Chi-Bao Le
Industrial University of Ho Chi Minh City

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Journal : Bulletin of Electrical Engineering and Informatics

Ergodic capacity computation in cognitive radio aided non-orthogonal multiple access systems Dinh-Thuan Do; Chi-Bao Le
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.v11i1.3297

Abstract

In this article, the performance of cognitive radio system benefits from non-orthogonal multiple access (NOMA) scheme. We then examine system metrics to adjust its quality of signal processing. We focus on performance of the secondary network containing NOMA users which have some impacts from normal user and primary nodes. We refer to enhancement of the fairness and spectrum utilization by enabling spectrum sharing. In particular, the NOMA power allocation factors are assigned to provide different ergodic capacities for two NOMA users in the downlink of such cognitive radio-non-orthogonal multiple access (CR-NOMA) system. This article presents approximated ergodic capacity of secondary users, in which this system adopts the Rayleigh fading. The closed-form expressions are expected to match with Monte-Carklo simulation results and main system parameters can be determined to control performance of such CR-NOMA. Finally, this system is prominent once its performance outperforms than that of conventional orthogonal multiple access (OMA)-based system.
Secure outage probability of cognitive radio network relying non-orthogonal multiple access scheme Chi-Bao Le; Dinh-Thuan Do
Bulletin of Electrical Engineering and Informatics Vol 10, No 2: April 2021
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/eei.v10i2.2116

Abstract

This paper studies the secondary network relying relay selection to transmit signal from the secondary source (base station) to two destinations. Especially, two destinations are required non-orthogonal multiple access (NOMA) scheme and it benefits to implementation of the Internet of Things (IoT) systems. However, eavesdropper over-hears signal related link from selected relay to destination. This paper measure secure performance via metric, namely secure outage probability (SOP). In particular, signal to noise ratio (SNR) criterion is used to evalute SOP to provide reliable transmission to the terminal node. Main results indicates that the considered scheme provides performance gap among two signals at destination. The exactness of derived expressions is confirmed via numerical simulation.
Studying strictly positive secure capacity in cognitive radio-based non-orthogonal multiple access Chi-Bao Le; Dinh-Thuan Do
Bulletin of Electrical Engineering and Informatics Vol 10, No 2: April 2021
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/eei.v10i2.2117

Abstract

This paper studies a downlink security-aware secure outage performance in the secondary network of cognitive radio-assisted non-orthogonal multiple access network (CR-NOMA). The multiple relay is employed to assist transmission from the secondary source to destinations. The security-aware performance is subject to constraints in fixed power allocation factor assigned to each secondary user. The security-aware secure performance is based on channel state information (CSI) at the physical layer in which an eavesdropper intends to steal information. According to the considered system, exact expressions of Strictly positive secure capacity (SPSC) are proved to analyze system in terms of secure performance. Finally, the secondary user secure problem is evaluated via Monte-Carlo simulation method. The main results indicate that the secure performance of proposed system can be improved significantly.
A new look on performance of small-cell network with design of multiple antennas and full-duplex Chi-Bao Le; Dinh-Thuan Do
Bulletin of Electrical Engineering and Informatics Vol 10, No 4: August 2021
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/eei.v10i4.2721

Abstract

A downlink of small-cell network is studied in this paper studies in term of outage performance. We beneļ¬t by design of multiple antennas at the base station and fullduplex transmission mode. The scenario of multiple surrounded small-cell networks is considered to look the impact of interference. We derive the closed-form expression of outage probability to show performance of mobile user. We investigate target rate is main factor affecting to outage performance. According to the considered system, simulation results indicate reasonable value of outage probability and throughput as well. Finally, Monte-Carlo simulation method is deployed to determine exactness of main results found in this article. Finally, the considered system can exhibit improved performance if controlling interference term.
Security performance analysis for power domain NOMA employing in cognitive radio networks Thi-Anh Hoang; Chi-Bao Le; Dinh-Thuan Do
Bulletin of Electrical Engineering and Informatics Vol 9, No 3: June 2020
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1076.26 KB) | DOI: 10.11591/eei.v9i3.1639

Abstract

The power domain non-orthogonal multiple access (NOMA) technique introduces one of the fundamental characteristics and it exhibits the possibility of users to decode the messages of the other paired users on the same resources. In cognitive radio inspired NOMA (CR-NOMA), the base station (BS) has to serve untrusted users or users with different security clearance. This phenomenon raises a security threat particularly in such CR-NOMA. This paper develops a tractable analysis framework to evaluate the security performance of cooperative non-orthogonal multiple access (NOMA) in cognitive networks, where relay is able to serve two far NOMA users in the presence of external eavesdropper. In particular, we study the secrecy outage probability in a two-user NOMA system. This situation happens in practical the BS is pairing a legitimate user with another untrusted user. Main reason is that the non-uniform distribution in terms of trusted and untrusted users in the cell. By performing numerical results demonstrate the performance improvements of the proposed NOMA scheme in comparison to that of several situations in terms of different parameters. Furthermore, the security performance of NOMA is shown to verify the derived expressions.
Outage performance analysis of NOMA over log-normal fading distribution in presence of CSI and SIC imperfections Chi-Bao Le; Hong-Nhu Nguyen; Huy Hung Nguyen; Thi-Hau Nguyen; Nhan Duc Nguyen
Bulletin of Electrical Engineering and Informatics Vol 11, No 3: June 2022
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/eei.v11i3.3395

Abstract

The evolution of wireless communication networks has introduced various applications that require massive device connectivity and high spectral efficiency. Non-orthogonal multiple access (NOMA) technique is one of the most promising technologies to perform efficiently data transmission. The NOMA technique can allocate the same resource block for two users by super-imposing signals. At the receiver, the signals are separated by performing successive interference cancellation (SIC) technique. For efficient data transmission, the fading and shadowing effects of channels also play a pivotal role. Many researches have considered Rayleigh, Rician, Nakagami-m, and other fading channels in various perspectives. In our paper, a system model based on a NOMA network with two users over log-normal fading distribution in the presence of channel estimation errors and SIC imperfections is proposed. The performance is analyzed in terms of outage probability and simulations are performed with the assistance of Monte-Carlo simulations. The obtained results shown the effectiveness in comparison with the traditionally used fading distributions. The same analysis is also performed in various scenarios of power allocation levels, target rates, and imperfections. The transmit SNR and power allocation of the users are important for efficient communication in any fading distribution as shown in this paper.
UAV-assisted underlay CR-NOMA network: performance analysis Dinh-Thuan Do; Chi-Bao Le
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.v11i4.3104

Abstract

We highlight the potential of non-orthogonal multiple access (NOMA) integration with unmanned aerial vehicle (UAV) for future communications networks in beyond 5 generation (B5G) networks to enhance cellular communication, support massive connections and increase data rates. We consider a scenario, where a UAV communicates in a downlink underlay cognitive radio based NOMA network (CR-NOMA) with two destination users, a cellular device, and a primary destination following Nakagami-m fading distribution. We study the impact of perfect and imperfect successive interference cancellation (SIC) on outage probability (OP). To help analyze this impact, we derive exact outage results for different network users under perfect and imperfect SIC conditions. Consequently, we make use of Monte Carlo simulations to confirm the analytical results.