检索结果-内蒙古大学图书馆

Performance of ZF and MMSE decoders for massive multi-cell MIMO systems in impulsive and Laplacian noise channels

SIGNAL IMAGE AND VIDEO PROCESSING 2020年第1期14卷 49-56页

作者： Abu Hilal, Hasan Higher Coll Technol Abu Dhabi U Arab Emirates

In this paper, we examine the performance of zero forcing (ZF) and minimum mean square error (MMSE) ZF linear detection methods in non-Gaussian impulsive and Laplacian multi-cell MIMO channels. We start by showing the symbol error rate performance in non-Gaussian channels for ZF detection, and then we build over it and extend to the derivations for MMSE ZF system. The lower and upper bound derivations are clearly shown and verified through computer software Montecarlo simulations.

关键词： Multi-cell Impulsive noise MIMO linear precoding

来源：评论

学校读者我要写书评

暂无评论

Unified SER Performance Analysis and Improvement for Multiuser MIMO Downlink with Correlation Rotation linear precoding

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2013年第4期12卷 1678-1685页

作者： Liu, Zu-Jun Wang, Jie-Ling Sun, De-Chun Yi, Ke-Chu Xidian Univ State Key Lab Integrated Serv Networks Xian 710071 Peoples R China

In multiuser multiple-input multiple-output (MIMO) downlink communications, system performance suffers from multiuser interference (MUI). Contrary to common practice where MUI is suppressed, correlation rotation (CR) linear precoding makes MUI constructive via rotating the angle of correlation between transmitted symbols. With the derived closed-form instantaneous SINR expression, we analyze the unified SER performance for CR precoding, and identify the channel condition under which the MUI exploitation via CR precoding will fail and consequently lead to the unified SER performance degradation. To solve the problem, two power allocation schemes that are subject to power constraint are proposed: one is iterative scheme that directly minimizes the unified SER, and the other has a closed-form solution that maximizes the minimum user SINR. The asymptotic behavior and computational complexity of the proposed schemes are analyzed. Numerical and simulation results show that both schemes can avoid the degradation of unified SER performance and furthermore offer performance gains. Moreover, the closed-form solution with much lower complexity can provide a comparable performance to that of the iterative scheme.

关键词： Multiuser multiple-input multiple-output (MIMO) multiuser interference (MUI) correlation rotation (CR) linear precoding power allocation

来源：评论

学校读者我要写书评

暂无评论

Robust Regularized ZF in Cooperative Broadcast Channel Under Distributed CSIT

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2020年第3期66卷 1845-1860页

作者： Li, Qianrui de Kerret, Paul Gesbert, David Gresset, Nicolas EURECOM Commun Syst Dept F-06410 Biot France Mitsubishi Elect R&D Ctr Europe F-35708 Rennes France Mantu AI Lab F-06410 Biot France

In this work, we consider the sum rate performance of joint processing coordinated multi-point transmission network (JP-CoMP, a.k.a Network MIMO) in a so-called distributed channel state information (D-CSI) setting. In the D-CSI setting, the various transmitters (TXs) acquire a local, TX-dependent, estimate of the global multi-user channel state matrix obtained via terminal feedback and limited backhauling. The CSI noise across TXs can be independent or correlated, so as to reflect the degree to which TXs can exchange information over the backhaul, hence allowing to model a range of situations bridging fully distributed and fully centralized CSI settings. In this context we aim to study the price of CSI distributiveness in terms of sum rate at finite SNR when compared with conventional centralized scenarios. We consider the family of JP-CoMP precoders known as regularized zero-forcing (RZF). We conduct our study in the large scale antenna regime, as it is currently envisioned to be used in real 5G deployments. It is then possible to obtain accurate approximations on so-called deterministic equivalents of the signal to interference and noise ratios. Guided by the obtained deterministic equivalents, we propose an approach to derive a RZF scheme that is robust to the distributed aspect of the CSI, whereby the key idea lies in the optimization of a TX-dependent power level and regularization factor. Our analysis confirms the improved robustness of the proposed scheme with respect to CSI inconsistency at different TXs, even with moderate number of antennas and receivers (RXs).

关键词： Multiuser channels cooperative communication coordinated multi-point transmission network random matrix theory limited feedback limited backhaul linear precoding

来源：评论

学校读者我要写书评

暂无评论

Comparative Analysis of Procedures and Solutions to Improve Energy Efficiency of Massive MIMO

引用

INTERNATIONAL JOURNAL OF ELECTRONICS AND TELECOMMUNICATIONS 2022年第4期68卷 677-686页

作者： Phogat, Ritu Singh Joshi, Rutvij Gujarat Technol Univ Ahmadabad India Parul Univ Vadodara India

blustery growth of high data rate applications leads to more energy consumption in wireless networks to satisfy service quality. Therefore, energy-efficient communications have been paid more attention to limited energy resources and environmentally friendly transmission functioning. Countless publications are present in this domain which focuses on intensifying network energy efficiency for uplink-downlink transmission. It is done either by using linear precoding schemes, by amending the number of antennas per BS, by power control problem formulation, antenna selection schemes, level of hardware impairments, and by considering cell-free (CF) Massive-MIMO. After reviewing these techniques, still there are many barriers to implement them practically. The strategies mentioned in this review show the performance of EE under the schemes as raised above. The chief contribution of this work is the comparative study of how Massive MIMO EE performs under the background of different methods and architectures and the solutions to few problem formulations that affect the EE of network systems. This study will help choose the best criteria to improve EE of Massive MIMO while formulating a newer edition of testing standards. This survey provides the base for interested readers in energy efficient Massive MIMO.

关键词： -EE Uplink-Downlink Transmission Power Control linear precoding CF Massive MIMO

来源：评论

学校读者我要写书评

暂无评论

Large System Analysis of linear precoding in MISO Broadcast Channels with Confidential Messages

引用

IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 2013年第9期31卷 1660-1671页

作者： Geraci, Giovanni Couillet, Romain Yuan, Jinhong Debbah, Merouane Collings, Iain B. Univ New S Wales Sch Elect Engn & Telecommun Sydney NSW 2052 Australia Supelec Dept Telecommun Gif Sur Yvette France Supelec Alcatel Lucent Chair Flexible Radio Gif Sur Yvette France CSIRO ICT Ctr Wireless & Networking Technol Lab Sydney NSW Australia

In this paper, we study the performance of regularized channel inversion (RCI) precoding in large MISO broadcast channels with confidential messages (BCC). We obtain a deterministic approximation for the achievable secrecy sum-rate which is almost surely exact as the number of transmit antennas M and the number of users K grow to infinity in a fixed ratio beta = K/M. We derive the optimal regularization parameter. and the optimal network load beta that maximize the per-antenna secrecy sum-rate. We then propose a linear precoder based on RCI and power reduction (RCI-PR) that significantly increases the high-SNR secrecy sum-rate for 1 < beta < 2. Our proposed precoder achieves a per-user secrecy rate which has the same high-SNR scaling factor as both the following upper bounds: (i) the rate of the optimum RCI precoder without secrecy requirements, and (ii) the secrecy capacity of a single-user system without interference. Furthermore, we obtain a deterministic approximation for the secrecy sum-rate achievable by RCI precoding in the presence of channel state information (CSI) error. We also analyze the performance of our proposed RCI-PR precoder with CSI error, and we determine how the error must scale with the SNR in order to maintain a given rate gap to the case with perfect CSI.

关键词： Physical layer security broadcast channel random matrix theory linear precoding multi-user systems

来源：评论

学校读者我要写书评

暂无评论

Multi-User Precoder Designs for RGB Visible Light Communication Systems

引用

SENSORS 2020年第23期20卷 6836-6836页

作者： Vinals, Roser Munoz, Olga Agustin, Adrian Vidal, Josep Univ Politecn Catalunya UPC Dept Signal Theory & Comunicat Barcelona 08034 Spain Ecole Polytech Fed Lausanne EPFL Signal Proc Lab LTS5 CH-1015 Lausanne Switzerland

In this paper, we design linear precoders for the downlink of a visible light communication (VLC) system that simultaneously serves multiple users. Instead of using phosphor-coated white light-emitting diodes (PWLEDs), we focus on Red-Green-Blue light-emitting diodes (RGB-LEDs) that allow modulating three separate data streams on the three primary colors of the RGB-LEDs. For this system, we design a zero-forcing (ZF) precoder that maximizes the weighted sum rate for a multilevel pulse amplitude modulation (M-PAM). The precoding design in RGB-based systems presents some challenges due to the system constraints, such as the limited power, the non-negative amplitude constraints per light-emitting diode (LED), and the need to guarantee white light emission while transmitting with RGB-LEDs. For comparison purposes, we also consider the ZF design for a PWLED-based system and evaluate the performance of both a PWLED- and an RGB-based system.

关键词： visible light communications multi-user linear precoding adaptive modulation zero forcing weighted sum-rate maximization Red-Green-Blue RGB-LEDs

来源：评论

学校读者我要写书评

暂无评论

Energy efficient downlink MIMO transmission with linear precoding

引用

Science China(Information Sciences) 2013年第2期56卷 90-101页

作者： XU Jie LI ShiChao QIU Ling SLIMANE Ben S. YU ChengWen Department of Electronic Engineering and Information Science University of Science and Technology of China Department of Communication Systems (CoS) ICT The Royal Institute of Technology (KTH) Wireless Research Huawei Technologies Company Limited

Energy efficiency (EE) is becoming increasingly important for wireless cellular networks. This paper addresses EE optimization problems in downlink multiuser MIMO systems with linear precoding. Referring to different active transmit/receive antenna sets and transmission schemes as different modes, we propose a joint bandwidth/power optimization and mode switching scheme to maximize EE. With a specific mode, we prove that the optimal bandwidth and transmit power is either full transmit power or full bandwidth. After deriving the optimal bandwidth and transmit power, we further propose mode switching to select the mode with optimal EE. Since the optimal mode switching, i.e. exhaustive search, is too complex to implement, an alternative heuristic method is developed to decrease the complexity through reducing the search size and avoiding the EE calculation during each search. Through simulations, we demonstrate that the proposed methods can significantly improve EE and the performance is similar to the optimal exhaustive search.

关键词： energy efficiency downlink multiuser MIMO linear precoding bandwidth/power optimization mode switching low complexity

来源：评论

学校读者我要写书评

暂无评论

Low Spatial Peak-to-Average Power Ratio Transmission for Improved Energy Efficiency in Massive MIMO Systems

引用

SENSORS 2021年第16期21卷 5534-5534页

作者： Rezaei Aghdam, Sina Eriksson, Thomas Chalmers Univ Technol Dept Elect Engn S-41296 Gothenburg Sweden

A significant portion of the operating power of a base station is consumed by power amplifiers (PAs). Much of this power is dissipated in the form of heat, as the overall efficiency of currently deployed PAs is typically very low. This is because the structure of conventional precoding techniques typically results in a relatively high variation in output power at different antennas in the array, and many PAs are operated well below saturation to avoid distortion of the transmitted signals. In this work, we use a realistic model for power consumption in PAs and study the impact of power variation across antennas in the array on the energy efficiency of a massive MIMO downlink system. We introduce a family of linear precoding matrices that allow us to control the spatial peak-to-average power ratio by projecting a fraction of the transmitted power onto the null space of the channel. These precoding matrices preserve the structure of conventional precoders;e.g., they suppress multiuser interference when used together with zeroforcing precoding and bring advantages over these precoders by operating PAs in a more power-efficient region and reducing the total radiated distortion. Our numerical results show that by controlling the power variations between antennas in the array and incorporating the nonlinearity properties of PA into the precoder optimization, significant gains in energy efficiency can be achieved over conventional precoding techniques.

关键词： energy efficiency massive MIMO downlink linear precoding spatial PAPR nonlinear power amplifier

来源：评论

学校读者我要写书评

暂无评论

DESIGN AND IMPLEMENTATION OF linear precoding LTE DOWNLINK BASED ON FPGA

DESIGN AND IMPLEMENTATION OF LINEAR PRECODING LTE DOWNLINK B...

引用

IEEE International Conference on Communications, Networks, and Satellite (COMNETSAT)

作者： Chaeriyah, Nur Astuti, Rina Pudji Darlis, Denny Telkom Univ Sch Engn Bandung Indonesia

ISBN: (纸本)9781467360562

The problem that often occur in multi-antenna wireless communication is how to maximize the throughput. precoding is a generalization of beamforming to support multi-layer transmission in multi-antenna wireless communications. Beamforming is a signal processing technique used in sensor arrays for directional signal transmission or reception. In conventional single-layer beamforming, the same signal is emitted from each of the transmit antennas with appropriate weighting such that the signal power is maximized at the receiver output. When the receiver has multiple antennas, single-layer beamforming cannot simultaneously maximize the signal level at all of the receive antennas. Thus, in order to maximize throughput in a receiving antenna system, integrated precoding in multi-layer beamforming is required. LTE linear precoding system for the transmitter side is built in this research. The precoding system will be built in VHDL code and will be implemented on FPGA. In this research, the precoding sistem consists of 64-QAM Mapper as input system, and will be connected to OFDM (IFFT) block. The precoding is built based on Transmission Mode (TM) 6 of LTE release 9 and will be using 3GPP codebook standard as the precoding matrix for TM 6 for 2x2 MIMO. [GRAPHICS] The research shows that by the used of linear precoding system in transmission, it decreases the complexion of detection system in precoding block on the receiver side. The implementation process shows that the research is implementable on hardware and will use 62% occupied slices, 11% slice register, and 27% of bounded IOBs resources of FPGA. with 2021 clock in total process, 121 clock in delay process and 1900 clocks to produce one OFDM symbol. The bitrate of the system is 161.68 Mbps.

关键词： linear precoding codebook FPGA VHDL MIMO

来源：评论

学校读者我要写书评

暂无评论

Wavelet OFDM with Overlap FDE for non-Gaussian channels in precoded NOMA based systems

引用

FUTURE GENERATION COMPUTER SYSTEMS-THE INTERNATIONAL JOURNAL OF ESCIENCE 2019年 97卷 165-179页

作者： Khan, Arsla Khan, Saud Baig, Sobia Asif, Hafiz Muhammad Shin, Soo Young Kumoh Natl Inst Technol Dept IT Convergence Engn Gumi South Korea COMSATS Univ Islamabad Elect & Comp Engn Lahore Campus Lahore 59000 Pakistan

Non-orthogonal multiple access (NOMA) is considered as a prominent multiple access technique for fifth generation (5G) systems mainly because of its high spectral efficiency (SE). NOMA based system employs superposition coding (SC) and successive interference cancellation (SIC) at the transmitter and receiver side respectively. Classical multi-carrier NOMA adopts orthogonal frequency division multiplexing (OFDM) as a multi-carrier modulation (MCM) technique;however, high peak to average power ratio (PAPR) and cyclic prefix (CP) inclusion makes OFDM an inadequate choice for NOMA. To improve SE of the OFDM-NOMA, wavelet transform (WT) has been proposed for NOMA. This article proposes new physical layer techniques based on OFDM-NOMA and Wavelet OFDM (WOFDM) -NOMA for tactile internet and investigates their performance in the presence of Gaussian and non-Gaussian channels. Overlap frequency domain equalization (OFDE) is proposed as a robust equalization technique to improve the performance of SIC in the presence of Gaussian and non-Gaussian channels for OFDM-NOMA and WOFDM-NOMA. Moreover, to enhance the equalization efficiency of the OFDE, linear precoding (LP) in the form of Walsh Hadamard transform (WHT) is also recommended for OFDM and WOFDM based NOMA transceivers which improves the reliability of the network. Performance of the proposed precoded OFDM-NOMA and precoded WOFDM-NOMA with OFDE is analyzed in the presence of additive white Gaussian noise (AWGN) and impulse noise for Rayleigh fading channel. Link level performance of the presented structures for downlink NOMA is evaluated in terms of bit error rate (BER), PAPR, SE and computational complexity (CC). Furthermore, performance of the proposed architectures is also compared in the presence of impulse noise having different intensities. Simulation results via computer show that the proposed precoded WOFDM-NOMA with OFDE transceiver incorporates low latency through waveform shaping and enhanced reliability throu

关键词： Tactile internet Low latency Ultra high reliability Multi-carrier non-orthogonal multiple access Non-Gaussian channel Successive interference cancellation Overlap frequency domain equalization Wavelet transform Impulse noise linear precoding

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

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

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：