International Journal of Innovations & Advancement in Computer Science

IJIACS

ISSN 2347 – 8616

Volume 7, Issue 5

May 2018

Performance Evaluation of Different Channels in Optical

Communication Systems using Optisystem Simulator

Rajbir Singh, Payal, Deepak Sharma

Student, ECE Department, UIET, MDU Rohtak

Abstract:

Nowadays increasing multimedia hungry applications requires high speed data transmission from source to

destination. The recent advancement in optical technology such as WDM, DWDM and the recent orthogonal

frequency based Elastic Optical Networks (EONs) have paved way for efficient resource allocations. This

paper presents a comparative performance evaluation of three different optical channels single mode fiber,

Free Space Optics (FSO) and optical wireless communication Channel (OWC) using non return-to-zero

(NRZ) modulation scheme at 10Gbps. The performance of designed system is on the basis of Q-factor using

Optisystem Simulator.

Keywords: FSO, EDFA, NRZ, OWC

1 Introduction

Over decades the low-loss optical transmission fibers have a significant role in efficient and optimum

bandwidth utilization, WDM technology is used, which permits several channels to be multiplexed onto a

single optical fiber. The goal of any communication is to increase the data rate and transmission distance as

well. The recent advancement in optical technology such as WDM, DWDM and the recent orthogonal

frequency based Elastic Optical Networks (EONs) have paved way for efficient resource allocation [1]. For

this, it becomes necessary to study the several characteristics of optical fibers (attenuation and dispersion) that

affect the performance of optical fiber communication. Fiber optics is a medium for carrying information

from one point to another in the form of light and it is not electrical in nature. A basic fiber optic system

consists of transmitting device that converts an electrical signal into a light signal, an optical fiber cable that

carries the light, and a receiver that accepts the light signal and converts it back into an electrical signal

.Guided and unguided medium are the types of Optical communication systems. In the case of unguided

optical communication systems, the optical beam emitted by the transmitter propagated through space, similar

to Optical Wireless Communication (OWC) systems and free-space optical communication (FSO) [2].

Free space optics (FSO) communications, also known as wireless optical communication (WOC), as it uses

In optical fibers, FSO

near-infrared beams through the atmosphere to obtain optical communications [3].

techniques uses lasers to transmit data, but instead of enclosing the data stream in a glass fiber, it is

transmitted through the air [4].

In FSO communication, the collimated light beam is transmitted from one location to another by using low

power infrared lasers. The light from a FSO channel is intercepted by system of lenses, capable of focusing

photons on highly sensitive detector receivers. The enough transmitter power is guaranteed as long as there is

a clear line of sight between the source and the destination. FSO data rates, comparable to optical fiber

transmission, and can be carried with very low error rates, while the extremely narrow laser beam widths.

The optical communication channels are used to transport the optical signal from transmitter to receiver

without distorting it. Mostly, light wave communication systems use optical fibers as the communication

channel because fibers can transmit light with a relatively small amount of power loss. Fiber loss is an

important design issue, as it determines directly the repeater spacing of a long-haul light wave system.

Another important design issue is fiber dispersion, which leads the individual pulses inside the fiber will be

broadening [5].

186 Rajbir Singh, Payal, Deepak Sharma

International Journal of Innovations & Advancement in Computer Science

IJIACS

ISSN 2347 – 8616

Volume 7, Issue 5

May 2018

2 OWC

OWC uses light at near-infrared frequency to communicate. Transmitter, propagation channel and receiver

are three main communication parts of OWC system. Figure 1 shows the basic block diagram of an OWC

system. OWC channel is considered to be outer space where it is assumed to be vacuum and free from

atmospheric attenuation factors and provides high security, low cost, low power, and high rates due to the

unregulated bandwidth [6]. The wireless optical channel component is also free-space optics that can be used

for large distances where the atmospheric attenuation is not the major source of penalties.

Fig1. Proposed Block diagram

3 FSO

In FSO communications the transmission of modulated visible or infrared beams through the atmosphere used

to obtain optical communications [7]. FSO as shown in Figure 2. Describes a typical free space optical link,

rather than through a conductor such as a wire or fiber, or through a waveguide of some sort. It is unaffected

by electromagnetic interference and radio frequency interference is another important feature of FSO, which

increasingly plague radio based communication systems [8]. FSO systems are used in disaster recovery

applications and for temporary connectivity while cabled networks are being deployed. Free space optical

communication is simply effected by atmospheric distortion hence FSO become most secure and high speed

medium of data transmission [9].

Fig 2. Free Space Optics FSO System

187 Rajbir Singh, Payal, Deepak Sharma

International Journal of Innovations & Advancement in Computer Science

IJIACS

ISSN 2347 – 8616

Volume 7, Issue 5

May 2018

4. System Design Model

The proposed block diagram to simulate transmission system with Single mode fiber, FSO channel and OWC

channel is shown in figure 1 and the designed model of simulated system with Optisystem software is shown

in figure 3. Input signal with 1550 nm wave-length and input power of 10 dBm which is externally modulated

at 10 G bits/s with a non-return-zero (NRZ) pseudorandom binary sequence. Input signal is splitted into three

signals of equal power using a fork and is then applied individually to three channels [10]. The optical

receiver has a cutoff frequency is 0.75 Bit rate Hz.

Fig3.The designed model of simulated system with Opti system software

5. Results and Discussions

The simulation and optimization of the design is done by Optisystem simulation software. I have evaluated the

performance of SMF at a distance of 25, 50, 75 and 100km.Table 1 shows the values of Q-Factor for SMF

Table: I Variation of Q-factor with distance for single mode fiber

Sr. No.

Distance

Q-Factor

100

14.04

11.87

2.91

2.68

Fig 3 shows the graphical variation of Q Factor for SMF with variation in transmission distance.

Variation of Q-factor with distance

Distance (km)

Fig. 3 Variation of Q-factor with distance for single mode fiber

100

188 Rajbir Singh, Payal, Deepak Sharma

International Journal of Innovations & Advancement in Computer Science

IJIACS

ISSN 2347 – 8616

Volume 7, Issue 5

May 2018

From figure 3, it is evident that the value of Q-factor decreases with increase in transmission distance.

Table II shows the values of Q-factor for FSO. I have evaluated the performance of SMF at a distance of 250,

500, 750 and 1000meter.

Table: II Variation of Q-factor with distance for free space optics

Sr. No.

Distance (meter)

Q-Factor

250

500

750

1000

53.96

16.58

7.603

4.36

Variation of Q-factor with distance

250

500

Distance (m)

750

1000

Fig.4 Variation of Q-factor with distance for free space optics

Fig 4. Shows the graphical variation of Q Factor for FSO with variation in transmission distance. It is evident

that the value of Q-factor decreases with increase in transmission distance. Table III shows the values of Q-

Factor for OWC.

Table: III Variation of Q-factor with distance for optical wireless communication

Sr. No.

Distance

Q-Factor

100

77.05

21.61

10.02

5.72

Variation of Q-factor with distance

Distance (km)

100

Fig 5 Variation of Q-factor with distance for Optical wireless communication

189 Rajbir Singh, Payal, Deepak Sharma

International Journal of Innovations & Advancement in Computer Science

IJIACS

ISSN 2347 – 8616

Volume 7, Issue 5

May 2018

Fig. 5 shows the graphical variation of Q Factor for OWC with variation in transmission distance. In figure 4,

it is evident that the value of Q-factor decreases with increase in transmission distance.

(a)

(b)

(c)

(d)

Fig 6 Eye diagram of SMF (a)At optical fiber length 25km, (b) At optical fiber length 50km, (c) At optical

fiber length 75km and (d) At optical fiber length 100km

(a)

(b)

Fig 7 Eye diagram of FSO (a) At optical fiber length 250m, (b) At optical fiber length 500m, (c) At optical

fiber length 750m and (d) At optical fiber length 1000m

190 Rajbir Singh, Payal, Deepak Sharma

International Journal of Innovations & Advancement in Computer Science

IJIACS

ISSN 2347 – 8616

Volume 7, Issue 5

May 2018

(a) (b)

(c)

(d)

Fig 8 Eye diagram of OWC (a) At optical fiber length 25km, (b) At optical fiber length 50km, (c) At optical

fiber length 75km, and (d) At optical fiber length 100km

Figure 6, 7 and 8 shows the eye diagrams of three different channels at different transmission distances. The

SMF and OWC gives good eye opening even at higher transmission distances but can very narrow eye

diagrams for FSO channel because increasing noise and interference by increase distances.

5 Conclusions

In this paper, the performance of three optic communication channels was evaluated using optisystem. For

SMF and OWC, the communication range of 25, 50, 75 and 100km is taken. For FSO, the performance is

evaluated at transmission range of 250, 500, 750 and 1000meter. From simulative results, OWC and SMF

channel give the best results i.e. reduced the value of minimum bit error rate the best channel and increased

the values of signal output power and the quality factor when compared with other channels FSO channel for

long distance communication.

6 References

[1] Deepak Sharma, Col. (Dr) Suresh Kumar, “An Overview of Elastic Optical Networks and its Enabling

Technologies”. International Journal of Engineering and Technology (IJET) Vol. 9 No 3 Jun-Jul 2017, pp (1643-

1649) ISSN 0975-4024. DOI: 10.21817/ijet/2017/v9i3/170903022.

[2] Prachi Sharma, Suraj Pardesh, Rohit Kumar Arora, Mandeep Singh " A Review of the Development in the Field of

Fiber Optic Communication Systems" International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com .Journal, Volume 3, Issue 5, May 2013.

[3] X. Zhu and J. M. Kahn, "Free-space optical communication through atmospheric turbulence channels," IEEE Trans.

Com-mune., vol. 50, pp.1293–1300, 2002.

[4] Payal ,Dr. (Col.) Suresh Kumar, Deepak Sharma, “Performance Analysis of NRZ and RZ Modulation Schemes in

Optical Fiber Link Using EDFA” International Journal of Advanced Research in Computer Science and Software

Engineering

ISSN: 2277 128X DOI:

August 2017

10.23956/ijarcsse/V7I8/0102 .

(IJARCSSE),Vol. 7,Issue 8

,pp(161-168)

[5] T. H. Carbonneau and D. R. Wisley, "Opportunities and challenges for optical wireless; the competitive advantage of

free space telecommunications links in today’s crowded mar-ket place", SPIE Conference on Optical Wireless

Communica-tions, Massachusetts, pp- 119-128, 1998

191 Rajbir Singh, Payal, Deepak Sharma

International Journal of Innovations & Advancement in Computer Science

IJIACS

ISSN 2347 – 8616

Volume 7, Issue 5

May 2018

[6] Rajbir Singh, Manoj Ahlawat, Deepak Sharma, “Study and Performance Analysis of Radio over Fiber using Mach-

Zehnder Modulator” International Journal of Advanced Research in Computer Science(IJARCS), Volume 8, No. 5,

May – June 2017pp(1095-1100) ISSN:0976-5697

[7] F. Nadeem, V. Kvicera, M.S. Awan, E. Leitgeb, S.S. Mu-hammad, and G. Kandus, "Weather Effects on Hybrid

[8] Rajbir

FSO/RF Communication Link", IEEE Journal on Selected Areas In Communications, vol. 27, pp.1687-1697, 2009.

using

“Radio

Mach Zehnder Modulator”, International Journal of Enhanced Research in Management & Computer Applications,

Vol. 6 Issue 6, June-2017,pp(16-25) ISSN: 2319-7471

Singh, Deepak

Performance

Analysis

Sharma

,Anjali,

Fiber

over

[9] Aida Hasfiza Binti, "Modeling intersatellite optical wireless communication system", a thesis submitted in

fulfillment of the requirements for the award of the degree Bachelor of Elec-trical Engineering (Telecommunication)

Faculty of Electrical Engineering Universiti Teknologi Malaysia MAY 2009.

[10] Payal ,Dr. (Col.) Suresh Kumar, Deepak Sharma, “A Review of Optical Communication link design using EDFA”

International Journal of Enhanced Research in Management & Computer Applications, Volume 6, Issue3, March

2017pp (33-38) ISSN: 2319-7471

192 Rajbir Singh, Payal, Deepak Sharma