45 research outputs found
Evaluation of the key words used in articles of the Acta Cirurgica Brasileira from 1997 to 2012
Herpetofauna of an Atlantic rainforest area (Morro São João) in Rio de Janeiro State, Brazil
Evaluation of functional rehabilitation physiotherapy protocol in the postoperative patients with anterior cruciate ligament reconstruction through clinical prognosis: an observational prospective study
Parameters from the community of leaf-litter frogs from Estação Ecológica Estadual Paraíso, Guapimirim, Rio de Janeiro State, southeastern Brazil
Indicadores Microbiológicos de Solo em Pastagem com Aplicação Sucessiva de Dejetos De Suínos
A relação entre o desenvolvimento fonológico e aprendizagem inicial da escrita em diferentes contextos socioeducacionais
Experimental investigation and digital compensation of DGD for 112 Gb/s PDM-QPSK clock recovery
For asynchronous sampled systems such as Polarization Division Multiplexed Quadrature Phase Shift Keying, (PDM-QPSK), phase and frequency of the sampling clock is typically not synchronized to the data symbols. Therefore, timing adjustment, so called clock recovery and interpolation, must be performed in digital domain prior to signal demodulation in order to avoid cycle slips. For the first time, the impact of first order PMD, (DGD), is experimentally investigated and quantified for 112 Gb/s PDM-QPSK signal. We experimentally show that the combined effect of polarization mixing and first order PMD can significantly affect the performance of the timing error detector gain, even for moderate values leading to system outage. We propose and experimentally demonstrate a novel digital adaptive timing error detector is robust to polarization mixing and DGD. The proposed timing error detector algorithm combines the Gardner timing error detector algorithm with an adaptive structure based on gradient method