Performance Analysis of 4 10Gb/s DWDM Soliton System Using Different Parameters

Transcription

1 International Journal for Science, Management and Technology ISSN : Performance Analysis of 4 10Gb/s DWDM Soliton System Using Different Parameters Savita Anurag Sharma Dept Electronics & Communication Dept Electronics & Communication CT Institute of Technology & Research CT Institute of Technology & Research Jalandhar, Punjab Jalandhar, Punjab bhagatshweta04@gmail.com er.anurags@gmail.com (Received 17 August, 2016 Accepted 08 September, 2016 Abstract The use of the soliton in optical communication is marvel in nature. As the WDM systems are the backbone of the optical networks. In this paper, the dense conditions that proves these solitary pulse were absolute possible theoretically[8]. In 1967 the exact solution of KDV equation was found known as the NonLinear Equation. Wavelength division multiplexing (DWDM Soliton This means soliton waves are the solution of the Nonlinear communication for 4 users has been done. The equations such as: performance of the 4 users system has been analyzed in the terms of,q factor, dispersion analysis. Also in this paper the system is analyzed in the form of and q factors at different distances. The reference wavelength of 1.55nm has been used. The analysis of the system is done using OptiSystem 7.0 simulator. The analysis of simulation results shows that with the increase in distance the bit error rate increases and the quality factor decreases The Kortewegde Vries (KDV equation The NonLinear Schodinger equation Keywords DWDM, Soliton,, Dispersion, Power 1. INTRODUCTION The word soliton implies ''Solitary Solution'' intended to describe the particle like behavior of the optical pulses which is in propagation through a nonlinear medium [2]. The soliton is a selfstrengthening solitory wave (a wave bundle or pulse that keeps its shape while going at steady speed means the pulse envelope for soliton not just proliferates undistorted additionally also survives collision just as the particles do. Soliton pulse appears as the arrangement of a widespread class of the nondirect dispersed particles differential condition defining the physical system[12]. The properties of soliton are: 1. They are of perpetual structure. 2. They are confined with in a locale. 3. They can connect with solitons and rise up out of the collision unchanged with the exception of a phase shift. The main preferences of the soliton utilized as a part of the fiber optics media transmission medium are that it does not change a pulse shape during the propagation from transmitter to receiver section [5]. The soliton pulse was first described by John Scott Russell, a Scottish engineer at Edinburgh (1834 who observed solitary wave in the union canal in Scotland. In 1965 the word soliton was used in the research paper and solved Kortewegde Vries (KDV equation by boundary The soliton pulses are exceptionally narrow, high intensity optical pulses that hold their shape through the collaboration of adjusting pulse scattering with the nonlinear properties of an optical channel [710]. In the event that the relative impact of SPM and GVD are controlled simply right, and proper pulse shape is chosen, the pulse coming about because of SPM can precisely counter balance the pulse widening impact of GVD[1]. Contingent on the specific pulse shape picked, the pulse either does not change its shape as it propagates, or undergoes repeated change in shape periodically. The pulse whose shape remains constant during the transmission are known as the fundamental solitons. On the other side, the pulses that doesnot retains their shape known as the higher order solitons [1112]. As discussed before, when a highpower pulse is coupled to fiber, the refractive index modulates by the optical power as seen by the optical excitation [9 ]. This actuates phase changes in the propagating wave, in this manner impelling a chirping impact in the pulse. At the point when such a pulse crosses a medium with a positive GVD for the constituent frequency, the main part of the beat is moved towards a more longer wavelength, so that the speed in that part increments. Then again, in the trailing half, the frequency rises so the speed diminishes [78]. This causes the trailing edge to be further postponed. Therefore, not withstanding a spectral change with length, the energy in the focal point of the pulse is scattered to either side, and then the end take a rectangular shape. Then again, when a limited highintensity pulse crosses a medium with negative GVD for the constituents frequency, GVD checks the chirp created by SPM. Presently, GVD impedes the low frequency in the front end of the wave and advances the high frequencies at the back [10]. The result is that sharped peaks soliton pulses of high the intensity change neither its shape nor its spectrum as it travel along the fiber. Provided the pulse energy adequately strong, 17

2 International Journal for Science, Management and Technology ISSN : this pulse shape is maintained as it goes along the fiber. In a standard optical fiber, there is a zero scattering point around 1320 nm wavelength and β 2 is positive for the shorter wavelengths than 1320nm and longer for greater wavelengths than1320nm[713]. All the more particularly, a chirped pulse can be compressed at the early stage of propagation when the GVD parameter β2 and chirp parameter C have inverse sign so that β2c is negative[7]. The nonlinear effect of SPM imposes chirp on the optical pulse such that C > 0. Since β2 <0 in the 1550 nm wavelength locale, the condition β2c < 0 is promptly fulfilled. Besides, the chirp induced by the SPM effect is power dependent it is not hard to imagine that under certain condition SPM and GVD may coordinate in such a way that the SPMactuated chirp is simply right to cancel out the GVDactuated expanding of the pulses[14]. The optical pulses would then spread undistorted as soliton. In this paper, we utilized Wavelength Division Multiplexing (WDM system which is spine of all optical systems, in view of interest of high capacity for the information transmission[16]. In this, different optical signals can be effectively transmitted over a solitary optical fiber. In WDM system every correspondence channel have diverse wavelength and which are multiplexed by multiplexer onto a solitary fiber and the other way around, demultiplexer is utilized at the receiver section which isolates the diverse wavelength[167]. In section 1 the introduction has been described. Section 2 contains the performance measurement using which the performance of the system is measured. Section 3 detailed some related work on the soliton communication system. Section 4 describes the system description and the simulation. Section 5 describes the results and the discussion. Section 6 detailed the conclusion of the system performance. 2. Performance Measures The performance of a communication system can be measured using the parameters such as Bit Error rate (, Quality factor (Qfactor, OSNR (optical signal to noise ratio. QFactor: Qfactor is defined as the signal to noise ratio received at the receiver unit and is basically dimensionless. It consider the soliton interaction and the nonlinear effects. : The is defined as the number of errors made per second in the output pulse and provides the upper limit of the signal that degraded at the receiver section. The is estimated from the Qfactor and it should be Q>6 for of 10 9 ].Mathematically the relation between and qfactor can be calculated as: = 1 2 erfc Q 2 OSNR: Optical Signal to Noise Ratio(dB is the measure of the ratio of signal power to noise power in an optical channel. Mathematically, it can be calculated as: OSNR=10 db log 10 ( S N 3. Related Work 1. Malhotra J. et al [12] analyze the different data format at 10 Gb/s of soliton at initial chirp and TOD(third order dispersion effect. 2. Singh M. et al[15] presents optical WDM communication system for the propagation of CW pulses and solitons waves. 3. Kumar M. et al[2] presents the performance analysis of soliton pulses in loss managed 10 GBPS transmission link using various parameters. 4. Singh P. et al[16] presents the 4 channel WDM transmission and analyze the simulation result based on and eye opening. 4. System Description We have carried out simulation to investigate the pattern of the pulses in the DWDM (dense wavelength division multiplexing at 40 Gb/s transmission also to analyze the performance of the system at different distances at different input power. Figure 1 indicates a simulation model of an optical communication system at 10 Gb/s around 1550nm wavelength. The simulation setup carried out the 4 input channels with a channel spacing of 0.4nm wavelength. The simulation has been done using a commercial simulation package OptiSystem 7.0. The simulation have been carried out at fixed bit rate such as: B=10Gb/s. The simulation has been done for different fiber lengths or distances for different input peak power of the system. The bit pattern considered for each channel in WDM soliton system is taken as a 16 bit pattern that proceed by the zeros. The attenuation in the is taken as 0.2db/km. The Kerr Nonlinear coefficients consider as the fiber parameters are given as: γ= n 2ω 0 ca eff The refractive index is given by n 2 = 2.6 e 20 m 2 /W and ω 0 c = 2π λ = 2π/ m 1 Whereas A eff is taken as 80 μm 2 β 2 is the second order dispersion in the soliton system and inversly proportion to the group velocity of the pulses. β 2 = λ2 D 2πc =20ps2 /km The dispersive length can be calculated L D = T 0 2 In solitons the pulse width must be of small fraction of the bit slot to ensure that the soliton are well separated from each other. β 2 18

3 International Journal for Science, Management and Technology ISSN : β = 1/2q 0 T 0 Where 2q 0 T 0 is the separation between two soliton pulses. Here, as shown in the simulation setup, at the transmitter side the bit sequence generator is used to generate the bit sequence of 16 bits that is essential for the generation of the soliton pulse. The same bit sequence is used for all the channels. The evaluates the rate of errors at which they occurs and defines as the probability of occurrence of error per transported bits. Typical benchmark rates for are 10 9 and10 12.In the Optisystem tool allows the straight forward access to extensive sets of characterized data of the system. An extensive library of active and passive components includes the realistic and wavedependent parameter. Figure 1: Simulation Setup for MultiChannel WDM Soliton System The bits sequence generated by the sequence generator inputs to the optical sech pulse generator that generates the pulse of sech profile. At the sech pulse generator the entire four channels have difference central frequency like channel 1 have center frequency equal to center frequency + channel spacing. Initially the input peak power is taken as zero watt and biased at 100dbm. The output of all the channels is multiplexed or combined by power combiner with losses considers as zero and through them transmitted over the fiber. Initially the length of fiber was taken as 15km and at the receiver section the power separator separates each channel output pulse. The receiver section also contains a fine tune filter to tune the particular output wavelength of particular channel. A spectrum analyzer at the receiver end gives the output power spectrum in the frequency domain and the time domain. The tester gives the for the input signals as well as a number of useful parameters such as the Qfactor and the properties of electrical eye such as the height, width and extinction ratio also the can be calculated using the Monte Carlo algorithm depending upon the nature of the noise sources during simulation. 5. Results and Discussion Based on simulation the investigations have been reported on the input and output pattern carried out at 10 Gb/s in an optical transmission link the distance is ranging from 10 km to 25 km. The common used parameters during the whole transmission are as: Parameters Bit Rate Reference Wavelength Channel Spacing Dispersion Slope Dispersion Value 40Gb/s 1550nm 0.4nm 0.075ps/nm^2/km 16.75ps/nm/km Table 1: Parameters values used in the Simulation Setup 19

4 International Journal for Science, Management and Technology ISSN : The system performance analysis based on the input and output pulse shape with β 2 C is negative with initially the input pulse power is taken as 0 dbm. The bit sequence is taken as 16 bits proceeded with zeros. Here, in this paper the input and output pulse spectrum of one of the all users has been described. The initial length of the fiber is taken as 15 km and the attenuation loss for the system 0.2db/km is constant for whole the transmission. Figure 2: Pulse in frequency domain Figure 4: Output Pulse in frequency domain Figure 3: Pulse in time domain Figure 2 and 3 shows the input pulse shape of sech profile in the frequency and time domain. From the frequency domain it has been observed that the pulse is started at 1.55µm that is generated by the optical sech pulse generator with the bit pattern of 16 bit sequence. On the other hand, the time domain graph shows the input pulse profile in the time domain. The pulse in the time domain starts at the 300ps and ends at the 500ps with the amplitude of 1mw. Similarly from the other users the input wavelength with channel spacing 0.4 nm are taken and the applied to the power combiner to combine so that all the inputs can be transmitted through single mode fiber at same time. After multiplexing all the inputs are transmitted through the single mode fiber. Figure 5: Output Pulse in time domain Figure 4 and 5 shows the output spectrum of the sech pulse shape in frequency and time domain respectively. From the fiber the multiplexed signal is passed to the demultiplexer. The demultiplexer separates all the wavelengths of all users. The output of each channel after demultiplexing consist of its own sech pulse with addition of the noises. To compensate the noise present in the output pulse the optical Gaussian filter is used at each output. From the figure 4 of frequency domain it has been observed that in the pulse shape remain sustain but get compressed due to the chirping effect present in the system. Also the system performance has been analyzed at different distances in the form of value and qfactor for all the four users initially the input power kept at 0 dbm. 20

5 International Journal for Science, Management and Technology ISSN : The and the Q factor of all the four users in DWDM Soliton system at various distances are shown as: Distance (Km User 1 User 2 User 3 User E E E E E E E E E E E E E E E E41 Table 2: of all users with distance Table 2 describes the values of all the four users in the DWDM Soliton system at different distances such as 10 to 25 Km. Distance QFactor (Km User 1 User 2 User 3 User Figure 7: Qfactor analysis at v Table 3: Q factor all users with distance Table 3 describes the variations of Q factors of all the four users in the DWDM Soliton system at different distances such as 10 to 25 Km. Figure 6: analysis at various distances 21

6 International Journal for Science, Management and Technology ISSN : managed means the output pulse is less dispersed as compare to the input pulse also the power at the system output reduces. 5.2 Analysis of at different input power at varying distance Power(mw (5km E E E E 171 (10km 24.5E E E E 132 (15km 2.47E E E E 97 (20km 2.40E E E E 90 (25km 1.2E E E E 81 Table 4: distance of 1 user with different input power and By analyzing the graph or figure 6 and 7 of and Qfactor of all users at different distance it has been observed that as the distance increases the of all the users also incrases but on the other hands, the q factor decreases with the increment in the length of the fiber. If the relation of Q factor and has been considered such as the Qfactor should be greater than 6 for value. By analyzing the graphs it has been observed that and the Qfactor both are decreases with the increase in the distance. This implies that this system with above defined parameters works good at the distance upto 20km. 5.1 Parametric Analysis Parame ters Disper sion (ps/nm Noise (dbm OSNR (db Power (dbm User1 7.98E E E^ User2 7.98E E 1.18E User3 7.9E E E 1.18E User4 7.97E E 1.18E Output at 1550n m 2.06E E 2.76E Output at 1551n m 2.05E E 01 Power(m w Q factor(5k m Q factor (10k m Q factor (15k m Q factor (20k m Q factor (25k m Table 5: QFactor of 1 user with different input power and distance From the table 4,it shows the analysis of the of the 1user at varying input power and distance. From the table it has been observed that the optimized value of is obtained as the distance increases with the increased input power. Similarly the Table 5 consist the Qfactor at different input power with different lengths and it has been observed that the qfactor value gets optimized as the distance increases. Table3: Parametric analysis of system The Above table shows the parametric analysis input and output in the form of dispersion, noise, OSNR, output power of the system. From the table it has been observed that the noise present in the system remain constant during the whole transmission. Whereas the dispersion in the system has been 22

7 International Journal for Science, Management and Technology ISSN : dispersion of the system output also has been managed. The noise present in the system remain constant throughout the transmission also the output power of the system deceases as compare to the input power of each user. The soliton approach of transmission makes the stable transmission and improved the performance of the system due to high Q factor, bit error rate and lesser drop in the power. Figure 8: Graph between and input power at varying length Figure 8 show the graphical view of the and the input power at varying fiber length and it has been observed that at the more input or pump power with increased distance a good has been obtained. Figure 9: Graph between Qfactor and input power at varying length Figure9:show the graphical view of the Qfactor and the input power at varying fiber length as the and the Qfactor are related to each other and it has been observed at the more input or pump power with increased distance the optimized value of Qfactor is obtained and concluded that at long distance by using the more input power the system can perform better. 5. CONCLUSION The Soliton is a balance of the group velocity dispersion(gvdand self phase modulation(spm otherwise which are detrimental effects. We have simulated the transmission of the four channel DWDM soliton system. It has been conclude that the increases as the distance increases whereas the Qfactor decreases. It can be also seen that the 6. ACKNOWLEDGEMENT I am highly thankful to our learned faculty Er. Anurag Sharma for his active guidance and invaluable contribution, motivation and discussions throughout the completion of this research work. I would also like to thank all the faculty members, the staff of Electronics and Communication, CT Institute of Technology and Research, Jalandhar. They have made the institute a wonderful place to gain knowledge and an enjoyable place to work. REFERENCES [1]Singh M., Sharma A., Kaler S., Kumar M., Timing jitter dependence on data format for ideal dispersion compensated 10 Gbps optical communication systems, Journal of Optik, Elsevier, Vol119,pp ,2008. [2] Kumar M., Sharma A., Kamal S., Performance evaluation of pathaveraged soliton pulses in lossmanaged 10Gbps soliton transmission link over a long haul, Journal of Optik, Elsevier,Vol121,pp 6876,2010. [3] Kumar M., Sharma A., Kamal S., 10 Gbps optical soliton transmission link using inline SOA on standard SMF at 1.3 um, Journal of Optik,Elsevier,Vol118,pp3437,2007. [4] Essiambre R., Agarwal G., Timing jitter analysis for optical communication systems using ultrashort solitons and dispersiondecreasing fibers, Optical Communications, Elsevier,Vol.131,pp274278,1996. [5] Bohac L., The Soliton Transmissions In Optical Fibers, Advances In Electrical And Electronic Engineering,Vol.8 No.5,pp107110,Dec [6] Zhou G., Xin M., Kaertner F., Chang G., Timing jitter of Raman solitons, Optics Letters, Vol.40,No.21, pp , [7] Otero F., Posada P., Bundled solitons collisioninduced frequency shifts in multiplechannel WDM dispersion managed systems, Optics Communication,Elsevier,Vol.332,pp18, [8] Gangwar R., Singh S. P., Singh N., Soliton Based Optical Communication, Progress In Electromagnetics Research, Vol.74, pp157166, [9] Nakazawa M., Kubota H., Suzuki K., Yamada E., Sahara A., Recent progress in soliton transmission technology, American Institute of Physics, Vol.10 No.3, pp , [10] Ganapathy R., Soliton dispersion management in nonlinear optical fibers Elsevier,Vol.17, pp , [11] Li L., Song Y., Zhang H., Shen D., Tang D., Dark Soliton Operation Fiber Lasers, Proceeding of IEEE,

8 International Journal for Science, Management and Technology ISSN : [12] Malhotra J., Kumar M., Performance analysis of NRZ, RZ, CRZ and CSRZ data formats in 10 Gb/s optical soliton transmission link under the impact of chirp and TOD, Elsevier, Vol.121,pp ,2010. [13] Kumar M., Sharma A., Kamal T.S., Malhotra J., Comparative investigation and suitability of various data formats for10 Gb/s optical transmission links at different chirps, Elsevier, Vol.120,pp ,2009. [14] Bagga P., Sarangal H., Simulation of 4 3 Gbits/sec WDM System based on Optical Amplifiers at 130km Transmission Distance, SSRG International Journal of Electronics and Communication Engineering, Vol.2,pp.66 69,2015. [15] Singh M., Saini H., High Performance Soliton WDM Optical Communication System, Fourth International Conference on Advances in Computing and Communications, IEEE, pp.2024,2014. [16] Singh P., Kumar L., Malhotra N., Performance Analysis of 4 Channel WDM System, International Journal for Science and Emerging, pp