arXiv subjects

Hongyun Chu

Publications and source records attributed to Hongyun Chu.

4 recordsLinked to original sources

arXiv2025

6DMA-Assisted Secure Wireless Communications

Six-dimensional movable antenna (6DMA) has been widely studied for capacity enhancement, but its potential for physical layer security (PLS) remains largely unexplored. By adjusting both three-dimensional (3D) positions and 3D rotations of distributed antenna surfaces, 6DMA can increase spatial degrees of freedom (DoFs). The extra DoFs enable dynamic shaping of legitimate channels and suppresses eavesdropping channels, thereby offering unique advantages in enhancing secrecy performance. Motivated by this, this letter proposes a novel 6DMA-assisted secure wireless communication system, where the base station (BS) is equipped with 6DMA to enhance secrecy performance. Specifically, to simultaneously serve multiple legitimate users and counter cooperative interception by multiple eavesdroppers (Eves), we formulate a sum secrecy rate (SSR) maximization problem by jointly optimizing the transmit and artificial noise (AN) beamformers, as well as the 3D positions and 3D rotations of antenna surfaces. To solve this non-convex problem, we propose an alternating optimization (AO) algorithm that decomposes the original problem into two subproblems and solves them iteratively to obtain a high-quality suboptimal solution. Simulation results demonstrate the superior secrecy performance over partially movable and conventional fixed-position antenna systems.

eess.SY↗

arXiv2020

mmWave/THz Channel Estimation Using Frequency-Selective Atomic Norm Minimization

We propose a MIMO channel estimation method for millimeter-wave (mmWave) and terahertz (THz) systems based on frequency-selective atomic norm minimization (FS-ANM). For the strong line-of-sight property of the channel in such high-frequency bands, prior knowledge on the ranges of angles of departure/arrival (AoD/AoA) can be obtained as the prior knowledge, which can be exploited by the proposed channel estimator to improve the estimation accuracy. Simulation results show that the proposed method can achieve considerable performance gain when compared with the existing approaches without incorporating the the strong line-of-sight property.

eess.SP↗

arXiv2019

Joint Timing Offset and Channel Estimation for Multi-user UFMC Uplink

Universal filtered multi-carrier (UFMC), which groups and filters subcarriers before transmission, is a potential multi-carrier modulation technique investigated for the emerging Machine-Type Communications (MTC). Considering the relaxed timing synchronization requirement of UFMC, we design a novel joint timing synchronization and channel estimation method for multi-user UFMC uplink transmission. Aiming at reducing overhead for higher system performance, the joint estimation problem is formulated using atomic norm minimization that enhances the sparsity of timing offset in the continuous frequency domain. Simulation results show that the proposed method can achieve considerable performance gain, as compared with its counterparts.

eess.SP↗

arXiv2018

Super-Resolution mmWave Channel Estimation using Atomic Norm Minimization

We propose super-resolution MIMO channel estimators for millimeter-wave (mmWave) systems that employ hybrid analog and digital beamforming and generalized spatial modulation, respectively. Exploiting the inherent sparsity of mmWave channels, the channel estimation problem is formulated as an atomic norm minimization that enhances sparsity in the continuous angles of departure and arrival. Both pilot-assisted and data-aided channel estimators are developed, with the former one formulated as a convex problem and the latter as a non-convex problem. To solve these formulated channel estimation problems, we develop a computationally efficient conjugate gradient descent method based on non-convex factorization which restricts the search space to low-rank matrices. Simulation results are presented to illustrate the superior channel estimation performance of the proposed algorithms for both types of mmWave systems compared to the existing compressed-sensing-based estimators with finely quantized angle grids.

cs.IT↗