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Multi-User Precoder Designs for RGB Visible Light Communication Systems

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

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Block-ordered layered detector for MIMO-STBC using joint eigen-beamformers and ad-hoc power discrimination scheme

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JOURNAL OF COMMUNICATIONS AND NETWORKS 2006年第3期8卷 275-285页

作者： Lee, Won Cheol Soongsil Univ Sch Elect Engn Seoul South Korea

Suitable for multi-input multi-output (MIMO) communications, the joint beamforming space-time block coding (JBSTBC) scheme is proposed for high-speed downlink transmission. The major functionality of the scheme entails space-time block encoder and joint transmit and receive eigen-beamformer (EBF) incorporating with block-ordered layered decoder (BOLD), and its operating principle is described in this paper. Within these functionalities, the joint EBFs will be utilized for decorrelating fading channels to cause an enhancement in the spatial diversity gain. Furthermore, to fortify the capability of layered successive interference cancellation (LSIC) in block-ordered layered decoding process, this paper will develop a simple ad-hoc transmit power discrimination scheme (TPDS) based on a particular power discrimination function (PDF). To confirm the superior behavior of the proposed JBSTBC scheme employing ad-hoc TPDS, computer simulations will be conducted under various channel conditions with the provision of detailed mathematical derivations for clarifying its functionality.

关键词： eigen-beamformer (EBF) layered interference cancellation linear precoding multiple-input multiple-output (MIMO) systems orthogonal space-time block coding (OSTBC)

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Multiantenna Secure Cognitive Radio Networks With Finite-Alphabet Inputs: A Global Optimization Approach for Precoder Design

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2016年第4期15卷 3044-3057页

作者： Zeng, Weiliang Zheng, Yahong Rosa Xiao, Chengshan Missouri Univ Sci & Technol Rolla MO USA Qualcomm Res San Diego CA 92121 USA Missouri Univ Sci & Technol Dept Elect & Comp Engn Rolla MO 65409 USA

This paper considers the precoder design for multi-antenna secure cognitive radio networks. We use finite-alphabet inputs as the signaling and exploit statistical channel state information (CSI) at the transmitter. We maximize the secrecy rate of the secondary user and control the transmit power and the power leakage to the primary receivers that share the same frequency spectrum. The secrecy rate maximization is important for practical systems, but challenging to solve, mainly due to two reasons. First, the secrecy rate with statistical CSI is computationally prohibitive to evaluate. Second, the optimization over the precoder is a nondeterministic polynomial-time hard (NP-hard) problem. We utilize an accurate approximation of the secrecy rate to reduce the computational effort and then propose a global optimization approach based on branch-and-bound method. The idea is to define a simplex and transform the secrecy rate into a concave function. The derived concave function converges to the secrecy rate when the defined simplex shrinks down. Using this feature, we solve a sequence of concave maximization problems over iteratively shrinking simplices and eventually attain the globally optimal solution that maximizes the approximation of the secrecy rate. When the complexity is concerned, a low-complexity variant with limited number of iterations can be used in practice. We demonstrate the performance gains when compared with others through numerical examples.

关键词： Multiantenna secure cognitive radio networks finite-alphabet inputs statistical channel state information linear precoding multiple-input multiple-output global optimization

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Joint precoding and Decoding in MU-MIMO Downlink Systems with Perfect Channel State Information (CSI)

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Procedia Technology 2012年 6卷 708-715页

作者： M.Raja P. Muthuchidambaranathan Department of Electronics and Communication Engineering National Institute of Technology Tiruchirappalli India

In this paper, we propose an joint optimization of precoder and decoder for downlink transmissions in multiuser multiple-input, multiple-output (MU-MIMO) systems with perfect channel state information (CSI). This paper focuses on the scenario when an improper constellation such as binary phase shift-keying (BPSK) or M -ary amplitude shift-keying ( M -ASK) is employed. The proposed joint design aims to minimize all the users total mean-squared-error (TMSE) under the constraint of total transmit power. Simulation results show that the proposed joint linear precoder and decoder designs improves BER performance of MU-MIMO downlink systems and verify its effectiveness.

关键词： Multiple-input multiple-output (MIMO) Total mean square error (TMSE) Channel state information (CSI) linear precoding Diversity Improper modulations

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Spatial Resources Optimization in Distributed MIMO Networks with Limited Data Sharing

Spatial Resources Optimization in Distributed MIMO Networks ...

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IEEE Globecom Workshops (GC Wkshps)

作者： Gotsis, Antonis G. Alexiou, Angeliki Univ Piraeus Dept Digital Syst Piraeus Greece

ISBN: (纸本)9781479928514

Wireless access through a large distributed network of low-complexity infrastructure nodes empowered with cooperation and coordination capabilities, is an emerging radio architecture, candidate to deal with the mobile data capacity crunch. In the 3GPP evolutionary path, this is known as the Cloud-RAN paradigm for future radio. In such a complex network, distributed MIMO resources optimization is of paramount importance, in order to achieve capacity scaling. In this paper, we investigate eff cient strategies towards optimizing the pairing of access nodes with users as well as linear precoding designs for providing fair QoS experience across the whole network, when data sharing is limited due to complexity and overhead constraints. We propose a method for obtaining a spatial resources allocation optimization solution which can be applied in networks of limited scale, as well as an approximation algorithm with bounded polynomial complexity which can be used in larger networks. The particular algorithm outperforms existing user-oriented clustering techniques and achieves quite high quality-of-service levels with reasonable complexity.

关键词： C-RAN Distributed MIMO Backhaul Overhead Minimization Pairing linear precoding MI-SOCP

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ON THE IMPACT OF SPATIAL CORRELATION AND PRECODER DESIGN ON THE PERFORMANCE OF MIMO SYSTEMS WITH SPACE-TIME CODING

ON THE IMPACT OF SPATIAL CORRELATION AND PRECODER DESIGN ON ...

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IEEE International Conference on Acoustics, Speech and Signal Processing

作者： Bjoernson, Emil Ottersten, Bjoern Jorswieck, Eduard Royal Inst Technol Signal Proc Lab ACCESS Linnaeus Ctr Stockholm Sweden Tech Univ Dresden Commun Lab Chair Commun Theory Dresden Germany

ISBN: (纸本)9781424423538

The symbol error performance of spatially correlated multi-antenna systems is analyzed herein. When the transmitter only has statistical channel information, the use of space-time block codes still pen-nits spatial multiplexing and mitigation of fading. The statistical information can be used for precoding to optimize some quality measure. Herein, we analyze the performance in terms of the symbol error rate (SER). It is shown analytically that spatial correlation at the receiver decreases the performance both without precoding and with an SER minimizing precoder. Without precoding, correlation should also be avoided at the transmitter side, but with an SER minimizing precoder the performance is actually improved by increasing spatial correlation at the transmitter. The structure of the optimized precoder is analyzed and the asymptotic properties at high and low SNRs are characterized and illustrated numerically.

关键词： linear precoding Majorization MIMO Systems Orthogonal Space-Time Block Codes Symbol Error Rate

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An Efficient Method for MSE Transceiver Design With Imperfect CSIat Both Ends of a MIMO Link

An Efficient Method for MSE Transceiver Design With Imperfec...

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International Conference on Communication Technology and System Design

作者： Sudhir, A. Ch. Rajasekhar, Ch. PrabhakaraRao, B. Krishnachaitanaya, M. Saimdhuri, P. JignashReddy, K. GITAM Univ GIT Dept ECE Visakhapatnam Andhra Pradesh India JNTU Univ Dept ECE Kakinada Andhra Pradesh India

Multiple transmit and receive antennas can be used to form multiple-input multiple-output (MIMO) channels to increase the capacity by a factor of the minimum number of transmit and receive antennas. In this paper, we propose a novel joint linear transceiver design for single-user multiple-input, multiple-output (SU-MIMO) systems employing improper signal constellations. In particular, improved minimum mean square error (MMSE) transceiver is designed based on modified cost functions, with channel mean as well as both transmit and receive correlation information at both ends. The joint design is formulated into an optimization problem. The optimum closed-form precoder and decoder are derived. Compared to the case with perfect channel state information (CSI), linear filters are added at both ends to balance the suppression of channel noise and the noise from imperfect channel estimation. The superiority of the proposed joint linear transceiver design over the conventional solutions is verified by simulation results. (C) 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of ICCTSD 2011

关键词： Channel state information (CSI) mean-square error (MSE multiple-input multiple-output (MIMO) linear precoding spatial multiplexing

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The Performance of Massive MIMO Systems under Correlated Channel

The Performance of Massive MIMO Systems under Correlated Cha...

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19th IEEE International Conference on Networks (ICON)

作者： Fang, Xin Fang, Sheng Ying, Na Cao, Haiyan Liu, Chao Southeast Univ Natl Mobile Commun Res Lab Nanjing Jiangsu Peoples R China Hangzhou Dianzi Univ Coll Commun Engn Hangzhou Zhejiang Peoples R China

ISBN: (纸本)9781479920846

Most researches on the massive multiple-input multiple-output (MIMO) systems are based on the assumption that the MIMO channels are independent, in reality, the above assumption is very difficult to realize when the number of multiple antennas are very large. Hence the simulation on massive MIMO systems under correlated channels has some degree of guiding significance for practical application of massive MIMO systems. Simulation results show that the performance of massive MIMO systems becomes worse when the correlation coefficients of the channels increase. And when the channel correlation coefficient becomes smaller than a certain small value, the performance of massive MIMO systems will be enhanced quickly as the number of Base Station (BS) antennas increases;while the channel correlation coefficient is larger than the certain value, the performance is enhanced slowly as the number of BS antennas increases.

关键词： massive MIMO correlated channel channel estimate linear precoding

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Single- and Multiple-RF Load Controlled Parasitic Antenna Arrays Operating at Cm-Wave Frequencies: Design and Applications for 5G Wireless Access / Backhaul 56

Single- and Multiple-RF Load Controlled Parasitic Antenna Ar...

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56th FITCE Congress

作者： Ntougias, Konstantinos Ntaikos, Dimitrios Papadias, Constantinos B. AIT 44 Kifissias Ave Maroussi 15125 Greece

ISBN: (纸本)9781538605660

MIMO technology is expected to play a key role in the endeavour to reach the capacity target of 5G systems, in conjunction with the use of frequencies above 6 GHz. This communication paradigm is anticipated to be utilised also in the wireless backhaul domain, in order to meet the high capacity requirements of the future wireless transport networks. The performance of the considered MIMO transmission methods is determined by the number of antennas that can be deployed on the transmitting nodes, which in turn is limited by cost and energy consumption constraints. Load controlled parasitic antenna arrays represent a type of antenna systems which are able to boost the performance of these communication schemes, while employing a small number of antennas. In this paper, we present the design of single-and multiple-fed parasitic antenna arrays operating at the 19 GHz frequency band. Moreover, we describe a simple and robust technique that allows us to perform arbitrary channel-dependent precoding with such arrays. Furthermore, we study a low-complexity communication protocol that can be applied to setups that are equipped with such antenna systems and used in low-mobility scenarios, such as wireless backhaul applications. The numerical simulation results showcase the validity of these approaches for both wireless access and backhaul applications and demonstrate the superiority of the parasitic antenna arrays over equivalent, regarding the number of their antenna elements, antenna systems.

关键词： Coordinated multiple-input multiple-output (Co-MIMO) channel state information (CSI) linear precoding load-controlled parasitic antenna array (LC-PAA) wireless backhaul

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linear MMSE Transceiver Optimization for General MIMO Wiretap Channels with QoS Constraints

Linear MMSE Transceiver Optimization for General MIMO Wireta...

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2nd IEEE/CIC International Conference on Communications in China (ICCC)

作者： Pei, Minyan Wang, Lei Ma, Dongtang NUDT Coll Elect Sci & Engn Changsha 410073 Hunan Peoples R China Naval Acad Armament Beijing 100036 Peoples R China

ISBN: (纸本)9781467328159

In this paper, we investigate the problem of jointly designing optimum linear precoder and decoder with secrecy constraints, where two legitimate parties communicate in the presence of an eavesdropper over multiple-input multiple-output (MIMO) Gaussian channels. In particular, we focus on optimizing the linear transceiver to guarantee a certain quality of service (QoS) level for the legitimate receiver in terms of mean square error (MSE), whilst employing the artificial noise to maximally degrade the MSE for the eavesdropper. We assume that the transmitter may not or may have the channel state information (CSI) for the eavesdropper, and then propose two design formulations. With the aid of majorization theory, we characterize the forms of optimal transmit precoder when both the legitimate receiver and the eavesdropper employ the optimal linear MMSE receiver. Numerical results illustrate main conclusions.

关键词： MIMO wiretap channels secure communications MMSE linear precoding

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