Tuesday, October 3, 2017

New M.Tech. Thesis Submitted from electronics


Fso (Free Space Optical Communication) is that technique which is capable of working at bandwidth which is high and also having much acceptable data rates. Because nowadays internet is in trend, the capacity of speed of data should be very high. In other words, Free space optical (fso) communication is that type of communication technique which is effective in cost and having excessive bandwidth, whose demand has increased with recent commercialization utility. FSO communication technique is utilised in various telecommunication applications, underwater communication applications, intersatellite applications, indoor communication etc. Apart from these prevalencies, because of proliferation in free space, the signal gets deflated and information is lost till it arrives the receiver. These aspects affecting the exchange of information in FSO ought to have amplifiers to improve the information transmission from transmitter and receiver. Thus, in the optical field of communication, reclamation of signals electronically have become very costly process. Different power amplifiers have been employed which are capable of converting optical to electronic signals with much admissible costs. Here, various combinations of these amplifiers are analysed with spatial diversity technique in FSO. Amplifiers are used as hybrid amplifiers in order to overcome each amplifier’s obstruction. High peculiarity can be gained by using the technique of spatial diversity which is a process of posting several copies of same signal which is to be transmitted. Authenticity and availability of the FSO system is increased by concurrently transmitting same signal. Moreover BER degradation that's produced by way of atmospheric turbulence is diminished by using diversity. Highquality of the signal decreases due to environmental effect like fog, haze, rain and dirt in free space optical communication system. In spatial diversity, it is viable to lessen fading and in response greater traits of signal may be increased. The proposed system consists of 8 Tx/Rx as a spatial diversity technique along with hybrid amplifiers being placed on both transmitter as well as receiver side not only in series but also in parallel. Simulations are performed using Optisystem software and it has been observed that in proposed system EDFA-EDFA proves to be the best combination when employed either in parallel and series with less BER as compared to other two hybrid combinations for clear and haze weather. By using this parallel EDFA-EDFA combination Q-Factor is increased to 69.16 % as compared to SOA-EDFA and 11.43% when compared to RAMAN-EDFA in clear weather condition.Moreover while placing this combination in series Q-Factor is increased to 45.98% as compared to SOA-EDFA and 10.61% when compared to RAMANEDFA in haze weather condition. While analysing in Foggy weather in parallel configuration, RAMANEDFA performs better with its Q-Factor being increased to 50.3%comparing with SOA-EDFA and 4.5% as compared to EDFA-EDFA. Moreover power received is greater in parallel combination of amplifiers rather than placing them in series but errors are more in parallel than series configuration. EDFA-EDFA gives best results at 40 Km with much acceptable Quality Factor in clear weather, 6 Km in case of Haze weather and 3Km in Foggy weather in both series and parallel.