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Your search keyword '"Nguyen, Toan-Van"' showing total 149 results
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149 results on '"Nguyen, Toan-Van"'

1. MIMO Detection with Spatial Sigma-Delta ADCs: A Variational Bayesian Approach

Author

Nguyen, Toan-Van, Nassirpour, Sajjad, Atzeni, Italo, Tolli, Antti, Swindlehurst, A. Lee, and Nguyen, Duy H. N.

Subjects
Electrical Engineering and Systems Science - Signal Processing
Abstract

The spatial Sigma-Delta ($\Sigma\Delta$) architecture can be leveraged to reduce the quantization noise and enhance the effective resolution of few-bit analog-to-digital converters (ADCs) at certain spatial frequencies of interest. Utilizing the variational Bayesian (VB) inference framework, this paper develops novel data detection algorithms tailored for massive multiple-input multiple-output (MIMO) systems with few-bit $\Sigma\Delta$ ADCs and angular channel models, where uplink signals are confined to a specific angular sector. We start by modeling the corresponding Bayesian networks for the $1^{\mathrm{st}}$- and $2^{\mathrm{nd}}$-order $\Sigma\Delta$ receivers. Next, we propose an iterative algorithm, referred to as Sigma-Delta variational Bayes (SD-VB), for MIMO detection, offering low-complexity updates through closed-form expressions of the variational densities of the latent variables. Simulation results show that the proposed $2^{\mathrm{nd}}$-order SD-VB algorithm delivers the best symbol error rate (SER) performance while maintaining the same computational complexity as in unquantized systems, matched-filtering VB with conventional quantization, and linear minimum mean-squared error (LMMSE) methods. Moreover, the $1^{\mathrm{st}}$- and $2^{\mathrm{nd}}$-order SD-VB algorithms achieve their lowest SER at an antenna separation of one-fourth wavelength for a fixed number of antenna elements. The effects of the steering angle of the $\Sigma\Delta$ architecture, the number of ADC resolution bits, and the number of antennas and users are also extensively analyzed., Comment: 13 pages, 12 figures, under submission for a journal publication

Published
2024

2. An Efficient Deep CNN Design for EH Short-Packet Communications in Multihop Cognitive IoT Networks

Author

Nguyen, Toan-Van, Huynh-The, Thien, Nguyen, Van-Dinh, da Costa, Daniel Benevides, Hu, Rose Qingyang, and An, Beongku

Subjects
Computer Science - Information Theory
Abstract

In this paper, we design an efficient deep convolutional neural network (CNN) to improve and predict the performance of energy harvesting (EH) short-packet communications in multi-hop cognitive Internet-of-Things (IoT) networks. Specifically, we propose a Sum-EH scheme that allows IoT nodes to harvest energy from either a power beacon or primary transmitters to improve not only packet transmissions but also energy harvesting capabilities. We then build a novel deep CNN framework with feature enhancement-collection blocks based on the proposed Sum-EH scheme to simultaneously estimate the block error rate (BLER) and throughput with high accuracy and low execution time. Simulation results show that the proposed CNN framework achieves almost exactly the BLER and throughput of Sum-EH one, while it considerably reduces computational complexity, suggesting a real-time setting for IoT systems under complex scenarios. Moreover, the designed CNN model achieves the root-mean-square-error (RMSE) of ${1.33\times10^{-2}}$ on the considered dataset, which exhibits the lowest RMSE compared to the deep neural network and state-of-the-art machine learning approaches.

Published
2022

13. Performance Analysis of Wireless Energy Harvesting Multihop Cluster-Based Networks Over Nakagami- ${m}$ Fading Channels

Author

Nguyen Toan Van, Tri Nhu Do, Vo Nguyen Quoc Bao, and Beongku An

Subjects
Energy harvesting, multihop networks, Nakagami-m fading channel, outage probability, power beacon, relay selection, Electrical engineering. Electronics. Nuclear engineering, TK1-9971
Abstract

This paper studies the performance analysis of wireless energy harvesting (EH) cluster-based multi-hop networks, where all communication nodes harvest energy from the radiated signals transmitted by multiple power beacons (PBs) to support the information transmission. To this end, we propose three relay selection schemes. The first scheme tries to select the relay harvesting the largest energy to forward information. The second scheme chooses the relay, providing the best data channel gain from the transmitter to forward information. In the third scheme, two relays in two consecutive clusters will be selected based on the maximum EH link and maximum data link. The destination node is equipped with multiple antennas and applies the maximal ratio combining technique to combine its received signal. The system performances in terms of outage probability of three schemes are evaluated in Nakagami-m fading environments and verified by Monte Carlo simulations.

Published
2018
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22. Authentication and PHY-Security Schemes for Electric Vehicle Dynamic Wireless Charging

Author

Nguyen, Toan-Van, Sun, Haijian, Wang, Hongjie, and Hu, Rose Qingyang

Abstract

This article proposes authentication and physical layer security schemes to improve secure communications between the electric vehicle (EV) and charging infrastructure in dynamic wireless power transfer (DWPT) systems. In particular, a double-encryption with the signature (DoES) scheme is proposed for session key exchange between EV and charging station which provides data authenticity and integrity. To enable low-latency authentication between EV and power transmitter (PT) in DWPT systems, a sign-encrypt-message (SEM) authentication code scheme is designed leveraging symmetric keys for dynamic charging, which ensures privacy and resistance to tampering attacks. The artificial noise-based physical layer security (AN-based PLS) scheme is also proposed at the physical layer to degrade the wiretapped signal quality of multiple eavesdroppers operating in non-colluding and colluding cases. Closed-form expressions for the secrecy outage probability (SOP) and intercept probability (IP) of the considered system with the non-colluding case are derived to show that the proposed AN-based PLS scheme provides lower SOP and IP than the conventional ones without AN. The distance between eavesdroppers and the PT also affects the system SOP and IP in both non-colluding and colluding cases. Moreover, the EV using the DoES scheme takes 52 ms for obtaining session keys from the charging station while it only spends 8.23 ms with the SEM scheme to authenticate with PT for the charging process.

Published
2024
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