High-speed DPSK coherent systems in the presence of chromatic dispersion and Kerr effect

Abstract

In this paper the error probability of a singlechannel coherent optical DPSK transmission system based on repeterless links in the presence of fiber chromatic dispersion and Kerr effect is evaluated. An accurate model for both the optical signal propagation and the probability distribution of the receiver decision variable is adopted by using a numerical solution of the non-linear Shrodinger equation and the characteristic function method. The obtained results show that the selection of an optimized IF filter bandwidth is crucial in order to obtain the best system performance. When chromatic dispersion dominates its combination with Kerr effect causes best performances to be achieved in normal dispersion region while, when Kerr effect is the most relevant limitation factor for the system performances, the lowest error probability is attained in anomalous regime. As a matter of fact in this regime Kerr effect and chromatic dispersion tends to partially compensate each other. In any case the error probability curves shows a relative minimum that is always attained in the anomalous region. Finally the maximum link length is limited by the presence of Kerr effect independently from the amount of transmitted optical power to be shorter than a threshold length if an error probability of is to be achieved.

Nonlinear Evolution of Amplitude and Phase Modulated Signals and Performance Evaluation of Single-channel Systems in Long Haul Optical Fiber Links

“…This is possible in absence of ASE [14,15], or in presence of ASE at the zero dispersion wavelength [11]. Therefore the system performances are reported in terms of eye degradation penalty [16] on the basis of 800 bits obtained by 50 simulations presenting different seeds for the generation of the ASE noise.…”

“…In the case of the PSK coherent homodyne systems the receiver is composed by an electrical third-order Butterworth filter, with a bandwidth equal to R, followed by a phase detector and an electrical second-order Butterworth filter with a bandwidth equal to 0.8 R [8,14].…”

Performace Evaluation of ASK and DPSK Optical Coherent Systems affected by Chromatic Dispersion and Polarization Mode Dispersion

“…In the case of ASK system we modulate the signal amplitude from 0 to Ρ (Ρ is the transmitted peak power), while in the DPSK system it is the phase of the transmitted signal that is modulated between 0 and π. The modulating function is a raised cosine function with a rise time equal to 1/(4R), where R is the bit rate [4][5]. The output signal EO U , is obtained by (3).…”

“…The method we used is the same as in [4][5], in which system performances were evaluated in presence of Kerr non-linearities. Such a technique is based on the assumption that, in presence of PMD and CD, the signal propagation in optical fibers is a deterministic process and the noise can be assumed present only at the receiver in terms of shot noise.…”

Partial Differential Phase Shift Keying – Theory and Motivation

“…Refs. [3][4][5][6][7][8][9][10]. Recently it was demonstrated, both experimentally and numerically [11,12], that the impairments due to optical spectrum narrowing can be partially compensated by using a DI having a differential delay smaller than the symbol time slot, i.e.,…”