scholarly journals Advancing High-Speed Transmissions over OCDMA Networks by Employing an Intelligently Structured Receiver for Noise Mitigation

2018 ◽  
Vol 8 (12) ◽  
pp. 2408 ◽  
Author(s):  
Kai-Sheng Chen ◽  
Yi-Chang Chen ◽  
Long-Guang Liao
Keyword(s):  
Interference Cancellation ◽  
High Speed ◽  
Noise Suppression ◽  
Optical Signal ◽  
Spectral Amplitude ◽  
Light Sources ◽  
Bit Rate ◽  
Noise Mitigation ◽  
Compact Structure ◽  
Code Division Multiple

We propose an intelligently structured receiver to achieve high-speed transmissions over optical code-division multiple access (OCDMA) networks. Employing spectral-amplitude coding (SAC) reduces multiuser interference (MUI) in OCDMA, but the network bit-rate is limited by phase-induced intensity noise (PIIN) coming from the incoherency of light sources. To mitigate PIIN, the receiver performs interference estimations and regenerations through consecutive stages. The MUI is removed by subtracting the estimated interference term from the received multiplexed signals. For PIIN variance, it is both dependent on and positively related to user number and bit-rate. Reducing the number of interference users allows the network to support transmissions with a higher speed under a given noise level. The proposed scheme has the advantages of all-optical signal processing and a compact structure. Additionally, the function of noise suppression is rarely studied in the existing MUI elimination schemes, such as serial interference cancellation (SIC) and parallel interference cancellation (PIC). The simulation results show the proposed receiver achieves significant increment in bit-rate than the conventional balanced detector in SAC–OCDMA networks.

A Review on Successive Interference Cancellation Scheme Based on Optical CDMA Network

2014 ◽  
Vol 35 (4) ◽  
Author(s):  
N. Alsowaidi ◽  
T. Eltaif ◽  
M. R. Mokhtar
Keyword(s):  
Interference Cancellation ◽  
Multiple Access ◽  
Direct Detection ◽  
Multiple Access Interference ◽  
Successive Interference Cancellation ◽  
Optical Cdma ◽  
Spectral Amplitude ◽  
Cdma System ◽  
Spectral Amplitude Coding ◽  
Code Division Multiple

AbstractDue to various desirable features of optical code division multiple access (OCDMA), it is believed this technique once developed and commercially available will be an integral part of optical access networks. Optical CDMA system suffers from a problem called multiple access interference (MAI) which limits the number of active users, it occurs when number of active users share the same carriers. The aim of this paper is to review successive interference cancellation (SIC) scheme based on optical CDMA system. The paper also reviews the system performance in presence of shot noise, thermal noise, and phase–induced intensity noise (PIIN). A comprehensive review on the mathematical model of SIC scheme using direct detection (DS) and spectral amplitude coding (SAC) were presented in this article.

Performance Analysis of SAC Optical PPM-CDMA System-Based Interference Rejection Technique

2016 ◽  
Vol 37 (1) ◽  
Author(s):  
N. Alsowaidi ◽  
Tawfig Eltaif ◽  
M. R. Mokhtar
Keyword(s):  
Interference Cancellation ◽  
Code Division Multiple Access ◽  
Multiple Access ◽  
Multiple Access Interference ◽  
Spectral Amplitude ◽  
Cdma System ◽  
Pulse Position Modulation ◽  
Interference Rejection ◽  
Spectral Amplitude Coding ◽  
Code Division Multiple

AbstractIn this paper, we aim to theoretically analyse optical code division multiple access (OCDMA) system that based on successive interference cancellation (SIC) using pulse position modulation (PPM), considering the interference between the users, imperfection cancellation occurred during the cancellation process and receiver noises. Spectral amplitude coding (SAC) scheme is used to suppress the overlapping between the users and reduce the receiver noises effect. The theoretical analysis of the multiple access interference (MAI)-limited performance of this approach indicates the influence of the size of

scholarly journals Nonlinear Effect and MAI Impact on SAC-OCDMA System Based on 2D Multi-Diagonal Code and Laser Array

2021 ◽  
Vol 11 (18) ◽  
pp. 8528
Author(s):  
Hichem Mrabet ◽  
Faouzi Bahloul ◽  
Abdullah S. Karar ◽  
Abdelhamid Cherifi ◽  
Aymen Belghith
Keyword(s):  
Multiple Access ◽  
Nonlinear Effects ◽  
Passive Optical Network ◽  
Spectral Amplitude ◽  
Bit Rate ◽  
Laser Array ◽  
Third Order ◽  
Optical Source ◽  
Fiber Dispersion ◽  
Code Division Multiple

A new architecture for Spectral Amplitude Coding Optical Code Division Multiple Access (SAC-OCDMA) system based on two Dimensional Multi Diagonal (2D-MD) codes named 2D-MD SAC-OCDMA and utilizing a laser optical source is proposed for Long-Reach Passive Optical Network (LR-PON). In this work, a computer simulator tool is used, for the first time, as a SAC-OCDMA simulation set-up utilizing the unique combination of a coherent laser array and 2D-MD codes. In addition, the system performance is addressed numerically by taking into account Multiple Access Interference (MAI), optical coherent source noise, first, second and third order fiber dispersion, nonlinear effects and photo-detector noise. Simulation results indicate that for a single user (i.e., without considering MAI), the system can operate at a maximum bit rate of 55 Gb/s over 250 km of Single Mode Fiber (SMF), with a Bit Error Rate (BER) below 10−9 (Q-limit = 15.5 dB), when only first order fiber dispersion is considered. However, including the effects of second and third order fiber dispersion as frequency domain parameters, results in a reduction of the maximum bit rate to 40 Gb/s, while maintaining a Q-factor above the Q-limit under the same transmission distance. Furthermore, we demonstrate that the proposed architecture extends the SMF transmission reach up to 600 km and 480 km, when considering linear and nonlinear effects, respectively. Finally, we show that our proposed 2D-MD SAC-OCDMA system outperforms existing solutions presented in the literature for LR-PON configuration, in terms of both aggregate bit rate and transmission reach.

scholarly journals Comparison Simulator Data Rate Modulation QPSK and 16 QAM System WCDMA (Wide Code Division Multiple Access) and HSDPA (High Speed Downlink Packet Access)

2015 ◽  
Vol 1 (1) ◽  
pp. 34-42
Author(s):  
Herdianna Kusuma W
Keyword(s):  
High Speed ◽  
Adaptive Modulation ◽  
Data Rate ◽  
User Equipment ◽  
Expected Improvement ◽  
Modulation Scheme ◽  
Bit Rate ◽  
Symbol Rate ◽  
Packet Access ◽  
Code Division Multiple

HSDPA (High Speed Downlink Packet Access) is the upgrade performance data packets extraordinary against WCDMA thus producing top speed 14,4 Mbps. One of the goals the creation of HSDPA is as an improvement over previous technologies. The expected improvement of HSDPA technology increasing the data rate is capable of exceeding data rate in order to WCDMA customer satisfaction in accessing multimedia content such as streaming video and data at high speed. Data Rate is the maximum data rate that can be accepted by the UE (User Equipment) in ideal conditions. One of the factors that affect the data rate is modulation scheme used by each of the technologies. QPSK modulation is used in WCDMA system and adaptive modulation (QPSK and 16QAM) is used in HSDPA system.In the research the results obtained by selection of symbol rate of 480 kbps bit rate will yield 960 kbps while the selection symbol rate is 960 kbps will produce 1920 kbps bit rate using modulation QPSK modulation. As for 16QAM modulation, symbol rate of 480 kbps produces 1920 kbps and symbol rate is 960 kbps bit rate produces 3840 kbps. Of the trial results, the more number of bits sent then the higher data rate that can be accepted by the UE (user equipment).

SAC-OCDMA over Indoor Optical Wireless Communication (OWC) System Based on Zero Cross Correlation (ZCC) Code

2016 ◽  
Vol 857 ◽  
pp. 603-607 ◽  
Author(s):  
Emad Ahmed Alyan ◽  
S.A. Aljunid ◽  
M.S. Anuar ◽  
C.B.M. Rashidi
Keyword(s):  
Wireless Communication ◽  
Code Division Multiple Access ◽  
Multiple Access ◽  
High Speed ◽  
Cross Correlation ◽  
Spectral Amplitude ◽  
Optical Wireless Communication ◽  
Optical Wireless ◽  
Code Division Multiple ◽  
Indoor Optical Wireless Communication

This article investigates the spectral amplitude coding, optical code division multiple access (SAC-OCDMA) over indoor optical wireless communication (WO) system for various data rates and different receiver’s positions under the effect of ambient light noise. OW technology offers high speed communication with high level of security during data transmission. But it suffers from the multiple access interference (MAI) and phase induced intensity noise (PIIN) when the system associated with simultaneous multiple users. Therefore, the optical code division multiple access (OCDMA) technology is used based on zero cross correlation (ZCC) code in order to reduce those impairments that existed in OWC systems. The major advantage of ZCC code is its ability to eliminate the PIIN, thus minimize the MAI. The results show that at a bit error rate (BER) of 10-9, the system has the ability to perform at a transmission rate up to 1.2 Gbps. It also offers an excellent degree of mobility at all positions within the room at a data rate of 622 Mbps.

Measurement of High Speed Polarization Change of Optical Signal through an OPGW Caused by Serge Current

2016 ◽  
Vol 136 (7) ◽  
pp. 887-892
Author(s):  
Ikuo Yamashita ◽  
Shun Morimura ◽  
Hitoshi Murai ◽  
Osamu Ogawa ◽  
Masahiro Kurono
Keyword(s):  
High Speed ◽  
Optical Signal ◽  
Polarization Change

An all optical photonic crystal half adder suitable for optical processing applications

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hamed Azhdari ◽  
Sahel Javahernia
Keyword(s):  
Photonic Crystal ◽  
Optical Waveguides ◽  
High Speed ◽  
Building Blocks ◽  
Optical Signal ◽  
Ring Resonators ◽  
Optical Processing ◽  
Nonlinear Photonic Crystal ◽  
Half Adder ◽  
All Optical

Abstract Increasing the speed of operation in all optical signal processing is very important. For reaching this goal one needs high speed optical devices. Optical half adders are one of the important building blocks required in optical processing. In this paper an optical half adder was proposed by combining nonlinear photonic crystal ring resonators with optical waveguides. Finite difference time domain method wase used for simulating the final structure. The simulation results confirmed that the rise time for the proposed structure is about 1 ps.

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