检索结果-内蒙古大学图书馆

Dynamic Electromagnetic Exposure Allocation for Rayleigh Fading MIMO Channels

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2021年第2期20卷 728-740页

作者： Castellanos, Miguel R. Ying, Dawei Love, David J. Peleato, Borja Hochwald, Bertrand M. Purdue Univ Sch Elect & Comp Engn W Lafayette IN 47907 USA Intel Corp Hillsboro OR 97124 USA Univ Notre Dame Dept Elect & Comp Engn Notre Dame IN 46556 USA

Future wearable and portable devices with multiple transmit antennas operating below 6 GHz are constrained by regulatory limitations on the level of electromagnetic radiation a user can be exposed to, measured using the specific absorption rate (SAR). Signaling designs that are optimized to include SAR constraints can improve the performance of uplink transmission. These signaling schemes could include closed-loop beamforming, closed-loop precoding, and space-time coding, which have all been shown to achieve increased rates when optimized as a function of SAR. Previous research addressed SAR constrained optimization only within a single coherence time block. In this paper, we present transmit policies that dynamically allocate user electromagnetic radiation exposure over time. We propose three exposure allocation methods - optimal, uniform, and asymptotic - in the practical case with causal channel state information (CSI), and an on-off transmission approach for the low SAR-to-noise ratio regime. Our results demonstrate that the performance of SAR-aware transmission can be further improved by exploiting frequency and time diversity.

关键词： Resource management Transmitting antennas Wireless communication Covariance matrices Electromagnetic radiation Optimization multiple antenna array specific absorption rate convex optimization dynamic programming

来源：评论

学校读者我要写书评

暂无评论

Fault early warning in air-insulated substations by RSSI-based angle of arrival estimation and monopole UHF wireless sensor array

引用

IET GENERATION TRANSMISSION & DISTRIBUTION 2020年第12期14卷 2345-2351页

作者： Wu, Fan Luo, Lingen Song, Hui Sheng, Gehao Jiang, Xiuchen Shanghai Jiao Tong Univ Dept Elect Engn 800 Dongchuan Rd Shanghai Peoples R China

To achieve comprehensive insulation deterioration monitoring of power equipment and fault early warning in air-insulated substations, the detection and localisation of partial discharge (PD) using ultra-high frequency (UHF) antennas were widely studied. The existing UHF PD localisation system is mainly based on time-difference of electromagnetic wave signal, which requires very high time synchronisation accuracy and sampling rate. This study proposes a received signal strength indicator (RSSI)-based angle of arrival (AoA) method using the monopole UHF wireless sensor array. multiple antennas are evenly placed in a circle frame and form an antenna array. Then an AoA estimation scheme is derived from the radiation pattern of designed UHF antenna. RSSI difference data, interpolation, and clustering are applied to improve the AoA resolution. A field test is performed to verify the effectiveness of the proposed PD localisation system. The results show that the estimated error on average is below 3.5 degrees. Compared to the time-difference-based method, the accuracy of the designed system is more feasible for practical application of fault early warning considering its significant low-cost feature.

关键词： wireless sensor networks sensor arrays UHF antennas direction-of-arrival estimation alarm systems monopole antenna arrays air insulation substation insulation antenna radiation patterns interpolation array signal processing air-insulated substations ultrahigh frequency antennas electromagnetic wave signal high time synchronisation accuracy received signal strength indicator-based angle multiple antenna array AoA estimation scheme RSSI difference data time-difference-based method power equipment insulation deterioration monitoring UHF antenna design UHF PD localisation system interpolation pattern clustering monopole UHF wireless sensor array RSSI-based angle of arrival method fault early warning system received signal strength indicator

来源：评论

学校读者我要写书评

暂无评论

Reduced-Complexity Coherent Versus Non-Coherent QAM-Aided Space-Time Shift Keying

引用

IEEE TRANSACTIONS ON COMMUNICATIONS 2011年第11期59卷 3090-3101页

作者： Sugiura, Shinya Xu, Chao Ng, Soon Xin Hanzo, Lajos Toyota Cent Res & Dev Labs Inc Toyoake Aichi 4801192 Japan Univ Southampton Sch Elect & Comp Sci Southampton SO17 1BJ Hants England

A novel reduced-complexity near-optimal detection algorithm is proposed for enhancing the recent Coherently-detected Space-Time Shift Keying (CSTSK) scheme employing arbitrary constellations, such as L-point Phase-Shift Keying (PSK) and Quadrature Amplitude Modulation (QAM). The proposed detector relies on a modified Matched Filter (MF) concept. More specifically, we exploit both the constellation diagram of the modulation scheme employed as well as the Inter-Element-Interference (IEI)-free STSK architecture. Furthermore, we generalize the Pulse Amplitude Modulation (PAM)- or PSK-aided Differentially-encoded STSK (DSTSK) concept and conceive its more bandwidth-efficient QAM-aided counterpart. Then, the proposed reduced-complexity CSTSK detector is applied to the QAM-aided DSTSK scheme, which enables us to carry out low-complexity non-coherent detection, while dispensing with channel estimation. It is revealed that the proposed detector is capable of approaching the optimal Maximum Likelihood (ML) detector's performance, while avoiding the exhaustive ML search. Interestingly, our simulation results also demonstrate that the reduced-complexity detector advocated may achieve the same performance as that of the optimal ML detector for the specific STSK scheme's parameters. Another novelty of this paper is that the star-QAM STSK scheme tends to outperform its square-QAM counterpart, especially for high number of dispersion matrices. Furthermore, we provided both the theoretical analysis and the simulations, in order to support this unexpected fact.

关键词： Differential encoding diversity and multiplexing tradeoff space-time shift keying spatial modulation matched filter multiple antenna array non-coherent detection

来源：评论

学校读者我要写书评

暂无评论

Generalized Space-Time Shift Keying Designed for Flexible Diversity-, multiplexing- and Complexity-Tradeoffs

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2011年第4期10卷 1144-1153页

作者： Sugiura, Shinya Chen, Sheng Hanzo, Lajos Univ Southampton Sch Elect & Comp Sci Southampton SO17 1BJ Hants England

In this paper, motivated by the recent concept of Spatial Modulation (SM), we propose a novel Generalized Space-Time Shift Keying (G-STSK) architecture, which acts as a unified multiple-Input multiple-Output (MIMO) framework. More specifically, our G-STSK scheme is based on the rationale that P out of Q dispersion matrices are selected and linearly combined in conjunction with the classic PSK/QAM modulation, where activating P out of Q dispersion matrices provides an implicit means of conveying information bits in addition to the classic modem. Due to its substantial flexibility, our G-STSK framework includes diverse MIMO arrangements, such as SM, Space-Shift Keying (SSK), Linear Dispersion Codes (LDCs), Space-Time Block Codes (STBCs) and Bell Lab's Layered Space-Time (BLAST) scheme. Hence it has the potential of subsuming all of them, when flexibly adapting a set of system parameters. Moreover, we also derive the Discrete-input Continuous-output Memoryless Channel (DCMC) capacity for our G-STSK scheme, which serves as the unified capacity limit, hence quantifying the capacity of the class of MIMO arrangements. Furthermore, EXtrinsic Information Transfer (EXIT) chart analysis is used for designing our G-STSK scheme and for characterizing its iterative decoding convergence.

关键词： Diversity and multiplexing tradeoff space-time shift keying spatial modulation linear dispersion code maximum likelihood detection multiple antenna array

来源：评论

学校读者我要写书评

暂无评论

Dispersion Matrix Optimization for Space-Time Shift Keying

引用

IEEE COMMUNICATIONS LETTERS 2011年第11期15卷 1152-1155页

作者： Sugiura, Shinya Toyota Cent Res & Dev Labs Inc Toyota Aichi 4801192 Japan

In this Letter, we introduce an efficient dispersion-matrix optimization technique for the recent concept of Space-Time Shift Keying (STSK). By exploiting the STSK-specific signal structure relying on the dispersion-matrix activation, rather than the classic spatial multiplexing, computational complexity imposed by the system optimization is reduced by tens of times, in comparison to that of the conventional approach. Our simulation results reveal that the proposed technique substantially reduces computational cost and time required for the dispersion-matrix optimization, which is especially beneficial for large search-space scenarios, such as a high number of transmit antennas, symbols per space-time block and constellation points.

关键词： Dispersion matrix diversity and multiplexing tradeoff space-time shift keying multiple antenna array

来源：评论

学校读者我要写书评

暂无评论

Reduced-Complexity QAM-Aided Space-Time Shift Keying

Reduced-Complexity QAM-Aided Space-Time Shift Keying

引用

54th Annual IEEE Global Telecommunications Conference (GLOBECOM)

作者： Sugiura, Shinya Xu, Chao Hanzo, Lajos Toyota Cent Res & Dev Labs Inc Aichi 4801192 Japan Univ Southampton Sch ECS Southampton SO17 1BJ Hants England

ISBN: (纸本)9781424492688

A novel reduced-complexity near-optimal detection algorithm is proposed for enhancing the recent coherently-detected Space-Time Shift Keying (STSK) scheme employing arbitrary constellations, such as L-point Phase-Shift Keying (PSK) and Quadrature Amplitude Modulation (QAM). The proposed detector relies on a modified Matched Filter (MF) concept. More specifically, we exploit both the constellation diagram of the modulation scheme employed as well as the Inter-Element-Interference (IEI)-free STSK architecture. It is revealed that the proposed detector is capable of approaching the optimal Maximum Likelihood (ML) detector's performance, while avoiding the exhaustive ML search.

关键词： Diversity and multiplexing tradeoff space-time shift keying spatial modulation matched filter multiple antenna array

来源：评论

学校读者我要写书评

暂无评论

Bounds and Tradeoffs for Cooperative DoA-Only Localization of Primary Users

Bounds and Tradeoffs for Cooperative DoA-Only Localization o...

引用

54th Annual IEEE Global Telecommunications Conference (GLOBECOM)

作者： Penna, Federico Cabric, Danijela Politecn Torino I-10129 Turin Italy Univ Calif Los Angeles Los Angeles CA 90024 USA

ISBN: (纸本)9781424492688

Direction-of-arrival (DoA)-based localization is a suitable approach for estimating the position of primary users in cognitive radio networks, as it does not require knowledge of transmission power or propagation channel. In this paper we consider a scenario where secondary users obtain DoA estimates by multiple antennas or virtual antenna arrays. We express the Cramer Rao bound of the localization error as a function of the problem geometry and of array-specific parameters. Then, we investigate how the bound scales with the number of sensors and the number of antennas per sensor, and we address the following question: is it better to have more sensors with fewer antennas, or fewer sensors with more antennas?

关键词： antenna arrays Cramer Rao bound Direction of arrival estimation Estimation Sensor arrays Signal to noise ratio antenna arrays array-specific parameters cognitive radio cognitive radio networks cooperative DoA-only localization direction-of-arrival estimation direction-of-arrival-based localization localization error multiple antenna array position estimation primary users propagation channel virtual antenna arrays wireless channels

来源：评论

学校读者我要写书评

暂无评论

Coherent and Differential Space-Time Shift Keying: A Dispersion Matrix Approach

引用

IEEE TRANSACTIONS ON COMMUNICATIONS 2010年第11期58卷 3219-3230页

作者： Sugiura, Shinya Chen, Sheng Hanzo, Lajos Univ Southampton Sch Elect & Comp Sci Southampton SO17 1BJ Hants England Toyota Cent Res & Dev Labs Inc Aichi 4801192 Japan

Motivated by the recent concept of Spatial Modulation (SM), we propose a novel Space-Time Shift Keying (STSK) modulation scheme for multiple-Input multiple-Output (MIMO) communication systems, where the concept of SM is extended to include both the space and time dimensions, in order to provide a general shift-keying framework. More specifically, in the proposed STSK scheme one out of.. dispersion matrices is activated during each transmitted block, which enables us to strike a flexible diversity and multiplexing tradeoff. This is achieved by optimizing both the space-time block duration as well as the number of the dispersion matrices in addition to the number of transmit and receive antennas. We will demonstrate that the resultant equivalent system model does not impose any Inter-Channel Interference (ICI), and hence the employment of single-stream Maximum Likelihood (ML) detection becomes realistic at a low-complexity. Furthermore, we propose a Differential STSK (DSTSK) scheme, assisted by the Cayley unitary transform, which does not require any Channel State Information (CSI) at the receiver. Here, the usual error-doubling, caused by the differential decoding, gives rise to 3-dB performance penalty in comparison to Coherent STSK (CSTSK). Additionally, we introduce an enhanced CSTSK scheme, which avoids the requirement of Inter-antenna Synchronization (IAS) between the RF chains associated with the transmit antenna Elements (AEs) by imposing a certain constraint on the dispersion matrix design, where each column of the dispersion matrices includes only a single non-zero component. Moreover, according to the turbo-coding principle, the proposed CSTSK and DSTSK schemes are combined with multiple serially concatenated codes and an iterative bit-to-symbol soft-demapper. More specifically, the associated STSK parameters are optimized with the aid of EXtrinsic Information Transfer (EXIT) charts, for the sake of achieving a near-capacity performance.

关键词： Diversity and multiplexing tradeoff space-time coding spatial modulation linear dispersion code maximum likelihood detection multiple antenna array non-coherent detection

来源：评论

学校读者我要写书评

暂无评论

Space Shift Keying Modulation for MIMO Channels

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2009年第7期8卷 3692-3703页

作者： Jeganathan, Jeyadeepan Ghrayeb, Ali Szczecinski, Leszek Ceron, Andres Concordia Univ ECE Dept Montreal PQ Canada Univ Quebec INRS EMT Montreal PQ H3C 3P8 Canada Univ Tecn Federico Santa Maria Dept Elect Engn Valparaiso Chile

In this paper, we present space shift keying (SSK) as a new modulation scheme, which is based on spatial modulation (SM) concepts. Fading is exploited for multiple-input multiple-output (MIMO) channels to provide better performance over conventional amplitude/phase modulation (APM) techniques. In SSK, it is the antenna index used during transmission that relays information, rather than the transmitted symbols themselves. This absence of symbol information eliminates the transceiver elements necessary for APM transmission and detection (such as coherent detectors). As well, the simplicity involved in modulation reduces the detection complexity compared to that of SM, while achieving almost identical performance gains. Throughout the paper, we illustrate SSK's strength by studying its interaction with the fading channel. We obtain tight upper bounds on bit error probability, and discuss SSK's performance under some non-ideal channel conditions (estimation error and spatial correlation). Analytical and simulation results show performance gains over APM systems (3 dB at a bit error rate of 10(-5)), making SSK an interesting candidate for future wireless applications. We then extend SSK concepts to incorporate channel coding, where in particular, we consider a bit interleaved coded modulation (BICM) system using iterative decoding for both convolutional and turbo codes. Capacity results are derived, and improvements over APM are illustrated (up to 1 bits/s/Rz), with performance gains of up to 5 dB.

关键词： multiple antenna array spatial modulation

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：