- Email: [email protected]
Comparative Analysis of Inter Satellite Optical Wireless Channel for NRZ and RZ Modulation Formats for Different Levels of Input Power
Available online at www.sciencedirect.com
ScienceDirect Procedia Computer Science 58 (2015) 572 – 577
Second International Symposium on Computer Vision and the Internet (VisionNet’15)
Comparative analysis of Inter satellite Optical Wireless Channel for NRZ and RZ modulation formats for different levels of input power Prabhdeep Kaura*, Amit Guptab,Mandeep Chaudhary c a
Chandigarh University, Gharuan, India Chandigarh University Gharuan, India School of Engineering and Digital Arts, University of Kent, Canterbury, Kent, UK. b
c
Abstract Integration of DWDM in Optical wireless communication has undoubtedly revolutionized the satellite communication systems for use in the coming future. Thus OWC systems have become popular due to their outstanding performance uniqueness. This paper looks into the performance of Inter Satellite Optical Wireless Communication system link using DWDM multiplexing technique for long distance transmission. The Inter satellite link has been modeled at a data rate of 10 Gbps for communication range of 5000 kilometers. Furthermore, it demonstrates a comparative analysis of RZ (Return to zero) and NRZ (Non-return to zero) modulation formats by varying the levels of input power. ©©2015 by Elsevier B.V. by This is an open access article under the CC BY-NC-ND license 2015Published The Authors. Published Elsevier B.V. (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of organizing committee of the Second International Symposium on Computer Vision and the Peer-review under responsibility of organizing committee of the Second International Symposium on Computer Vision and the Internet Internet(VisionNet’15). (VisionNet’15) Keywords: Modulation; inter satellite optical wireless communication; BER; Q-factor.
1. Introduction The upcoming generations of Lightwave systems persevere for high data rate systems capable of supporting large number of user capacity. The increasing demand thus insists to look up for robust networks having minimal linear and non linear distortions which arise due to the network configurations at very high speeds. The linear impairments include chromatic dispersion, polarization mode dispersions as in case of optical fibers and non linear impairments may include self phase modulation, cross phase modulation, four wave mixing, etc [1]. To overcome the same, an optimum modulation format is required having a narrow optical spectrum that could not only withstand more distortion but also improvise the spectral efficiency. With constant optical power a modulation format becomes less susceptible to self phase modulation and cross phase modulation. Furthermore, in case of long haul optical networks, amplified spontaneous emission i.e. ASE, the noise introduced by erbium doped fiber amplifiers comes into picture which can also be reduced subsequently by choosing an optimum modulation
1877-0509 © 2015 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of organizing committee of the Second International Symposium on Computer Vision and the Internet (VisionNet’15) doi:10.1016/j.procs.2015.08.075
Prabhdeep Kaur et al. / Procedia Computer Science 58 (2015) 572 – 577
573
format. Thus the choice for modulation format plays a crucial role while designing any proficient network for communication [2]. The optical wireless communication systems have conquered the communication world in enormous applications because of their key benefits over the existing microwave communication systems, for satellite communication. The OWC systems are setting up a landmark for low cost, low power consumption and long distance transmission applications where it is very difficult to deploy long fiber optic cables. The Inter satellite optical wireless communication systems as clear from its name utilizes communication between two satellites for communication that carry the optical signal through unguided wireless links leading to a fusion of optical and wireless transmission [3]. Thus the utility of satellites in many applications and due to their numerous advantages, IS-OWC systems have been into practice for communication during these days. Besides the above mentioned advantages, the systems suffer from some problems like bandwidth inefficiency, erroneous transmissions, power constraints, and noises in communication systems that need to be overcome for better efficiency [4]. In this paper, simulative analysis on IS-OWC systems has been performed using two different modulation formats and the effect of input power on the Quality factor and Bit error rate of the system has been analyzed at 10 Gbps. The paper is organized as follows: Section II describes the simulation setup, Section III elaborates the results and discussion and Section IV concludes the paper. 2. Simulation Setup Figure 1 shows the simulation setup for the modeled system using various components.
Fig.1. Simulation setup for a 32-channel DWDM IS-OWC system
2.1 System Model:
574
Prabhdeep Kaur et al. / Procedia Computer Science 58 (2015) 572 – 577
A 32 channel DWDM system has been modeled for a distance of 5000 kilometers using inter satellite optical wireless communication channel for different power levels and the results have been analyzed for two different modulation formats- the RZ and the NRZ modulation format. The system consists of the following main components: 1. DWDM transmitter, 2. OWC channel, 3. Optical Amplifiers, 4. Loop control, 5.DWDM receiver. A 32 channel DWDM transmitter is modeled at a wavelength of 1550 nanometers for a 10 Gbps system [14]. Generally, Lasers are used for creation of light pulses at the transmitter side. The transmitter consists of a channel spacing of 150 GHz and a line width of 5 MHz. The optical transmitter and receiver antenna diameters are taken to be 15 cm and additional losses due to attenuation, atmospheric effects and variations are ideally assumed to be zero. The OWC channel acts as the propagation medium between the transmitter and the receiver. The OWC channel is modeled at a distance of 5000 kilometers using loop control and optical amplifiers. Loop control methodology can be opted for increasing the range of optical communication systems. The number of loops decides the distance travelled by the optical signal from transmitter to receiver. As the number of loops increases, the distance travelled multiplies the OWC link distance and hence results in long distance transmission system for communication [13]. At the receiver side, Avalanche photodiode is used as a detector at the output side due to its better performance characteristics than PIN photodiode. APD can measure even lower level light and due to its high sensitivity, high speed and internal gain mechanism, thus widely used in optical distance measurement and optical communications involving long distance transmissions. BER analyzers and optical time domain visualizers have been applied at the output for analyzing the output characteristics of the system for varying input characteristics [5, 6]. 2.2 System specifications: The modelled system has been configured for a specific set of parameters at the transmitter, channel as well as the receiver side. The parameters are selected either on the basis of their type or mathematical value according to the simulation system requirements. The various parameters like input power of the DWDM transmitter, input wavelength, distance covered, type of amplifiers used, multiplexing scheme, are described for the proposed simulation set-up. The proposed IS-OWC system specifications have been summarized in Table 1. Table1. The proposed IS-OWC system specifications
S.No 1.
Parameter Input power(in dBm)
Value/Type 10,20,30
2.
Transmitter wavelength(in nm)
900
3.
Data rate(in Gbps)
10
4.
Distance(in kilometres)
5000
5.
1550
6.
Channel wavelength(in nm) Modulation scheme
7.
Amplifier used
EDFA black box
8.
DWDM transmitter
32 channel
NRZ,RZ
Prabhdeep Kaur et al. / Procedia Computer Science 58 (2015) 572 – 577
575
3. Results and Discussions:
Fig.2 (a) Eye diagram for NRZ modulation for an input power of 10dBm (b). Eye diagram for RZ modulation for an input power of 10 dBm
Figure 2(a) depicts the eye diagram for an input power of 10 dBm at a distance of 5000 kilometres using NRZ modulation format. It has been observed that a Quality factor of 12.99 and a bit error rate of 6.74*10^-39 has been attained for the same which is acceptable for such a long distance transmission. Figure 2(b) explains the eye diagram using RZ modulation format at a distance of 5000 kilometres for an input power of 10 dBm. A Quality factor of 12.26 has been attained with a bit error rate of 1.28*10^-38 which is acceptable but still less as compared to the NRZ modulation format. A Quality factor of 12.26 is considerable for such a long distance transmission by application of low input power. Hence a reduced input power can therefore be advantageous for an efficient communication system but at the cost of reduced system performance characteristics [7, 8].
Fig.3 (a) Eye diagram for NRZ modulation for an input power of 20dBm (b). Eye diagram for RZ modulation for an input power of 20 dBm
Fig. 3(a) shows the eye diagram at an input power of 20dbm using the same NRZ modulation format. The diagram shows that if we increase the input power by 10 dBm to the previously used power, the Quality factor increases to 13.36 and the bit error rate decreases to 4.92*10^-41 which are also acceptable but at the cost of increased input power. The eye diagram in Figure 3(b) reveals that using a 20 dBm input power a Quality factor of 12.98 and a BER of 7.9* 10^-39 can be accomplished using the RZ modulation format. The results are better as compared to those obtained for an input power of 10 dBm.
576
Prabhdeep Kaur et al. / Procedia Computer Science 58 (2015) 572 – 577
Fig.4 (a) Eye diagram for NRZ modulation for an input power of 30dBm (b). Eye diagram for RZ modulation for an input power of 30 dBm
In Fig. 4(a), the eye diagram has been analyzed for an input power of 30 dBm at a distance of 5000 kilometres by using the NRZ modulation format. The eye diagram reveals that if we increase the input power to 30 dBm for the same system configuration, a diminutive increase in the value of Q-factor is seen and so does the BER is affected showing a diminutive decrease in its value. Thus a Q factor of 13.37 and a BER of 4.5*10^-41 has been observed which is almost same as for 20 dBm input power. So it is preferable to operate the system at 20 dBm input power rather than 30 dBm for best performance of the system. Fig. 4(b) depicts the analysis of the system for an input power of 30 dBm using RZ modulation format. A minor increase in the Q factor and a minute decrease in the value of BER have been observed for an input power of 30 dBm. The Q-factor comes out to be 13.09 and a BER of 1.72*10^-39 has been achieved. Hence it is preferable to use an input power of 20 dBm rather than 30 dm for optimum working of the system as it makes a trade off between the input power as well as the system’s Quality factor and Bit error rate [9, 10, 11, 12]. Table 2. Comparison of results for different levels of input power
For 10 dBm input power Q-Factor BER For 20 dBm input power Q-factor BER For 30 dBm input power Q-factor BER
NRZ
RZ
12.99 6.74*10^-39
12.26 1.28*10^-38
13.36 4.92*10^-41
12.98 7.9* 10^-39
13.37 4.5*10^-41
13.09 1.72*10^-39
Table 2 shows the comparison based on the variations in the levels of input power for the two modulation formats. From the table, it is very clear that NRZ format outperforms the RZ format for all the three levels of input power i.e. 10 dBm, 20 dBm and 30 dBm as well. And out of the three power levels it is advisable to use 20 dBm for both NRZ as well as RZ modulation format as it produces almost similar results as obtained for 30 dBm input power [15].
Prabhdeep Kaur et al. / Procedia Computer Science 58 (2015) 572 – 577
4. Conclusion The modeled system encompasses a 32 channel IS-OWC system operating at 10 Gbps using different modulation formats for varying levels of input power. The system is designed to cover a long distance of 5000 kilometers and the results have been verified using Optisystem. The comparative analysis discloses that the NRZ scheme performs better than the RZ scheme in terms of system efficiency due to attainment of a high Quality factor and a low BER. The system performs best for an input power of 30 dBm using the RZ modulation format but a very high input power is required for arriving at the same. So it is more preferable to use an input power of 20 dBm with NRZ modulation scheme for most favorable results. References 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
S. Saini, A. Gupta, “Modelling and Performance Analysis of DWDM Based 100 Gbps Low Power Inter-satellite Optical Wireless Communication (LP-IsOWC) System”, SOP Transactions On Signal Processing, ISSN-2377-0546, vol. 2, no.1, January ,2015. A.W. Naji, W.A. Khateeb, “Performance analysis of a free space optical link with multiple transmitters/receivers”, IEEE International Conference on Space Science and Communication, 2012. I. Aggarwal, P. Chawla, R. Gupta, “Performance evaluation of inter-satellite free space optical communication system with varied parameters and transreceiver diversity”, ISSN 2231-1297, vol. 3, no. 7, pp.847-852, 2013. R. Antil, Pinki, S. Beniwal,” An Overview of DWDM Technology & Network”, International Journal Of Scientific & Technology Research, vol. 1, issue 11, December, 2012. K. Singh, M.S. Bhamrah,” Investigations of Transmitted Power in Intersatellite Optical Wireless Communication”, IRACST International Journal of Computer Science and Information Technology & Security (IJCSITS), ISSN: 2249-9555, vol. 2, no.3, June 2012. V. Sarup, A. Gupta, “Performance Analysis Of An Ultra High Capacity 1 Tbps DWDM-RoF System For Very Narrow Channel Spacing”, WECN, IEEE, September 2014. A.K. Jaiswal, Anil Kumar, Santosh Tripathi, Amarendra Kumar Chaudhary, “To Study the Effect of BER and Q-factor in Intersatellite Optical Wireless Communication System”, IOSR Journal of Electronics and Communication Engineering (IOSR-JECE) ISSN: 22782834, ISBN: 2278-8735, vol. 3, issue 4,September-October, 2012. M. Asif, H. Ali, H.M.Rehan Afzal, T. A. Siddiqui, “ Comparative Analysis and Power Optimization for Return to Zero and non Return to Zero Coded Transmission in 40 Gbps Fiber Optics System”, 7th International Congress on Image and Signal Processing,2014. M. Kaur, G. Bharti, “Performance Analysis of Optical Fiber Communication Systems For NRZ, RZ and Doubinary Formats”, International Journal of Advanced Engineering Research and Science (IJAERS) , vol.1, issue 5, October, 2014. R.S. Kaler, A. K.Sharma , T.S. Kamal, “Comparison of pre-, post- and symmetrical-dispersion compensation schemes for 10 Gb/s NRZ links using standard and dispersion compensated fibers”, Elesevier, Optics Communications,2002. Y. Wang, Y. Guan, “Performance Simulations for a High-speed Optical Transmission System Based on OptiSystem”, 7th International Congress on Image and Signal Processing, 2014. V. Sharma, N. Kumar, “Modeling of 2.5 Gbps-inter-satellite optical wireless communications (Is-OWC) system”, Science Direct Journal, Optic, 2013. Optical systems- WDM Design.[Online]. Available: http://www.optiwave.com. N. Vinayak, A. Gupta, “Comparative analysis of WDM system using Cascaded amplifiers in Optical wireless channel over a distance of 10000 Km”, SOP Transactions On Signal Processing, vol. 1, no. 1, pp.25-32, October, 2014. N. Kaur, G. Soni, “ Performance analysis of inter-satellite optical wireless communication (IsOWC) system by using NRZ and RZ modulation”, International Journal of Scientific and Research Publications, vol.5, issue 1, January 2015.
577
ScienceDirect Procedia Computer Science 58 (2015) 572 – 577
Second International Symposium on Computer Vision and the Internet (VisionNet’15)
Comparative analysis of Inter satellite Optical Wireless Channel for NRZ and RZ modulation formats for different levels of input power Prabhdeep Kaura*, Amit Guptab,Mandeep Chaudhary c a
Chandigarh University, Gharuan, India Chandigarh University Gharuan, India School of Engineering and Digital Arts, University of Kent, Canterbury, Kent, UK. b
c
Abstract Integration of DWDM in Optical wireless communication has undoubtedly revolutionized the satellite communication systems for use in the coming future. Thus OWC systems have become popular due to their outstanding performance uniqueness. This paper looks into the performance of Inter Satellite Optical Wireless Communication system link using DWDM multiplexing technique for long distance transmission. The Inter satellite link has been modeled at a data rate of 10 Gbps for communication range of 5000 kilometers. Furthermore, it demonstrates a comparative analysis of RZ (Return to zero) and NRZ (Non-return to zero) modulation formats by varying the levels of input power. ©©2015 by Elsevier B.V. by This is an open access article under the CC BY-NC-ND license 2015Published The Authors. Published Elsevier B.V. (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of organizing committee of the Second International Symposium on Computer Vision and the Peer-review under responsibility of organizing committee of the Second International Symposium on Computer Vision and the Internet Internet(VisionNet’15). (VisionNet’15) Keywords: Modulation; inter satellite optical wireless communication; BER; Q-factor.
1. Introduction The upcoming generations of Lightwave systems persevere for high data rate systems capable of supporting large number of user capacity. The increasing demand thus insists to look up for robust networks having minimal linear and non linear distortions which arise due to the network configurations at very high speeds. The linear impairments include chromatic dispersion, polarization mode dispersions as in case of optical fibers and non linear impairments may include self phase modulation, cross phase modulation, four wave mixing, etc [1]. To overcome the same, an optimum modulation format is required having a narrow optical spectrum that could not only withstand more distortion but also improvise the spectral efficiency. With constant optical power a modulation format becomes less susceptible to self phase modulation and cross phase modulation. Furthermore, in case of long haul optical networks, amplified spontaneous emission i.e. ASE, the noise introduced by erbium doped fiber amplifiers comes into picture which can also be reduced subsequently by choosing an optimum modulation
1877-0509 © 2015 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of organizing committee of the Second International Symposium on Computer Vision and the Internet (VisionNet’15) doi:10.1016/j.procs.2015.08.075
Prabhdeep Kaur et al. / Procedia Computer Science 58 (2015) 572 – 577
573
format. Thus the choice for modulation format plays a crucial role while designing any proficient network for communication [2]. The optical wireless communication systems have conquered the communication world in enormous applications because of their key benefits over the existing microwave communication systems, for satellite communication. The OWC systems are setting up a landmark for low cost, low power consumption and long distance transmission applications where it is very difficult to deploy long fiber optic cables. The Inter satellite optical wireless communication systems as clear from its name utilizes communication between two satellites for communication that carry the optical signal through unguided wireless links leading to a fusion of optical and wireless transmission [3]. Thus the utility of satellites in many applications and due to their numerous advantages, IS-OWC systems have been into practice for communication during these days. Besides the above mentioned advantages, the systems suffer from some problems like bandwidth inefficiency, erroneous transmissions, power constraints, and noises in communication systems that need to be overcome for better efficiency [4]. In this paper, simulative analysis on IS-OWC systems has been performed using two different modulation formats and the effect of input power on the Quality factor and Bit error rate of the system has been analyzed at 10 Gbps. The paper is organized as follows: Section II describes the simulation setup, Section III elaborates the results and discussion and Section IV concludes the paper. 2. Simulation Setup Figure 1 shows the simulation setup for the modeled system using various components.
Fig.1. Simulation setup for a 32-channel DWDM IS-OWC system
2.1 System Model:
574
Prabhdeep Kaur et al. / Procedia Computer Science 58 (2015) 572 – 577
A 32 channel DWDM system has been modeled for a distance of 5000 kilometers using inter satellite optical wireless communication channel for different power levels and the results have been analyzed for two different modulation formats- the RZ and the NRZ modulation format. The system consists of the following main components: 1. DWDM transmitter, 2. OWC channel, 3. Optical Amplifiers, 4. Loop control, 5.DWDM receiver. A 32 channel DWDM transmitter is modeled at a wavelength of 1550 nanometers for a 10 Gbps system [14]. Generally, Lasers are used for creation of light pulses at the transmitter side. The transmitter consists of a channel spacing of 150 GHz and a line width of 5 MHz. The optical transmitter and receiver antenna diameters are taken to be 15 cm and additional losses due to attenuation, atmospheric effects and variations are ideally assumed to be zero. The OWC channel acts as the propagation medium between the transmitter and the receiver. The OWC channel is modeled at a distance of 5000 kilometers using loop control and optical amplifiers. Loop control methodology can be opted for increasing the range of optical communication systems. The number of loops decides the distance travelled by the optical signal from transmitter to receiver. As the number of loops increases, the distance travelled multiplies the OWC link distance and hence results in long distance transmission system for communication [13]. At the receiver side, Avalanche photodiode is used as a detector at the output side due to its better performance characteristics than PIN photodiode. APD can measure even lower level light and due to its high sensitivity, high speed and internal gain mechanism, thus widely used in optical distance measurement and optical communications involving long distance transmissions. BER analyzers and optical time domain visualizers have been applied at the output for analyzing the output characteristics of the system for varying input characteristics [5, 6]. 2.2 System specifications: The modelled system has been configured for a specific set of parameters at the transmitter, channel as well as the receiver side. The parameters are selected either on the basis of their type or mathematical value according to the simulation system requirements. The various parameters like input power of the DWDM transmitter, input wavelength, distance covered, type of amplifiers used, multiplexing scheme, are described for the proposed simulation set-up. The proposed IS-OWC system specifications have been summarized in Table 1. Table1. The proposed IS-OWC system specifications
S.No 1.
Parameter Input power(in dBm)
Value/Type 10,20,30
2.
Transmitter wavelength(in nm)
900
3.
Data rate(in Gbps)
10
4.
Distance(in kilometres)
5000
5.
1550
6.
Channel wavelength(in nm) Modulation scheme
7.
Amplifier used
EDFA black box
8.
DWDM transmitter
32 channel
NRZ,RZ
Prabhdeep Kaur et al. / Procedia Computer Science 58 (2015) 572 – 577
575
3. Results and Discussions:
Fig.2 (a) Eye diagram for NRZ modulation for an input power of 10dBm (b). Eye diagram for RZ modulation for an input power of 10 dBm
Figure 2(a) depicts the eye diagram for an input power of 10 dBm at a distance of 5000 kilometres using NRZ modulation format. It has been observed that a Quality factor of 12.99 and a bit error rate of 6.74*10^-39 has been attained for the same which is acceptable for such a long distance transmission. Figure 2(b) explains the eye diagram using RZ modulation format at a distance of 5000 kilometres for an input power of 10 dBm. A Quality factor of 12.26 has been attained with a bit error rate of 1.28*10^-38 which is acceptable but still less as compared to the NRZ modulation format. A Quality factor of 12.26 is considerable for such a long distance transmission by application of low input power. Hence a reduced input power can therefore be advantageous for an efficient communication system but at the cost of reduced system performance characteristics [7, 8].
Fig.3 (a) Eye diagram for NRZ modulation for an input power of 20dBm (b). Eye diagram for RZ modulation for an input power of 20 dBm
Fig. 3(a) shows the eye diagram at an input power of 20dbm using the same NRZ modulation format. The diagram shows that if we increase the input power by 10 dBm to the previously used power, the Quality factor increases to 13.36 and the bit error rate decreases to 4.92*10^-41 which are also acceptable but at the cost of increased input power. The eye diagram in Figure 3(b) reveals that using a 20 dBm input power a Quality factor of 12.98 and a BER of 7.9* 10^-39 can be accomplished using the RZ modulation format. The results are better as compared to those obtained for an input power of 10 dBm.
576
Prabhdeep Kaur et al. / Procedia Computer Science 58 (2015) 572 – 577
Fig.4 (a) Eye diagram for NRZ modulation for an input power of 30dBm (b). Eye diagram for RZ modulation for an input power of 30 dBm
In Fig. 4(a), the eye diagram has been analyzed for an input power of 30 dBm at a distance of 5000 kilometres by using the NRZ modulation format. The eye diagram reveals that if we increase the input power to 30 dBm for the same system configuration, a diminutive increase in the value of Q-factor is seen and so does the BER is affected showing a diminutive decrease in its value. Thus a Q factor of 13.37 and a BER of 4.5*10^-41 has been observed which is almost same as for 20 dBm input power. So it is preferable to operate the system at 20 dBm input power rather than 30 dBm for best performance of the system. Fig. 4(b) depicts the analysis of the system for an input power of 30 dBm using RZ modulation format. A minor increase in the Q factor and a minute decrease in the value of BER have been observed for an input power of 30 dBm. The Q-factor comes out to be 13.09 and a BER of 1.72*10^-39 has been achieved. Hence it is preferable to use an input power of 20 dBm rather than 30 dm for optimum working of the system as it makes a trade off between the input power as well as the system’s Quality factor and Bit error rate [9, 10, 11, 12]. Table 2. Comparison of results for different levels of input power
For 10 dBm input power Q-Factor BER For 20 dBm input power Q-factor BER For 30 dBm input power Q-factor BER
NRZ
RZ
12.99 6.74*10^-39
12.26 1.28*10^-38
13.36 4.92*10^-41
12.98 7.9* 10^-39
13.37 4.5*10^-41
13.09 1.72*10^-39
Table 2 shows the comparison based on the variations in the levels of input power for the two modulation formats. From the table, it is very clear that NRZ format outperforms the RZ format for all the three levels of input power i.e. 10 dBm, 20 dBm and 30 dBm as well. And out of the three power levels it is advisable to use 20 dBm for both NRZ as well as RZ modulation format as it produces almost similar results as obtained for 30 dBm input power [15].
Prabhdeep Kaur et al. / Procedia Computer Science 58 (2015) 572 – 577
4. Conclusion The modeled system encompasses a 32 channel IS-OWC system operating at 10 Gbps using different modulation formats for varying levels of input power. The system is designed to cover a long distance of 5000 kilometers and the results have been verified using Optisystem. The comparative analysis discloses that the NRZ scheme performs better than the RZ scheme in terms of system efficiency due to attainment of a high Quality factor and a low BER. The system performs best for an input power of 30 dBm using the RZ modulation format but a very high input power is required for arriving at the same. So it is more preferable to use an input power of 20 dBm with NRZ modulation scheme for most favorable results. References 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
S. Saini, A. Gupta, “Modelling and Performance Analysis of DWDM Based 100 Gbps Low Power Inter-satellite Optical Wireless Communication (LP-IsOWC) System”, SOP Transactions On Signal Processing, ISSN-2377-0546, vol. 2, no.1, January ,2015. A.W. Naji, W.A. Khateeb, “Performance analysis of a free space optical link with multiple transmitters/receivers”, IEEE International Conference on Space Science and Communication, 2012. I. Aggarwal, P. Chawla, R. Gupta, “Performance evaluation of inter-satellite free space optical communication system with varied parameters and transreceiver diversity”, ISSN 2231-1297, vol. 3, no. 7, pp.847-852, 2013. R. Antil, Pinki, S. Beniwal,” An Overview of DWDM Technology & Network”, International Journal Of Scientific & Technology Research, vol. 1, issue 11, December, 2012. K. Singh, M.S. Bhamrah,” Investigations of Transmitted Power in Intersatellite Optical Wireless Communication”, IRACST International Journal of Computer Science and Information Technology & Security (IJCSITS), ISSN: 2249-9555, vol. 2, no.3, June 2012. V. Sarup, A. Gupta, “Performance Analysis Of An Ultra High Capacity 1 Tbps DWDM-RoF System For Very Narrow Channel Spacing”, WECN, IEEE, September 2014. A.K. Jaiswal, Anil Kumar, Santosh Tripathi, Amarendra Kumar Chaudhary, “To Study the Effect of BER and Q-factor in Intersatellite Optical Wireless Communication System”, IOSR Journal of Electronics and Communication Engineering (IOSR-JECE) ISSN: 22782834, ISBN: 2278-8735, vol. 3, issue 4,September-October, 2012. M. Asif, H. Ali, H.M.Rehan Afzal, T. A. Siddiqui, “ Comparative Analysis and Power Optimization for Return to Zero and non Return to Zero Coded Transmission in 40 Gbps Fiber Optics System”, 7th International Congress on Image and Signal Processing,2014. M. Kaur, G. Bharti, “Performance Analysis of Optical Fiber Communication Systems For NRZ, RZ and Doubinary Formats”, International Journal of Advanced Engineering Research and Science (IJAERS) , vol.1, issue 5, October, 2014. R.S. Kaler, A. K.Sharma , T.S. Kamal, “Comparison of pre-, post- and symmetrical-dispersion compensation schemes for 10 Gb/s NRZ links using standard and dispersion compensated fibers”, Elesevier, Optics Communications,2002. Y. Wang, Y. Guan, “Performance Simulations for a High-speed Optical Transmission System Based on OptiSystem”, 7th International Congress on Image and Signal Processing, 2014. V. Sharma, N. Kumar, “Modeling of 2.5 Gbps-inter-satellite optical wireless communications (Is-OWC) system”, Science Direct Journal, Optic, 2013. Optical systems- WDM Design.[Online]. Available: http://www.optiwave.com. N. Vinayak, A. Gupta, “Comparative analysis of WDM system using Cascaded amplifiers in Optical wireless channel over a distance of 10000 Km”, SOP Transactions On Signal Processing, vol. 1, no. 1, pp.25-32, October, 2014. N. Kaur, G. Soni, “ Performance analysis of inter-satellite optical wireless communication (IsOWC) system by using NRZ and RZ modulation”, International Journal of Scientific and Research Publications, vol.5, issue 1, January 2015.
577