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linear precoding Based on Polynomial Expansion: Large-Scale Multi-Cell MIMO Systems

IEEE JOURNAL OF SELECTED TOPICS IN SIGNAL PROCESSING 2014年第5期8卷 861-875页

作者： Kammoun, Abla Mueller, Axel Bjornson, Emil Debbah, Merouane SUPELEC Alcatel Lucent Chair Flexible Radio F-91190 Gif Sur Yvette France KTH Royal Inst Technol ACCESS Linnaeus Ctr Signal Proc Lab S-10044 Stockholm Sweden

Large-scale MIMO systems can yield a substantial improvements in spectral efficiency for future communication systems. Due to the finer spatial resolution and array gain achieved by a massive number of antennas at the base station, these systems have shown to be robust to inter-user interference and the use of linear precoding appears to be asymptotically optimal. However, from a practical point of view, most precoding schemes exhibit prohibitively high computational complexity as the system dimensions increase. For example, the near-optimal regularized zero forcing (RZF) precoding requires the inversion of a large matrix. To solve this issue, we propose in this paper to approximate the matrix inverse by a truncated polynomial expansion (TPE), where the polynomial coefficients are optimized to maximize the system performance. This technique has been recently applied in single cell scenarios and it was shown that a small number of coefficients is sufficient to reach performance similar to that of RZF, while it was not possible to surpass RZF. In a realistic multi-cell scenario involving large-scale multi-user MIMO systems, the optimization of RZF precoding has, thus far, not been feasible. This is mainly attributed to the high complexity of the scenario and the non-linear impact of the necessary regularizing parameters. On the other hand, the scalar coefficients in TPE precoding give hope for possible throughput optimization. To this end, we exploit random matrix theory to derive a deterministic expression of the asymptotic signal-to-interference-and-noise ratio for each user based on channel statistics. We also provide an optimization algorithm to approximate the coefficients that maximize the network-wide weighted max-min fairness. The optimization weights can be used to mimic the user throughput distribution of RZF precoding. Using simulations, we compare the network throughput of the proposed TPE precoding with that of the suboptimal RZF scheme and show that our

关键词： Large-scale MIMO linear precoding multi-user systems polynomial expansion random matrix theory

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linear precoding for the MIMO Multiple Access Channel With Finite Alphabet Inputs and Statistical CSI

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2015年第2期14卷 983-997页

作者： Wu, Yongpeng Wen, Chao-Kai Xiao, Chengshan Gao, Xiqi Schober, Robert Southeast Univ Natl Mobile Commun Res Lab Nanjing 210096 Jiangsu Peoples R China Natl Sun Yat Sen Univ Inst Commun Engn Kaohsiung 804 Taiwan Missouri Univ Sci & Technol Dept Elect & Comp Engn Rolla MO 65409 USA Univ Erlangen Nurnberg Inst Digital Commun D-91058 Erlangen Germany

In this paper, we investigate the design of linear precoders for the multiple-input-multiple-output (MIMO) multiple access channel (MAC). We assume that statistical channel state information (CSI) is available at the transmitters and consider the problem under the practical finite alphabet input assumption. First, we derive an asymptotic (in the large system limit) expression for the weighted sum rate (WSR) of the MIMO MAC with finite alphabet inputs and Weichselberger's MIMO channel model. Subsequently, we obtain the optimal structures of the linear precoders of the users maximizing the asymptotic WSR and an iterative algorithm for determining the precoders. We show that the complexity of the proposed precoder design is significantly lower than that of MIMO MAC precoders designed for finite alphabet inputs and instantaneous CSI. Simulation results for finite alphabet signaling indicate that the proposed precoder achieves significant performance gains over existing precoder designs.

关键词： Finite alphabet linear precoding MIMO MAC statistical CSI

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linear precoding and Equalization for Network MIMO With Partial Cooperation

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2012年第5期61卷 2083-2096页

作者： Kaviani, Saeed Simeone, Osvaldo Krzymien, Witold A. Shamai (Shitz), Shlomo Univ Alberta Dept Elect & Comp Engn Edmonton AB T6A 2G4 Canada TRLabs Edmonton AB T5K 2M5 Canada New Jersey Inst Technol Ctr Wireless Commun & Signal Proc Res Newark NJ 07102 USA Technion Israel Inst Technol Dept Elect Engn IL-32000 Haifa Israel

A cellular multiple-input-multiple-output (MIMO) downlink system is studied, in which each base station (BS) transmits to some of the users so that each user receives its intended signal from a subset of the BSs. This scenario is referred to as network MIMO with partial cooperation since only a subset of the BSs is able to coordinate their transmission toward any user. The focus of this paper is on the optimization of linear beamforming strategies at the BSs and at the users for network MIMO with partial cooperation. Individual power constraints at the BSs are enforced, along with constraints on the number of streams per user. It is first shown that the system is equivalent to a MIMO interference channel with generalized linear constraints (MIMO-IFC-GC). The problems of maximizing the sum rate (SR) and minimizing the weighted sum mean square error (WSMSE) of the data estimates are nonconvex, and suboptimal solutions with reasonable complexity need to be devised. Based on this, suboptimal techniques that aim at maximizing the SR for the MIMO-IFC-GC are reviewed from recent literature and extended to the MIMO-IFC-GC where necessary. Novel designs that aim at minimizing the WSMSE are then proposed. Extensive numerical simulations are provided to compare the performance of the considered schemes for realistic cellular systems.

关键词： Cooperative communication linear precoding multicell processing network MIMO partial cooperation

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linear precoding with Friendly Jamming in Overloaded MU-MIMO Wiretap Networks

Linear Precoding with Friendly Jamming in Overloaded MU-MIMO...

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IEEE Conference on Communications and Network Security (CNS)

作者： Siyari, Peyman Krunz, Marwan Univ Arizona Dept Elect & Comp Engn Tucson AZ 85721 USA

ISBN: (纸本)9781538671177

We consider the downlink of a multiuser MIMO (MU-MIMO) network in the presence of an external eavesdropper (Eve). No knowledge of Eve's location is assumed at the access point (Alice). The information signals for downlink users (Bobs) are accompanied by bogus signals (a.k.a. friendly jamming) that are generated from Alice. The network is studied in underloaded and overloaded conditions. In an underloaded (overloaded) network, the number of antennas at Alice is larger (smaller) than the total number of Bobs' antennas. In the overloaded setting, traditional methods of creating friendly jamming (FJ), such as zero-forcing-based methods, are infeasible. We propose a linear precoding scheme that relaxes such infeasibility in overloaded MU-MIMO networks. In the worst-case scenario where Eve has knowledge of the channels between Alice and Bobs, we show that our method imposes the most stringent condition on the number of antennas required at Eve to cancel out FJ signals. We verify our analysis with simulations. It turns out that choosing the number of data streams has an important role in achieving a tradeoff between security, reliability, and the achievable rate.

关键词： Multiuser MIMO linear precoding physical-layer security friendly jamming

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linear precoding in the Intelligent Reflecting Surface Assisted MIMO Broadcast Channel 23

Linear Precoding in the Intelligent Reflecting Surface Assis...

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23rd International Workshop on Signal Processing Advances in Wireless Communication (SPAWC)

作者： Semmler, Dominik Joham, Michael Utschick, Wolfgang Tech Univ Munich Inst Signal Proc D-80333 Munich Germany

ISBN: (数字)9781665494557

ISBN: (纸本)9781665494557

We propose efficient algorithms to solve the sumrate maximization in the Intelligent Reflecting Surface (IRS) assisted Multiple-Input Multiple-Output (MIMO) Downlink (DL) scenario. The recommended methods are based on linear Successive Allocation (LISA), a well performing linear precoding algorithm for the traditional MIMO DL. Taking LISA as a basis, we can exploit its characteristic zero-forcing structure which allows to obtain a special form of alternating optimization. This special form enables a quick convergence and we observe a reduced iteration number together with a good performance of the proposed methods in the simulations.

关键词： MIMO Downlink IRS LISA linear precoding Zero-Forcing

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linear precoding Based On Correlation Rotation For The Multi-User MIMO Downlink

Linear Precoding Based On Correlation Rotation For The Multi...

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54th Annual IEEE Global Telecommunications Conference (GLOBECOM)

作者： Masouros, C. Queens Univ Belfast Sch Elect Engn Elect & Comp Sci Belfast BT7 1NN Antrim North Ireland

ISBN: (纸本)9781424492688

This paper investigates the potential of exploiting interference power in order to enhance the performance of multiple input multiple output (MIMO) broadcast systems using phase shift keying (PSK) modulation. Towards this end, the proposed linear precoding aims at adaptively rotating, rather than zeroing, the correlation between the MIMO sub-streams depending on the transmitted data, so that the signal of interfering transmissions is aligned to the signal of interest at each receive antenna. By doing so, the co-channel interference (CCI) is always kept constructive and the received signal to interference-plus-noise ratio (SINR) delivered to the mobile units (MUs) is enhanced without the need to invest additional signal power per transmitted symbol at the MIMO base station (BS). It is shown by means of theoretical analysis and simulations that by using interference as a source of green energy the proposed technique outperforms conventional precoding.

关键词： Adaptive transmission channel inversion known interference multi-user MIMO linear precoding

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Blind Channel Estimation Based linear precoding using MIMO-OFCDM

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WIRELESS PERSONAL COMMUNICATIONS 2017年第4期97卷 5969-5981页

作者： Sujitha, J. Baskaran, K. Sri Ramakrishna Engn Coll Elect & Commun Engn Dept Coimbatore Tamil Nadu India Govt Coll Technol Dept Elect Engn Coimbatore Tamil Nadu India

MIMO-OFCDM is one of the emerging wireless communication technologies which provide very high data rate transmission with multicarrier modulation technique. OFCDM utilizes spatial diversity method that uses many transmitters and receivers to transmit more than one data in the same frequency at the same time. This paper proposes blind channel estimation based on linear precoding (LP) approach for 2 by 2 MIMO-OFCDM broadband communication system. The uniqueness of the proposed method is to estimate the channel response in blind fashion and minimize the BER in MIMO-OFCDM. linear precoding based blind channel estimation is implemented to estimate the performance of the MIMO-OFCDM for various parameters including different number of users, three different modulations such as BPSK, QPSK and 16 QAM, two types of Spreading Factors over AWGN and Rayleigh channels. The system performance is then compared with the other existing methods. It is found that the blind channel estimation provides better performance with minimum BER. It also suggests that the LP based blind channel estimation in MIMO OFCDM system outperforms with QPSK modulation with more users and high spreading factor over Rayleigh channel.

关键词： Blind channel estimation linear precoding Spreading factor MIMO OFCDM Walsh-Hadamard code

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Analysis of One-Bit Quantized linear precoding Schemes in Multi-Cell Massive MIMO Downlink

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IEEE TRANSACTIONS ON COMMUNICATIONS 2024年第5期72卷 2577-2594页

作者： Nadeem, Qurrat-Ul-Ain Chaaban, Anas Univ British Columbia Sch Engn Kelowna BC Canada

This work studies a multi-cell one-bit massive multiple-input multiple-output (MIMO) system that employs one-bit analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) at each base station (BS). We utilize Bussgang decomposition to derive downlink signal-to-quantization-plus-interference-plus-noise ratio (SQINR) and ergodic achievable rate expressions under one-bit quantized maximum ratio transmission (MRT) and zero-forcing (ZF) precoding schemes considering scenarios with and without pilot contamination (PC) in the derived channel estimates. The results are also simplified for the mixed architecture that employs full resolution (FR) ADCs and one-bit DACs, and the conventional architecture that employs FR ADCs and DACs. The SQINR is shown to decrease by a factor of 2/pi and4/pi(2) in the one-bit setting compared to that achieved in the mixed setting and conventional setting respectively under MRT precoding without PC. Interestingly, the decrease in SQINR is less when we consider PC, which is shown to adversely impact the conventional system more than the one-bit system. Similar insights are obtained under ZF precoding with the decrease in the SQINR with the use of one-bit ADCs and DACs being more pronounced. We utilize the derived expressions to yield performance insights related to power efficiency, the numbers of antennas needed by the three architectures to achieve the same sum-rate, and energy efficiency.

关键词： Massive MIMO precoding Downlink Computer architecture Uplink Quantization (signal) Channel estimation Multi-cell massive MIMO one-bit quantization Bussgang decomposition linear precoding achievable rates

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Two low -complexity high-performance linear precoding schemes for secure spatial modulation ?

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PHYSICAL COMMUNICATION 2020年 41卷 101099-101099页

作者： Liu, Lin Wang, Zhengwang Zhuang, Zhihong Liu, Tingting Zhou, Xiaobo Hu, Jinsong Han, Zhu Shu, Feng Nanjing Univ Sci & Technol Sch Elect & Opt Engn Nanjing 210094 Peoples R China Fuzhou Univ Coll Phys & Informat Engn Fuzhou 350116 Peoples R China Univ Houston Dept Elect & Comp Engn Houston TX 77004 USA

In this work, we investigate linear precoding for secure spatial modulation. With secure spatial modulation, the achievable secrecy rate does not have an easy-to-compute mathematical expression, and hence, has to be evaluated numerically, which leads to high complexity in the optimal precoder design. To address this issue, an accurate and analytical approximation of the secrecy rate is derived in this work. Using this approximation as the objective function, two low-complexity linear precoding methods based on gradient descent (GD) and successive convex approximation (SCA) are proposed. The GD-based method has much lower complexity but usually converges to a local optimum. On the other hand, the SCA-based method uses semi-definite relaxation to deal with the non-convexity in the precoder optimization problem and achieves near-optimal solution. Compared with the existing GD-based precoder design in the literature that directly uses the exact and numerically evaluated secrecy capacity as the objective function, the two proposed designs have significantly lower complexity. Our SCA-based design even achieves a higher secrecy rate than the existing GD-based design.

关键词： MIMO Secure spatial modulation linear precoding Gradient descent Successive convex approximation

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Asymptotic Per-User Rate Analysis of Downlink MIMO Cellular Networks with linear precoding

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2012年第12期11卷 4536-4548页

作者： Liu, Zhiyang Dai, Lin City Univ Hong Kong Dept Elect Engn Kowloon Tong Hong Kong Peoples R China

Extensive studies have been conducted on the rate analysis of downlink multiuser multiple-input-multiple-output (MIMO) systems. Most of them, nevertheless, focused on the sum rate of all the users where the effect of large-scale fading is either ignored or simplified. For interference-limited MIMO cellular networks, users in various locations may achieve drastically different rates due to distinct large-scale fading and interference levels. It is, therefore, of great practical interest to characterize the rate performance of each single user under various power allocation strategies and precoding schemes. This paper presents an asymptotic per-user rate analysis for a 1-tier (i.e., 7-cell) downlink MIMO cellular network with M base-station antennas co-located at the center of each cell and K uniformly distributed users each equipped with N antennas. Explicit expressions of the ergodic rate with two representative linear precoding schemes, singular-value-decomposition (SVD) transmission and block diagonalization (BD), are derived, based on which the effect of power allocation strategies is further evaluated. The analysis shows that the rate performance of each user is sensitive to its position even if the average received power is kept a constant. To achieve a uniform rate all over the cell, an interference-aware power allocation scheme is proposed, with which the transmit power allocated to each user is carefully adjusted according to the large-scale fading coefficients from the user to its own and neighboring base stations. The tradeoff between fairness and sum rate performance is also identified, which highlights the importance of the characterization of per-user rate.

关键词： Asymptotic rate analysis MIMO downlink cellular networks power allocation linear precoding block diagonalization singular-value-decomposition transmission

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