Improving the Bit Error Rate Performance of Free Space Optical Communication due to Atmospheric Turbulence Effect using New Double Multiple-Input Multiple-Output Technique

This paper focus on mitigating the atmospheric turbulence effect in free space optical (FSO) communications by using double multiple input multiple output (DMIMO)technique. This technique is an enhancement of the conventional multiple input multiple output (MIMO) technique in improving the performance of FSO system. The combination of double MIMO with differential detection mode at the receiver resulting in superior modulation against the turbulence especially in reducing the scintillation index, enhance the power received and improve the threshold signal level. The analysis result shows that under strong turbulence conditions, the bit error rate can be improved by 20 percent in terms of free space optical distance propagation

The analysis of soft error in c-elements

Soft errors are a serious concern in state holders as it can cause temporarily malfunction of the circuit. C-element is one of the state holders that is used widely in the asynchronous circuit. In this paper, the investigation will focus on the vulnerability of two types of C-element towards soft errors. A framework has been proposed for the rate of error due to neutron spectrum energy that can cause failure in the state holder. Effective analysis has been conducted on two different C-elements at different nodes by using UMC90 nm technology and 180nm technology. Based on the vulnerability data, a method for assessing vulnerability on a different implementation of C-elements has been developed. From the obtained data, it can be concluded that SIL is more resistant towards soft errors. © 2018 Institute of Advanced Engineering and Science. All rights reserved

Subtraction dual-wavelength for enhanced transmission performance of free-space optical communication over turbulence effect

Performance of a free-space optical communication system is influenced by atmospheric turbulence which degrades signal transmission quality. A gamma–gamma channel model is employed to characterise this turbulence under weak-to-strong conditions. The proposed dual diffuser modulation using subtraction dual-wavelength concept is combined with a phase screen diffuser to improve signal transmission. Its performances are compared with conventional intensity modulationdirect detection on off keying and partial coherent beam on off keying techniques. In comparison, results show that the dual diffuser modulation demonstrates superior performances in both received power and bit rate transmission under different turbulence conditions

Impact of Rain Attenuation in Borneo using Free Space Optics Propagation

In recent years, Free Space Optics (FSO) communication provides attractive bandwidth enhancement with unlicensed bands worldwide spectrum. However, the link capacity and availability are the major concern in the different atmospheric conditions. The reliability of the link is highly dependent on weather conditions that attenuate the signal strength. In the tropical region specifically in Borneo Sarawak, rain is the dominant weather that act as the limiting factor to FSO performance. Hence, this study highlights on the impact of rain attenuation to the performance of FSO communication system. The finding is based on atmospheric model and performed through the simulation of OptiSystem software. The design of parameters in the simulation involves iteration of wavelengths, size of transmitter and receiver aperture and beam divergence angle. The simulation result shows longer wavelength 1550nm is much better than 785nm. The 0.25m of receiver aperture and transmitter aperture at 0.05m can reduce the loss. Narrow beam divergence angle can reduce the power consumption and maintain the high power at receiver. The analysis indicates that proposed FSO communication system is capable to withstand the attenuation from rain weather

Wearable Coaching System

Wearable Coaching System is a multi-sensor device for real-time training coaching. The system comprises of six modules which are shoulder, waist, a pair of wrist and a pair of ankle modules. It is compact, light, comfortable to wear and is suitable for any size of user. It system has five main embedded sensors: heart rate, three-axis acceleration, gyro, temperature and blood oxygen saturation (SpO2) sensor. It operates in streaming mode for real-time data processing using two telecommunication tools: Zigbee and Bluetooth and low energy interface for recording mode is using an internal flash memory. In this paper, a wearable coaching system is designed to help athlete or trainer to perform proper and efficient exercise suitable to one’s body needs. It measures the parameter of the body, analyze and provide feedback in a form of an advice. In order to improve the system, arm gesture mode performed by the wrist modules of the system is applied. This mode is to enable user to manage their exercising level to a more appropriate pace, suitable with their individual body by reproducing the feedback. In a supervised coaching training, percentage of heart rate threshold target is increasing, hence, producing a greater performance of training. It is proven in this paper, that wearable coaching system performs an accurate measurement in enhancing sports and coaching training, adding value to novel lifestyle exercising and health monitoring

Performance Analysis of Double-MIMO Free Space Optical System under Atmospheric Turbulence

Over the last few years, free space optical communication (FSO) has emerged as a viable alternative to radio frequency communication. It provides a promising high-speed point�to-point communication solution. However, atmospheric absorption, scattering and turbulence degrade wireless optical communication significantly, lowering device efficiency. The attenuation of signals due to the above atmospheric reasons is another major factor that affects device efficiency. The atmospheric turbulence conditions are observed implemented into different models of FSO systems, such as Single Input Single Output (SISO), Multiple Input Multiple Output (MIMO), Wavelength Division Multiplexing MIMO (WDM-MIMO) and proposed model Double Multiple Input Multiple Output (DMIMO) using the Gamma-Gamma model for a variety of reasons. The OptiSystem 7.0 software was used to run simulations to study how various weather conditions (clear, haze and fog) affected the performance of the channel. Simulation results show that implementing Double Multiple Input Multiple Output (DMIMO) techniques for FSO systems provides high quality factor for various ranges while still achieving accurate transmitted data at the receiver side. In the presence of atmospheric turbulence conditions such as clear air, haze and fog, performance improvements signal power levels, quality factor and link distance range have been demonstrated

Investigation to Reduce Flux Variance Effects Using Partial Coherent Beam in Free Space Optical Communication

This paper focus on the employment of partial coherent beam (PCB) in free space optical communication to reduce the flux variance effects in the system. The implementation of PCB in the free space optical system is significantly able to reduce the flux variance effect. The reduction of the flux variance effect by using PCB in free space optical communication by using Gamma-Gamma distribution is presented in this paper. The analysis result shows that the FSO system with PCB have an improved in performance compares with FSO system without PCB implemented on it as it capable to decrease the flux variance and scintillation index. This can help FSO system to encounter with severe turbulence effect for optimum operation

Wearable Coaching System

Wearable Coaching System is a multi-sensor device for real-time training coaching. The system comprises of six modules which are shoulder, waist, a pair of wrist and a pair of ankle modules. It is compact, light, comfortable to wear and is suitable for any size of user. Itsystem has five main embedded sensors: heart rate, three-axis acceleration, gyro, temperature and blood oxygen saturation (SpO2) sensor. It operates in streaming mode for real-time data processing using two telecommunication tools: ZigBee and Bluetooth and low energy interface for recording mode is using an internal flash memory. In this paper, a wearable coaching system is designed to help athlete or trainer to perform proper and efficient exercise suitable to one’s body needs. It measures the parameter of the body, analyze and provide feedback in a form of an advice. In order to improve the system, arm gesture mode performed by the wrist modules of the system is applied. This mode is to enable user to manage their exercising level to a more appropriate pace, suitable with their individual body by reproducing the feedback. In a supervised coaching training, percentage of heart rate threshold target is increasing, hence, producing a greater performance of training. It is proven in this paper, that wearable coaching system performs an accurate measurement in enhancing sports and coaching training, adding value to novel lifestyle exercising and health monitoring

A Compact Antenna Design for Fifth Generation Wireless Communication System

This paper proposes a compact antenna design for wireless communication system that can operate at dual band frequencies which are 24.25 GHz and 38 GHz. The antenna with an overall size of 6.3 mm X 6.0 mm is printed on RogersRT5880 type of substrate with a thickness of 0.787 mm. The simulated reflection coefficient result is < -10 dB for both frequencies which makes it suitable for 5G applications. The proposed antenna has a stable gain value of 7.23 dBi at 24.25 GHz and 3.69 dBi at 38 GHz. All the simulation result was performed by using CST Microwave Studio Software. The result shows the feasibility of this antenna to be applied for future 5G application. © The Authors, published by EDP Sciences, 2017

Comparison of wavelength propagation for free space optical communications

This paper presents the effect of atmospheric attenuation during severe hazy days for Free Space Optical Communications. The usage of Free Space Optical Communications is still rare in Malaysia due to environment factor. The FSO technology is also known as unguided beam or ‘optical wireless’ or infrared broadband. This study offers quick preliminary investigation on possible FSO performance based on wavelength selection before final commissioning and installation at site. Thus, FSO installers could make quick judgment before giving recommendation of a suitable wavelength to the customers. Preliminary evaluation of system performance of system performance is done by using local weather data obtained from metrological department. Current study among designers and FSO users show that 1550nm light produce less atmospheric attenuation in the transmission under all weather conditions. In this study, a suitable wavelength for FSO system is found for a particular site in low visibility. The best wavelength selection would result in optimized quality of FSO transmission in hazy conditions