טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentAndrey Dolgin
SubjectNoise Calculation in Optical Communication Systems using
Volterra Series
DepartmentDepartment of Electrical Engineering
Supervisor Full Professor Horowitz Moshe


Abstract

The performance of optical communication systems has grown rapidly in the recent years. However, the capacity of optical systems is only slightly behind the demands due to the fast increase of the internet. Studying theoretically novel methods in order to improve the performance of optical systems is a complicate challenge due to the need to take into account nonlinear effects that limit optical systems and were previously neglected. Accurate computation of the statistical properties of optical communication systems is one of the most important tasks required in order to improve the performance of optical systems. This work presents a closed-form non-iterative and a deterministic method for calculating the bit-error rate and other important statistical properties of optical communication systems. Previous methods, beside Monte-Carlo simulation, for calculating the bit-error rate in optical communication systems were based on the linearization of the noise added by the optical amplifier, as it propagates through the fiber. This assumption neglects the nonlinear interaction of the noise with itself during propagation in fibers. The validity of this assumption is not ensured for different types of optical communication systems and it must be approved in any particular case. The method proposed in this paper is based on using the Volterra series representation approach to describe the input-output relation of nonlinear and dispersive optical communication system. This method enables to analyze optical communication systems in a closed-form formulation, that takes into account nonlinear noise-noise beating during the transmission of light in fibers. It also allows to analyze the effect of different types of linear and nonlinear optical devices located between the transmitter and the receiver. We believe that our new method will enable to improve design and to accurately analyze novel optical systems as required in modern optical communication systems.