Network Cost Savings Enabled By Probabilistic Shaping In Dp-16qam 200-gb/s Systems

We evaluate potential network cost savings enabled by probabilistic shaping in DP-16QAM 200-Gb/s systems, based on experimental measurements and analytical derivations. The results indicate savings of up to 6.7% in the average number of transceivers.Optical Fiber Communications Conference and Exhibition (OFC)MAR 20-24, 2016Anaheim, C

Network cost savings enabled by probabilistic shaping in DP-16QAM 200-Gb/s systems

We evaluate potential network cost savings enabled by probabilistic shaping in DP-16QAM 200-Gb/s systems, based on experimental measurements and analytical derivations. The results indicate savings of up to 6.7% in the average number of transceiversOptical Fiber Communications Conference and Exhibition (OFC)sem informaçã

Mitigation of nonlinear transmission effects for OFDM 16-QAM optical signal using adaptive modulation

The impact of the fiber Kerr effect on error statistics in the nonlinear (high power) transmission of the OFDM 16-QAM signal over a 2000 km EDFA-based link is examined. We observed and quantified the difference in the error statistics for constellation points located at three power-defined rings. Theoretical analysis of a trade-off between redundancy and error rate reduction using probabilistic coding of three constellation power rings decreasing the symbol-error rate of OFDM 16-QAM signal is presented. Based on this analysis, we propose to mitigate the nonlinear impairments using the adaptive modulation technique applied to the OFDM 16-QAM signal. We demonstrate through numerical modelling the system performance improvement by the adaptive modulation for the large number of OFDM subcarriers (more than 100). We also show that a similar technique can be applied to single carrier transmission

Optical network cost reduction techniques bases on multiple modulation formats

Orientadores: Darli Augusto de Arruda Mello, Miquel Garrich AlabarceDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de ComputaçãoResumo: A utilização de redes ópticas elásticas viabiliza o melhor aproveitamento da infraestrutura óptica já instalada, possibilitando a acomodação da demanda crescente de tráfego. Esta tecnologia combina transceptores de banda variável e arquiteturas de nós de rede flexíveis, baseados em chaves seletoras de comprimento de onda, em um sistema capaz de rotear sinais heterogêneos. Os transceptores de banda variável permitem o ajuste de seus parâmetros de forma a variar formato de modulação, taxa de símbolo e taxa de bit da transmissão de acordo com as restrições impostas pelo canal de comunicação e dispositivos da rede. Contudo, as altas potências necessárias para transmissões de longas distâncias (e o consequente aumento de não-linearidades) e a baixa imunidade ao ruído dos formatos de modulação de altas ordens, são dois importantes desafios a serem superados. De fato, é tema de pesquisa emergente a busca por algoritmos de compensação de não-linearidades de baixa complexidade computacional. Neste trabalho, analisamos duas técnicas de redução de custo da rede baseadas nos múltiplos formatos de modulação proporcionados pelas redes elásticas. As duas técnicas são complementares à complexa compensação não-linear. A primeira técnica é a formatação probabilística que, alterando a probabilidade de envio dos símbolos da constelação, permite o aumento da capacidade de um formato de modulação de alta ordem mantendo-se a energia média do sinal transmitido. A segunda técnica é conhecida por arquitetura sob demanda, na qual os nós da rede óptica são sintetizados de acordo com a demanda por tráfego. No caso da formatação probabilística, observou-se um ganho superior ao da compensação não-linear intracanal perfeita, com uma economia no número médio de transceptores utilizados de até 6,7% analisando-se dados experimentais. Os resultados indicam que a formatação probabilística pode muitas vezes substituir a compensação não-linear, reduzindo significativamente a complexidade computacional do receptor. Já no caso da arquitetura sob demanda, observou-se um aumento da taxa de bit média transmitida por canal para baixas cargasAbstract: The deployment of elastic optical networking is able to extend the lifetime of already deployed optical fibers to accommodate the ever-increasing network traffic demand. This technology combines bandwidth-variable transponders and wavelength selective switch-based nodes with flexible architectures in a system capable of routing heterogeneous signals. Bandwidth-variable transponders can adjust their modulation format, symbol and code rates according to constraints imposed by the communication channel and network devices. However, the nonlinearities generated at the high power levels required by long-distance transmission, and the low tolerance to noise of high-order modulation formats, are two important factors that limit the optical transmission reach. Accordingly, low-complexity signal processing for the compensation of nonlinearities is an active research field. In this work, we analyze two network cost reduction techniques based on multiple modulation formats enabled by elastic optical networks. Both techniques are complementary to non-linear compensation. The first technique is probabilistic shaping, which increases the capacity of communications systems by changing the transmission probability of constellation symbols, while maintaining the average transmitted power. The second technique is known as architecture on demand (AoD), by which optical network nodes are synthetized according to the traffic demand. The results indicate that probabilistic shaping outperforms ideal intrachannel non-linear compensation for a full-spectrum occupation. Our framework, based on theoretical derivations and experimental data analysis, showed to be possible do reduce the average number of transceivers per link in up to 6.7%. In addition, probabilistic shaping replaced non-linear compensation in various scenarios, considerably decreasing the computational complexity at the receiver. The results on AoD, in turn, showed to be possible to increase the average bit rate per channel for low traffic loadMestradoTelecomunicações e TelemáticaMestra em Engenharia Elétric