso de transmissão analógica
de radio-sobre-fibra (RoF) na rede de acesso da infraestrutura ORCIP.
São estudados e caracterizados transmissores óticos SFP de baixo custo,
modificados para transmissão de sinais analógicos. Adicionalmente, é
projetada uma unidade de rádio remota contendo um frontend de radio
frequência e os transmissores óticos analógicos. O frontend de radio
frequência é projetado para operar na banda 7 do LTE. A performance
do frontend em conjunto com a ligação ótica é analisada para transmissão
de um sinal 4G-LTE real.Mestrado em Engenharia Eletrónica e Telecomunicaçõe
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