Article
Engineering, Electrical & Electronic
Anran Wang, Chang Chen, Weidong Chen
Summary: In this article, a cluster adaptive matching pursuit (CAMP) algorithm is proposed for multipolarization through-wall radar imaging (TWRI) by exploiting the common sparsity property of the multipolarization images. The proposed algorithm utilizes a multiple-measurement vector (MMV) model to capture the common sparsity among the multipolarization images. The algorithm also incorporates an adaptive clustering strategy and a two-layer matching pursuit method to accurately locate targets in TWRI.
IEEE SENSORS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Ashish Basireddy, Hassan Moradi
Summary: With advancements in autonomous driving technologies, the automotive industry is making significant progress in driving comfort and safety. The utilization of technologies such as ADAS and OFDM waveforms can improve the robustness of autonomous driving systems against interference and ghost target detection.
IEEE SENSORS JOURNAL
(2021)
Article
Engineering, Electrical & Electronic
Amir Masoud Molaei, Okan Yurduseven, Vincent Fusco
Summary: The VMD-CBFSS algorithm is introduced for waveform diversity in MIMO systems, allowing efficient signal decomposition and decoding through grouping, frequency shifting, and binary encoding. It enhances transmission efficiency and robustness against channel noise, as demonstrated in a near-field MIMO millimeter-wave imaging system with numerical simulations.
IET RADAR SONAR AND NAVIGATION
(2021)
Article
Engineering, Electrical & Electronic
Rui Yang, Hong Jiang, Qi Zhang, Liangdong Qu
Summary: This study introduces a novel ADMM algorithm for efficient MIMO radar waveform design in a spectrally crowded environment, achieving almost the same performance as existing algorithms but with higher computational efficiency.
IET SIGNAL PROCESSING
(2022)
Article
Computer Science, Information Systems
Chun-Hua Chu, Qun Zhang, Yi-Jun Chen
Summary: This paper proposes a waveform design method for MIMO radar based on joint optimization of spatial and spectral domain interferences suppression in multi-target scenarios. By considering target characteristics and environmental conditions, this method achieves effective waveform design and transmission waveform optimization, improving radar performance and interference resistance.
Article
Chemistry, Analytical
Eun-Hee Kim, Han-Saeng Kim, Ki-Won Lee
Summary: The proposed MIMO radar method can efficiently increase radar performance by orthogonal separation of signals in time, frequency, or code domains while maintaining waveform separation. By spreading interference signals outside the range bins of interest through changing the pulse repetition frequency and additional doppler processing, angular accuracy for a small number of air targets can be significantly improved. However, there may be limitations in using this method for many targets or in high clutter environments.
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
Engineering, Electrical & Electronic
Takayuki Kitamura, Kei Suwa
Summary: This article introduces a novel multiple-input-multiple-output synthetic aperture radar imaging algorithm, which can be applied to security checkpoints attached to a moving walkway. The algorithm features transmitting-signal multiplexing on the Doppler frequency domain, reducing data acquisition time and achieving image reconstruction of dangerous objects.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2022)
Article
Environmental Sciences
Weijie Xiong, Jinfeng Hu, Kai Zhong, Yibao Sun, Xiangqing Xiao, Gangyong Zhu
Summary: In this paper, we propose a direct beampattern matching without relaxation (DBMWR) method for multiple-input multiple-output (MIMO) radar transmit waveform design. The aim is to approximate the actual beampattern and minimize the cross-correlation sidelobes under the constant modulus constraint (CMC). Unlike existing methods that solve the non-convex problem with relaxation, our method utilizes the physical characteristic of the CMC as the product of complex circles (CC). Simulation results show that the proposed DBMWR method achieves a balance between accuracy and computation complexity compared with other methods.
Article
Engineering, Electrical & Electronic
Xianxiang Yu, Xue Yao, Jing Yang, Lidong Zhang, Lingjiang Kong, Guolong Cui
Summary: This paper proposes an integrated waveform design method to achieve both radar beampattern and multi-users communication in a MIMO system. The method adjusts the spatial waveform energy spectral density for communication and minimizes the integrated sidelobe level for radar detectability. Experimental results demonstrate the effectiveness of the proposed method.
IEEE TRANSACTIONS ON SIGNAL PROCESSING
(2022)
Article
Engineering, Electrical & Electronic
Kaiyan Xu, Pengcheng Gong, Yuntao Wu, Jie Li, Xiong Deng
Summary: This article proposes a transmission beampattern design method based on ADMM to address the high sidelobe and large fluctuation amplitude issues when matching the radar beampattern of MIMO radar. The method uses the Least-Most-Rule for design, effectively constraining the sum of power over the mainside and sidelobe under power limitation and PAR constraint.
DIGITAL SIGNAL PROCESSING
(2022)
Article
Engineering, Electrical & Electronic
Jinkun Zhu, Wei Li, Kai-Kit Wong, Tian Jin, Kang An
Summary: This letter addresses the waveform design of dual-function radar and communication (DFRC) to improve target detectability in clutter environment and ensure the quality of service for communication users. The objective is to maximize the signal-to-clutter-plus-noise ratio (SCNR) of MIMO radar while minimizing received symbol errors for communication users. The proposed coordinate descent algorithm and Dinkelbach algorithm effectively solve the optimization problem and improve the convergence rate. Simulation results demonstrate the effectiveness of the proposed techniques.
IEEE SIGNAL PROCESSING LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Oded Bialer, Amnon Jonas, Tom Tirer
Summary: This paper proposes a novel code optimization method to reduce the side-lobes of the radar's ambiguity function, improving the probability of detection in the case of multiple targets. By analyzing the ambiguity function side-lobes and developing an optimization algorithm, the optimized code achieves an improvement in side-lobes attenuation and probability of detection compared to reference codes.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Ke-di Zhang, Qing-song Zhou, Jing Wang, Jian-yun Zhang, Zhi-hui Li
Summary: Precision electronic warfare (PREW), an energy-focussed delivery technology, has been used to address limitations in traditional electronic warfare. This paper considers the task characteristics of PREW applications and proposes an iterative solution method to obtain jamming waveforms.
IET SIGNAL PROCESSING
(2022)
Article
Engineering, Electrical & Electronic
Wenhua Wu, Guojun Han, Yunhe Cao, Yongwei Huang, Tat-Soon Yeo
Summary: This paper proposes a space-time coding scheme for transmit beamforming and communication information embedding in a multiple-input multiple-output (MIMO) radar system, aiming to solve the cross-interference problem. The transmit waveforms are optimized using shape approximation and integrated power approximation criteria, and direct constellation mapping (DCM) and phase-rotation constellation mapping (PRCM) methods are proposed for information symbol embedding. Experimental results show that the proposed scheme can prevent missing information symbols and achieve better performance in bit-error rate (BER). Moreover, the scheme reduces the dependence of communication data rate on radar pulse repetition frequency (PRF).
IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS
(2022)
Article
Telecommunications
Taegyun Noh, Junil Choi
Summary: This study proposes a novel algorithm that utilizes intelligent reflecting surfaces to enhance the performance of cell-free massive MIMO systems beyond 5G networks, through statistical channel state information and dynamic power allocation.
IEEE COMMUNICATIONS LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Dong-Hyun Jung, Joon-Gyu Ryu, Woo-Jin Byun, Junil Choi
Summary: This paper investigates downlink low Earth orbit (LEO) satellite communication systems, where multiple LEO satellites are uniformly distributed according to a homogeneous binomial point process (BPP). By analyzing distance distributions and serving satellite cases, the exact outage probability is derived for system throughput maximization under satellite-visibility and outage constraints.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2022)
Article
Engineering, Electrical & Electronic
Seungsik Moon, Hyeongtaek Lee, Junil Choi, Youngjoo Lee
Summary: The paper proposes a cost-efficient beamforming optimization algorithm for multi-user wireless communication systems associated with intelligent reflecting surfaces (IRS). Several optimization techniques are introduced to reduce computation complexity while maintaining performance, resulting in a significant reduction in computational costs and practical solutions for next-generation IRS-aided communication.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Sucheol Kim, Hyeongtaek Lee, Jihoon Cha, Sung-Jin Kim, Jaeyong Park, Junil Choi
Summary: This paper proposes channel estimation techniques and phase shift design for IRS-empowered SU-MIMO systems. The proposed SPAC and SEROM methods have low training overhead and achieve high spectral efficiency in practical applications.
IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS
(2022)
Article
Engineering, Electrical & Electronic
Sucheol Kim, Hyeongtaek Lee, Hwanjin Kim, Yongyun Choi, Junil Choi
Summary: This paper proposes a beamforming method, named complete power reallocation (CPR), under a per-antenna power constraint (PAPC). CPR can generate high-performance beamformers using only linear operations, while many other PAPC beamformer designs require solving complex optimization problems. The CPR method is designed with a simple structure, providing high flexibility and practicality. Three variations of CPR are developed in this paper, taking into consideration algorithm convergence speed, sum-rate maximization, and robustness to channel uncertainty. Simulation results confirm that CPR and its variations meet the design criteria, making CPR readily applicable for various purposes.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2023)
Article
Engineering, Electrical & Electronic
Gyoseung Lee, Hyeongtaek Lee, Jaeky Oh, Jaehoon Chung, Junil Choi
Summary: A channel estimation technique is proposed for reconfigurable intelligent surface (RIS)-aided multi-user multiple-input single-output communication systems in this paper. By deploying a small number of active elements at the RIS, the RIS can receive and process the training signals. The proposed technique based on the linear combination of partial CSI outperforms other schemes in terms of the normalized mean squared error when the number of active elements is small.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2023)
Article
Computer Science, Information Systems
Jangho Lee, Junil Choi, Joonhyuk Kang
Summary: In this letter, the authors propose a novel harmony search-based alternating optimization (AO) algorithm to improve the downlink sum-rate for multi-antenna OFDMA systems with multiple reconfigurable intelligent surfaces (RISs). The proposed technique outperforms the AO algorithm with random initialization, making it highly practical.
IEEE WIRELESS COMMUNICATIONS LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Dong-Hyun Jung, Gyeongrae Im, Joon-Gyu Ryu, Seungkeun Park, Heejung Yu, Junil Choi
Summary: Megaconstellations of LEO satellites are being considered as a solution for global coverage with low latency and high throughput. However, as the number of satellites and operators increases, inter-satellite interference becomes a concern. This article introduces the concept of satellite clusters that can enhance network performance through cooperative transmissions. Simulation results show that clustered networks outperform unclustered ones, and viable network architectures are proposed based on 3GPP standards. The future applications of clustered satellite networks are also discussed.
IEEE VEHICULAR TECHNOLOGY MAGAZINE
(2023)
Correction
Computer Science, Information Systems
Hyuckjin Choi, Jaeky Oh, Jaehoon Chung, George C. Alexandropoulos, Junil Choi
Article
Computer Science, Information Systems
Hyuckjin Choi, Jaeky Oh, Jaehoon Chung, George C. Alexandropoulos, Junil Choi
Summary: This paper presents a novel three-dimensional (3D) ray-tracing simulator called WiThRay for performance assessment in smart wireless environments. WiThRay incorporates reconfigurable intelligent surfaces (RISs), which are key for RIS-enabled smart wireless communications. Channel data obtained from WiThRay matches well with the fundamental EM propagation theory.
Proceedings Paper
Engineering, Electrical & Electronic
Sucheol Kim, Hyeongtaek Lee, Jihoon Cha, Junil Choi
Summary: This paper proposes a practical millimeter-wave (mmWave) channel estimation technique for intelligent reflecting surface (IRS)-assisted single-user multiple-input multiple-output (SIMO) systems. The proposed technique utilizes both uplink and downlink signalings as well as analog feedback, achieving low training overhead with an extremely short training sequence length, which leads to a higher effective spectral efficiency.
2022 IEEE 12TH SENSOR ARRAY AND MULTICHANNEL SIGNAL PROCESSING WORKSHOP (SAM)
(2022)
Article
Computer Science, Information Systems
Hyesang Cho, Junil Choi
Summary: This paper proposes techniques to minimize energy consumption in UAVs with the help of multiple intelligent reflecting surfaces (IRSs). By expanding the probabilistic line-of-sight model, a tight upper bound is derived for the ergodic achievable rate, leading to tractable optimization problems. The proposed algorithms significantly reduce UAV energy consumption compared to benchmarks, indicating the effectiveness of leveraging IRSs to decrease energy consumption in UAVs.
JOURNAL OF COMMUNICATIONS AND NETWORKS
(2022)
Article
Computer Science, Theory & Methods
Dong-Hyun Jung, Joon-Gyu Ryu, Junil Choi
Summary: This paper investigates the distribution of satellite eavesdroppers in satellite communication systems and their impact on system security. Different types of antennas are used for directional beamforming, and the analysis results in the secrecy capacity and performance of the system. The research findings contribute to the evaluation of system security and the design of secure satellite constellations.
IEEE TRANSACTIONS ON INFORMATION FORENSICS AND SECURITY
(2022)
Proceedings Paper
Computer Science, Information Systems
Sucheol Kim, Hyeongtaek Lee, Jihoon Cha, Junil Choi
Summary: In this paper, a novel channel estimation technique for IRS-aided SU-MIMO systems is proposed, which conducts parameter estimation based on dominant single-path channel approximation for IRS-related channels. This technique has lower training overhead compared to typical channel estimations, leading to higher effective spectral efficiency.
2022 IEEE WIRELESS COMMUNICATIONS AND NETWORKING CONFERENCE (WCNC)
(2022)
Proceedings Paper
Computer Science, Information Systems
Hyesang Cho, Junil Choi
Summary: In this study, we propose a technique for minimizing the energy consumption of unmanned aerial vehicles (UAVs) through the assistance of multiple terrestrial intelligent reflecting surfaces (IRSs). By introducing a channel model capturing the characteristics of the IRSs and user equipments (UEs), we formulate an optimization problem and obtain a local optimum solution through problem transformations and the successive convex approximation technique. The results confirm the significant benefits of exploiting IRSs in minimizing UAV energy consumption.
2022 IEEE WIRELESS COMMUNICATIONS AND NETWORKING CONFERENCE (WCNC)
(2022)
