Low-Cost Encoding Device for Optical Code Division Multiple Access System

Abstract

Problem statement: Instead of using Fiber Bragg Grating (FBG) to develop the coded spectrums, which consist of expensive elements, the grating also are highly sensitive to environmental changes and this will contribute to the increment of capital and operational expenditures (CAPEX and OPEX). Approach: This study presented the development of low-cost 16-ports encoding device for Optical Code Division Multiple Access (OCDMA) systems based on Arrayed Waveguide Grating (AWG) devices and optical switches. The encoding device is one of the new technologies that used to transmit the coded data in the optical communication system by using AWG and optical switches. It provided a high security for data transmission due to all data will be transmitted in binary code form. The output signals from AWG were coded with a binary code that given to an optical switch before it signal modulate with the carrier and transmitted to the receiver. The 16-ports encoding device used 16 Double Pole Double Throw (DPDT) toggle switches to control the polarization of voltage source from +5 V to -5 V for 16 optical switches. When +5 V was given, the optical switch will give code '1' and vice versa. Results: We found that the insertion loss, crosstalk, uniformity and Optical Signal-NoiseRatio (OSNR) for the developed prototype are <12 dB, 9.77 dB, <1.63dB and ≥20 dB. Conclusion: We had successful developed the AWG-based OCDMA encoding device prototype and characterized using linearity testing and continuous signal testing. The developed prototype was expected to be applied in the optical communication system on Passive Optical Networks (PONs).

Optical Code-Division Multiple-Access and Wavelength Division Multiplexing: Hybrid Scheme Review

“…In contrast, the incoherent systems require more standard techniques of intensity modulation and simpler detection with incoherent source, such as a broadband Amplified Spontaneous Emission (ASE) source, while coherent approaches are based on the optical phase for signal modulation and detection (Lam, 2000). The most common incoherent OCDMA approaches refer to Spectral-Amplitude-Coding (SAC) (Smith et al, 1998;Wei et al, 2001;Aljunid et al, 2004;Ab-Rahman et al, 2009;Sahbudin et al, 2011), temporal (time) spreading (Sotobayashi et al, 2004), spatial coding (Hassan et al, 1995) and Wavelength-Hopping Time-Spreading (WHTS) and two-dimensional code (Yegnanarayanan et al, 2000;Yim et al, 2002;Kwong et al, 2005;Algalbi, 2009). Many of these codes have been developed for either increasing the capacity of systems or enhancing the security of authorized users' data, or both.…”

Optical Add Drop Multiplexer (OADM) Based on Dense Wavelength Division Multiplexing Technology in Next Generation Optical Networks

“…DWDM systems being deployed today can increase a single fiber's capacity sixteen fold, to a throughput of 40 Gbit/s. This cutting edge technology when combined with network management systems and add-drop multiplexers enables carriers to adopt optically-based transmission optical networks that will meet the next 2 generation of transmitted bandwidth demand at a significantly lower cost than installing new fiber [2].…”

“…Wavelength selective optical add/drop filter is required for adding and dropping a particular Wavelength Division Multiplexing (WDM) channel at each subscriber's node in the WDM based optical access networks [2]. In these WDM based optical networks, Dense Wavelength Division Multiplexing (DWDM) technology is necessary for maximizing the limited transmission bandwidth.…”

A Comparison between Electrical and Optical Chromatic Dispersion Compensation in Wavelength Divison Multiplexing Network Regarding to Electrical Pulse Shapes

“…Instead of offering high transmission rate (bandwidth), survivability and security is the compensated features of the new optical network which used to cater the technologies evolved in the ICT application (Ab-Rahman et al, 2009a) (Ab-Rahman et al, 2009c) (Ab-Rahman and Mahir 2011). For example Internet traffic has been increasing at incredible rate ranging from 75-125% yearly.…”