COMPARATIVE ANALYSIS OF 64 CHANNEL IS-OWC SYSTEM THROUGH CHIRPED, AMI AND DPSK MODULATION TECHNIQUES by Ravneet Kaur
Abstract
Inter-satellite Optical Wireless communication has been a hot research area, where modulation techniques are useful due to its enormous advantages and applications in satellite network. While FSO systems are used for transmission of data and signals, but due to turbulences and pointing errors, they are less used.IS-OWC system is preferred due to high bandwidth, free from turbulences, immunity to RF and microwave frequencies. IS-OWC system while implemented with WDM systems provides high capacity, less bit errors and huge security. The current work carried out using Optisystem software demonstrates IS-OWC system with the modulation techniques which is the best challenge for future communication system because it has the resistance to dispersion, four wave-mixing and improved narrow band filtering. Modulation techniques have been useful to provide integration with WDM systems as WDM multiplexer allows 64 multliplexers to multiplex signals using EDFA and OWC channel with the use of Loop Control. This technique increases the efficiency of the system. In this thesiswork, Ultra-high capacity IS-OWC systems having 64 channels are designed using modulation techniques at bit rates of 10, 20 and 40 Gbps.Here the proposed IS-OWC system is implemented using Chirped modulation, Alternate mark inversion and Differential phase keying modulation technique. The results of the proposed system is measured at different bit rates and distances and thus compared at the range of 750 nm. Performance analysis in terms of Q-Factor, Optical Spectrum Analyzer, BER and Eye Height has been done. From the results, it has been concluded that DPSK modulation technique gives best performance with the Q-Factor of 20 and BER OF 1.5 and 10-91than the other techniques at the bit rates of 10 Gbps and 20 Gbps. DPSK shows 60% improvement in terms of Q-Factor respectively. AMI modulation technique can provide best Q- factor of 4.08 and improvement of 40 % at bit rate of 40 Gbps for a distance of 2500 km. Chirped Modulation achieves good performance at 10 and 20 Gbps. It is observed that IS-OWC systems using three different modulation techniques works well at 10 Gbps than 20 Gbps and 40 Gbps. The main challenge for this system is to eliminate noise, chromatic dispersion, selfphase and cross-phase modulation. So these modulation techniques improve the bandwidth, capacity and data rates of the proposed IS-OWC system.
