检索结果-内蒙古大学图书馆

High-Throughput, Sorted QR Accelerator for Non-Linear Processing in Open-RAN Systems

IEEE ACCESS 2024年 12卷 44564-44572页

作者： Thomas, Thomas James Filo, Marcin Nikitopoulos, Konstantinos Univ Surrey Inst Commun Syst 5G & 6G Innovat Ctr Wireless Syst Lab Guildford GU27XH England

Open Radio Access Networks (Open-RANs) require cost- and energy-efficient solutions to facilitate their large-scale deployment. A significant concern in multiple-input multiple-output (MIMO) systems employing traditional linear processing is the substantial number of radio frequency (RF) chains at the base station (BS), which is required to ensure accurate decoding of the spatially multiplexed streams. Recently, however, practical non-linear approaches, which facilitate near-optimal parallelizable tree searches, have been successfully implemented on actual systems and have demonstrated the capability to considerably reduce the required RF chains without affecting user performance. Similar to QR decomposition (QRD), which is used to perform channel inversion in linear systems, these non-linear approaches employ a sorted QRD (SQRD) to curtail the search complexity. However, this can be a significant bottleneck for general software-based non-linear solutions, preventing them from fully exploiting their gains. To address the latency limitations of SQRD, this work presents a high-throughput hardware accelerator based on reformulating the underlying Modified Gram Schmidt process (MGS) to extract further parallelism than previous designs. Implementations of the proposed architecture demonstrate at least 2-fold improvements in the achievable throughput and processing latency over existing 4 x 4 and 8 x 8 field-programmable gate array (FPGA) implementations and can be scaled up to 16 x 16 MIMO systems. Furthermore, the proposed accelerator was integrated with a software framework that can considerably offload the processing burden for a higher number of streams under strict latency conditions.

关键词： Streams MIMO communication Software Throughput Complexity theory Sorting Hardware acceleration Open radio access network multiple-input multiple-output sorted QR decomposition non-linear detection field programmable gate array

来源：评论

学校读者我要写书评

暂无评论

A Survey on Complementary-Coded MIMO CDMA Wireless Communications

引用

IEEE COMMUNICATIONS SURVEYS AND TUTORIALS 2015年第1期17卷 52-69页

作者： Sun, Si-Yue Chen, Hsiao-Hwa Meng, Wei-Xiao Harbin Inst Technol Dept Elect Informat Engn Harbin 150001 Peoples R China Natl Cheng Kung Univ Dept Engn Sci Tainan 701 Taiwan

In this paper, we present a comprehensive survey on complementary code (CC)-based multiple-input multiple-output (MIMO) code-division multiple access (CDMA) for futuristic wireless communications. This paper starts with the construction of CCs and then proceeds to describe the design of CC-based CDMA and MIMO wireless communication systems. Complementary-coded chip-level space-time coding offers a unique paradigm to implement multiuser MIMO systems, opening up a new dimension to combine multiple-access and multiple-antenna techniques in a unified platform for a possible system design optimization of a wireless communication system in the future. In this paper, we will also discuss various potential research topics and technical challenges that need to be tackled before a complementary-coded MIMO CDMA system can be implemented in practical wireless applications.

关键词： Complementary code multiple-input multiple-output code division multiple access chip-level space-time coding

来源：评论

学校读者我要写书评

暂无评论

Physical Layer Security for Visible Light Communication Systems: A Survey

引用

IEEE COMMUNICATIONS SURVEYS AND TUTORIALS 2020年第3期22卷 1887-1908页

作者： Arfaoui, Mohamed Amine Soltani, Mohammad Dehghani Tavakkolnia, Iman Ghrayeb, Ali Safari, Majid Assi, Chadi M. Haas, Harald Concordia Univ Concordia Inst Informat Syst Engn Montreal PQ H3G 1M8 Canada Univ Edinburgh Sch Engn Inst Digital Commun LiFi Res & Dev Ctr Edinburgh EH9 3FD Midlothian Scotland Texas A&M Univ Qatar Dept ECE Doha Qatar

Due to the dramatic increase in high data rate services and in order to meet the demands of the fifth-generation (5G) networks, researchers from both academia and industry are exploring advanced transmission techniques, new network architectures and new frequency spectrum such as the visible light and the millimeter wave (mmWave) spectra. Visible light communication (VLC) particularly is an emerging technology that has been introduced as a promising solution for 5G and beyond, owing to the large unexploited spectrum, which translates to significantly high data rates. Although VLC systems are more immune against interference and less susceptible to security vulnerabilities since light does not penetrate through walls, security issues arise naturally in VLC channels due to their open and broadcasting nature, compared to fiber-optic systems. In addition, since VLC is considered to be an enabling technology for 5G, and security is one of the 5G fundamental requirements, security issues should be carefully addressed and resolved in the VLC context. On the other hand, due to the success of physical layer security (PLS) in improving the security of radio-frequency (RF) wireless networks, extending such PLS techniques to VLC systems has been of great interest. Only two survey papers on security in VLC have been published in the literature. However, a comparative and unified survey on PLS for VLC from information theoretic and signal processing point of views is still missing. This paper covers almost all aspects of PLS for VLC, including different channel models, input distributions, network configurations, precoding/signaling strategies, and secrecy capacity and information rates. Furthermore, we propose a number of timely and open research directions for PLS-VLC systems, including the application of measurement-based indoor and outdoor channel models, incorporating user mobility and device orientation into the channel model, and combining VLC and RF systems to realize the

关键词： Security Radio frequency 5G mobile communication Channel models Physical layer Light emitting diodes Modulation 5G and beyond Internet-of-Things visible light communication light-fidelity physical layer security multiple-input multiple-output eavesdropping secrecy rates

来源：评论

学校读者我要写书评

暂无评论

Channel Estimation for Frequency Division Duplexing Multi-user Massive MIMO Systems via Tensor Compressive Sensing

引用

DEFENCE SCIENCE JOURNAL 2017年第6期67卷 668-673页

作者： Wang, Qingzhu Wei, Mengying Zhu, Yihai Northeast Elect Power Univ Sch Informat Engn Jilin Jilin Peoples R China CRRC Changchun Railway Vehicles Co Ltd Engn Technol Ctr Changchun Jilin Peoples R China

To make full use of space multiplexing gains for the multi-user massive multiple-input multiple-output, accurate channel state information at the transmitter (CSIT) is required. However, the large number of users and antennas make CSIT a higher-order data representation. Tensor-based compressive sensing (TCS) is a promising method that is suitable for high-dimensional data processing;it can reduce training pilot and feedback overhead during channel estimation. In this paper, we consider the channel estimation in frequency division duplexing (FDD) multi-user massive MIMO system. A novel estimation framework for three dimensional CSIT is presented, in which the modes include the number of transmitting antennas, receiving antennas, and users. The TCS technique is employed to complete the reconstruction of three dimensional CSIT. The simulation results are given to demonstrate that the proposed estimation approach outperforms existing algorithms.

关键词： Compressive sensing Tensor decomposition Channel estimation Massive MIMO multiple-input multiple-output

来源：评论

学校读者我要写书评

暂无评论

An Iterative MIMO Receiver Employing Virtual Channels with a Turbo Decoder for OFDM Wireless Systems

引用

IEICE TRANSACTIONS ON COMMUNICATIONS 2015年第5期E98B卷 878-889页

作者： Taya, Akihito Denno, Satoshi Yamamoto, Koji Morikura, Masahiro Umehara, Daisuke Murata, Hidekazu Yoshida, Susumu Kyoto Univ Grad Sch Informat Kyoto 6068501 Japan Okayama Univ Grad Sch Nat Sci & Technol Okayama 7008530 Japan Kyoto Inst Technol Grad Sch Sci & Technol Kyoto 6068585 Japan

This paper proposes a novel iterative multiple-input multiple-output (MIMO) receiver for orthogonal frequency division multiplexing (OFDM) systems, named as an "iterative MIMO receiver employing virtual channels with a Turbo decoder." The proposed MIMO receiver comprises a MIMO detector with virtual channel detection and a Turbo decoder, between which signals are exchanged iteratively. This paper proposes a semi hard input soft output (SHISO) iterative decoding for the iterative MIMO receiver that achieves better performance than a soft input soft output (SISO) iterative decoding. Moreover, this paper proposes a new criterion for the MIMO detector to select the most likely virtual channel. The performance of the proposed receiver is verified in a 6 x 2 MIMO-OFDM system by computer simulation. The proposed receiver achieves better performance than the SISO MAP iterative receiver by 1.5 dB at the bit error rate (BER) of 10(-4), by optimizing the number of the Turbo iteration per the SHISO iteration. Moreover, the proposed detection criterion enables the proposed receiver to achieve a gain of 3.0dB at the BER of 10(-5), compared with the SISO MAP iterative receiver with the Turbo decoder.

关键词： multiple-input multiple-output virtual channel soft-input soft-output log likelihood ratio iterative scheme

来源：评论

学校读者我要写书评

暂无评论

Coupled Multicore Fiber Design With Low Intercore Differential Mode Delay for High-Density Space Division multiplexing

引用

JOURNAL OF LIGHTWAVE TECHNOLOGY 2015年第6期33卷 1175-1181页

作者： Sakamoto, Taiji Mori, Takayoshi Wada, Masaki Yamamoto, Takashi Yamamoto, Fumihiko NTT Access Networks Serv Syst Labs Tsukuba Ibaraki 3050805 Japan

A moderately coupled multicore fiber (MCF) design is proposed with the aim of realizing both low intercore multiple-input multiple-output (MIMO) processing complexity and highspace utilization efficiency. We numerically and experimentally investigated the influence of mode coupling on the intercore differential mode delay (DMD) in homogeneous core MCF, and show a moderately coupled MCF design to avoid increasing the intercore DMD, which enables us to compensate for the intercore crosstalk by MIMO processing with low computational complexity. Finally, we fabricated 125-mu m-cladding two LP-mode six-core fiber and experimentally realized the highest normalized channel multiplicity of 18 without a noticeable DMD increase induced by mode coupling.

关键词： Differential mode delay few-mode fiber multicore fiber multiple-input multiple-output

来源：评论

学校读者我要写书评

暂无评论

MIMO channel estimation and evaluation for airborne traffic surveillance in cellular networks

引用

JOURNAL OF APPLIED REMOTE SENSING 2018年第1期12卷

作者： Vahidi, Vahid Saberinia, Ebrahim Univ Nevada Dept Elect & Comp Engn Las Vegas NV 89154 USA

A channel estimation (CE) procedure based on compressed sensing is proposed to estimate the multiple-input multiple-output sparse channel for traffic data transmission from drones to ground stations. The proposed procedure consists of an offline phase and a real-time phase. In the offline phase, a pilot arrangement method, which considers the interblock and block mutual coherence simultaneously, is proposed. The real-time phase contains three steps. At the first step, it obtains the priori estimate of the channel by block orthogonal matching pursuit;afterward, it utilizes that estimated channel to calculate the linear minimum mean square error of the received pilots. Finally, the block compressive sampling matching pursuit utilizes the enhanced received pilots to estimate the channel more accurately. The performance of the CE procedure is evaluated by simulating the transmission of traffic data through the communication channel and evaluating its fidelity for car detection after demodulation. Simulation results indicate that the proposed CE technique enhances the performance of the car detection in a traffic image considerably. (C) 2018 Society of Photo- Optical Instrumentation Engineers (SPIE).

关键词： channel estimation compressed sensing orthogonal frequency-division multiplexing multiple-input multiple-output group sparsity linear minimum mean square error

来源：评论

学校读者我要写书评

暂无评论

2D Generalized Optical Spatial Modulation for MIMO-OWC Systems

IEEE PHOTONICS JOURNAL

引用

IEEE PHOTONICS JOURNAL 2022年第4期14卷 1页

作者： Chen, Chen Zeng, Lin Zhong, Xin Fu, Shu Zeng, Zhihong Liu, Min Haas, Harald Chongqing Univ Sch Microelect & Commun Engn Chongqing 400044 Peoples R China Univ Edinburgh LiFi Res & Dev Ctr Inst Digital Commun Edinburgh EH9 3JL Midlothian Scotland Univ Strathclyde Technol Innovat Ctr Glasgow G1 1RD Lanark Scotland Univ Strathclyde Dept Elect & Elect Engn Glasgow G1 1RD Lanark Scotland

In this paper, a novel two-dimensional (2D) generalized optical spatial modulation (GOSM) scheme is proposed for multiple-input multiple-output optical wireless communication (MIMO-OWC) systems. By grouping multiple successive time slots as one time block, 2D GOSM mapping can be performed not only in the space domain but also in the time domain. Specifically, two types of 2D GOSM mapping schemes are designed, including 2D-1 and 2D-2 GOSM mappings. Moreover, to address the high complexity issue of optimal joint maximum-likelihood (ML) detection and the noise amplification and error propagation issues of zero-forcing-based ML (ZF-ML) detection, a deep neural network (DNN)-aided detection scheme is further designed for 2D GOSM systems. Simulation results demonstrate the superiority of the proposed 2D GOSM scheme with deep learning-aided detection for high-speed and low-complexity MIMO-OWC systems. More specifically, a remarkable 3.4-dB signal-to-noise ratio (SNR) gain can be achieved by 2D GOSM in comparison to the conventional one-dimensional (1D) GOSM, when applying the DNN-aided detection.

关键词： Light emitting diodes Symbols Modulation Optical transmitters Optical modulation Adaptive optics High-speed optical techniques Deep learning multiple-input multiple-output Optical wireless communication

来源：评论

学校读者我要写书评

暂无评论

Knowledge Distillation-Aided End-to-End Learning for Linear Precoding in Multiuser MIMO Downlink Systems With Finite-Rate Feedback

引用

IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2021年第10期70卷 11095-11100页

作者： Kong, Kyeongbo Song, Woo-Jin Min, Moonsik Pukyong Natl Univ Coll Liberal Arts Busan 48513 South Korea Pohang Univ Sci & Technol Dept Elect Engn Pohang 37673 South Korea Kyungpook Natl Univ Sch Elect Engn Daegu 41566 South Korea Kyungpook Natl Univ Sch Elect & Elect Engn Daegu 41566 South Korea

We propose a deep learning-based channel estimation, quantization, feedback, and precoding method for downlink multiuser multiple-input and multiple-output systems. In the proposed system, channel estimation and quantization for limited feedback are handled by a receiver deep neural network (DNN). Precoder selection is handled by a transmitter DNN. To emulate the traditional channel quantization, a binarization layer is adopted at each receiver DNN, and the binarization layer is also used to enable end-to-end learning. However, this can lead to inaccurate gradients, which can trap the receiver DNNs at a poor local minimum during training. To address this, we consider knowledge distillation, in which the existing DNNs are jointly trained with an auxiliary transmitter DNN. The use of an auxiliary DNN as a teacher network allows the receiver DNNs to additionally exploit lossless gradients, which is useful in avoiding a poor local minimum. For the same number of feedback bits, our DNN-based precoding scheme can achieve a higher downlink rate compared to conventional linear precoding with codebook-based limited feedback.

关键词： Precoding Receivers Channel estimation Auxiliary transmitters Downlink MIMO communication Quantization (signal) Deep learning multiple-input multiple-output limited feedback spatial multiplexing linear precoding

来源：评论

学校读者我要写书评

暂无评论

Blind Identification of SFBC-OFDM Signals Based on the Central Limit Theorem

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2019年第7期18卷 3500-3514页

作者： Gao, Mingjun Li, Yongzhao Dobre, Octavia A. Al-Dhahir, Naofal Xidian Univ State Key Lab Integrated Serv Networks Xian 710071 Shaanxi Peoples R China Mem Univ Dept Elect & Comp Engn St John NF A1B 3X5 Canada Univ Texas Dallas Dept Elect & Comp Engn Richardson TX 75080 USA

Previous approaches for blind identification of space-frequency block codes (SFBCs) do not perform well for short observation periods due to their inefficient utilization of frequency-domain redundancy. This paper proposes a hypothesis test (HT)-based algorithm and a support vector machine (SVM)-based algorithm for the SFBC signals' identification over frequency-selective fading channels to exploit two-dimensional space-frequency domain redundancy. Based on the central limit theorem, space-domain redundancy is used to construct the cross-correlation function of the estimator and frequency-domain redundancy is incorporated in the construction of the statistics. The difference between two proposed algorithms is that the HT-based algorithm constructs a chi-square statistic and employs an HT to make the decision, while the SVM-based algorithm constructs a non-central chi-square statistic with unknown mean as a strongly distinguishable statistical feature and uses SVM to make the decision. Both the algorithms do not require knowledge of the channel coefficients, modulation type, or noise power, and the SVM-based algorithm does not require timing synchronization. The simulation results verify the superior performance of the proposed algorithms for short observation periods with comparable computational complexity to conventional algorithms, as well as their acceptable identification performance in the presence of transmission impairments.

关键词： Blind identification multiple-input multiple-output orthogonal frequency division multiplexing space-frequency block code support vector machine (SVM)

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：