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All Journal International Journal of Electrical and Computer Engineering Perfecting a Video Game with Game Metrics Bulletin of Electrical Engineering and Informatics
Miroslav Voznak
VSB-Technical University of Ostrava
Computer Science & IT Electrical & Electronics Engineering

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Wireless power transfer enabled NOMA relay systems: two SIC modes and performance evaluation Dinh-Thuan Do; Chi-Bao Le; Hong-Nhu Nguyen; Tam Nguyen Kieu; Si-Phu Le; Ngoc-Long Nguyen; Nhat-Tien Nguyen; Miroslav Voznak
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 17, No 6: December 2019
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v17i6.12218

Abstract

In this study, we deploy design and performance analysis in new system model using a relaying model, energy harvesting, and non-orthogonal multi-access (NOMA) network. It is called such topology as wireless powered NOMA relaying (WPNR). In the proposed model, NOMA will be investigated in two cases including single successive interference cancellation (SIC) and dual SIC. Moreover, the simultaneous wireless information and power transfer (SWIPT) technology can be employed to feed energy to relays who intend to serve far NOMA users. In particular, exact outage probability expressions are provided to performance evaluation. The results from the simulations are used to demonstrate the outage performance of the proposed model in comparison with the current models and to verify correct of derived expressions.
Influence of Dual-layer and Triple-layer Remote Phosphor Package on Optical Properties of White LEDs Nguyen Thi Phuong Thao; Nguyen Doan Quoc Anh; Kamil Postava; Miroslav Voznak; Phan Xuan Le
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 16, No 5: October 2018
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v16i5.9505

Abstract

In this paper, the influence of the distance between phosphor layers in the dual-layer and triple- layer remote package on luminous flux and color rendering property is presented and analyzed. During the simulation, it is recognized that an appropriate distance can produce higher quality of the multi-chip white LED (MCW-LEDs) through adjusting the distance between two and three phosphor layers. According to the research results, 0.1mm is the outstanding distance between two phosphor layers so that the performance of MCW-LEDs can be accomplished the best optimal effect. In addition, the simulation results show that the dual-layer structure yielded higher optical properties than the triple-layer structure in relation to the distance. The highest lumen output of triple layer-structure can be achieved at the distance of 0.6 mm and dual-layer structure is 0.1 mm. Meanwhile, the color rendering index (CRI) changes insignificantly when the distance increases. Triple layer package is not practical for high power white LEDs due to high cost and low conversion efficiency. Dual-layer remote phosphor package with the distance between two phosphor layers of 0.1mm is an optimal structure of LEDs in improving the luminous efficiency and the color quality.
Considering the κ − µ fading channels adopted in multiple antennas downlink non-orthogonal multiple access Chi- Bao Le; Hong- Nhu Nguyen; Ngoc- Long Nguyen; Miroslav Voznak; Nhan Duc Nguyen
Bulletin of Electrical Engineering and Informatics Vol 11, No 1: February 2022
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/eei.v11i1.3453

Abstract

Massive connectivity and effective spectrum usage have become more important as the use of wireless communication devices and networks has grown dramatically. The approach of non-orthogonal multiple access (NOMA) is advocated as a viable solution for meeting consumers’ current needs. The signals are overlaid with various power levels for each user in a NOMA-assisted system, and then broadcast to the receiver. SIC (successive interference cancellation) is used by the receiver to discriminate and get the needed signal. Until far, most studies have concentrated on SIC with ideal features, with only a handful focusing on SIC with imperfect qualities (ipSIC). While the perfect SIC (pSIC) represents the ideal condition of no data loss and no external sounds, the ipSIC represents data transfer in a real-time context. In this research, we will assess the system performance metrics of the investigated NOMA system in the presence of ipSIC and compare them to the performance of the same user’s pSIC. We define channels as κ−µ fading distributions, which is more essential. For two destinations, we construct accurate outage probability formulas. Meanwhile, Monte-Carlo simulations are run to ensure that the mathematical expressions derived are genuine.
Outage performance analysis of NOMA under fading channels in presence of imperfect SIC Nhat-Tien Nguyen; Hong-Nhu Nguyen; Miroslav Voznak; Le-Chi Bao; Nhan Duc Nguyen
Bulletin of Electrical Engineering and Informatics Vol 11, No 4: August 2022
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/eei.v11i4.3572

Abstract

The introduction of 5th and 6th-generation wireless networks has elevated the demand for huge device connectivity, spectral efficacy, and improved signal quality. The non-orthogonal multiple access technique (NOMA) has been demonstrated to be a candidate to address these requirements. NOMA can assist many users using the same resource block by varying the assigned power levels fairness to the users. To perform this, the NOMA technique superimposes the signals from both the users and transmits them to the receiver. On the receiver side, it performs successive interference cancellation (SIC) techniques to separate the respective signals. Meanwhile, the fading channels also play a major role in deciding the quality of the signal that is being transmitted. In our paper, a NOMA system is considered in presence of two users having  fading channels. The closed-form expressions are derived for outage probability and throughput of the system in presence of perfect SIC and imperfect SIC. The expressions are numerically analyzed by varying various parameters such as fading channels, power level coefficients, and the number of antennas at the receivers. The obtained results demonstrate that each parameter plays a major role in enhancing the quality of each user's signal and the outage performance of the system.
Throughput analysis of non-orthogonal multiple access and orthogonal multiple access assisted wireless energy harvesting K-hop relaying networks Phung Ton That; Nhat-Tien Nguyen; Duy-Hung Ha; Miroslav Voznak
International Journal of Electrical and Computer Engineering (IJECE) Vol 13, No 1: February 2023
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijece.v13i1.pp522-530

Abstract

This study introduces the non-orthogonal multiple access (NOMA) technique into the wireless energy harvesting K-hop relay network to increase throughput. The relays have no dedicated energy source and thus depend on energy harvested by wireless from a power beacon (PB). Recently, NOMA has been promoted as a technology with the potential to enhance connectivity, reduce latency, increase fairness amongst users, and raise spectral effectiveness compared to orthogonal multiple access (OMA) technology. For performance considerations, we derive exact throughput expressions for NOMA and OMA-assisted multi-hop relaying and compare the performance between the two. The obtained results are validated via Monte Carlo simulations.
Enabling unmanned aerial vehicle to serve ground users in downlink NOMA system Nhat-Tien Nguyen; Hong-Nhu Nguyen; Leminh Thien Huynh; Miroslav Voznak
Bulletin of Electrical Engineering and Informatics Vol 11, No 6: December 2022
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/eei.v11i6.3945

Abstract

The emergence of internet-of-things (IoT) devices in homes and industry, has resulted in the current and future generation of wireless communications facing unique challenges in spectral efficiency, energy efficiency, and massive connectivity issues. Non-orthogonal multiple access (NOMA) has been proposed as a viable solution to address these challenges as it offers low-latency, spectral efficiency, and massive connectivity capabilities, which are key requirements in upcoming next-generation networks. In addition, another technology that has emerged as a solution to spectral efficiency and coverage is an unmanned aerial vehicle (UAV). Therefore, the combination of UAVs with NOMA has great potential to minimize the challenges and maximize the benefits. Specifically, we investigate the outage performance of the NOMA-UAV network over Nakagami-m channel fading. To this end, we derive a closed-form outage performance metric. The formulated framework is validated using simulations to verify the effectiveness of the proposed solution.
Secrecy performance analysis on spatial modeling of wireless communications with unmanned aerial vehicle and ground devices Cuu Ho Van; Hong-Nhu Nguyen; Si-Phu Le; Miroslav Voznak
International Journal of Electrical and Computer Engineering (IJECE) Vol 13, No 6: December 2023
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijece.v13i6.pp6410-6418

Abstract

In this paper, the secrecy performance of the spatial modeling for ground devices with randomly placed eavesdroppers when an unmanned aerial vehicle (UAV) acted as two hops decode and forward (DF) was investigated. We characterize the secrecy outage probability (SOP) and intercept probability (IP) expressions. Our capacity performance analysis is based on the Rayleigh fading distributions. After analytical results by Monte Carlo simulation, and the Gauss-Chebyshev parameter was selected to yield a close approximation, the results demonstrate the SOP with the average signal-to-noise ratio (SNR) between UAV and ground users among the eavesdroppers and the IP relationship with the ability to intercept the information of the ground users successfully.
Co-Authors Chi- Bao Le Chi-Bao Le Cuu Ho Van Dinh-Thuan Do Duy-Hung Ha Hong- Nhu Nguyen Hong-Nhu Nguyen Hong-Nhu Nguyen Hong-Nhu Nguyen Kamil Postava Le-Chi Bao Leminh Thien Huynh Ngoc- Long Nguyen Ngoc-Long Nguyen Nguyen Doan Quoc Anh Nguyen Thi Phuong Thao Nhan Duc Nguyen Nhat-Tien Nguyen Nhat-Tien Nguyen Phan Xuan Le Phung Ton That Si-Phu Le Tam Nguyen Kieu