This document summarizes an optical code division multiple access (OCDMA) system based on fiber Bragg grating (FBG) encoders and decoders. It identifies major challenges in OCDMA like bit error rate and multiple access interference. It then describes using FBG encoders and decoders to overcome these challenges by simulating an OCDMA system with FBG transmitters and receivers over 1 km and 100 km of fiber. The simulation results show this approach can address bit error rate issues in OCDMA. Potential applications of this FBG-based OCDMA system include local and access networks, all-optical multicasting, and switching.

1. by
BRIJESH BHARTI
(CIT-06/16)
Under the supervision of
Dr. Gausia Qazi
Department of Electronics & Communication Engineering
National Institute of Technology,
Srinagar
In optical fiber communication
112-12-2017 National Institute of Technology, Srinagar
OPTICAL CDMA system

2. Outline
• Introduction
• Find major challenges in OCDMA
• Method to overcome the challenges
• Simulation of OCDMA
• Application
2

3. Introduction
3
optical fiber communication use in very high speed data
transmission .to take full advantage of optical fiber
communication still we are working on the optical
communication for enhance the performance of entire
communication system .
Nowadays, we using optical CDMA system for multiple
user ,data send through the different advanced coding
scheme ,for particular user ,on the optical channel ,

4. Find challenges in OCDMA
• The major challenge in OCDMA system
• BER
• OCDMA MAI
• Components cost and complexity
• Signal loss in fiber cable
• Attenuation and dispersion
Our focus on only BER and MAI, because is major challenge in OCDMA [1]
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5. Method to overcome the challenges
• Using spectral amplitude coding (SAC)[1]
• Spectral phase coding (SPC).[2]
• Based on fiber Bragg grating (FBG)encoder /decoder[3]
our focus on only FBG encoder /decoder , because it overcome the BER issue in
OCDMA system
Simulation of OCDMA in OPTISYSTEM 15
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6. FGB transmitter
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Simulation of OCDMA Based on (FBG)encoder /decoder

7. Simulation of OCDMA Based on (FBG)encoder /decoder
FBG receiver
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8. Simulation result Of FBG OCDMA
 Simulation parameters in FGB based Optical CDMA
 Optical channel
 Distance 1km
 Attenuation 0.2 dB/Km
 Reference wave length 1550 nm
 Dispersion 16.75 ps/nm/km
 Dispersion slop 0.075 ps/nm/km
 Uniform FGB
 Bit rate 10e+009 bps
 Time window 0.1024e-006 s
 Number per sample 64
 Signal bit rate 200 mbps
 Sequence length 1024 bits
 Samples rate 640e+009Hz
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9. For 1km distance
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10. For 100 km distance
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11. Application of OCDMA
 From LAN to PON
 OCDMA for access networks
 All-optical multicasting
 All-optical switching and label routing
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12. Refrences
 [1] https://www.osapublishing.org/ao/abstract.cfm?URI=ao-47-9-1263.
 [2] 2015 11th International Conference on Innovations in Information
Technology (IIT)
Spectral Phase Coding based LR-PON
[3] Hooshang Ghafouri_Shiraz, M. Massoud Karbassian(auth.)-Optical CDMA
Networks_ Principles, Analysis and Applications-Wiley-IEEE Press (2012)
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13. 13
Thank You