the project is "Comparison of different methods for digital nonlinearity compensation in optical fibers"
network of long-haul optical communication systems link countries and continents in order to supply the increasing demand for high rate data.
simultaneous compensation of fiber nonlinearity and dispersion is required to enable higher launch powers and larger constellation sizes.
The two most popular methods for simultaneous digital compensation of both dispersion and nonlinearity are Digital-back-propagation (DBP) and Volterra series methods . Both involve solving the main signal propagation model – namely the nonlinear Shrodinger equation – backwards to achieve channel equalization. DBP offers higher accuracy but large numerical complexity, while Volterra methods uses an approximation procedure for solving the propagation model with lower numerical complexity at the expense of lower accuracy.
i need to compare an analytical approximation (Volterra) vs DBP
The main goal of the research is providing a designing tool for long-haul optical communication systems. This tool can be achieved by obtaining two correct equations of Q factor or BER vs SNR in DBP and Volterra methods. First, These equations can provide the system designer planning tool which would discover the maximum distance between each correction according to the system requirements (tolerable error). Second, the designer will know what method is better for the specific system by comparing the results.
In order to achieve this goal i need to reach some objectives:
Wave propagation model in long optic fiber. - *matlab
code for DBP solution. - matlab
code for Volterra solution. - matlab
running the simulation for both solutions with various parameters (different launch power, different tolerable error and so) and ploting on one graph the two solutions - "the design tool"
for each method, i need a code with and without noise interferance.
Please describe every line in the code.
The codes may be found in the internet, fill free to look for them.
The case i am simulating is Single-mode (wich simplifies the problem) without Soliton
*there is a known code for (1) from the book
G.P. Agrawal, The Nonlinear Fiber Optics (attached file)
U may use that code – but please change the units. metric units instead of L_D and so.