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Network coding with diversity and outdated channel state information
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作者 Tong CHEN Kanapathippillai CUMANAN +1 位作者 Zhiguo DING Guiyun TIAN 《Journal of Modern Transportation》 2012年第4期261-267,共7页
Physical-layer network coding (PNC) has the potential to significantly improve the throughput of wireless networks where the channels can be modeled as additive white Gaussian noise (AWGN) channel. As extending to... Physical-layer network coding (PNC) has the potential to significantly improve the throughput of wireless networks where the channels can be modeled as additive white Gaussian noise (AWGN) channel. As extending to mul- tiple channels, this technique requires both amplitude and phase compensation at each transmitter and will lead to inef- ficient systems yielding no diversity even with perfect channel state information (CSI). In order to avoid these limita- tions, we apply network coding with diversity (NCD) to achieve a form of selection diversity and extend NCD to coop- erative multiple access channels in this paper. However, in practical wireless communication systems, the CSI could become outdated due to the difference between the CSI used in the relay selection and data transmission phases. Hence, the selected relay may not be the best one during data transmission phase due to the dynamic change in the wireless channels. Therefore, we first explore the relation between the present and past CSIs. Exploiting this relationship, the NCD scheme with outdated CSI is investigated based on the past CSI. To evaluate the performance of this scheme, an information-theoretic metric, namely the outage capacity, is studied under this condition. 展开更多
关键词 network coding with diversity (NCD) cooperative multiple access channels channel state information (csi
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Imperfect Channel State Information of AF and DF Energy Harvesting Cooperative Networks 被引量:2
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作者 Hoang-Sy NGUYEN Anh-Hoa BUI +1 位作者 Dinh-Thuan DO Miroslav VOZNAK 《China Communications》 SCIE CSCD 2016年第10期11-19,共9页
Wireless information and powered transfer networks(WIPT) has recently been implemented in 5th generation wireless networks. In this paper, we consider half-duplex relaying system in which the energy constrained relay ... Wireless information and powered transfer networks(WIPT) has recently been implemented in 5th generation wireless networks. In this paper, we consider half-duplex relaying system in which the energy constrained relay node collects energy via radio frequency(RF) signals from the surrounding resources. Regarding energy harvesting protocol, we propose power time switching-based relaying(PTSR) architecture for both amplify-and-forward(AF) and decode-and-forward(DF). Especially, we reveal the analytical expressions of achievable throughput, ergodic capacity and energy-efficient in case of imperfect channel state information(CSI) for both AF and DF network. Through numerical analysis, we analyse the throughput performance, energy-efficient and ergodic capacity for different parameters, including power splitting ratio and energy harvesting time. Moreover, we also depict the performance comparison between AF and DF network with perfect and imperfect CSI. The results in numerical analysis reveal that the result of AF relaying network is less significant than DF relaying network in the various scenarios. 展开更多
关键词 AMPLIFY-AND-FORWARD DECODE-AND-FORWARD energy harvesting THROUGHPUT channel state information(csi)
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Wireless Physical Layer Security with Imperfect Channel State Information: A Survey 被引量:5
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作者 Biao He Xiangyun Zhou Thushara D.Abhayapala 《ZTE Communications》 2013年第3期11-19,共9页
Physical layer security is an emerging technique for improving wireless communication security, which is widely regarded as a complement to cryptographic technologies. To design physical layer security techniques for ... Physical layer security is an emerging technique for improving wireless communication security, which is widely regarded as a complement to cryptographic technologies. To design physical layer security techniques for practical scenarios, uncertainty and imperfections in the channel knowledge need to be taken into account. This paper is a survey of recent research on physical layer security that considers imperfect channel state information (CSI) at communication nodes. We first give an overview of the main information-theoretic measures of secrecy performance with imperfect CSI. Then, we describe several signal processing enhancements in secure transmission designs. These enhancements include secure on-off transmission, beamforming with artificial noise, and secure communication assisted by relay nodes or in cognitive radio systems. Recent studies of physical layer security in large-scale decentralized wireless networks are also summarized. Finally, open problems for on-going and future research are discussed. 展开更多
关键词 physical layer security fading channels channel uncertainty imperfect channel state information
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A Survey of Wi-Fi Sensing Techniques with Channel State Information 被引量:2
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作者 MICHEN Liangqin TIAN Liping +1 位作者 XU Zhimeng CHEN Zhizhang 《ZTE Communications》 2020年第3期57-63,共7页
A review of signal processing algorithms employing Wi-Fi signals for positioning and recognition of human activities is presented.The principles of how channel state information(CSI)is used and how the Wi-Fi sensing s... A review of signal processing algorithms employing Wi-Fi signals for positioning and recognition of human activities is presented.The principles of how channel state information(CSI)is used and how the Wi-Fi sensing systems operate are reviewed.It provides a brief introduction to the algorithms that perform signal processing,feature extraction and recognitions,including location,activity recognition,physiological signal detection and personal identification.Challenges and future trends of Wi-Fi sensing are also discussed in the end. 展开更多
关键词 Wi-Fi sensing channel state information signal processing CLASSIFICATIONS feature extraction POSITIONING LOCATION recognitions
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Device-Free Through-the-Wall Activity Recognition Using Bi-Directional Long Short-Term Memory and WiFi Channel State Information
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作者 Zi-Yuan Gong Xiang Lu +2 位作者 Yu-Xuan Liu Huan-Huan Hou Rui Zhou 《Journal of Electronic Science and Technology》 CAS CSCD 2021年第4期357-368,共12页
Activity recognition plays a key role in health management and security.Traditional approaches are based on vision or wearables,which only work under the line of sight(LOS)or require the targets to carry dedicated dev... Activity recognition plays a key role in health management and security.Traditional approaches are based on vision or wearables,which only work under the line of sight(LOS)or require the targets to carry dedicated devices.As human bodies and their movements have influences on WiFi propagation,this paper proposes the recognition of human activities by analyzing the channel state information(CSI)from the WiFi physical layer.The method requires only the commodity:WiFi transmitters and receivers that can operate through a wall,under LOS and non-line of sight(NLOS),while the targets are not required to carry dedicated devices.After collecting CSI,the discrete wavelet transform is applied to reduce the noise,followed by outlier detection based on the local outlier factor to extract the activity segment.Activity recognition is fulfilled by using the bi-directional long short-term memory that takes the sequential features into consideration.Experiments in through-the-wall environments achieve recognition accuracy>95%for six common activities,such as standing up,squatting down,walking,running,jumping,and falling,outperforming existing work in this field. 展开更多
关键词 Activity recognition bi-directional long short-term memory(Bi-LSTM) channel state information(csi) device-free through-the-wall.
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Capacity of a Class of Dirty-Tape Gaussian Orthogonal Relay Channel with State Information at the Source and Relay
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作者 邓志祥 王保云 郎非 《China Communications》 SCIE CSCD 2013年第9期104-113,共10页
A Gaussian channel with additive interference that is causally known to the transmitter is called a Dirty-Tape Channel(DTC).In this paper,we consider a state-dependent dirty-tape Gaussian relay channel with orthogonal... A Gaussian channel with additive interference that is causally known to the transmitter is called a Dirty-Tape Channel(DTC).In this paper,we consider a state-dependent dirty-tape Gaussian relay channel with orthogonal channels from the source to the relay and from the source and relay to the destination.The orthogonal channels are corrupted by two independent additive interferences causally known to both the source and relay.The lower and upper bounds of the channel capacity are established.The lower bound is obtained by employing superposition coding at the source,Partial Decode-and-Forward(PDF)relaying at the relay,and a strategy similar to that used by Shannon at the source and relay.The explicit capacity is characterised when the power of the relay is sufficiently large.Finally,several numerical examples are provided to illustrate the impact of additive interferences and the role of the relay in information transmission and in removing the interference. 展开更多
关键词 state-dependent relay channel relay channel with orthogonal components causal channel state information DTC
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DFF-EDR:An Indoor Fingerprint Location Technology Using Dynamic Fusion Features of Channel State Information and Improved Edit Distance on Real Sequence
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作者 Ke Han Yunfei Xu +1 位作者 Zhongliang Deng Jiawei Fu 《China Communications》 SCIE CSCD 2021年第4期40-63,共24页
Positioning technology based on wireless network signals in indoor environments has developed rapidly in recent years as the demand for locationbased services continues to increase.Channel state information(CSI)can be... Positioning technology based on wireless network signals in indoor environments has developed rapidly in recent years as the demand for locationbased services continues to increase.Channel state information(CSI)can be used as location feature information in fingerprint-based positioning systems because it can reflect the characteristics of the signal on multiple subcarriers.However,the random noise contained in the raw CSI information increases the likelihood of confusion when matching fingerprint data.In this paper,the Dynamic Fusion Feature(DFF)is proposed as a new fingerprint formation method to remove the noise and improve the feature resolution of the system,which combines the pre-processed amplitude and phase data.Then,the improved edit distance on real sequence(IEDR)is used as a similarity metric for fingerprint matching.Based on the above studies,we propose a new indoor fingerprint positioning method,named DFF-EDR,for improving positioning performance.During the experimental stage,data were collected and analyzed in two typical indoor environments.The results show that the proposed localization method in this paper effectively improves the feature resolution of the system in terms of both fingerprint features and similarity measures,has good anti-noise capability,and effectively reduces the localization errors. 展开更多
关键词 channel state information indoor positioning edit distance on real sequence dynamic parameters feature resolution
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Adaptive Energy-Efficient Power Allocation for DAS with Imperfect Channel State Information and Antenna Selection
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作者 Weiye Xu Min Lin +1 位作者 Yu Yang Xiangbin Yu 《China Communications》 SCIE CSCD 2016年第7期127-134,共8页
Considering that perfect channel state information(CSI) is difficult to obtain in practice,energy efficiency(EE) for distributed antenna systems(DAS) based on imperfect CSI and antennas selection is investigated in Ra... Considering that perfect channel state information(CSI) is difficult to obtain in practice,energy efficiency(EE) for distributed antenna systems(DAS) based on imperfect CSI and antennas selection is investigated in Rayleigh fading channel.A novel EE that is defined as the average transmission rate divided by the total consumed power is introduced.In accordance with this definition,an adaptive power allocation(PA) scheme for DAS is proposed to maximize the EE under the maximum transmit power constraint.The solution of PA in the constrained EE optimization does exist and is unique.A practical iterative algorithm with Newton method is presented to obtain the solution of PA.The proposed scheme includes the one under perfect CSI as a special case,and it only needs large scale and statistical information.As a result,the scheme has low overhead and good robustness.The theoretical EE is also derived for performance evaluation,and simulation result shows the validity of the theoretical analysis.Moreover,EE can be enhanced by decreasing the estimation error and/or path loss exponents. 展开更多
关键词 distributed antenna system energy efficiency adaptive power allocation imperfect channel state information antenna selection
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A novel quantum information hiding protocol based on entanglement swapping of high-level Bell states 被引量:1
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作者 徐淑奖 陈秀波 +2 位作者 王连海 钮心忻 杨义先 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第5期231-238,共8页
Using entanglement swapping of high-level Bell states, we first derive a covert layer between the secret message and the possible output results of the entanglement swapping between any two generalized Bell states, an... Using entanglement swapping of high-level Bell states, we first derive a covert layer between the secret message and the possible output results of the entanglement swapping between any two generalized Bell states, and then propose a novel high-efficiency quantum information hiding protocol based on the covert layer. In the proposed scheme, a covert channel can be built up under the cover of a high-level quantum secure direct communication (QSDC) channel for securely transmitting secret messages without consuming any auxiliary quantum state or any extra communication resource. It is shown that this protocol not only has a high embedding efficiency but also achieves a good imperceptibility as well as a high security. 展开更多
关键词 quantum information hiding quantum covert'channel entanglement swapping high-level Bell states
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An Efficient CSI Feedback Scheme for Dual-Polarized MIMO Systems Using Layered Multi-Paths Information
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作者 Feng Zheng Yijian Chen +1 位作者 Qian Zhan Jie Zhang 《China Communications》 SCIE CSCD 2017年第5期91-104,共14页
Massive MIMO is one of tile enabling technologies tbr beyond 4G and 5G systems due to its ability to provide beamforming gain and reduce interference Dual-polarized antenna is widely adopted to accommodate a large num... Massive MIMO is one of tile enabling technologies tbr beyond 4G and 5G systems due to its ability to provide beamforming gain and reduce interference Dual-polarized antenna is widely adopted to accommodate a large number of antenna elements in limited space. However, current CSI(channel state information) feedback schemes developed in LTE for conventional MIMO systems are not efficient enough for massive MIMO systems since the overhead increases almost linearly with the number of antenna. Moreover, the codebook for massive MIMO will be huge and difficult to design with the LTE methodology. This paper proposes a novel CSI feedback scheme named layered Multi-paths Information based CSI Feedback (LMPIF), which can achieve higher spectrum efficiency for dual-polarized antenna system with low feedback overhead. The MIMO channel is decomposed into long term components (multipath directions and amplitudes) and short term components (multipath phases). The relationship between the two components and the optimal precoder is derived in closed form. To reduce the overhead, different granularities in feedback time have been applied for the long term components and short term components Link and system level simulation results prove that LMPIF can improve performance considerably with low CSI feedback overhead. 展开更多
关键词 communication and information system: efficient csi feedback: channel characteristie analysis dual-polarized: massive MIMO: layered Multi-Paths information codeword model
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Covert Rate Characterization under Multi-Antenna Detection:A Study on Warden’s CSI Availability and Noise Uncertainty
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作者 Zhang Yuchen Xiao Sa +3 位作者 Wang Jianquan Ning Boyu Yuan Xiaojun TangWanbin 《China Communications》 2025年第2期143-159,共17页
In this paper,we investigate covert communications under multi-antenna detection,and explore the impacts of the warden’s channel state information(CSI)availability and the noise uncertainty on system covert capabilit... In this paper,we investigate covert communications under multi-antenna detection,and explore the impacts of the warden’s channel state information(CSI)availability and the noise uncertainty on system covert capability.The detection performance at warden is analyzed in two cases under the perfect and statistical CSI at warden,respectively.In particular,for the former one,the warden utilizes the likelihood ratio(LR)detector,while for the latter one,the generalized likelihood ratio(GLR)detector is adopted.We first consider the scenario where the blocklength is finite,and demonstrate that the covert rate under both cases asymptotically goes to zero as the blocklength goes to infinity.Subsequently,we take the noise uncertainty at the warden into account which leads to positive covert rate,and characterize the covert rate for infinite blocklength.Specially,we derive the optimal transmit power for the legitimate transmitter that maximizes the covert rate.Besides,the rate gap under two cases,with different CSI availability at the warden,can be presented in closed form.Finally,numerical results validate the effectiveness of our theoretical analysis and also demonstrate the impacts of the factors studied on the system covertness. 展开更多
关键词 channel state information covert communications multiple antenna noise uncertainty
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一种基于CSI数据预处理的人体行为识别方法
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作者 史伟光 姜皓元 《天津工业大学学报》 CAS 北大核心 2024年第6期66-72,共7页
针对已有基于信道状态信息(CSI)的行为识别方法存在冗余信息多、识别精度低等问题,提出一种基于CSI数据预处理的行为识别方法。首先通过计算子载波的贡献度进行子载波的选择,有效降低了CSI中的冗余信息;在此基础上,提出一种CSI动态特征... 针对已有基于信道状态信息(CSI)的行为识别方法存在冗余信息多、识别精度低等问题,提出一种基于CSI数据预处理的行为识别方法。首先通过计算子载波的贡献度进行子载波的选择,有效降低了CSI中的冗余信息;在此基础上,提出一种CSI动态特征增强算法,从原始CSI信息中分离出动态分量,实现对人体行为的准确表达,从而达到动态特征增强的目的。使用开源的CSI数据进行实验验证。结果表明:将预处理后的CSI数据用于行为识别,准确率较预处理前提升约30.5%;与WiFall、WiAnti预处理方案相比,本文所提方法准确率分别提高了7.5%与3.3%,证实了本文方法的有效性。 展开更多
关键词 信道状态信息(csi) 行为识别 数据预处理
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基于CSI实例标准化的域泛化人体动作识别模型 被引量:1
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作者 王杨 许佳炜 +3 位作者 王傲 夏慧娟 赵传信 季一木 《通信学报》 EI CSCD 北大核心 2024年第6期196-209,共14页
为了实现完全不依赖目标域数据的Wi-Fi跨域人体动作感知,提出了一种基于CSI实例标准化的域泛化人体动作识别模型INDG-Fi。INDG-Fi使用实例标准化去除CSI特征表示的领域信息,接着构建共享特征提取的动作分类器和域分类器,并通过动作偏向... 为了实现完全不依赖目标域数据的Wi-Fi跨域人体动作感知,提出了一种基于CSI实例标准化的域泛化人体动作识别模型INDG-Fi。INDG-Fi使用实例标准化去除CSI特征表示的领域信息,接着构建共享特征提取的动作分类器和域分类器,并通过动作偏向学习和对抗性的域学习,将编码层提取的特征偏向人体动作引起的信号特征,同时远离领域信号影响。为了让模型关注受人体动作影响更显著的子载波信号,在编码层中加入子载波注意力模块。实现结果表明,所提INDG-Fi在不可见的用户和位置的感知性能分别为97.99%和92.73%,能够实现鲁棒的跨域感知。 展开更多
关键词 信道状态信息 无线感知 人体动作识别 域泛化
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非完美CSI下基于D2D通信的V2X频谱分配方案
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作者 权仕鑫 孙志国 +1 位作者 孙溶辰 刘留 《北京交通大学学报》 CSCD 北大核心 2024年第5期30-38,共9页
在设备到设备通信的车联网场景(Vehicle to Everything-Device to Device,V2X-D2D)下,信道的快速时变会导致基站(Base Station,BS)端通常无法获取完美信道状态信息(Channel State Information,CSI).为解决现有频谱分配方案不适用于V2X-... 在设备到设备通信的车联网场景(Vehicle to Everything-Device to Device,V2X-D2D)下,信道的快速时变会导致基站(Base Station,BS)端通常无法获取完美信道状态信息(Channel State Information,CSI).为解决现有频谱分配方案不适用于V2X-D2D场景的问题,考虑车对车(Vehicle-to-Vehicle,V2V)链路可靠性、最大发射功率、频谱复用的约束,建立V2X的场景模型与通信模型.明确了在满足V2V链路可靠性的前提下,最大化车与基础设施(Vehicle to Infrastructure,V2I)链路的遍历容量的优化目标;在考虑信道快速时变影响的情况下,推导V2V链路的中断概率、V2I链路遍历容量的闭式表达式;针对一对一模式和一对多模式下的频谱分配问题,分别提出基于改进匈牙利算法的快速频谱分配方案和基于图着色-偏好列表的频谱分配方案.仿真结果表明:与现有算法相比,基于改进匈牙利算法的快速频谱分配方案接入率更高、复杂度更低,基于图着色-偏好列表的频谱分配方案也具有接入率、频谱利用率高的优势. 展开更多
关键词 无线通信 设备到设备 车联网 频谱分配 非完美信道状态信息
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RIS辅助MIMO NOMA系统中利用统计CSI的下行传输方法
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作者 陆佳程 王斌 +1 位作者 张军 倪艺洋 《电子与信息学报》 EI CAS CSCD 北大核心 2024年第4期1257-1265,共9页
针对可重构智能反射表面(RIS)辅助多输入多输出(MIMO)非正交多址接入(NOMA)下行传输系统,该文提出利用统计信道状态信息(CSI)的基站发送协方差矩阵与RIS相移矩阵设计方法。首先,在莱斯空间相关信道假设下,利用大维随机矩阵理论,推导了RI... 针对可重构智能反射表面(RIS)辅助多输入多输出(MIMO)非正交多址接入(NOMA)下行传输系统,该文提出利用统计信道状态信息(CSI)的基站发送协方差矩阵与RIS相移矩阵设计方法。首先,在莱斯空间相关信道假设下,利用大维随机矩阵理论,推导了RIS辅助MIMO NOMA系统遍历和速率的确定性表达式;然后,在弱用户速率约束与发送功率受限的条件下,通过最大化确定性大系统近似和速率,利用统计CSI,分别设计了强、弱用户的次优发送协方差矩阵和RIS的相移矩阵。仿真结果表明,所推导的近似表达式具有很好的近似效果,所设计的发送协方差矩阵和相移矩阵能显著提升系统的和速率。 展开更多
关键词 统计信道状态信息 非正交多址接入 可重构智能反射表面 发送协方差 大维随机矩阵理论
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CGAC:一种基于CSI的人体动作识别方法
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作者 苏健 郑毓煌 陈思光 《南京邮电大学学报(自然科学版)》 北大核心 2024年第6期12-24,共13页
WiFi的信道状态信息(CSI)在人体动作识别(HAR)领域具有广泛的应用前景。目前基于CSI的HAR大多在准确率以及不同环境中的鲁棒性上存在不足。针对这类问题,提出了一种结合卷积神经网络、门控循环单元以及注意力机制的复合人体动作识别模型... WiFi的信道状态信息(CSI)在人体动作识别(HAR)领域具有广泛的应用前景。目前基于CSI的HAR大多在准确率以及不同环境中的鲁棒性上存在不足。针对这类问题,提出了一种结合卷积神经网络、门控循环单元以及注意力机制的复合人体动作识别模型(CGAC)。首先使用CNN对输入数据进行时序特征提取,通过池化操作减小特征尺寸,再使用BiGRU对时序特征进行建模,通过注意力机制增强对关键特征的关注度。在3个公开数据集进行实验,CGAC在UT-HAR数据集中达到了99.70%的准确率,在NTU-Fi的HAR数据集中达到了97.50%的准确率,在Human-ID数据集上达到了97.81%的准确率,实验结果表明CGAC模型高于该领域现有方法的准确率,证明了方法的有效性。 展开更多
关键词 人体动作识别 信道状态信息 深度学习 卷积神经网络 门控循环单元 注意力机制
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基于Transformer大规模MIMO的CSI反馈网络
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作者 王昱凯 张志晨 +2 位作者 王荣 李军 何波 《齐鲁工业大学学报》 CAS 2024年第2期1-7,共7页
针对频分双工大规模多输入多输出系统中信道状态信息反馈方法反馈精度低的问题,提出了一种名为CDTransformer的基于Transformer和卷积分解(convolutional decomposition,CD)的CSI反馈网络。CDTransformer将卷积分解融入改进的Transforme... 针对频分双工大规模多输入多输出系统中信道状态信息反馈方法反馈精度低的问题,提出了一种名为CDTransformer的基于Transformer和卷积分解(convolutional decomposition,CD)的CSI反馈网络。CDTransformer将卷积分解融入改进的Transformer结构网络中,在不增加计算复杂度的情况下提升网络性能,并通过对网络的全连接层进行二值化实现轻量级部署。针对用户端功率有限的情况,提出了一种MixedTransformer网络模型。其中编码器采用计算成本较低、结构简单的单层卷积神经网络,而解码器则采用与CDTransformer模型相同的结构。CDTransformer模型融合了Transformer结构和卷积分解,提高了CSI反馈精度并实现轻量级部署。此外,引入了MixedTransformer模型,结合了CDTransformer和卷积神经网络的优点,以在功率有限情况下提供更好的性能。结果显示,相比于CsiTransformer网络模型,CDTransformer网络模型在归一化均方误差和余弦相似度方面分别提高了37.7%和0.2%。 展开更多
关键词 频分双工 大规模MIMO TRANSFORMER 信道状态信息 卷积神经网络
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基于特征融合的大规模MIMO系统CSI反馈
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作者 安永丽 蔡浩然 +1 位作者 胡泽冰 纪占林 《南京邮电大学学报(自然科学版)》 北大核心 2024年第3期1-7,共7页
信道状态信息(Channel State Information,CSI)反馈是大规模多输入多输出(Multiple-Input Multiple-Output,MIMO)系统的一个关键问题。大规模MIMO系统中基站天线数量巨大,CSI反馈出现了反馈开销大、反馈精度低等问题。为了降低反馈开销... 信道状态信息(Channel State Information,CSI)反馈是大规模多输入多输出(Multiple-Input Multiple-Output,MIMO)系统的一个关键问题。大规模MIMO系统中基站天线数量巨大,CSI反馈出现了反馈开销大、反馈精度低等问题。为了降低反馈开销,提高反馈精度,采用深度学习方法,提出了一种基于特征融合的CSI反馈网络(Feature Fusion Net,FFNet)。利用基于注意力机制的特征融合在编码器中融合不同尺度的CSI特征,并在解码器中使用多通道多分辨率卷积网络以及通道重排,从而高精度地重建压缩后的CSI。仿真结果表明,与几种经典的深度学习CSI反馈方法相比,在室内和室外信道条件下,均具有更高的反馈精度。 展开更多
关键词 大规模MIMO 信道状态信息 深度学习 卷积神经网络 特征融合
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差分编码辅助的机器学习CSI反馈方法
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作者 卿朝进 刘文慧 +3 位作者 刘宇畅 叶青 王子龙 陈金良 《电子信息对抗技术》 2024年第2期64-71,共8页
在大规模多输入多输出(massive Multiple Input Multiple Output,mMIMO)系统中,信道状态信息(Channel State Information,CSI)反馈严重占用上行带宽资源。为此,提出差分编码辅助的机器学习CSI反馈,探索节省上行带宽资源,减小用户设备(Us... 在大规模多输入多输出(massive Multiple Input Multiple Output,mMIMO)系统中,信道状态信息(Channel State Information,CSI)反馈严重占用上行带宽资源。为此,提出差分编码辅助的机器学习CSI反馈,探索节省上行带宽资源,减小用户设备(User Equipment,UE)能量开销的途径。在UE端,通过差分编码方式反馈CSI,避免UE端发送用于上行信道估计的导引,从而减小上行带宽资源占用,并节省UE能量开销。在基站(Base Station,BS)端,首先对接收信号进行差分译码,随后构建轻量化神经网络恢复下行CSI。仿真结果表明,相对于上行导引信道估计的CSI反馈,所研究的差分编码辅助的机器学习CSI反馈方法在节省上行带宽资源、减小UE能量消耗的同时,提高了下行CSI的重构精度。 展开更多
关键词 csi 差分编码 带宽资源 能量消耗
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基于多通道特征融合的人体动作识别方法
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作者 陶志勇 郭希俊 +2 位作者 任晓奎 刘影 王泽民 《工程科学与技术》 北大核心 2025年第1期68-79,共12页
现阶段,深度学习已在基于WiFi的人体动作识别领域得到广泛应用且取得显著成果。然而,在利用多输入、多输出(MIMO)系统强大的空间分集特性进行动作识别时,受多径效应影响,获得信道状态信息(CSI)存在对相同动作的特征描述存在差异、不同... 现阶段,深度学习已在基于WiFi的人体动作识别领域得到广泛应用且取得显著成果。然而,在利用多输入、多输出(MIMO)系统强大的空间分集特性进行动作识别时,受多径效应影响,获得信道状态信息(CSI)存在对相同动作的特征描述存在差异、不同动作的特征描述存在类似、特征提取不完整和动作分类复杂的问题。为解决上述问题,本文提出一种基于双重注意力机制和多通道、多尺度的时间卷积网络的动作识别方法。首先,根据MIMO系统的空间分集特性,构建多通道信息提取模型,从各个天线接收到的信道中提取出有关动作的特性信息。然后,设计多尺度的统合机制,强化同一动作在不同通道接收数据的表征,通过整合不同尺度的动作特征,增强对动作的表征能力。再次,采用特征图融合注意力机制和特征通道注意力机制对各通道的动作特征进行聚合。注意力机制能有效地找出对最终动作识别有重要贡献的特征,使模型可以更好地进行特征聚焦。与此同时,将时间卷积网络应用于特征处理过程,使不同时间步的动作特征间的长期依赖关系得以维持,增加对复杂和连续动作的识别能力。最终,利用全局平均池化层(GAP)将各通道的特征图与动作分类器进行连接,以便多通道的动作特性能有效聚合在一起,进一步提高动作识别的精度。本文提出的模型在公共数据集7种动作测试中,实现98.72%的平均准确率。同时在自行搭建的实验室、教室和走廊等真实环境下进行测试时,10种不同的动作分别获得97.94%、97.28%和95.66%的识别准确率。实验结果充分证明了本文所提出的基于WiFi的人体动作识别模型在不同环境的有效性和优越性。 展开更多
关键词 动作识别 深度学习 信道状态信息 TCN 注意力
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