Duong Huu Ai

University of Danang

The continuous development of Internet of things (IoT) technology enables many devices to be interconnected through the external environment. Meanwhile, 5G technology provides an enhanced quality of services with high data transmission rates, requiring IoT implementation in the 5G architecture. Free space optical communication (FSO) is considered a...

Although AlGaN/GaN high electron mobility transistor (HEMT) has been attracted great attention due to its wide bandgap energy of 3.4 eV, high breakdown electric field of 3 MV/cm, superior thermal properties, and high electron mobility, very little was reported for the effect of insulator dielectric passivation layer on the breakdown voltage (Vbr) o...

The InGaP/GaAs heterojunction phototransistor (HPT) and GaAs solar cell were monolithically integrated on an HPT epitaxial wafer, and the battery-free operation of the photosensor was successfully demonstrated for energy harvestingand its measured electrical characteristics are consistent with simulation results. Radiation hardness of the energy-ha...

This paper presents performance bounds of amplify-and-forward (AF) relay-assisted free-space optical (FSO) communication systems employing subcarrier quadrature amplitude modulation (SC-QAM) signal over gamma-gamma distributed atmospheric turbulence channels and pointing errors. An analytical expression is derived to evaluate the average symbol err...

This paper presents the theoretical analysis of pointing error effects on the average channel capacity performance of amplify-and-forward (AF) relay-assisted free-space optical (FSO) systems employing subcarrier quadrature amplitude modulation (SC-QAM) signal over log-normal distributed atmospheric turbulence channels. The average channel capacity...

Công nghệ kết nối vạn vật (Internet of things – IoT) ngày càng phát triển không ngừng, cho phép nhiều thiết bị có thể kết nối với nhau thông qua môi trường bên ngoài. Trong khi đó, công nghệ 5G cung cấp những dịch vụ có chất lượng nâng cao với tốc độ truyền dữ liệu cao, đòi hỏi phải khai triển IoT trong kiến trúc 5G. Truyền thông quang trong không...

In this work, we analyse pointing error effects on the performance of amplify-and-forward (AF) relaying multiple-input multiple-output (MIMO) free-space optical (FSO) communication system employing sub-carrier quadrature amplitude modulation (SC-QAM) signal over log-normal and gamma-gamma distributed atmospheric turbulence channels. We study the po...

In this paper, we theoretically analyze the performance of amplify-and-forward (AF) serial relaying free-space optical (FSO) systems using avalanche photodiodes (APD) and subcarrier quadrature amplitude modulation (SC-QAM) over strong atmospheric turbulence channels modelled by gamma-gamma distribution. Closed-form expression for average bit error...

In amplify-and-forward (AF) relay channel, when the direct link between source and destination terminals is deeply faded, the signal from the source terminal to the destination terminal propagates through the relay terminals, each of which relays a signal received from the previous terminal to the next terminal in series. This paper, we theoretical...

In amplify-and-forward (AF) relay channel, when the direct link between source and destination terminals is deeply faded, the signal from the source terminal to the destination terminal propagates through the relay terminals, each of which relays a signal received from the previous terminal to the next terminal in series. This paper, we theoretical...

With the FSO system combining the relay stations, performance evaluation parameters of system such as average symbol error rate (ASER), average channel capacity (ACC) has been introduced in a number of recent studies. Several formulas performance analysis of Amplify-and-Forward Relaying FSO/SC-QAM, with channel model: Log-Normal and Gamma-Gamma, Co...

In an amplify-and-forward (AF) relaying channel, the signal from source node travels to destination node through a number of relaying nodes, in which each node forwards the received signal from the previous node to the next node. In this paper, we mathematically analyze the channel capacity of AF free-space optical (FSO) systems over atmospheric tu...

This paper presents the theoretical analysis of average channel capacity performance of amplify-and-forward (AF) multiple-input multiple-output (MIMO) free-space optical (FSO) systems over atmospheric turbulence channels and misalignment fading. The AF - MIMO/FSO average channel capacity (ACC), which is expressed in terms of average spectral effici...

This paper presents the theoretical analysis of misalignment fading effects on performance of free-space optical (FSO) communication system based on Amplify-and-Forward (AF) relaying technology. This system uses subcarrier quadrature amplitude modulation (SC-QAM) over weak atmospheric turbulence modelled by Log-Normal distribution. The misalignment...

Basically, Free-space Optical communication channel is subjected to atmospheric attenuation, atmospheric turbulence and misalignment fading. Among these parameters, the atmospheric turbulence caused critical impact to the operation of free-space optical communication because of its randomness and uncertainty. In order to determine the level of turb...

In this paper, the performance of amplify-and-forward (AF) relay-assisted multiple-input multiple-output free-space optical communication (MIMO/FSO) systems using sub-carrier intensity quadrature amplitude modulation (QAM) over Gamma-Gamma fading channels, which is represented for the case of strong atmospheric turbulence region, is studied. More s...

This paper presents the theoretical analysis of the average symbol error rate (ASER) of Amplify-and-Forward (AF) relaying multiple-input multiple-output (MIMO) free space optical (FSO) communication system employing subcarrier quadrature amplitude modulation (SC-QAM) signal over strong atmospheric turbulence, which is modeled by Gamma-Gamma distrib...

In this work, we analyze pointing error effects on performance of Amplify-and-Forward (AF) relaying multiple-input multiple-output (MIMO) free space optical (FSO) communication system employing subcarrier quadrature amplitude modulation (SC-QAM) signal over log-normal distributed atmospheric turbulence channels. We study the pointing error effect b...

This paper gives an analyze the performance of Amplify-and-Forward (AF) relaying multiple-input multiple-output (MIMO) free space optical (FSO) communication system employing subcarrier quadrature amplitude modulation (SC-QAM) signal over atmospheric turbulence channels. The system's average symbol error rate (ASER) is derived, taking into account...

In this paper, we theoretically analyze the performance of multiple-input multiple-output (MIMO) free-space optical (FSO) systems. The MIMO/FSO average channel capacity (ACC), which is expressed in terms of average spectral efficiency (ASE) is derived taking into account the atmospheric turbulence effects on the MIMO/FSO channel. They are modeled b...

This paper presents theoretically performance of free-space optical (FSO) communication system combining with Amplify-and-Forward (AF) relaying multiple-input multiple-output (MIMO) technology. This system uses subcarrier quadrature amplitude modulation (SC-QAM) over weak atmospheric turbulence channels modelled by log-normal distribution. Unlike p...

This paper introduce our research about average symbol error rate (ASER) and performance evaluation of FSO/SC-QAM system. We theoretically analyze the performance of the free-space optical (FSO) communication systems using subcarrier intensity quadrature amplitude modulation (SC-QAM) over atmospheric turbulence channels in the presence of pointing...