High performance duobinary optical communication through bioinspired algorithms

Abstract

In optical long-haul transmission networks, the optical fiber newlinecommunication system plays a critical part. The significant requirement of this newlinecommunication is high bit rate transmission and increase capability, which newlinenecessitate effective modulation and demodulation schemes with improved newlinesecurity. Many improved modulation schemes have been proposed to increase newlinecapability and high bit rate transmission. One such technique is Optical newlineDuobinary Modulation (ODB), which can broadcast high-speed optical signals newlineover bandwidth-limited channels. Many modulation techniques have been newlinepresented to work with huge data traffic. The conventional schemes employ the newlineNon-Return-to-Zero (NRZ) modulation and Return-to-Zero (RZ) modulation newlinetechniques. These schemes decrease spectrum width and increase the dispersion newlinetolerance. However the effect of Inter-Symbol Interference (ISI) is present newlinebetween the pulses. These techniques give reduced performance for high bit rate newlinetransmissions and transmission over long distances.This thesis presents a scheme for the implementation of Duobinary modulation with added security features. The bio-inspired chaos-masking scheme generates the security key using the Spider Security Pattern Generator (SSPG) to provide improved security. The security key generated from the newlineSSPG is embedded with the chaotic carrier signal generated using the optical newlineoscillator. The chaotic signal embedded with the SWSP modulates the duobinary newlinesignal that is then transmitted. The actual signal is recovered from the chaotic newlinesignal by synchronizing the chaotic laser located at the receiving end with the newlinelaser located at the transmitter end. The actual signal is recovered at the newlinereceiving end by applying the subtraction rule. At the receiver end also, the newlinechaotic signal is generated by the chaotic laser synchronized with the laser at the newlinetransmitter. The SWSP is generated using SSPG and is also added to the chaotic newlinewave generated by the receiver end chaotic laser. While generating at the newlinereceiving end, the pattern generated