Phase Encoded Optical Code Division Multiplexing Access System

2015 ◽  
pp. 121-149
Keyword(s):  
Bit Error Rate ◽  
System Performance ◽  
Single Mode ◽  
Optical Signal ◽  
Single Mode Fiber ◽  
Approximate Analytical Expression ◽  
Access System ◽  
Transmission Distance ◽  
Code Division Multiple ◽  
Multiple Access System

Phase encoded optical code division multiple-access system is evaluated in a dispersive fiber medium in this chapter. An approximate analytical expression for the root mean square (rms) width of the phase encoded signal (pseudorandom optical signal with low intensity) propagating in linear dispersive fibers is derived. Bit-Error Rate (BER) analysis of the system is performed in the case of both ordinary Single-Mode Fiber (SMF) and Dispersion-Shifted Fiber (DSF). The numerical results demonstrate that even though system performance improves due to the smaller width of initial Gaussian optical pulse, the effect from dispersion is higher. Larger code length reduces the effect of dispersion and the use of DSF greatly increases the transmission distance.

scholarly journals Enhanced Spectral Amplitude Coding OCDMA System Utilizing a Single Photodiode Detection

2018 ◽  
Vol 8 (10) ◽  
pp. 1861 ◽  
Author(s):  
Somia Abd El-Mottaleb ◽  
Heba Fayed ◽  
Ahmed Abd El-Aziz ◽  
Mohamed Metawee ◽  
Moustafa Aly
Keyword(s):  
System Performance ◽  
Multiple Access ◽  
Group Velocity Dispersion ◽  
Single Mode ◽  
Fiber Amplifier ◽  
Single Mode Fiber ◽  
Spectral Amplitude ◽  
Erbium Doped Fiber Amplifier ◽  
Spectral Amplitude Coding ◽  
Code Division Multiple

In this paper, the performance of a spectral amplitude coding-optical code division multiple access (SAC-OCDMA) system is investigated utilizing a single photodiode (SPD) detection technique. The proposed system uses enhanced double weight (EDW) codes as signature codes with three simultaneous users to overcome both phase-induced intensity noise (PIIN) and multiple access interference (MAI). In addition, a dispersion compensating fiber (DCF) is used in order to decrease the group velocity dispersion (GVD) caused in the single mode fiber. An erbium-doped fiber amplifier (EDFA) is used to overcome the attenuation. The use of both DCF and EDFA leads to an appreciable enhancement in the system performance. The system performance is evaluated through its bit error rate (BER), Q-factor, and received power. A comparison between the EDW codes and modified double weight (MDW) codes on the SAC-OCDMA system is demonstrated. Simulation is carried out through Optisystem ver. 7. The simulation results show that: (a) using an avalanche photodiode (APD) over PIN photodiode allows data transmission over longer distances; (b) the use of DCF improves the system BER;(c) using MDW codes gives better BER than using EDW codes.

scholarly journals High Speed OTDM-DWDM Bit Compressed Network for Long-Haul Communication

2019 ◽  
Vol 18 (2) ◽  
pp. 57-65
Author(s):  
Tadbirul Islam ◽  
Mohammad Nasir Uddin
Keyword(s):  
High Speed ◽  
Data Transfer ◽  
Time Window ◽  
Single Mode ◽  
Optical Amplifier ◽  
Optical Signal ◽  
Single Mode Fiber ◽  
Sequence Length ◽  
Transmission Distance ◽  
Communication Network Design

This paper represents an optical communication network design that incorporates both OTDM and DWDM techniques which provides up to 240 Gbit/s data transfer rate, long-haul communication distance of 2700 km with a maximum number of 384 channels in this designed architecture. Each channel has a bitrate of 625 Mbit/s that follows optical signal hierarchy OC-12, STS-12 (SONET ANSI), and STM-4 (SDH CCITT), and the design maintains standard parameters for commercially available channel grids at 100 GHz spacing. The communication is done by Single Mode Fiber (SMF) of 50 km and Dispersion Compensating Fiber (DCF) of 10 km followed by one optical amplifier gain in each span. Bit error rate (BER) remains significantly low while transmission distance for only OTDM is 18000 km at a BER < 10-12, and for the hybrid OTDM-DWDM it is 2700 km at a BER < 10-16. Both values are measured under 128 bits sequence length. Three compression stages are used for 8 channels each in order to minimize the gap between bits, and to utilize the space for more channels within a specific time window.

40 Gb/s High-speed mode-division multiplexing transmission employing NRZ modulation format

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Rabiu Imam Sabitu ◽  
Nafizah Goriman Khan ◽  
Amin Malekmohammadi
Keyword(s):  
System Performance ◽  
High Speed ◽  
Direct Detection ◽  
Signal To Noise Ratio ◽  
Optical Signal ◽  
Threshold Power ◽  
Modulation Format ◽  
Transmission Distance ◽  
Mode Division Multiplexing ◽  
Speed Mode

AbstractThis report examines the performance of a high-speed MDM transmission system supporting four nondegenerate spatial modes at 10 Gb/s. The analysis adopts the NRZ modulation format to evaluate the system performance in terms of a minimum power required (PN) and the nonlinear threshold power (PTH) at a BER of 10−9. The receiver sensitivity, optical signal-to-noise ratio, and the maximum transmission distance were investigated using the direct detection by employing a multimode erbium-doped amplifier (MM-EDFA). It was found that by properly optimizing the MM-EDFA, the system performance can significantly be improved.

Switchable and tunable linear cavity erbium-doped fiber laser based on FBGs embedded in Sagnac rings

Laser Physics ◽  
2021 ◽  
Vol 32 (1) ◽  
pp. 015101
Author(s):  
Gangxiao Yan ◽  
Weihua Zhang ◽  
Peng Li ◽  
Qiuhao Jiang ◽  
Meng Wu ◽  
...  
Keyword(s):  
Fiber Laser ◽  
Low Cost ◽  
Single Mode ◽  
Optical Signal ◽  
Single Mode Fiber ◽  
Hole Burning ◽  
Linear Cavity ◽  
Erbium Doped ◽  
Optical Fiber Sensing ◽  
Birefringence Effect

Abstract A switchable and tunable erbium-doped fiber laser with a linear cavity based on fiber Bragg gratings embedded in Sagnac rings is proposed and experimentally verified. Due to the stress birefringence effect and the polarized hole burning effect, which are introduced into the single-mode fiber in the polarization controllers (PCs) by the PCs, the designed laser can achieve seven kinds of laser-states output including three kinds of single-wavelength laser states, three kinds of dual-wavelength laser states and one kind of triple-wavelength laser state. The optical signal-to-noise ratios of the output wavelengths are all higher than 52 dB, and the wavelength shifts are all less than 0.04 nm. Furthermore, the temperature tuning of the wavelength range is also researched, which is about 1.2 nm. Due to advantages, such as low cost, simple structure, easy switching and multiple laser states, the designed laser has great application potential in laser radar, optical fiber sensing and so on.

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