scholarly journals Investigation of Jervol Water Types Properties Effects on Underwater Optical Wireless OCDMA System Performances for Different Modulation Techniques

2021 ◽  
Author(s):  
Chahinaz Kandouci
Keyword(s):  
Inclination Angle ◽  
Cross Correlation ◽  
Direct Detection ◽  
Optical Channel ◽  
Transmitted Power ◽  
Analytical Evaluation ◽  
Optical Wireless ◽  
Water Types ◽  
Modulation Techniques ◽  
Simulation Parameters

Abstract In this paper, an analytical evaluation of direct detection OCDMA system using zero cross correlation codes is presented in an underwater wireless optical channel (UWOC). Performances were evaluated by varying the main simulation parameters (range,transmitted power,number of users and inclination angle) considering different modulation techniques for different water types (categorized according to Jerlov classification).

scholarly journals Dual-Branch Pre-Distorted Enhanced ADO-OFDM for Full-Duplex Underwater Optical Wireless Communication System

Photonics ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 368
Author(s):  
Zixian Wei ◽  
Yibin Li ◽  
Zhaoming Wang ◽  
Junbin Fang ◽  
Hongyan Fu
Keyword(s):  
Wireless Communication ◽  
Spectral Efficiency ◽  
Orthogonal Frequency Division Multiplexing ◽  
Channel Model ◽  
Full Duplex ◽  
Optical Channel ◽  
Optical Wireless Communication ◽  
Optical Wireless ◽  
Hardware Complexity ◽  
Double Gamma Function

In this paper, dual-branch pre-distorted enhanced asymmetrically clipped direct current (DC) biased optical orthogonal frequency division multiplexing (PEADO-OFDM) for underwater optical wireless communication (UOWC) is firstly proposed and simulated. The performances of PEADO-OFDM on the underwater optical channel model (UOCM) are analyzed and further compared with the typical ADO-OFDM. Using the Monte Carlo method for the modeling of UOCM, we adopt a double-gamma function to represent three different water qualities including clear, coastal and harbor waters. The full-duplex architecture enables the removal of Hermitian symmetry (HS) from conventional optical OFDM and can increase the spectral efficiency at the cost of hardware complexity. A new PEADO-OFDM transmitter is also proposed to reduce the complexity of the transmitter. The simulation results exhibit that our proposed dual-branch PEADO-OFDM scheme outperforms the typical ADO-OFDM scheme in spectral efficiency, bit error rate (BER) and stability over the underwater channels of three different water qualities.

Analytical Evaluation of Switching Characteristics in Five-Phase Drives with Discontinuous Space Vector Pulse Width Modulation Techniques

EPE Journal ◽  
2013 ◽  
Vol 23 (2) ◽  
pp. 24-33 ◽  
Author(s):  
Joel Prieto ◽  
Federico Barrero ◽  
Sergio Toral ◽  
Emil Levi ◽  
Martin Jones ◽  
...  
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Analytical Evaluation ◽  
Space Vector ◽  
Modulation Techniques ◽  
Switching Characteristics

New Optical Codes Based on Construction of Parity Check Matrix of LDPC Codes

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohammed Amine Tehami ◽  
Chahinaz Kandouci ◽  
Ali Djebbari
Keyword(s):  
Code Division Multiple Access ◽  
Cross Correlation ◽  
Direct Detection ◽  
Ldpc Codes ◽  
Parity Check ◽  
Parity Check Matrix ◽  
Check Matrix ◽  
Eye Pattern ◽  
Balanced Detection ◽  
Code Division Multiple

AbstractIn this paper, new spectral optical codes based on the construction parity check matrix of LDPC codes were designed and implemented in an optical code-division multiple access communication system. Two types optical family codes can be obtained with respectively a cross correlation of {\lambda _c} = 0 and {\lambda _c} = 1. In each case, the codes can either be decoded using the direct detection or the balanced detection. Performance was evaluated by referring to the Q factor, the bit error rate and the eye pattern diagrams using Optisystem 9.0.

scholarly journals Signal Intensity Estimation in Transdermal Optical Wireless Links with Stochastic Pointing Errors Effect

Technologies ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 60
Author(s):  
George K. Varotsos ◽  
Hector E. Nistazakis ◽  
Konstantinos Aidinis ◽  
Fadi Jaber ◽  
K. K. Mujeeb Rahman
Keyword(s):  
Signal Intensity ◽  
High Speed ◽  
Direct Detection ◽  
Minimum Mean Square Error ◽  
Path Loss ◽  
Optical Signal ◽  
Photon Absorption ◽  
Optical Wireless ◽  
Detection Scheme ◽  
Pointing Errors

Transdermal optical wireless (TOW) communication links have recently gained particular research and commercial attention as a viable alternative for establishing high speed and effective implantable data transmissions, which is vital for a variety of neuroprosthetic and other medical applications. However, the development of this optical telemetry modality with medical implanted devices (IMDs) is adversely affected by skin-induced photon absorption, scattering and pointing errors effects. Thus, in this work a minimum mean-square error (MMSE) criterion is proposed for the estimation of the optical signal intensity in a typical TOW link of varying path loss and misalignment-induced fading characteristics. In this context, the stochastic nature of the transmitter–receiver misalignment has been considered and jointly modeled with transdermal path loss. Additionally, the link is assumed to employ the suitable On–Off Keying (OOK) with intensity modulation and direct detection scheme as well as a PIN photodiode at the receiver side for signal detection. Under these assumptions the results demonstrate that the stochastic amount of pointing mismatch strongly affects the received irradiance estimation.

scholarly journals Layered ACO-OFDM for intensity-modulated direct-detection optical wireless transmission

2015 ◽  
Vol 23 (9) ◽  
pp. 12382 ◽  
Author(s):  
Qi Wang ◽  
Chen Qian ◽  
Xuhan Guo ◽  
Zhaocheng Wang ◽  
David G. Cunningham ◽  
...  
Keyword(s):  
Direct Detection ◽  
Wireless Transmission ◽  
Optical Wireless ◽  
Intensity Modulated
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