Increasing data rate in optical communication systems leads to nonlinear electromagnet phenomenon in optical signal along fiber, and causes distortion in it.Thefiber dispersion is a linear phenomenon that causes difficulties toachieve high bit rate a
nd distance product.The limiting of nonlinear effects requireslow input power level, but this induces lowsignal to noise ratio. So, we search another solutions.
This paper studies Split Step Fourier Transform Algorithm (SSFTM) used to solve partial differential nonlinear Schrödinger equation (NLSE).Then, we use it for simulating optical signal propagating in fiber by using MATLAB program, and designing fiber optic block could add it to MATLAB Simulink Library. Finally ,in this paper, we achieved results for selecting important parameters in single mode fiber for high bit rate, for improving bit error rate and Qcoefficient.
This works aims to study the performance of the mobile system via studying the
effects of adaptive modulation technique on the data rate. Fuzzy logic technique is used as
a tool to analyze the data rate of the downlink connection depending on type
of
modulation, coverage quality and the distant between the receiver and the transmitter. For
parameters were considered as input parameters for the fuzzy logic system mainly are:
power of the station, quality of coverage, the type of modulation technique and the signal
to interface noise ratio. One parameter is used as an output of the fuzzy system which is
spectrum efficiency in bit per second per hertz. Analytical study to select the optimal data
rates for different modulation techniques will be considered. Additionally, studying the
input and output memberships of the data rate parameters using fuzzy logic will be
explained. Keywords: Data rate, downlink, signal to noise ratio, modulation type, Fuzzy
logic, spectrum efficiency.
