Article
Engineering, Electrical & Electronic
Weijun Yin, Zhengmin Kong, Yusha Liu, Yuli Yang, Lajos Hanzo
Summary: In this paper, an artificial noise aided channel quality indicator mapped generalized spatial modulation scheme is proposed to enhance the security of legitimate links. The proposed scheme outperforms its CQI-mapped modulation counterpart in terms of secrecy rate and eavesdropper's error rate. Theoretically, the secrecy rate approaches the achievable data rate of the legitimate link, which is equivalent to the GSM capacity.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2023)
Article
Telecommunications
C. Rajesh Kumar, R. K. Jeyachitra
Summary: This paper presents three new SM-JGSM constellation designs for high correlated indoor MIMO-VLC channels, achieving performance optimization through precoding and providing different levels of performance improvements. Simulation results demonstrate a significant enhancement in symbol error ratio performance for precoded SM-JGSM constellations compared to non-precoded constellations.
WIRELESS PERSONAL COMMUNICATIONS
(2021)
Article
Engineering, Electrical & Electronic
Angeles Simarro, Victor M. Garcia-Molla, F. J. Martinez-Zaldivar, Alberto Gonzalez
Summary: This paper presents three algorithms that achieve ML performance for MIMO-GSM systems. The first algorithm utilizes different strategies, including preprocessing sorting and clipping, to reduce computational complexity. The other two algorithms can only be used with clipping, but they show significant savings in computational cost.
Article
Engineering, Electrical & Electronic
Deepak Jose, S. M. Sameer
Summary: Differential modulation schemes play a crucial role in receivers with power and processing limitations by improving spectral efficiency. The proposed schemes in this study use fewer antennas and lower order modulation schemes to achieve higher bit error rate performance.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2021)
Article
Computer Science, Information Systems
Christopher A. Rogers, Dimitrie C. Popescu
Summary: The article introduces a method for sparse representation of radar scenes using a MIMO radar system and applies compressed sensing techniques to improve target detection performance by designing radar waveforms and receiver filters based on CS methods. Numerical examples demonstrate that the MIMO radar system designed based on CS methods outperforms traditional methods.
IEEE SYSTEMS JOURNAL
(2021)
Article
Engineering, Electrical & Electronic
Keshav Singh, Ahmad Fauzi Makarim, Hasan Albinsaid, Chih-Peng Li, Zygmunt J. Haas
Summary: This paper studies a RIS-assisted GSM MIMO system to improve signal quality and spectral efficiency. It proposes a low complexity DNN detector for signal detection and cosine similarity-based and SDR-based algorithms to optimize the phase shifts at the RIS elements. Conventional signal detectors like ML, B-ZF, and B-MMSE are also applied. The proposed framework outperforms alternative traditional signal detectors in terms of BER performance and time complexity.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2023)
Article
Telecommunications
Majed Saad, Hussein Hijazi, Ali Chamas Al Ghouwayel, Faouzi Bader, Jacques Palicot
Summary: A novel detection scheme, (OSIC)-S-2-ML, for Generalized Spatial Modulation (GSM) systems is proposed to achieve optimal performance with controllable complexity-performance trade-off. The proposed detector is accompanied with ordering techniques to reduce complexity and improve performance, revealing a 99% complexity reduction while reaching non-linear ML detector performance.
IEEE COMMUNICATIONS LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Nizar Bouhlel, Majed Saad, Faouzi Bader
Summary: This paper addresses a MIMO communication system based on GSM and DP antennas in sub-THz bands, aiming to improve SE while reducing spatial correlation effects. The proposed ML and MOB-MMSE detectors jointly detect complex symbols and virtual bits conveyed by activated polarization and transmit antenna combination index. The DP-GSM system is studied over correlated fading channels, showing robustness to spatial correlation effects under Rician fading. Additionally, an ABEP upper bound is derived and analyzed for DP-GSM system over correlated fading channels, considering sub-THz impairments and comparing with DP-SMX and UP-GSM systems. DP-GSM with low order modulation outperforms UP-GSM and provides cost reduction by using a lower number of RF chains in transmitter architecture based on RF-switching.
IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS
(2021)
Article
Engineering, Electrical & Electronic
Jiancheng An, Chao Xu, Yusha Liu, Lu Gan, Lajos Hanzo
Summary: Generalized quadrature spatial modulation (GQSM) integrates GSM, QSM, and V-BLAST techniques, transmitting additional information bits implicitly through TA activation pattern. The separation of real and imaginary parts of transmit symbols in QSM increases attainable throughput. GQSM shows inherent benefits in terms of throughput and achieves higher rates compared to benchmark schemes, with simulation results showing a 150% rate increase over V-BLAST at 40 TAs using QPSK. Two low-complexity detectors, based on OSIC and OMP algorithms, are also proposed.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2022)
Article
Automation & Control Systems
Yifan Zhang, Yinbin Miao, Xinghua Li, Linfeng Wei, Zhiquan Liu, Kim-Kwang Raymond Choo, Robert H. Deng
Summary: Researchers propose a secure and communication-efficient federated learning scheme using improved compressed sensing and CKKS homomorphic encryption to solve the issue of data silos and privacy leakage in distributed machine learning.
IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS
(2023)
Article
Geochemistry & Geophysics
Jieru Ding, Min Wang, Hailong Kang, Zhiyi Wang
Summary: This paper proposes a novel sparse recovery method for multiple-input and multiple-output (MIMO) radar compressed sensing (CS) imaging algorithms. The method utilizes the prior structure of the measurement matrix to determine the target's location and estimate the sparsity level in the grid, thereby avoiding false targets in the imaging. Experimental results demonstrate the effectiveness of the proposed algorithm.
IEEE GEOSCIENCE AND REMOTE SENSING LETTERS
(2022)
Article
Multidisciplinary Sciences
Chaojin Qing, Qing Ye, Bin Cai, Wenhui Liu, Jiafan Wang
Summary: This paper proposes a deep learning scheme to improve the 1-bit compressed sensing-based superimposed CSI feedback in FDD massive MIMO systems. By compressing CSI on user side and constructing a multi-task detection network on BS side, this scheme enhances the recovery accuracy of UL-US and downlink CSI with lower processing delay.
Article
Engineering, Electrical & Electronic
Kai Zhang, Han Hai, Miaowen Wen, Xue-Qin Jiang, Runhe Qiu
Summary: This paper proposes a novel generalized space-code index modulation (GSCIM) scheme for spectrum-efficient and energy-saving transmission. The scheme not only transmits input information bits through modulated symbols, but also through activated transmit antennas pattern and selected spreading code patterns. An enhanced low-complexity detector is also proposed to achieve near-ML error performance. Simulation results have shown that the GSCIM scheme outperforms existing schemes in terms of error performance.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Le Qin, Junjie Li, Yong Luo, Xinping Rao, Zhenzhen Luo, Yuanlong Cao
Summary: This paper proposes a double-driven architecture named PC-DINN, which combines the model-based framework of pattern-coupled sparse Bayesian learning (PC-SBL) with a data-driven deep learning method. By introducing learnable scale parameters and unrolling the iterative sparse Bayesian learning algorithm, PC-DINN achieves favorable reconstruction accuracy and overcomes the vulnerability of parameter choice in the framework of PC-SBL for structured compressed sensing.
DIGITAL SIGNAL PROCESSING
(2022)
Article
Engineering, Electrical & Electronic
Xu Gao, Wenhao Hu, Zhijiang Dou, Kaiwei Li, Xuepeng Gong
Summary: In this paper, a method of optical fiber sensing signal processing based on Compressed Sensing (CS) is proposed to improve the accuracy of vibration location information in the Phi-OTDR system. The experimental results show that this method can improve the signal-to-noise ratio, simplify the signal processing process, and improve the positioning accuracy of the system.
IEEE SENSORS JOURNAL
(2022)
Article
Computer Science, Information Systems
Nuno Souto, Americo Correia
IEEE WIRELESS COMMUNICATIONS LETTERS
(2020)
Article
Computer Science, Information Systems
Luis Carlos Goncalves, Pedro Sebastiao, Nuno Souto, Americo Correia
Article
Optics
Joao Pedro Pavia, Nuno Souto, Marco Alexandre Ribeiro
Article
Chemistry, Multidisciplinary
Joao Pedro Pavia, Vasco Velez, Bernardo Brogueira, Nuno Souto, Americo Correia
APPLIED SCIENCES-BASEL
(2020)
Article
Chemistry, Analytical
Joao Pedro Pavia, Vasco Velez, Renato Ferreira, Nuno Souto, Marco Ribeiro, Joao Silva, Rui Dinis
Summary: Millimeter-wave and terahertz technologies are attracting attention due to their potential to offer large bandwidths for ultra-high-speed connections, but high signal attenuation at these frequencies necessitates the use of very large antenna arrays. To achieve low complexity and power consumption, a hybrid analog/digital design is required, and this paper presents an algorithm for multiuser MIMO systems that can incorporate different analog architectures and support various structures. The proposed approach can provide good trade-offs between spectral efficiency and simplified implementation as the number of users and data streams increases.
Article
Chemistry, Analytical
Renato Ferreira, Joao Gaspar, Pedro Sebastiao, Nuno Souto
Summary: This paper describes a portable system based on low-cost SDR platforms for protecting areas against unauthorized UAVs. The system supports target localization, effective jamming techniques, and generation of GPS spoofing signals. Real-life tests show that it can successfully prevent UAVs from receiving navigation signals and can alter or take control of their flight paths.
Article
Chemistry, Analytical
Sofia Figueiredo, Nuno Souto, Francisco Cercas
Summary: The future of healthcare systems is envisioned to be revolutionized by the development and integration of body-centric networks into future generations of communication systems, giving rise to the Internet of Bio-nano things. Molecular communications is seen as the most promising way of transmitting information for in-body communications, with channel coding being a key technique to address challenges like environmental noise and inter-symbol interference. Among the different channel codes, Tomlinson, Cercas, Hughes (TCH) codes are found to be effective in improving reliability in communication channels without introducing too much complexity or processing power.
Article
Chemistry, Multidisciplinary
Vasco Velez, Joao Pedro Pavia, Catarina Rita, Carolina Goncalves, Nuno Souto, Pedro Sebastiao, Americo Correia
Summary: Index modulation (IM) technology has been widely researched due to its potential to enhance spectral and energy efficiency in future wireless networks. A cloud radio access network (C-RAN) based on precoding-aided transmitter-side generalized space-frequency IM (PT-GSFIM) has been proposed for 5G and beyond systems, showing improved performance compared to generalized spatial modulation (GSM) and conventional MU-MIMO. Throughput assessments in standardized 5G New Radio scenarios demonstrate the benefits of the proposed PT-GSFIM scheme in utilizing frequency diversity.
APPLIED SCIENCES-BASEL
(2022)
Article
Computer Science, Information Systems
Joao Praia, Joao Pedro Pavia, Nuno Souto, Marco Ribeiro
Summary: In this work, an ultra-massive multiple-input multiple-output (UM-MIMO) THz communication system is proposed for typical indoor scenarios, where the direct link between the transmitter and receiver is obstructed. A nearby reconfigurable intelligent surface (RIS) is used to assist communication by adjusting the phase shifts. The proposed algorithm, based on the accelerated proximal gradient (APG) method, demonstrates its effectiveness in configuring the phase shifts of RIS elements and achieves significant improvements in communication range.
Article
Chemistry, Multidisciplinary
Joao Pedro Pavia, Vasco Velez, Nuno Souto, Marco Ribeiro, Pedro Sebastiao, Americo Correia
Summary: The fast-growing field of telecommunications has driven investment in the research, design, and deployment of new wireless communication systems. Terahertz (THz) communication is a potential technology for achieving high data rates and low latency. However, working in the THz band presents challenges such as signal losses, distance dependency, and hardware constraints. This paper explores the use of massive/ultramassive antenna arrays and hybrid precoding architectures to overcome these challenges. The evaluation of a cloud radio access network (C-RAN) for beyond 5G (B5G) systems shows that THz communication can achieve good performance in terms of throughput and coverage in indoor office scenarios.
APPLIED SCIENCES-BASEL
(2022)
Article
Telecommunications
Nuno Souto
Summary: In order to fully utilize the limited phase shifts in a reconfigurable intelligent surface (RIS), this study proposes a problem formulation that avoids explicit discrete constraints and incorporates their effects. An iterative algorithm is derived to efficiently solve the resulting problem, which can be very effective, especially with low-resolution phase shifts.
IEEE COMMUNICATIONS LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Nuno Souto, Joao C. Silva
Summary: In recent years, there has been a growing interest in reconfigurable intelligent surfaces (RISs) as enablers for smart radio propagation environments in future wireless networks. This paper studies the use of multiple RIS panels in a parallel or multi-hop configuration to improve multi-stream MIMO communication. A novel iterative algorithm based on the mAPG method is proposed to jointly design the transmit precoder and the phases of RIS elements for maximizing achievable rate. Simulation results demonstrate the effectiveness of multiple RIS panels combined with the proposed algorithm in improving achievable rates.
IEEE OPEN JOURNAL OF THE COMMUNICATIONS SOCIETY
(2023)
Article
Computer Science, Information Systems
Vasco R. J. Velez, Joao Pedro C. B. B. Pavia, Nuno M. B. Souto, Pedro J. A. Sebastiao, Americo M. C. Correia
Summary: Reconfigurable Intelligent Surfaces (RISs) are a key technology for 6G, providing high performance and energy efficiency. RISs use arrays of low-cost reflecting elements to shape radio wave propagation, enabling smart radio environments. This paper investigates the benefits of integrating RISs into post-5G/6G wireless networks and presents a joint design algorithm for access point precoders and RIS element phase-shifts. The evaluation shows improved throughput and coverage area in different environments.
Article
Computer Science, Information Systems
Vasco R. J. Velez, Joao Pedro C. B. B. Pavia, Nuno M. B. Souto, Pedro J. A. Sebastiao, Amercio M. C. Correia
Summary: The paper introduces a scheme for multiuser multiple-input multiple-output (MU-MIMO) scenarios, which integrates a precoder at the transmitter side to eliminate multiuser interference (MUI) and improve performance. By combining complex rotation matrices and subcarrier-level interleaving, performance can be enhanced without additional power or bandwidth. Simulation results show significant performance gains of the proposed scheme over traditional modes.
Article
Engineering, Electrical & Electronic
Nuno Souto, Americo Correia
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2020)