SPECTRAL AMPLITUDE CODING OPTICAL CODE DIVISION MULTIPLE ACCESS SYSTEM ON HIGH-SPEED DATA RATE
Presentation on M Tech Dissertation Part 1 Progress Work
Presented By:
SACHIN KUMAR (12/PIT/080)
Supervised By:
Dr. Rajesh Mishra
Content
INTRODUCTION INTRODUCTION
SPECTRAL AMPLITUDE CODING OPTICALCODE DIVISION MULTIPLE ACCESS
LITERATURE SURVEY
REFERENCES
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Introduction
• In CDMA, a unique code is assigned to each subscriber. These codes are designed to allow all users to transmit data simultaneously and asynchronously
• Optical code division multiple access (OCDMA) technique, which allows multiple users share the same transmission media by assigning different optical codes (OCs) to different users, is an attractive candidate for next generation broadband access networks.
• The key advantage of using OCDMA is that, OCDMA can be encoded and decoded in optical domain without converting the signal to electronic unless it needed to be. In OCDMA, the multi user interference (MUI) is the ultimate limit in system performance. MUI increases with the number of simultaneous users and severely limits the capacity of the system. There are two types of O-CDMA Techniques:-
O-CDMA with Unipolar Codes
O-CDMA with Bipolar Codes
O-CDMA with Unipolar Codes O-CDMA with Unipolar Codes
Elecrical Encoder
Pattern Generator
Elecrical Decoder
Optical DecoderNetworkData
Pattern
Detect Pattern
Outer ChannelOuter ChannelInner Channel
Data
An Optical Pattern
Corrupted Pattern
Fig. An optical CDMA network using two-dimensional codes
SPECTRAL AMPLITUDE CODING OPTICALSPECTRAL AMPLITUDE CODING OPTICALCODE DIVISION MULTIPLE ACCESSCODE DIVISION MULTIPLE ACCESS
• The spectral amplitude coding (SAC) OCDMA systems have attracted much attention because the multi-access interference (MAI) can in theory be removed when using code with fixed in phase cross-correlation.
• The spectral amplitude coding (SAC) OCDMA systems have attracted much attention because the multi-access interference (MAI) can in theory be removed when using code with fixed in phase cross-correlation . Codes for OCDMA systems employing intensity detection have to be unipolar, orthogonal (minimum cross-correlation) and constant weight to obtain low values of probability of error owing to MAI. Hence, a family of codes called optical orthogonal codes (OOCs) has been designed. Which improves the system performance and increases the number of simultaneous users by code design.
Literature Survey Literature Survey
Base paper- Abd T. , Aljunid S., Fadhil H. , Ahmad R. and M.A. Rashid, New approach for evaluation of the performance of spectral amplitude coding-optical code division multiple access system on high-speed data rate.
•In this paper author proposed the system performance of spectral amplitude coding optical code division multiple access (SAC-OCDMA) systems.
•The system performance is evaluated based on a new code called the dynamic cyclic shift (DCS) code algorithm.•Performance of the DCS code on high-speed OCDMA systems can be evaluated by using both the numerical computation as well as the simulation experiment.
Research GapsResearch Gaps
• The system performance is evaluated based on a new code called the dynamic cyclic shift (DCS) code.
• The DCS code reject the MAI noise, and the number of users could be doubled. It will not applicable for 3D next-generation OCDMA networks
Literature Survey: ObservationsLiterature Survey: Observations
• AL-KHAFAJI H. , ALJUNID S. , Amphawan A., A. Fadhil H., M. Safar A. , Reducing BER of spectral-amplitude coding optical code-division multiple-access systems by single photodiode detection technique., Opt. Soc. Rap. Public. 8 pub. 2 J. Europ. Opt. Soc. Rap. Public. 8, 13022 (2013) 013.
• In this paper author proposed the system performance of spectral amplitude coding optical code division multiple access (SAC-OCDMA) systems.
• The system performance is evaluated based on a new code called the dynamic cyclic shift (DCS) code algorithm.
• Performance of the DCS code on high-speed OCDMA systems can be evaluated by using both the numerical computation as well as the simulation experiment.
Research GapsResearch Gaps
• The DCS code reject the MAI noise, and the number of users could be doubled. It will not applicable for 3D next-generation OCDMA networks