Explanipedia

Downlink Channel Estimation for mmWave Systems with Impulsive Interference Open

Kwonyeol Park, Hyeongtaek Lee, Hwanjin Kim, Junil Choi · 2025

In this paper, we investigate a channel estimation problem in a downlink millimeter-wave (mmWave) multiple-input multiple-output (MIMO) system, which suffers from impulsive interference caused by hardware non-idealities or external disrupt…

Resilient LLM-Empowered Semantic MAC Protocols via Zero-Shot Adaptation and Knowledge Distillation Open

Yong-Jun Kim, Jihong Park, Mehdi Bennis, Junil Choi · 2025

Neural network-based medium access control (MAC) protocol models (NPMs) improve goodput through site-specific operations but are vulnerable to shifts from their training network environments, such as changes in the number of user equipment…

Low-resolution compressed sensing and beyond for communications and sensing: Trends and opportunities Open

Geethu Joseph, Venkata Gandikota, Ayush Bhandari, Junil Choi, In-Soo Kim , et al. · 2025

Machine Learning for Future Wireless Communications: Channel Prediction Perspectives Open

Hwanjin Kim, Junil Choi, David J. Love · 2025

Precise channel state knowledge is crucial in future wireless communication systems, which drives the need for accurate channel prediction without additional pilot overhead. While machine-learning (ML) methods for channel prediction show p…

Robust Transmission Design for Active RIS-Aided Systems Open

Jin‐Ho Yang, Hyeongtaek Lee, Junil Choi · 2025

Different from conventional passive reconfigurable intelligent surfaces (RISs), incident signals and thermal noise can be amplified at active RISs. By exploiting the amplifying capability of active RISs, noticeable performance improvement …

Meta-Learning-Based People Counting and Localization Models Employing CSI from Commodity WiFi NICs Open

Jihoon Cha, Hwanjin Kim, Junil Choi · 2025

In this paper, we consider people counting and localization systems exploiting channel state information (CSI) measured from commodity WiFi network interface cards (NICs). While CSI has useful information of amplitude and phase to describe…

Anomaly Detection-Based UE-Centric Inter-Cell Interference Suppression Open

Kwonyeol Park, Hyuckjin Choi, Beomsoo Ko, Minje Kim, Gyoseung Lee , et al. · 2025

The increasing spectral reuse can cause significant performance degradation due to interference from neighboring cells. In such scenarios, developing effective interference suppression schemes is necessary to improve overall system perform…

An Experimental Multi-Band Channel Characterization in the Upper Mid-Band Open

Roberto Bomfin, Ahmad Bazzi, Hao Guo, Hyeongtaek Lee, Marco Mezzavilla , et al. · 2024

The following paper provides a multi-band channel measurement analysis on the frequency range (FR)3. This study focuses on the FR3 low frequencies 6.5 GHz and 8.75 GHz with a setup tailored to the context of integrated sensing and communic…

Channel-Coded Precoding for Multi-User MISO Systems Open

Ly V. Nguyen, Junil Choi, Björn Ottersten, A. Lee Swindlehurst · 2024

Precoding is a critical and long-standing technique in multi-user communication systems. However, the majority of existing precoding methods do not consider channel coding in their designs. In this paper, we consider the precoding problem …

Modeling and Analysis of Hybrid GEO-LEO Satellite Networks Open

Dong‐Hyun Jung, Hongjae Nam, Junil Choi, David J. Love · 2024

As the number of low Earth orbit (LEO) satellites rapidly increases, the consideration of frequency sharing or cooperation between geosynchronous Earth orbit (GEO) and LEO satellites is gaining attention. In this paper, we consider a hybri…

Spatiotemporally modulated full-polarized light emission for multiplexed optical encryption Open

Jiawei Lv, Jeong Hyun Han, Geonho Han, Seongmin An, Seung Ju Kim , et al. · 2024

RIS-Enabled Cellular Systems Operated by Different Service Providers Open

Hyeongtaek Lee, Junil Choi · 2024

In realistic cellular communication systems, multiple service providers will operate within different frequency ranges. Each serving cell, which is managed by a distinct service provider, is designed individually due to the orthogonal freq…

Machine Learning-based Channel Prediction in Wideband Massive MIMO Systems with Small Overhead for Online Training Open

Beomsoo Ko, Hwanjin Kim, Minje Kim, Junil Choi · 2024

Channel prediction compensates for outdated channel state information in multiple-input multiple-output (MIMO) systems. Machine learning (ML) techniques have recently been implemented to design channel predictors by leveraging the temporal…

UV-Plane Beam Mapping for Non-Terrestrial Networks in 3GPP System-Level Simulations Open

Dong‐Hyun Jung, Sucheol Kim, Miyeon Lee, Joon-Gyu Ryu, Junil Choi · 2024

Due to the high altitudes and large beam sizes of satellites, the curvature of the Earth's surface can impact system-level performance. To consider this, 3GPP introduces the UV-plane beam mapping for system-level simulations of non-terrest…

Stochastic Geometry Analysis of RIS-Assisted Cellular Networks with Reflective Intelligent Surfaces on Roads Open

Chang‐Sik Choi, Junhyeong Kim, Junil Choi · 2024

Reconfigurable intelligent surfaces (RISs) provide alternative routes for reflected signals to network users, offering numerous applications. This paper explores an innovative approach of strategically deploying RISs along road areas to le…

Meta-Heuristic Fronthaul Bit Allocation for Cell-free Massive MIMO Systems Open

Minje Kim, In-Soo Kim, Junil Choi · 2024

Limited capacity of fronthaul links in a cell-free massive multiple-input multiple-output (MIMO) system can cause quantization errors at a central processing unit (CPU) during data transmission, complicating the centralized rate optimizati…

WMMSE-Based Rate Maximization for RIS-Assisted MU-MIMO Systems Open

Hyuckjin Choi, A. Lee Swindlehurst, Junil Choi · 2024

Reconfigurable intelligent surface (RIS) technology, given its ability to favorably modify wireless communication environments, will play a pivotal role in the evolution of future communication systems. This paper proposes rate maximizatio…

A Deep Reinforcement Learning Approach for Autonomous Reconfigurable Intelligent Surfaces Open

Hyuckjin Choi, Ly V. Nguyen, Junil Choi, A. Lee Swindlehurst · 2024

A reconfigurable intelligent surface (RIS) is a prospective wireless technology that enhances wireless channel quality. An RIS is often equipped with passive array of elements and provides cost and power-efficient solutions for coverage ex…

Smart Resource Allocation at mmWave/THz Frequencies with Cooperative Rate-Splitting Open

Hyesang Cho, Junil Choi · 2024

In this paper, we propose algorithms to minimize the energy consumption in millimeter wave/terahertz multi-user downlink communication systems. To ensure coverage in blockage-vulnerable high frequency systems, we consider cooperative rate-…

Analyzing Downlink Coverage in Clustered Low Earth Orbit Satellite Constellations: A Stochastic Geometry Approach Open

Miyeon Lee, Sucheol Kim, M. C. Kim, Dong‐Hyun Jung, Junil Choi · 2024

Satellite networks are emerging as vital solutions for global connectivity beyond 5G. As companies such as SpaceX, OneWeb, and Amazon are poised to launch a large number of satellites in low Earth orbit, the heightened inter-satellite inte…

Multi-Group Multicasting Systems Using Multiple RISs Open

Hyeongtaek Lee, Seungsik Moon, Youngjoo Lee, Jaeky Oh, Jaehoon Chung , et al. · 2024

In this paper, practical utilization of multiple distributed reconfigurable intelligent surfaces (RISs), which are able to conduct group-specific operations, for multi-group multicasting systems is investigated. To tackle the inter-group i…

Knowledge Distillation from Language-Oriented to Emergent Communication for Multi-Agent Remote Control Open

Yong-Jun Kim, Sejin Seo, Jihong Park, Mehdi Bennis, Seong‐Lyun Kim , et al. · 2024

In this work, we compare emergent communication (EC) built upon multi-agent deep reinforcement learning (MADRL) and language-oriented semantic communication (LSC) empowered by a pre-trained large language model (LLM) using human language. …

Joint Downlink and Uplink Optimization for RIS-Aided FDD MIMO Communication Systems Open

Gyoseung Lee, Hyeongtaek Lee, Dong Hwan Kim, Jaehoon Chung, A. Lee Swindlehurst , et al. · 2024

This paper investigates reconfigurable intelligent surface (RIS)-aided frequency division duplexing (FDD) communication systems. Since the downlink and uplink signals are simultaneously transmitted in FDD, the phase shifts at the RIS shoul…

From OTFS to AFDM: A Comparative Study of Next-Generation Waveforms for ISAC in Doubly-Dispersive Channels Open

Hyeon Seok Rou, Giuseppe Thadeu Freitas de Abreu, Junil Choi, David González G., Marios Kountouris , et al. · 2024

Next-generation wireless systems will offer integrated sensing and communications (ISAC) functionalities not only in order to enable new applications, but also as a means to mitigate challenges such as doubly-dispersive channels, which ari…

Machine Learning-Based Channel Prediction in Wideband Massive MIMO Systems With Small Overhead for Online Training Open

Beomsoo Ko, Hwanjin Kim, Minje Kim, Junil Choi · 2024

Channel prediction compensates for outdated channel state information in multiple-input multiple-output (MIMO) systems. Machine learning (ML) techniques have recently been implemented to design channel predictors by leveraging the temporal…

<i>K</i>-Means Clustering-Aided Power Control for UAV-Enabled OFDM Networks Open

Jae Cheol Park, Kyu‐Min Kang, Junil Choi · 2024

In this paper, we consider an unmanned aerial vehicle (UAV)-enabled orthogonal frequency division multiplexing (OFDM) network where the UAV acts as an aerial base station and employs the OFDM to transmit individual data to multiple users o…

Modeling and Analysis of GEO Satellite Networks Open

Dong‐Hyun Jung, Hongjae Nam, Junil Choi, David J. Love · 2023

The extensive coverage offered by satellites makes them effective in enhancing service continuity for users on dynamic airborne and maritime platforms, such as airplanes and ships. In particular, geosynchronous Earth orbit (GEO) satellites…

AFDM vs OTFS: A Comparative Study of Promising Waveforms for ISAC in Doubly-Dispersive Channels Open

Hyeon Seok Rou, Giuseppe Thadeu Freitas de Abreu, Junil Choi, David González G., Osvaldo Gonsa , et al. · 2023

**PLEASE FIND THE FULL EXTENDED ARTICLE "From OTFS to AFDM: A Comparative Study of Next-Generation Waveforms for ISAC in Doubly-Dispersive Channels" (Accepted for publication at the IEEE Signal Processing Magazine - Special Issue on Signal…

Rate-Splitting Multiple Access for 6G Networks: Ten Promising Scenarios and Applications Open

Jeonghun Park, Byungju Lee, Jin-Seok Choi, Hoon Lee, Namyoon Lee , et al. · 2023

In the upcoming 6G era, multiple access (MA) will play an essential role in achieving high throughput performances required in a wide range of wireless applications. Since MA and interference management are closely related issues, the conv…

Satellite Clusters Flying in Formation: Orbital Configuration-Dependent Performance Analyses Open

Dong-Hyun Jung, Joon-Gyu Ryu, Junil Choi · 2023

This paper considers a downlink satellite communication system where a satellite cluster, i.e., a satellite swarm consisting of one leader and multiple follower satellites, serves a ground terminal. The satellites in the cluster form eithe…

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