Performance Analysis of 4-Channel WDM System with and without EDFA

Transcription

1 Performance Analysis of 4-Channel WDM System with and without EDFA 1 Jyoti Gujral, 2 Maninder Singh 1,2 Indo Global College of Engineering, Abhipur, Mohali, Punjab, India Abstract The Scope of this paper is to analyze the performance of 4-Channel WDM System. A WDM system forms the backbone of Optical Networks. In this paper, we have presented two configurations of WDM systems. The first configuration is without using EDFA and second configuration is using EDFA. For long distance transmission, EDFA plays a significant role in optical communication systems. The proposed configurations consist of 4 input channels transmitter, one multiplexer, one demultiplexer, and EDFA as a booster and pre-amplifier. The length used for EDFA was 100km. Simulation of proposed model was carried out and results were analyzed. The analysis of simulation results shows that output peak power is increased many times and optimized by using EDFA.Q factor with EDFA configuration obtained was 20 db, BER equals to 1.63,Jitter was 0.086(ns),and Output peak power obtained was db. Keywords WDM, BER, EDFA, ASE, Q Factor, WAN, Pumping I. Introduction In recent years, due to huge capacity demand for data transmission the optical fiber communication technology has undergone an enormous growth [1]. In an optical fiber communication system, during long distance transmission the light signal gets attenuated and to recover from this problem we need an optical amplifier. Among various optical amplifiers available, a great preference is given to the EDFA because of its high gain and low noise feature. As the doping material used for EDFA is erbium, that s why it is called as Erbium Doped Fiber Amplifiers. EDFAs are very much reliable for long distance transmission using single and multi-wavelength sources because of their wide bandwidth and optimum Bit Error Rate (BER) [2]. Wavelength Division Multiplexing (WDM) Networks can provide multi-channel amplification without crosstalk by deploying EDFA [3]. WDM networks employing EDFA provides a cost effective solution for increased demand of network capacity for internet services [4]. EDFA enhances the quality of the signal and it helps to encounter the problems like attenuation, distortion and Rayleigh Scattering [5].The EDFA has two bands named as L-Band and C-Band, which are very commonly used these days [19]. Hwang [21] designed broadband EDFA with double pass configuration. He used both L and C-band for his proposed configuration. He also concluded that cost of WDM can be reduced by using EDFA. A. WDM Technology WDM is one of the most promising technologies for high capacity communication systems. Fig. 1, [16] is showing a basic WDM technology. In this scheme, high carrier bandwidth is utilized to a greater extent to transmit multiple optical signals through a single optical fiber. Fig. 1: Basic WDM Technology Each Communication channel is allocated a different wavelength and then are multiplexed by multiplexer onto a single fiber. At destination, different wavelengths are demultiplexed by using a demultiplexer and are spatially separated to different receiver channels. B. Basic Principle of EDFA As the amplification window of EDFA coincides with the third transmission window of silica based optical fiber, that s why it is the mostly used fiber amplifier [9]. Fig. 2 is showing the block diagram [17] of EDFA.The basic principle of EDFA is Stimulated Emission. EDFA is a conventional silica fiber doped with the Erbium. [12] When erbium is stimulated with some suitable wavelength (980nm or 1480nm pump source) light energy, erbium ions are excited to some high energy metastable state. After some time these ions decay back to ground state, by giving up their energy in the form of light. If during decay process some light energy already exist within the fiber then this decay process is stimulated. Hence, the name is stimulated emission. Fig. 2: Block Diagram of EDFA The two main parameters which have a direct impact on the performance of EDFA are Gain and Noise fig. [11]. The length of EDFA also has an impact on gain and noise figure. Main issue while using EDFA is selection of Pump source Wavelength. Martini M.M [13], used multiple numbers of pumps. He has done Multi-pump Optimization for Raman+EDFA Hybrid Amplifiers under pump Residual Recycling. Choi Bo-Hun [15] used a New Pump Wavelength of nm Band for Long-Wavelength- Band Erbium Doped fiber Amplifier. Pump direction also has an influence on EDFA. Bastos-Fillho [14], presented an influence of pump direction in All-Optical Gain Clamped Erbium Doped 70 International Journal of Electronics & Communication Technology

2 ISSN : (Online) ISSN : (Print) IJECT Vo l. 4, Is s u e Sp l - 3, Ap r i l - Ju n e 2013 Fiber Amplifier. This paper is organized into six sections. In section II Related Work has been discussed, while section III presents the configuration of proposed WDM system using EDFA. Section IV demonstrates the model Simulation details. Section V presents the results and discussions. Finally, the paper is concluded in section VI. II. Related Work In late 1980 s, EDFAs have been developed as the backbone of WDM Networks. This paper [1] demonstrated the research on EDFA applications in WDM communication system. He simulated EDFA amplifiers with a variable fiber length and investigated this optical amplifier operating parameters. He concluded the reduction in EDFA gain and ASE noise with the increase in input signal power. This paper [5] analyzed the performance of WDM/SCM system using EDFA. He used 16 channels of radio frequency carrier modulation of sub carrier multiplexing (SCM), integrated with WDM for radio over fiber link. This paper [6] proved the analysis of performance of various WDM systems. He studied the effect of dispersion values on WDM system. This paper [7] discussed the designing of broadband EDFA using dual forward pumping for next generation optical networks. This paper [8] presented flattened gain low noise EDFA for DWDM systems. He used EDFA to amplify multi-channel DWDM signals. This paper [10] presented the performance analysis of WDM and EDFA in C-band. He concluded that nm is the best wavelength to be used in WDM system. This paper [18] reviewed the optical amplifier technology in telecommunication network applications. Kinoshita S [20] focused on the developing amplifiers that are intended for a 1.3 µm zero-dispersion single mode fiber (SMF) transmission system. This paper [22] submitted a concept, based on a homogenous model for EDFA that produce optimum optical source power and wavelength to imitate multiple WDM channels for the purpose of scaling optical gain. This paper [23] presented a survey of advanced reservation routing and wavelength assignment in optical networks. He classified the types of advanced reservation and also discussed it for both WAN and Grid-based networks. This paper [24] demonstrated four channel signal transmission over 459 km using six EDFA. He confirmed the possibility of large capacity transmission systems employing WDM technology integrated with optical amplifiers. Fig. 3: WDM System The proposed configuration on the transmitter side consist of four transmitter channels, one optical combiner, optical fiber of length 100 km,an optical filter. The receiver side of the configuration consists of one optical splitter, PIN photodiode, and an electrical filter. This configuration suffers from losses and attenuation as there is no optical amplifier used. 2. WDM System using EDFA In a WDM System EDFA can be used as a Booster, Line amplifier and as a Pre-amplifier [9].In our proposed work, we are using EDFA as a Booster and Pre-amplifier. Fig.4 is showing the proposed WDM system using EDFA as a Booster and Pre-amplifier. The proposed configuration on the transmitter side consist of four transmitter channels, one optical combiner,edfa as a Booster and Pre-amplifier, one splice and an optical filter. The receiver side of the configuration consists of one optical splitter, PIN photodiode, and an electrical filter. This configuration doesn t suffer from losses and attenuation as there is optical amplifier used. III. Configuration of Proposed WDM System With and In this work, the simulated models of 4-Channel WDM Systems with and without using EDFA have been proposed. Bit Rate used for each channel was EDFA of length 100km was employed in the proposed system. The applied methodology is based on using Optical Amplifier in WDM Systems for enhancing the quality of the signal. Both the configurations were modeled, simulated and tabulated the parameter values. The parameter values were analyzed graphically to find out optimized values. The two proposed configurations are as follows: WDM System without using EDFA WDM System using EDFA. 1. WDM System without using EDFA Fig. 3. is showing the configuration of WDM system without using an EDFA. Fig. 4: WDM System Using EDFA IV. Simulated Models For Proposed Work The proposed model for WDM System integrated with and without EDFA was simulated using Software. Fig. 5 is showing the International Journal of Electronics & Communication Technology 71

3 simulated model of WDM System without EDFA.The transmitter consist of four channels with bit rate and laser line width of 10.The receiver consists of one optical splitter and one PIN photo detector In this model we are analyzing the output of one channel only.fig6. is showing the Eye diagram. Fig.7 is showing the simulated graph and result for output peak power. The peak value of output power is db which is quite low, as this configuration suffers from attenuation and dispersion losses-factor for this configuration obtained was 30 db. Fig. 8: Simulated Model of WDM System Using EDFA Fig. 5: Simulated Model of WDM System Without Using EDFA Fig. 9: Eye Diagram for Simulated model of WDM System without using EDFA Fig. 6: Eye Diagram for Simulated Model of WDM System Fig. 10: Peak Output Power for Simulated Model of WDM System using EDFA Fig. 7: Peak Output Power for Simulated Model of WDM System 72 International Journal of Electronics & Communication Technology Fig. 8 is showing the simulated model of WDM System using EDFA as a booster and pre-amplifier. The transmitter consists of four channels with bit rate and laser line width of 10.Splice was used to connect both booster and pre-amplifiers. In this model we are analyzing the output on one channel only. The receiver consists of one optical splitter and one PIN photo detector. In this

4 ISSN : (Online) ISSN : (Print) model we are analyzing the output of one channel only. Fig. 9 and Fig. 10 are showing the eye diagram and output peak power graph for the proposed model. The output peak power obtained was db which is quite large as compared to previous results. V. Results & Analysis Results obtained from the simulation models have been tabulated in Table 1 as shown below. For both configurations various parameters like Q-Factor, BER, Jitter and Output peak power were compared. Table 1: Results of Comparison of different parameters for WDM configuration with and without EDFA. As the output peak power in any WDM system should be high. The best part of our work is that, here we are getting very high output peak power. Following points can be summarized from the results obtained: Q-factor decreases with the use of EDFA. BER obtained was 1e-040 for without EDFA and 1.63 for WDM system with EDFA. Jitter obtained was ns for WDM system integrated with EDFA while for without EDFA it was ns. The output peak power was optimized to db in the WDM System using EDFA. V. Conclusion and Future Aspects WDM system with four channels have been proposed and simulated in this paper with and without using EDFA. The various results were analyzed and compared also.wdm is one of the very useful technologies for optical networks.wdm multiplexes number of optical signals onto a single fiber by using different wavelength. Based on results obtained and the result analysis, It can be concluded that the WDM System integrated with EDFA gives the optimized Q-Factor and Output Peak power. In Future, the WDM System integrated with High performance EDFA, and other advanced optical technologies, as well as the market demand of more Bandwidth at lower costs have made an optical networking an attractive solution for advanced networks. IJECT Vo l. 4, Is s u e Sp l - 3, Ap r i l - Ju n e 2013 References [1] Brobrovs.V et al, EDFA Application Research in WDM Communication Systems, ELEKTRONIKA IR ELEKTROTECHNIKA, Vol. 19, No. 2, [2] Gujral Jyoti et al, Analysis of Augmented Gain EDFA Systems using Single and Multi-wavelength Sources, International Journal of Computer Applications, Vol. 47, No. 4, June 2012 [3] Semmalar S., Poonkuzhali, Devi.P, Optimized Gain EDFA of different lengths with an influence of pump power, IEEE Paper, [4] Semmalar S., Gujral Jyoti, EDFA with Optimized Gain using Tri-Counter Directional Pumping, International Journal of Applied Engineering Research, Vol. 6, No. 5, April [5] Kumar Mukesh et al, Performance Analysis of WDM/SCM System Using EDFA, International Journal of Advanced Research in Computer Science and Software Engineering Vol. 2, June, 2012 [6] Singh Preet Kawal et al, Performance Analysis of different WDM Systems, International Journal of Engineering Science and Technology. Vol. 4, No. 3 March, [7] Goel Aditya et al, Design of broadband EDFA for next generation optical networks, journal of Neural Networks and applications, pp.9-13 Jan - June [8] Semmalar et al, Flattened Gain Low Noise EDFA for DWDM Systems, National Conference on Emerging Trends in Electronics and Communication Engineering (ETECE- 11),PIET Haryana, pp. 41 April [9] Chaugule Sachin et al, WDM and Optical Amplifier, 2nd International Conference on Mechanical ans Electronics Engineering (ICMEE 2010) IEEE Paper [10] Ismail M.M et al, Performance Analysis of WDM and EDFA in C-band for optical communication system, IJRRAS, Vol. 13, Issue 1, October, 2012 [11] Introduction to optical amplifiers (white paper) Jun 2010 [12] Introduction to EDFA technology (white paper) June [13] Martini M.M.J et al, Multi-pump Optimization for Raman + EDFA Hybrid Amplifiers under Pump Residual Recycling, IEEE Paper , Asian network for scientific information 2006 [14] Bastos-Fillho J.A Carmelo et al, Influence of Pump Direction in All-Optical Gain-Clamped Erbium Doped Fiber Amplifier, IEEE Paper [15] Choi Bo-Hun et al, New Pump Wavelength of nm Band for Long-Wavelength-Band Erbium Doped Fiber Amplifier, IEEE Journal of Quantum Technology, Vol. 39, No. 10 October 2003 [16] Aggarwal G.P, Non Linear Fiber Optics, 3rd edition, Academic Press, New York, 2001 [17] Keiser Gerd, Optical Fiber Communications, Tata McGraw- Hill International editions, Publishing Inc., [18] Othman M.A et al, Erbium Doped Fiber Amplifier for C-Band Optical Communication System, International Journal of Engineering & Technology, Vol. 12, No. 4, [19] Sun Yan et al, Optical Fiber Amplifiers for WDM Optical Networks, Bell Labs Technical Journal, [20] Kinoshita.S et al, Wideband WDM Erbium-Doped Optical Fiber Amplifier for 10 Gb/s, 32-Channel SMF Transmission System, FUJITSU Sci.Tech. J., Vol. 35, No. 1, International Journal of Electronics & Communication Technology 73

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