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Rapid Phase Ambiguity Elimination Methods for DOA Estimator via Hybrid Massive MIMO Receive Array

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Chinese Journal of electronics 2024年第1期33卷 175-184页

作者： Xichao ZHAN Zhongwen SUN Feng SHU Yiwen CHEN Xin CHENG Yuanyuan WU Qi ZHANG Yifan LI Peng ZHANG School of information and Communication engineering Hainan University School of electronic and Optical engineering Nanjing University of Science and Technology

For a sub-connected hybrid multiple-input multiple-output(MIMO) receiver with K subarrays and N antennas, there exists a challenging problem of how to rapidly remove phase ambiguity in only single time-slot. A direction of arrival(DOA) estimator of maximizing received power(Max-RP) is proposed to find the maximum value of K-subarray output powers, where each subarray is in charge of one sector, and the center angle of the sector corresponding to the maximum output is the estimated true DOA. To make an enhancement on precision, Max-RP plus quadratic interpolation(Max-RP-QI) method is designed. In the proposed Max-RP-QI, a quadratic interpolation scheme is adopted to interpolate the three DOA values corresponding to the largest three receive powers of *** achieve the Cramer Rao lower bound, a Root-MUSIC plus Max-RP-QI scheme is developed. Simulation results show that the proposed three methods eliminate the phase ambiguity during one time-slot and also show low computational complexities. The proposed Root-MUSIC plus Max-RP-QI scheme can reach the Cramer Rao lower bound,and the proposed Max-RP and Max-RP-QI are still some performance losses 2–4 d B compared to the Cramer Rao lower bound.

关键词： Phased arrays Interpolation Wireless sensor networks Direction-of-arrival estimation Simulation Receiving antennas Massive MIMO

Scale effect removal and range migration correction for hypersonic target coherent detection

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Journal of Systems engineering and electronics 2024年第1期35卷 14-23页

作者： WU Shang SUN Zhi JIANG Xingtao ZHANG Haonan DENG Jiangyun LI Xiaolong CUI Guolong School of information and Communication engineering University of Electronic Science and Technology of ChinaChengdu 611731China

The detection of hypersonic targets usually confronts range migration(RM)issue before coherent integration(CI).The traditional methods aiming at correcting RM to obtain CI mainly considers the narrow-band radar ***,with the increasing requirement of far-range detection,the time bandwidth product,which is corresponding to radar’s mean power,should be promoted in actual ***,the echo signal generates the scale effect(SE)at large time bandwidth product situation,influencing the intra and inter pulse integration *** eliminate SE and correct RM,this paper proposes an effective algorithm,i.e.,scaled location rotation transform(ScLRT).The ScLRT can remove SE to obtain the matching pulse compression(PC)as well as correct RM to complete CI via the location rotation transform,being implemented by seeking the actual rotation *** to the traditional coherent detection algorithms,Sc LRT can address the SE problem to achieve better detection/estimation *** last,this paper gives several simulations to assess the viability of ScLRT.

关键词： hypersonic target detection coherent integration(CI) scale effect(SE)removal range migration(RM)correction scaled location rotation transform(ScLRT)

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DLF-YOLOF:an improved YOLOF-based surface defect detection for steel plate

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Journal of Iron and Steel Research International 2024年第2期31卷 442-451页

作者： Guang-hu Liu Mao-xiang Chu Rong-fen Gong Ze-hao Zheng School of electronic and information engineering University of Science and Technology LiaoningAnshan114051LiaoningChina

Surface defects can affect the quality of steel *** methods based on computer vision are currently applied to surface defect detection of steel ***,their real-time performance and object detection of small defect are still *** improved object detection network based on You Only Look One-level Feature(YOLOF)is proposed to show excellent performance in surface defect detection of steel plate,called ***,the anchor-free detector is used to reduce the network ***,deformable convolution network and local spatial attention module are introduced into the feature extraction network to increase the contextual information in the feature ***,the soft non-maximum suppression is used to improve detection accuracy ***,data augmentation is performed for small defect objects during training to improve detection *** show the average precision and average precision for small objects are 42.7%and 33.5%at a detection speed of 62 frames per second on a single GPU,*** shows that DLF-YOLOF has excellent performance to meet the needs of industrial real-time detection.

关键词： Steel surface defects detection YOLOF Anchor-free detector Small object detection Real-time detection

Probabilistic modeling of multifunction radars with autoregressive kernel mixture network

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Defence Technology（防务技术） 2024年第5期35卷 275-288页

作者： Hancong Feng Kaili.Jiang Zhixing Zhou Yuxin Zhao Kailun Tian Haixin Yan Bin Tang School of information and Communication engineering University of Electronic Science and Technology of ChinaChengdu 611731China

The task of modeling and analyzing intercepted multifunction radars(MFRs)pulse trains is vital for cognitive electronic *** methodologies predominantly rely on prior information or heavily constrained models,posing challenges for non-cooperative *** paper introduces a novel approach to model MFRs using a Bayesian network,where the conditional probability density function is approximated by an autoregressive kernel mixture network(ARKMN).Utilizing the estimated probability density function,a dynamic programming algorithm is proposed for denoising and detecting change points in the intercepted MFRs pulse *** results affirm the proposed method's efficacy in modeling MFRs,outperforming the state-of-the-art in pulse train denoising and change point detection.

关键词： Probabilistic forecasting Multifunction radar Unsupervised learning Change point detection Outlier detection

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Weighted Linear Loss Large Margin Distribution Machine for Pattern Classification

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Chinese Journal of electronics 2024年第3期33卷 753-765页

作者： Ling LIU Maoxiang CHU Rongfen GONG Liming LIU Yonghui YANG School of electronic and information engineering University of Science and Technology Liaoning

Compared with support vector machine,large margin distribution machine(LDM) has better generalization *** central idea of LDM is to maximize the margin mean and minimize the margin variance *** the computational complexity of LDM is *** order to reduce the computational complexity of LDM,a weighted linear loss LDM(WLLDM) is *** framework of WLLDM is built based on LDM and the weighted linear *** weighted linear loss is adopted instead of the hinge loss in *** modification can transform the quadratic programming problem into a simple linear equation,resulting in lower computational ***,WLLDM has the potential to deal with large-scale *** WLLDM is similar in principle to the LDM algorithm,which can optimize the margin distribution and achieve better generalization *** WLLDM algorithm is compared with other models by conducting experiments on different *** results show that the proposed WLLDM has better generalization performance and faster training speed.

关键词： Training Support vector machines Pattern classification Transforms Fasteners Mathematical models Vectors

Blindness-free beam scanning antenna with array of array architecture: principle,design,and experiment

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science China(information sciences) 2024年第3期67卷 209-224页

作者： Jianxu SUN Yujian CHENG School of electronic science and engineering University of electronic science and Technology of China

This paper presents a 66–76-GHz sparsely-excited phased array antenna with the array of array(Ao A) architecture for eliminating the blindness and suppressing the grating lobe when scanning. For the array antennas printed on the thick dielectric layers with high relative permittivity, scanning blindness appears and seriously impacts the radiation performance. To address this issue, the Ao A topology is developed first. It finds that the scanning blindness appears due to the coupling of the radiating Floquet modes to the non-radiating surface wave(SW) modes. Therefore, the array is divided into two types of domino *** inner-phase distributions are introduced into the domino subarrays to break the one-to-one relationship between the Floquet mode and the SW mode. Then, the blindness inside ±60° scanning volume is eliminated by the aperiodic subarrays. Meanwhile, the aperiodic inner-phase distributions enhance the aperiodicity of the array and contribute to suppressing the grating lobe when scanning. Next, the meta-surface-based dipole with the shorted post is chosen as the unit cell for the proposed aperiodic array. Based on these methods,the array achieves the wide-scanning performance of ±60° in the E-plane and ±30° in the H-plane, without the blindness and the grating lobe. Finally, the 16×16 array is built and simulated with the dimension of32 mm × 32 mm. At the highest operating frequency, the simulated gains are 28.42, 25.17, and 24.01 d Bi when scanning to the broadside, 50° in the E-plane, and 30° in the H-plane, respectively. Compared to the ideal gain, it shows that the simulated radiation efficiency is about 84.13%, 62.08%, and 35.23% when scanning to the broadside, 50° in the E-plane, and 30° in the H-plane, respectively. The worst transmission coefficient, i.e., the worst isolation, is-11.97 d B between the central element and its two adjacent elements in the E-plane. The array prototypes are fabricated, and the experiments are carried out to ver

关键词： 6G communication systems phased array AoA aperiodic subarray wideband wide-scanning surface-wave scanning blindness grating lobe

Near-field wideband beam training for ELAA with uniform circular array

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science China(information sciences) 2024年第6期67卷 370-383页

作者： Yuhao CHEN Linglong DAI Department of electronic engineering Tsinghua UniversityBeijing National Research Center for Information Science and Technology (BNRist)

Extremely large-scale antenna array(ELAA) at millimeter wave(mmWave) and Terahertz(THz)band has been considered a key technology for combating high attenuation in high-frequency bands in future6G communications. Uniform circular arrays(UCAs) have attracted much attention because of their ability to provide flat beamforming gain at all angles. To realize efficient beamforming, beam training is widely used to acquire channel state information. However, with a large antenna number, the beam training overhead in ELAA systems becomes overwhelming. Moreover, with a large bandwidth, the beam defocus effect severely degrades beam training accuracy. To address these issues, this paper proposes a frequency-dependent focusing(FDF)-based beam training scheme to realize effective beam training in near-field wideband ELAA systems with UCA. Specifically, we first analyze the FDF property of UCA, where signals at different subcarriers can simultaneously focus on different distances. Then, by exploiting the FDF property to search different distances using different subcarriers simultaneously, we design a hierarchical codebook and propose an FDFbased beam training scheme. To reveal the effectiveness of the proposed scheme, we compare its necessary beam training overhead with that of existing schemes. Finally, the simulation results demonstrate that the proposed scheme can achieve accurate beam training in near-field wideband UCA systems with a low beam training overhead.

关键词： extremely large-scale antenna array (ELAA) uniform circular array (UCA) near-field wideband beam training

Novel self-embedding holographic watermarking image encryption protection scheme

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Chinese Physics B 2024年第5期33卷 281-290页

作者：王励年周楠润孙博曹颖鸿牟俊 School of information science and engineering Dalian Polytechnic UniversityDalian 116034 China School of electronic and Electrical engineering Shanghai University of Engineering ScienceShanghai 201620China

For digital image transmission security and information copyright,a new holographic image self-embedding watermarking encryption scheme is ***,the plaintext is converted to the RGB three-color channel,the corresponding phase hologram is obtained by holographic technology and the watermark is self-embedded in the frequency ***,by applying the Hilbert transform principle and genetic center law,a complete set of image encryption algorithms is constructed to realize the encryption of image ***,simulation results and security analysis indicate that the scheme can effectively encrypt and decrypt image information and realize the copyright protection of *** introduced scheme can provide some support for relevant theoretical research,and has practical significance.

关键词： color image encryption Hilbert transform self-embedding watermark holographic technology

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Visible Light Indoor Positioning System Based on Pisarenko Harmonic Decomposition and Neural Network

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Chinese Journal of electronics 2024年第1期33卷 195-203页

作者： Li ZHAO Yi REN Qi WANG Lange DENG Feng ZHANG School of electronic information engineering Xi’an Technological University

Visible-light indoor positioning is a new generation of positioning technology that can be integrated into smart lighting and optical communications. The current received signal strength(RSS)-based visible-light positioning systems struggle to overcome the interferences of background and indoor-reflected noise. Meanwhile, when ensuring the lighting, it is impossible to use the superposition of each light source to accurately distinguish light source information; furthermore, it is difficult to achieve accurate positioning in complex indoor environments. This study proposes an indoor positioning method based on a combination of power spectral density detection and a neural network. The system integrates the mechanism for visible-light radiation detection with RSS theory, to build a back propagation neural network model fitting for multiple reflection channels. Different frequency signals are loaded to different light sources at the beacon end, and the characteristic frequency and power vectors are obtained at the location end using the Pisarenko harmonic decomposition method. Then, a complete fingerprint database is established to train the neural network model and conduct location tests. Finally, the location effectiveness of the proposed algorithm is verified via actual positioning experiments. The simulation results show that, when four groups of sinusoidal waves with different frequencies are superimposed with white noise, the maximum frequency error is 0.104 Hz and the maximum power error is 0.0362 W. For the measured positioning stage, a 0.8 m × 0.8 m × 0.8 m solid wood stereoscopic positioning model is constructed, and the average error is 4.28 cm. This study provides an effective method for separating multi-source signal energies, overcoming background noise, and improving indoor visible-light positioning accuracies.

关键词： Neural networks Measurement uncertainty Position measurement Harmonic analysis Light emitting diodes Frequency estimation Indoor positioning systems