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Constellation coordination and pilot reuse for multi-cell large-scale MIMO systems

IET COMMUNICATIONS 2020年第2期14卷 357-363页

作者： Xu, Fangmin Wang, Haiquan Wang, Honggang Cao, Haiyan Hangzhou Dianzi Univ Inst Commun Engn Hangzhou Zhejiang Peoples R China Univ Massachusetts UMass Dartmouth Dept Elect & Comp Engn Dartmouth MA USA

To alleviate pilot contamination for multi-cell large-scale multiple-input multiple-output (MIMO) systems, here the authors propose a constellation coordination scheme according to a constellation coordination constraint (CC constraint) on the large-scale fading factors. In fact, a detailed analysis of the uplink process introduces the CC constraint, which reveals that if the CC constraint cannot be satisfied, the error probability will be larger than a threshold. Otherwise, the error probability goes to zero if both the number of antennas at the base station and signal-to-noise ratio go to infinity. Furthermore, by modelling the location of users as a Poisson point process, the authors derive a safe area threshold according to the CC constraint, through which an adaptive pilot reuse is proposed. In this scheme, users outside the dynamic safe area threshold are allowed to reuse the pilot, while other users are not allowed. Simulation results show that the CC scheme alleviates the pilot contamination effectively and the proposed pilot reuse scheme based on the safe area threshold improves the uplink achievable rate of the system significantly.

关键词： MIMO communication channel estimation cellular radio antenna arrays error statistics CC constraint large-scale fading factors uplink process error probability signal-to-noise ratio Poisson point process adaptive pilot reuse dynamic safe area threshold CC scheme pilot contamination pilot reuse scheme large-scale MIMO systems multiple-input multiple-output systems constellation coordination scheme constellation coordination constraint

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MMSE-based iterative processing with imperfect channel and parity check in MIMO systems

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IET COMMUNICATIONS 2019年第17期13卷 2660-2667页

作者： Jiang, Fan Li, Cheng Gong, Zijun Zhang, Yan Liu, Shudong Hao, Kun Mem Univ Newfoundland Dept Elect & Comp Engn Fac Engn & Appl Sci St John NF A1B 3X5 Canada Tianjin Chengjian Univ Dept Elect & Comp Engn Tianjin Peoples R China

It is known that the acquisition of the complete channel state information at receivers is difficult in multiple-input multiple-output (MIMO) systems. Channel estimation error is unavoidable in practical applications. Under imperfect channel conditions, the channel estimate is directly applied to the equalisation process in the conventional minimum mean-square error (MMSE)-based turbo equalisation scheme. A few studies treat the channel estimation error as an independent component from the channel estimate and slightly enhanced performance is achieved. Unlike the existing work, the authors derive the MMSE-based iterative processing conditioned on channel estimate. Moreover, they note that in low-density parity check coded systems, the parity-check procedure is also involved. The pass in parity check indicates that the message bitstream is successfully recovered. This information can be utilised to reduce the overall computational complexity by degrading the MIMO size since the unknown parameters are reduced. By extending the analysis in a small-scale MIMO system to a large-scale one, they propose to utilise the normalised transmission power in the development. Numerical results show the proposed schemes outperform the existing schemes in terms of system bit error rate and computational complexity performance.

关键词： parity check codes computational complexity equalisers channel estimation iterative methods MIMO communication least mean squares methods error statistics turbo codes wireless channels parity-check procedure small-scale MIMO system system bit error rate complete channel state information multiple-input multiple-output systems channel estimation error imperfect channel conditions equalisation process low-density parity check MMSE-based iterative processing minimum mean-square error-based turbo equalisation scheme

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Approximate distribution of log₂(A + χ²) and its applications

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IET COMMUNICATIONS 2013年第10期7卷 931-941页

作者： Qi, Yuan Qian, Rongrong Peng, Tao Wang, Wenbo Beijing Univ Posts & Telecommun Sch Elect Engn Beijing 100088 Peoples R China Beijing Univ Posts & Telecommun Automat Sch Beijing 100088 Peoples R China Beijing Univ Posts & Telecommun Minist Educ Key Lab Univ Wireless Commun Wireless Signal Proc & Network Lab Beijing 100088 Peoples R China

This study concerns the approximate distribution of the random variable log(2)(A + chi(2)) and its applications in the performance analysis of communication systems where A is 0 or 1 and chi(2) a chi-square distributed random variable. The authors prove that log(2)(A + chi(2)) is approximately Gaussian distributed and derive the expressions of the mean and variance of the approximate distribution. The approximate Gaussian distribution provides a new way to simplify the derivation of performance metrics and obtain analytical results. Then the authors utilise the approximate results in two applications, which are the approximation of the Gaussian Q-function and capacity analysis, respectively. For one thing, the approximate distribution can be explored to deduce a new approximate equivalent expression of the Q-function on the basis of which an accurate approximation of the Gaussian Q-function can be developed. For another, the approximate Gaussian distribution provides an intuitive approach to analyse the channel capacity of Rayleigh-fading multiple antenna systems. The approximate statistical distributions of the channel capacities of orthogonal space-time block codes, single-input multiple-output, multiple-input single-output, transmit antenna selection with maximal-ratio combining and multiple-input multiple-output systems are presented. The applicability of the approximate distribution can be demonstrated through simulation results in both applications.

关键词： antenna arrays channel capacity channel coding diversity reception Gaussian distribution MIMO communication Rayleigh channels transmitting antennas space-time block codes random variable log2(A + Ï‡2) approximate distribution communication systems distributed random variable approximate Gaussian distribution Gaussian Q-function capacity analysis approximate equivalent expression channel capacity Rayleigh-fading multiple antenna systems approximate statistical distributions orthogonal space-time block codes single-input multiple-output transmit antenna selection multiple-input single-output transmit antenna selection maximal-ratio combining multiple-input multiple-output systems

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Alternating Multiuser Detection with Soft Interference Cancellation for Heterogeneous-Signaling MIMO CDMA systems

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WIRELESS PERSONAL COMMUNICATIONS 2012年第4期67卷 811-828页

作者： Tu, Yung-Ping Lu, Hoang-Yang Fang, Wen-Hsien Natl Taiwan Ocean Univ Dept Elect Engn Keelung Taiwan Natl Taiwan Univ Sci & Technol Dept Elect Engn Taipei Taiwan

This paper presents an effective alternating multiuser detector for the uplink of heterogeneous-signaling multiple-input multiple-output code division multiple access systems over multipath fading channels, where the data are transmitted using either spatially multiplexing for high transmission rate or space-time block code for transmit diversity gains. The new MUD first separates users into two groups according to their transmission signaling schemes and then detects the transmitted symbols in each group alternately with the removal of iteratively refined soft information-assisted multiple access interference to enhance the interference cancellation capability. Moreover, for practical low-complexity implementations, the users in each group are further partitioned into smaller subgroups based on their effective channel correlations and then detected in parallel by a bank of minimum mean-squared error soft detectors to further reduce the computational load. Conducted simulations show that the proposed MUD can render superior performance compared with previous approaches, especially in highly loaded scenarios.

关键词： multiple-input multiple-output systems CDMA Multiuser detection Spatially multiplexing Space-time block code

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A power scaling analysis of norm-based antenna selection techniques

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2008年第8期7卷 3140-3149页

作者： Smith, Peter J. King, Timothy W. Garth, Lee M. Dohler, Mischa Univ Canterbury Dept Elect & Comp Engn Christchurch 1 New Zealand BAE Syst Adv Syst & Technol Div Merrimack NH 03054 USA Telecommun Technol Ctr Catalonia Barcelona 08860 Spain

In this paper we consider transmit and receive selection methods designed to achieve high channel capacities in a single-user MIMO link. A variety of radio channels are considered, including i.i.d. Rayleigh, correlated Rayleigh and Ricean fading environments. Also considered is the presence of imperfect channel state information (CSI) and a simplified waterfilling scheme. In all cases, we evaluate the performance of optimal selection, simple norm-based selection and other benchmark selection techniques. The major contribution is a general approach to analyzing the capacity of the norm-based selection schemes via a simple power scaling factor. We are able to assess the impact of different channels, imperfect CSI and power allocation using this power scaling factor. Furthermore, the analysis is valid for all scenarios: transmit selection, receive selection and joint transmit-receive selection. Results are shown which compare the capacity performance over a wide range of cases. A notable conclusion is that optimal selection, which is computationally intensive, is outperformed at low signal-to-noise-ratios by the simple norm-based approach with power allocation.

关键词： multiple-input multiple-output systems antenna selection techniques Rayleigh fading Ricean fading

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Improved Perfect Space-Time Block Codes

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IEEE TRANSACTIONS ON INFORMATION THEORY 2013年第12期59卷 7927-7935页

作者： Srinath, K. Pavan Rajan, B. Sundar Indian Inst Sci Dept Elect Commun Engn Bangalore 560012 Karnataka India

Perfect space-time block codes (STBCs) are based on four design criteria-full-rateness, nonvanishing determinant, cubic shaping, and uniform average transmitted energy per antenna per time slot. Cubic shaping and transmission at uniform average energy per antenna per time slot are important from the perspective of energy efficiency of STBCs. The shaping criterion demands that the generator matrix of the lattice from which each layer of the perfect STBC is carved be unitary. In this paper, it is shown that unitariness is not a necessary requirement for energy efficiency in the context of space-time coding with finite input constellations, and an alternative criterion is provided that enables one to obtain full-rate (rate of complex symbols per channel use for an transmit antenna system) STBCs with larger normalized minimum determinants than the perfect STBCs. Further, two such STBCs, one each for 4 and 6 transmit antennas, are presented and they are shown to have larger normalized minimum determinants than the comparable perfect STBCs which hitherto had the best-known normalized minimum determinants.

关键词： Cyclic division algebras Galois group multiple-input multiple-output systems nonvanishing determinant shaping criterion space-time block codes

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Performance analysis of adaptive DFE using set-membership binormalized data-reusing LMS algorithm for frequency selective MIMO channels

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AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS 2017年 77卷 91-99页

作者： Mishra, Ramesh Chandra Bhattacharjee, Ratnajit Indian Inst Technol Guwahati Dept Elect & Elect Engn Gauhati Assam India

This paper addresses the concern of complexity involved with adaptive equalization in wireless systems operating over time-varying and frequency selective multiple-input multiple-output (MIMO) channels. Here, we propose a decision feedback equalizer using binormalized data-reusing least mean square (BNLMS) algorithm with set-membership filtering for MIMO channels. The performance of the equalizer is investigated for a MIMO receiver in a multi-path fading environment as experienced in the indoor and pedestrian environment. The equalizer performance is also studied for channels having higher delay and Doppler spread. The convergence issues, BER performance and tracking capabilities are examined through computer simulations. Moreover, the computational complexity issue for this MIMO equalizer is compared with other existing data-selective algorithm based techniques. (C) 2017 Elsevier GmbH. All rights reserved.

关键词： Binormalized data-reusing least mean square Data-selective Decision feedback equalizer multiple-input multiple-output systems

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MIMO antenna selection using biogeography-based optimization with nonlinear migration models

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INTERNATIONAL JOURNAL OF COMMUNICATION systems 2018年第17期31卷 e3813-e3813页

作者： Fountoukidis, Konstantinos C. Kalialakis, Christos Psannis, Kostas E. Siakavara, Katherine Goudos, Sotirios K. Sarigiannidis, Panagiotis Obaidat, Mohammad Aristotle Univ Thessaloniki Dept Phys Thessaloniki Greece CTTC Microwave Syst & Nanotechnol Dept Castelldefels Spain Univ Macedonia Sch Informat Sci Dept Appl Informat Thessaloniki Greece Univ Western Macedonia Dept Informat & Telecommun Engn Kozani Greece Univ Jordan King Abdullah II Sch IT Amman Jordan

This papers deals with the problem of antenna selection (AS) for a multiple-input multiple-output (MIMO) wireless system under the constraint of the channel capacity maximization. The biogeography-based optimization (BBO) algorithm is applied on the joint transmitter and receiver AS problem. Moreover, the performance of different BBO migration models is compared with a real valued genetic algorithm (RVGA) as well as with the ant colony optimization (ACO). Representative simulation scenarios are provided in detail, involving selection of 2 x 4,3 x 5,4 x 6,8 x 8 antennas in a 16 x 16 MIMO system. The numerical results demonstrate the efficiency and the applicability of the BBO algorithm in modern MIMO wireless systems.

关键词： ant colony optimization antenna selection biogeography-based optimization evolutionaryr algorithms genetic algorithm multiple-input multiple-output systems

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Exact bit error probabilities and packet error statistics for SVD transmission over time-varying dual-branch MIMO systems obtained by a Markov model

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AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS 2013年第2期67卷 113-122页

作者： Ivanis, Predrag N. Stojnic, Milena M. Drajic, Dusan B. Univ Belgrade Fac Elect Engn Belgrade 11001 Serbia

Using a finite state Markov channel model, we develop an analytical method for evaluation of the packet error structure in multiple-input multiple-output (MIMO) systems based on singular value decomposition (SVD). We consider dual-branch MIMO systems, with either two transmit and arbitrary number of receive antennas, or arbitrary number of transmit and two receive antennas. The corresponding Markov model parameters are obtained using a novel closed-form expressions for probability density function and level crossing rate of the signal-to-noise ratio at the output of eigenchannels in a MIMO system, derived for a case of Rayleigh propagation, imperfect channel state information and any fixed power allocation. The exact bit error rate for the transmission of quadrature amplitude modulated (QAM) symbols through the eigenchannels is derived in polynomial closed form. Furthermore, by using the developed Markov model, the packet error statistics in the corresponding eigenchannels are determined, and the closed-form analytical expression for the system throughput is derived when 'go-back-N' automatic repeat request procedure is applied in time-varying eigenchannels. The analytical results are validated by using Monte Carlo simulations. (C) 2012 Elsevier GmbH. All rights reserved.

关键词： Automatic repeat request Beamforming Bit error rate Markov model multiple-input multiple-output systems Packet error structure Singular value decomposition

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QOSTBC coded MIMO system with reduced complexity and optimised decoding for rank deficient channels

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IET COMMUNICATIONS 2020年第4期14卷 646-654页

作者： Gupta, Bhasker Balyan, Vipin Saini, Davinder S. CCET ECE Dept Sect 26 Chandigarh India Cape Peninsula Univ Technol EEC Dept Cape Town South Africa

In multiple-input multiple-output (MIMO) systems, rank deficient channels are the most common and key areas of research. In these channels, the number of transmit antennas (M-Tx) is higher than receive antennas (M-Rx) and subsequently the unknown variables are more than the number of equations. In such situations, the conventional sphere decoder (SD) fails due to the presence of zero diagonal elements in Cholesky decomposition. This study analyses the quasi-orthogonal space-time block code (QOSTBC) of symbol rate-2 for M-Tx = 4 with modified double-layer SD detection to overcome rank deficiency problem. The first half of transmitted symbols is detected using two partially dependent SDs with optimised search radii. The remaining half is detected by employing single symbol maximum likelihood detection. Simulation and analytical results indicate that the proposed detection scheme reduces bit error rate and complexity compared to existing techniques.

关键词： channel coding space-time block codes maximum likelihood detection decoding transmitting antennas MIMO communication receiving antennas error statistics antenna arrays communication complexity search problems rank deficient channels multiple-input multiple-output systems transmitting antennas sphere decoder zero diagonal elements quasiorthogonal space-time block code symbol rate-2 modified double-layer SD detection rank deficiency problem single symbol maximum likelihood detection bit error rate QOSTBC coded MIMO system search radii optimisation receiving antennas Cholesky decomposition

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