1,721,071 research outputs found
Fondamenti di PMD e valutazione analitica del suo impatto
No full textTutorial su invito a Fotonica 200
A fast and accurate method for evaluating joint second-order PMD statistics
No full textA fast and efficient way for evaluating the joint probability density function of the polarization-mode dispersion (PMD) vector derivative components parallel and orthogonal to the PMD vector itself is presented. This allows for a fully analytical evaluation of outage probabilities, overcoming thus the limitation of the Monte Carlo method, which do not allow for reliable evaluation of probabilities smaller than about 10^(-4)
FM Click Statistics in the Presence of Phase Noise
No full textThe probability distribution function of the FM clicks is derived for the case of a carrier impaired by Wiener-Lèvy phase noise and detected by a limiter-discriminator receiver with pre- and post-detection filtering. The analysis is performed accounting for the effects of predetection (RF) filtering on signal and phase noise and holds for \Deltat\nu/B<<1, \Delta\nu being the 3-dB linewidth of the unmodulated carrier and B the bandwidth of the RF filter. How small \Delta\nu/B is to be will depend on the kind of RF filter. For the raised cosine filter with small rolloff \eps considered here the analysis holds for \Delta\nu/B<\eps. For other kinds of filters having transfer functions with smoother rolloffs, such as one- or two-pole filters, the condition \Delta\nu/B<0.1 is sufficient. For these normalized linewidths it is found that the phase noise affects the statistics of the clicks only through the signal envelope changes it causes (FM/AM conversion)
Nonlinear propagation in fiber-optic systems
No full textPresentazione su invito al X Convegno Biennale SIMAI 2010 svolto si a Cagliari dal 21 al 25 Giugno 2010.
http://openconference.simai.eu/index.php/sc/2010/schedConf/presentation
Analysis of Delay-and-Multiply Optical FSK Receivers with Line Coding and Non-Flat Laser FM Response
No full textIn this paper we present a theoretical analysis of the performance of coherent optical FSK systems when the driving laser signal is AMI or Manchester (biphase) line-coded to counteract the non-ideal FM characteristic of the transmit laser diode, and the received signal is heterodyned and detected by a delay-and-multiply demodulator.
The analysis takes into account IF filtering by assuming linear filtering of the noisy signal phase, accounting, for small linewidths, for laser phase noise in a straightforward and accurate manner. A simple equivalent baseband model of the system is derived for performance evaluation, applicable to both cases of large demodulator delay and when the delay tends to zero (ideal discriminator). Noise statistics include the clicks due to both signal and phase noise. The problem of performance evaluation is reduced to a classical intersymbol interference problem which is solved by mean of
the method of Gauss quadrature rules.
The analysis accurately predicts the effectiveness of AMI and Manchester line coding, depending on several system parameters such as linewidth, modulation index, IF bandwidth and laser FM response, and can be easily extended to other line coding techniques
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