PERFORMANCE EVALUATION OF TRANSMISSION DISTANCE AND BIT RATES IN INTER-SATELLITE OPTICAL WIRELESS COMMUNICATION SYSTEM

Transcription

1 PERFORMANCE EVALUATION OF TRANSMISSION DISTANCE AND BIT RATES IN INTER-SATELLITE OPTICAL WIRELESS COMMUNICATION SYSTEM Rohni Joy 1, Ami Lavingia 2, Prof. Kruti Lavingia 3 1 Electronic and Communication Department, SVBIT, (India) 2 Electronic and Communication Department, (India) 3 Computer Science and Engineering Department, Nirma Univerity, (India) ABSTRACT The day to day development ha advanced the optical communication ytem from long-lating fiber to wirele ytem uch a inter-atellite tranmiion ytem. Thi can be accomplihed a the optical ytem have reulted to be ued in pace communication a a medium between two atellite. The inter-atellite optical wirele communication link i deigned and imulated for performance characterization. In thi work we are uing optical wirele channel (OWC) for inter-atellite communication and optimize the data exchange depending upon the performance parameter like Quality factor, Bit error rate and Received power. In IOWC link parameter conidered mainly are bit rate and input tranmitted power. In thi, optical inter-atellite link i modelled uing imulation oftware and then the effect of varying the tranmitter power and bit rate of optical communication link i analyzed. The inter-atellite link were modelled and imulated with the help of optical ytem imulator named OPTISYSTEM. Keyword: BitRate, Free Space Optic, IOWC, Optiytem, Tranmiion Ditance I. INTRODUCTION The correpondence through the link infratructure ha turned into a piece of our pat. Following optical fiber communication i better in a few regard uch a vat eparation communication up to 40 km without requiring a repeater device, adaptable nature, which made it prepared to be utilized anyplace, duplex method of communication, EMI (electromagnetic interface) reitive nature and expanive tranfer peed upporting limit. Be that a it may, aide from all thee, preent day environment requet for more effective tranfer peed ue and better information heet, which prompt another method of communication called a free pace optical communication. Following optical fiber cabled foundation ha neglected to come to a le cell end point. In any cae, thi contraint i evacuated by free pace optical communication. It utilize free pace for the communication reaon, o otherwie called fiber gla optic or optical remote. 1.1 FSO for Inter-Satellite Communication Notwithtanding phyical correpondence, FSO additionally ha a huge part in pace application. In 1977, European Space Agency (ESA) began the project emiconductor laer Inter-atellite connection tet (SILEX) to undertand the correpondence between atellite in pace.[1] Thi program, which came to genuine operation 157 P a g e

2 in 2003, prompted reult in making the ESA all around perceived in pace bury atellite correpondence join. The eential application of FSO a between atellite i appeared in the Fig. 1. SILEX i taking into account a blend of two optical correpondence payload i.e. French Earth perception rocket. SPOT-4 furthermore, Advanced Relay and Technology Miion Satellite (ARTEMIS) which permit the information tranmiion of 50 Mbp by utilizing GaAlA laer diode [3]. Figure 1: FSO a Inter-Satellite communication link [3] The Interatellite Optical Wirele Communication (IOWC) ytem ha variou point of interet. To begin with, no licening i required in terretrial communication. Another point of interet i the invulnerability to the radio ignal interference; on the other hand immerion ha included the ecurity highlight in thi innovation. The point-to-point laer ignal i too hard to capture. It i difficult to tap the IOWC link. Ecological hrewd, FSO doe not contaminate the earth with electromagnetic radiation ince the wavelength of IOWC i jut from 850 nm to 1500 nm. The performance invetigation will be a far a meaured received power, eye pattern and BER. II. SYSTEM DESIGN The imulation i done uing OptiSytem Simulation Software. OptiSytem i a thorough programming outline uite that empower to arrange, tet, and rebuild optical connection in cutting edge optical ytem. Propoe algorithm comprie of a tranmitter with NRZ ignal, OWC channel, and optical receiver coniting of PIN photodetector, Beel filter and BER analyzer to analyze the yield reult. At the input ide CW laer i ued to provide the light ource to the link, along with that peudo random bit equence generator and mach zehnder modulator i taken a in. So a to invetigate the effect of bit rate on the optical fiber communication ytem, the tranmiion ditance of the optical ytem i varied. The imulation link i hown in below figure. Figure 2: Simulation link 158 P a g e

3 Q-factor The bit rate i varied from 1Gbp to 8Gbp and it effect on the output ignal i analyed in term of quality factor and bit error rate. The tranmiion ditance i varied from 1000km to 2000km and the obervation i taken for each tranmiion ditance. The input power level i kept contant of about 15dbm. The imulation i carried out on a ingle channel ytem. Table -1: Simulation Parameter Parameter Bit Rate Value 2, 4, 6, 8 Gbp Modulation NRZ Ditance (km) 1000,1200,1400,1600,180 0, 2000 Tx & Rx Pointing Error Angle 2.7μrad Power 15dbm Tx and Rx Efficiency 1 Wavelength 1550 nm The imulation i carried out under 1550nm wavelength at 15 dbm power. In OWC channel, the pointing error of bath tranmitter and receiver ide i kept 2.7μrad, the aperture diameter of kept at 15cm at both ide. The efficiency of tranmitter and receiver i taken a 1. The link i operated at different bit rate i.e, 2Gbp, 4Gbp, 6Gbp and 8Gbp from varied tranmiion ditance. III. SIMULATION RESULT AND ANALYSIS We have imulated the optical link working at varied bitrate. The tranmiion ditance effect are analyzed in term of Q Factor, BER with the ue of Eye Diagram. Following table how the impact on the Q-factor in accordance to the increae in tranmiion ditance for RZ modulation Ditance (km) 2Gbp 4Gbp 6Gbp Graph -1: Q-factor v. Ditance The eye diagram at 2000km for all varied bit rate i hown in figure below. 159 P a g e

4 (a) (b) (c) (d) Figure 3: Eye Diagram at 2000km at (a) 2Gbp (b) 4Gbp (c) 6Gbp (d) 8Gbp From figure 2 it i een that a the bit rate increae the reult get more ditorted. And alo from the graph it can be concluded that a the value of ditance increae the value of q-factor decreae. It i obtained that for 8Gbp link the bet maximum ditance i 1400km, after thi ditance the ignal goe rapidly ditorted. IV. CONCLUSION In thi paper, the effect of tranmiion ditance and bitrate i taken into conideration. The imulation i carried out for varied tranmiion ditance at different bitrate. It can be concluded that for longer ditance at higher bit rate the eye diagram ha maller eye opening. Here, the ytem i imulated at 8 Gbp, and the ytem get 9.26E- 14 BER uing NRZ ignal at 1400 km of tranmiion ditance, wherea at 2Gbp for longer tranmiion ditance of 2000km we are getting the ame reult i.e., 6.65E-14. From the chart of q factor v ditance it i een that a the bit rate increae it impact the overall ytem performance, alo Q factor decreae. REFERENCES [1] Murat Uyal and Hatef Nouri Optical Wirele Communication An Emerging Technology /14/$ IEEE. [2] Hamdy A. Sharhar and Eman Mohen El-gammal Comparative Analyi Study of Optical Inter Satellite link for Different Both Tranmiion Bit Rate and Operating Wavelength International Journal of Advanced Reearch in Computer Engineering &Technology, IJARCET P a g e

5 [3] Suhank Chaudhary, Angela Amphawan The Role and Challenge of Free-pace Optical JOURNAL OF OPTICAL COMMUNICATIONS, AUGUST 2014, DOI /joc [4] Govind Agrawal, Nonlinear Fiber Optic, Elevier, [5] Gerd Keier, Optical Fiber Communication, The McGraw-Hill, [6] S. Sheng, B. Wardman, G. Warner, L. F. Cranor, J. Hong, and C. Zhang, An empirical analyi of phihing blacklit, P a g e