scholarly journals Transmitting audio via fiber optics under nonlinear effects and optimized tuning parameters based on Co-simulation of matlab and optisystemTM

2020 ◽  
Vol 10 (3) ◽  
pp. 3253
Author(s):  
Abdulrasul A. Al-Hayder ◽  
H. J. Abd ◽  
Ahmed Samawi Alkhafaji
Keyword(s):  
Fiber Optics ◽  
Fiber Optic ◽  
Power Level ◽  
Audio Signal ◽  
Nonlinear Effects ◽  
Q Factor ◽  
Very High Frequency ◽  
Eye Diagram ◽  
Received Power ◽  
Modulation Signal

Limitations of conventional wires such as copper wires are causing dispersion and distortion of the message signal for long distances communication especially for the wide bandwidths. The ability of fiber optic to overcome this problem is making it a dominant transmission medium. Despite of this major positive attribute of optic fibers, there is still a downside for using the fiber optic communication; that is the nonlinearity problem especially at the very high frequency bandwidth. For the first time, a desigen of an audio signal is suggested and executed in MatLab with an integration with OptiSystemTM software to discuss and solve this issu. The audio signal is then transmitted in different shapes of modulation signals (NRZ, RZ & RC) for different distances (100 km & 75 km) via a fiber optic media to be received in a receiving part of the simulated system. Three tests are used to do so. The first is the Quality-factor (Q-Factor) against the received power, second test is eye diagram performance and finally is the measuring of the amplitude of output (received) signal for each modulation signal shape using the Oscilloscope Visualizer. The NZR modulation signal was found to be the best one of the three used signals’ types in all three tests. The Q-factor for NRZ pulse shape (=12) was higher than that for RZ (=10) and RC (=8) for a 100 km distance at the same received power level.

scholarly journals Advanced modulation coding schemes for an optical transceiver systems–based OWC communication channel model

2021 ◽  
Vol 10 (2) ◽  
pp. 767-775
Author(s):  
Hazem M. El-Hageen ◽  
Aadel M. Alatwi ◽  
Ahmed Nabih Zaki Rashed
Keyword(s):  
Communication Channel ◽  
Channel Model ◽  
Power Level ◽  
Q Factor ◽  
Code Scheme ◽  
Optical Wireless ◽  
Coding Schemes ◽  
Modulation Coding ◽  
Received Power ◽  
Modulation Code

This paper examines advanced modulation coding schemes for an optical transceiver systems–based optical wireless communication (OWC) channel model. These modulation techniquesinclude On-Off keying and return to zero (RZ)/non–return to zero (NRZ) coding. The signal power level against time and frequency spectral variations are measured. The max. Q factor and min. bit error rate (BER) are estimated and clarified for each modulation code scheme by using an optisystem simulation model. Transmission bit rates of up to 40 Gb/s can be achieved for possible distances up to 500 km with acceptable Q factor. The received power and max. Q factor are measured and clarified with OWC distance variations. The On-Off keying modulation code scheme resulted in better performance than the other modulation code schemes did.

scholarly journals Performance Analysis of a Free Space Optics Link with Multiple Transmitters/Receivers

2012 ◽  
Vol 13 (1) ◽  
Author(s):  
Nur Haedzerin Md Noor ◽  
Ahmed Wathik Naji ◽  
Wajdi Al-Khateeb
Keyword(s):  
Bit Error Rate ◽  
Error Rate ◽  
Free Space ◽  
Communication Systems ◽  
Theoretical Calculations ◽  
Power Level ◽  
Free Space Optics ◽  
Eye Diagram ◽  
Space Optics ◽  
Received Power

ABSTRACT:  Multiple transmitters/receivers (TX/RX) are used to improve the quality of Free Space Optics (FSO) communication systems. With the current needs of this technology for longer distance communication, the qualitative analysis of the system has become essential. In this work, the received power level (PR) and bit error rate (BER) are considered to influence the FSO link performance. The relationship between the two parameters are investigated and analysed. Furthermore, the received power for various numbers of TXs and RXs are experimentally measured and compared with the values obtained from theoretical calculations. The first part of the work deals with the theoretical calculation and simulation designs of multiple laser beams based on the commercial FSO used in actual sites. The second part describes the practical work and analysis of the system’s performance.ABSTRAK: Pemancar/penerima berganda (TX/RX) digunakan bagi meningkatkan kualiti sistem komunikasi Ruang Optik Bebas (FSO). Analisis kualitatif ke atas sistemnya adalah penting bagi keperluan semasa teknologi ini untuk jarak jauh. Di dalam kajian ini, aras kuasa penerima (PR) dan kadar ralat bit (BER) telah diambilkira bagi menentukan prestasi rangkaian FSO. Hubungan di antara kedua-dua parameter telah dikaji dan dianalisis. Seterusnya, kuasa penerima untuk pelbagai nombor TXs dan RXs diukur secara eksperimen dan dibandingkan dengan nilai teori yang dikira. Bahagian pertama skop kajian berkaitan dengan pengiraan teori dan rekabentuk simulasi sinaran laser berdasarkan FSO komersial di lapangan. Bahagian kedua kajian adalah kerja lapangan dan analisis prestasi sistem.KEY WORDS:  Free Space Optics (FSO) link; Multiple TX/RX FSO; bit error rate (BER); eye diagram.

scholarly journals Fiber Optic Sensing Technologies for Battery Management Systems and Energy Storage Applications

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1397
Author(s):  
Yang-Duan Su ◽  
Yuliya Preger ◽  
Hannah Burroughs ◽  
Chenhu Sun ◽  
Paul Ohodnicki
Keyword(s):  
Energy Storage ◽  
Fiber Optics ◽  
Fiber Optic ◽  
Gas Sensing ◽  
Fiber Optic Sensors ◽  
Management Systems ◽  
Practical Implementation ◽  
Battery Management ◽  
Battery Management Systems ◽  
Battery Systems

Applications of fiber optic sensors to battery monitoring have been increasing due to the growing need of enhanced battery management systems with accurate state estimations. The goal of this review is to discuss the advancements enabling the practical implementation of battery internal parameter measurements including local temperature, strain, pressure, and refractive index for general operation, as well as the external measurements such as temperature gradients and vent gas sensing for thermal runaway imminent detection. A reasonable matching is discussed between fiber optic sensors of different range capabilities with battery systems of three levels of scales, namely electric vehicle and heavy-duty electric truck battery packs, and grid-scale battery systems. The advantages of fiber optic sensors over electrical sensors are discussed, while electrochemical stability issues of fiber-implanted batteries are critically assessed. This review also includes the estimated sensing system costs for typical fiber optic sensors and identifies the high interrogation cost as one of the limitations in their practical deployment into batteries. Finally, future perspectives are considered in the implementation of fiber optics into high-value battery applications such as grid-scale energy storage fault detection and prediction systems.

scholarly journals An Indoor Visible Light Positioning System Using Tilted LEDs with High Accuracy

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 920
Author(s):  
Neha Chaudhary ◽  
Othman Isam Younus ◽  
Luis Nero Alves ◽  
Zabih Ghassemlooy ◽  
Stanislav Zvanovec ◽  
...  
Keyword(s):  
Visible Light ◽  
Polynomial Regression ◽  
Power Level ◽  
Least Square ◽  
Line Of Sight ◽  
Received Power ◽  
Strength Based ◽  
Complex Linear ◽  
Linear Least Square ◽  
First Time

The accuracy of the received signal strength-based visible light positioning (VLP) system in indoor applications is constrained by the tilt angles of transmitters (Txs) and receivers as well as multipath reflections. In this paper, for the first time, we show that tilting the Tx can be beneficial in VLP systems considering both line of sight (LoS) and non-line of sight transmission paths. With the Txs oriented towards the center of the receiving plane (i.e., the pointing center F), the received power level is maximized due to the LoS components on F. We also show that the proposed scheme offers a significant accuracy improvement of up to ~66% compared with a typical non-tilted Tx VLP at a dedicated location within a room using a low complex linear least square algorithm with polynomial regression. The effect of tilting the Tx on the lighting uniformity is also investigated and results proved that the uniformity achieved complies with the European Standard EN 12464-1. Furthermore, we show that the accuracy of VLP can be further enhanced with a minimum positioning error of 8 mm by changing the height of F.

Performance Enhancement of Encoding–Decoding Multidiagonal and Walsh Hadamard Codes for Spectral Amplitude Coding-Optical Code Division Multiple Access (SAC-OCDMA) Utilizing Dispersion Compensated Fiber

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Majidah H. Majeed ◽  
Riyadh Khlf Ahmed
Keyword(s):  
Multiple Access ◽  
Performance Enhancement ◽  
Optical Network ◽  
Spectral Amplitude ◽  
Q Factor ◽  
Data Traffic ◽  
Eye Diagram ◽  
Multiple User ◽  
Spectral Amplitude Coding ◽  
Code Division Multiple

AbstractSpectral Amplitude Coding-Optical Codes Division Multiple Access (SAC-OCDMA) is a future multiplexing technique that witnessed a dramatic attraction for eliminating the problems of the internet in optical network field such as multiple-user access and speed’s growth of the files or data traffic. In this research article, the performance of SAC-OCDMA system based on two encoding–decoding multidiagonal (MD) and Walsh Hadamard (WH) codes is enhanced utilizing three different schemes of dispersion compensating fiber (DCF): pre-, post- and symmetrical compensation. The system is simulated using Optisystem version 7.0 and Optigrating version 4.2. The performance of the proposed system is specified in terms of bit error rate (BER), Q-factor and eye diagram. It has been observed that the compensated system based on MD code is performs much better compared to the system based on WH code. On the other hand, the compensated SAC-OCDMA system with symmetrical DCF has the lowest values of BER and largest values of Q-factor, so it is considered the best simulated scheme contrasted with pre- and post-DCF.

scholarly journals Microanchored borehole fiber optics allows strain profiling of the shallow subsurface

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cheng-Cheng Zhang ◽  
Bin Shi ◽  
Song Zhang ◽  
Kai Gu ◽  
Su-Ping Liu ◽  
...  
Keyword(s):  
Fiber Optics ◽  
Field Experiments ◽  
Fiber Optic ◽  
Strain Sensing ◽  
Near Surface ◽  
Shallow Subsurface ◽  
Buried Cables ◽  
Capacity Theory ◽  
Confining Pressures ◽  
Strain Determination

AbstractVertical deformation profiles of subterranean geological formations are conventionally measured by borehole extensometry. Distributed strain sensing (DSS) paired with fiber-optic cables installed in the ground opens up possibilities for acquiring high-resolution static and quasistatic strain profiles of deforming strata, but it is currently limited by reduced data quality due to complicated patterns of interaction between the buried cables and their surroundings, especially in upper soil layers under low confining pressures. Extending recent DSS studies, we present an improved approach using microanchored fiber-optic cables—designed to optimize ground-to-cable coupling at the near surface—for strain determination along entire lengths of vertical boreholes. We proposed a novel criterion for soil–cable coupling evaluation based on the geotechnical bearing capacity theory. We applied this enhanced methodology to monitor groundwater-related vertical motions in both laboratory and field experiments. Corroborating extensometer recordings, acquired simultaneously, validated fiber optically determined displacements, suggesting microanchored DSS as an improved means for detecting and monitoring shallow subsurface strain profiles.

scholarly journals A study about signal variation with minor receiver displacement in a meeting room at 60 GHz: measurements and simulations

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Muhammad Usman Sheikh ◽  
Kalle Ruttik ◽  
Riku Jäntti ◽  
Jyri Hämäläinen
Keyword(s):  
Power Level ◽  
Three Dimensional ◽  
60 Ghz ◽  
System Configuration ◽  
Conference Room ◽  
Channel Characteristics ◽  
Received Power ◽  
Simulation Results ◽  
Small Change ◽  
The Impact

AbstractThe aim of this work is to study the impact of small receiver displacement on a signal propagation in a typical conference room environment at a millimeter wave frequency of 60 GHz. While channel measurements provide insights on the propagation phenomena, their use for the wireless system performance evaluation is challenging. Whereas, carefully executed three-dimensional ray tracing (RT) simulations represent a more flexible option. Nevertheless, a careful validation of simulation methodology is needed. The first target of this article is to highlight the benefits of an in-house built three-dimensional RT tool at 60 GHz and shows the effectiveness of simulations in predicting different characteristics of the channel. To validate the simulation results against the measurements, two different transmitter (Tx) positions and antenna types along with ten receiver (Rx) positions are considered in a typical conference room. In first system configuration, an omnidirectional antenna is placed in the middle of the table, while in the second system configuration a directed horn antenna is located in the corner of the meeting room. After validating the simulation results with the measurement data, in the second part of this work, the impact of a small change, i.e., 20 cm in the receiver position, is studied. To characterize the impact, we apply as performance indicators the received power level, root mean square delay spread (RMS-DS) and RMS angular spread (RMS-AS) in azimuth plane. The channel characteristics are considered with respect to the direct orientation (DO), i.e., the Rx antenna is directed toward the strongest incoming path. Different antenna configurations at the Tx and Rx side are applied to highlight the role of antenna properties on the considered channel characteristics. Especially, in the second system configuration the impact of different antenna half power beamwidth on different considered channel characteristics is highlighted through acquired simulation results. The validation of results shows the RMS error of only 2–3 dB between the measured and simulated received power levels for different Tx configurations in the direction of DO. Results indicate that only a small change of the Rx position may result a large difference in the received power level even in the presence of line-of-sight between the Tx and Rx. It is found that the STD of received power level across the room increases with the decrease in HPBW of the antenna. As can be expected, directed antennas offer lower value of RMS-DS and RMS-AS compared with isotropic antenna.

Fiber-optic transmission catheter for regional venous oxygen saturation and blood flow

1992 ◽  
Vol 72 (4) ◽  
pp. 1616-1621 ◽  
Author(s):  
H. Iwasaki ◽  
K. Yoshizaki ◽  
H. Koyano
Keyword(s):  
Blood Flow ◽  
Oxygen Saturation ◽  
Fiber Optics ◽  
Fiber Optic ◽  
Supply And Demand ◽  
Flow Measurements ◽  
Face To Face ◽  
Flexible Polymer ◽  
Venous Oxygen Saturation ◽  
The Face

We have developed a method for monitoring regional venous oxygen saturation. The key feature of this system is the use of highly flexible polymer fiber optics, and this flexibility allowed the production of a new fiber-optic transmission catheter. The space between the “face-to-face” positioned fiber-optic tips forms a remote catheter-based transmission cell. Our method applies Twersky's theory, in which absorption and scattering can be treated independently. Fresh rabbit blood was pumped through a disk oxygenator in which gas exchange occurred and passed the catheter. Simultaneous results obtained by the catheter and a cuvette oximeter were excellent (r = 0.99, SD = 1.1%). Oxygen saturation measured by this catheter was independent of vessel wall artifacts, blood pH, and flow velocity. Another application of this method is measurement of blood flow by the dye- (indocyanine green) dilution technique. The results of flow measurements by the catheter appeared to be satisfactory (r = 0.99, SD = 1.7%). This study concludes that our method is effective for monitoring the balance between regional oxygen supply and demand.

scholarly journals Pendulum-Type Hetero-Core Fiber Optic Accelerometer for Low-Frequency Vibration Monitoring

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2528 ◽  
Author(s):  
Hiroshi Yamazaki ◽  
Ichiro Kurose ◽  
Michiko Nishiyama ◽  
Kazuhiro Watanabe
Keyword(s):  
Fiber Optics ◽  
Electromagnetic Interference ◽  
Large Scale ◽  
Fiber Optic ◽  
Low Frequency ◽  
Fiber Optic Sensor ◽  
Vibration Monitoring ◽  
Vibration Measurement ◽  
Displacement Sensor ◽  
Core Fiber

In this paper, a novel pendulum-type accelerometer based on hetero-core fiber optics has been proposed for structural health monitoring targeting large-scale civil infrastructures. Vibration measurement is a non-destructive method for diagnosing the failure of structures by assessing natural frequencies and other vibration patterns. The hetero-core fiber optic sensor utilized in the proposed accelerometer can serve as a displacement sensor with robustness to temperature changes, in addition to immunity to electromagnetic interference and chemical corrosions. Thus, the hetero-core sensor inside the accelerometer measures applied acceleration by detecting the rotation of an internal pendulum. A series of experiments showed that the hetero-core fiber sensor linearly responded to the rotation angle of the pendulum ranging within (−6°, 4°), and furthermore the proposed accelerometer could reproduce the waveform of input vibration in a frequency band of several Hz order.

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