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Quantized Feedback-Based Diagonal Precoding for N x 1 MISO System With Generalized Orthogonal space-time block codes

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IEEE TRANSACTIONS ON COMMUNICATIONS 2018年第1期66卷 91-104页

作者： Garg, Ankit Bhatnagar, Manav R. Berder, Olivier Vrigneau, Baptiste IIT Delhi Dept Elect Engn New Delhi 110016 India Univ Rennes 1 CNRS UMR INRIA IRISA F-22300 Lannion France

In this paper, we propose an imperfect quantized feedback-based diagonal precoding scheme for generalized orthogonal space-time block codes in an N x 1 multiple-input single-output ( MISO) wireless communication system employing M-QAM constellation. It is well known that a feedback-based precoding scheme aids channel adaptive signaling in wireless communication system and capitulates large improvements in almost all performance metrics. However, a practical feedback link is susceptible to error due to wireless channel fading and leads to wrong precoder selection. Therefore, a signal-to-noise ratio (SNR) adaptive error-tolerant weighting scheme is introduced which provides significant gain in comparison with another proposed arbitrarily fixed SNR error-tolerant weighting scheme. At first, a tight approximate closed-form expression of average symbol-error-rate (SER) and an exact analytical expression of outage probability are derived under imperfect feedback information with the help of order statistics. By minimizing the derived average SER, optimized transmit weights for the diagonal precoding matrix (based on feedback bits) are obtained. Later, a closed-form expression of the ergodic capacity with erroneous feedback bits for arbitrary MISO system is also provided by using the moment generating function approach. Further, numerical results show that the considered error-tolerant schemes outperform the uniform power allocation scheme in term of all the investigated performance metrics.

关键词： Ergodic capacity feedback large MIMO moment generating function order statistics outage probability precoding space-time block code symbol-error-rate

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Efficient Quasi-Orthogonal space-time block codes for Five and Six Transmit Antennas

Efficient Quasi-Orthogonal Space-Time Block Codes for Five a...

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IEEE International Conference on Electronics Computing and Communication Technologies (CONECCT)

作者： Sindhu, P. Hameed, Abdul Govt Engn Coll Dept Elect Kozhikode India

ISBN: (纸本)9781479999859

space-time block codes offer transmit diversity in multiple antenna systems. Orthogonal and quasi-orthogonal space-time block codes have been developed for improving the performance of wireless communication systems. Orthogonal designs have full diversity and allow symbol-wise maximum likelyhood decoding. However, their code rate is strictly less than one for more than two transmit antennas. Quasi-orthogonal designs achieve a code rate of one, but diversity is sacrificed and decoding becomes more complex. Signal constellation rotation based quasi-orthogonal codes provide full diversity, but the code rate depends on the orthogonal design. This paper proposes two new constellation-rotation based quasi-orthogonal space-time block codes, one for five transmit antennas and one for six transmit antennas. The proposed codes achieve full diversity as well as a code rate of one. The new codes are presented with extensive simulation results to back the superiority of the codes developed. Our improved codes are found to perform better than the existing codes.

关键词： Diversity space-time block code Orthogonal STBC Quasi-orthogonal STBC Constellation Rotation Maximum Likelyhood Decoding

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Optimal 2 x 2 space-time block codes Based On Mutual Information in Rayleigh fading

Optimal 2 x 2 Space-Time Block Codes Based On Mutual Informa...

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26th IEEE Annual Canadian Conference on Electrical and Computer Engineering (CCECE)

作者： Syed, Tamseel Mahmood Tran, Nghi H. Univ Akron Dept Elect & Comp Engn Akron OH 44325 USA

ISBN: (纸本)9781479900336;9781479900312

This paper investigates the design of a 2 x 2 optimal space-time block code (SBTC) for a multi-input multi-output (MIMO) system using the mutual information between the finite-alphabet input and the channel output as a main design criterion over Rayleigh fading channels. Different from the STBC design methods using PEP analysis usually seen in the literature that are valid only at high SNRs, our design method can apply to any SNR region, which is of more interest from both information-theoretic and practical points of view. To accomplish this, we first develop in closed-form an expression of the mutual information. This simple criterion is helpful in finding an optimal STBC and it can be applied to any discrete constellation such as quadrature amplitude modulation (QAM) or phase shift keying (PSK). Numerical results indicate that our proposed STBCs provide a better mutual information performance than the previously well-known STBCs, including the Damen code and Golden code.

关键词： Multiple-Input Multiple-Output (MIMO) space-time block code Mutual Information Rayleigh Fading

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An adaptive power allocation scheme for space-time block coded MIMO systems

An adaptive power allocation scheme for space-time block cod...

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IEEE Wireless Communications and Networking Conference

作者： Xian, L Liu, HP Oregon State Univ Sch Elect Engn & Comp Sci Corvallis OR 97331 USA

ISBN: (纸本)0780389662

Receive diversity yields a higher signal-to-noise ratio (SNR) than transmit diversity when the total transmitted power and diversity order are the same. However, if the transmitter has complete or partial knowledge of channel, the SNR gap between these two schemes can be reduced. This paper introduces an adaptive power allocation scheme for space-time block coded (STBC) multiple-antenna systems to improve system performance. For any set of channel fading coefficients, the transmit power scaling factors are controlled by a single design parameter u. The proposed adaptive power allocation scheme improves the instantaneous SNR at the receiver. Special choices of U result in some existing STBC schemes. Performance gain of the proposed scheme over the conventional equal-power scheme under the condition of perfect and imperfect feedback is studied. The maximum achievable SNR gain limit over the conventional scheme is also derived.

关键词： error statistics space-time codes block codes MIMO systems power control adaptive control feedback diversity reception fading channels transmitting antennas receiving antennas adaptive power allocation space-time block code receive diversity signal-to-noise ratio transmit diversity perfect feedback imperfect feedback maximum achievable SNR gain STBC multiple-antenna systems system performance channel fading coefficients transmit power scaling factors instantaneous SNR multiple input multiple output systems diversity reception adaptive power allocation receive diversity transmitting antennas Receiving antennas space-time codes System performance block codes space time block coding Fading channels Power control adaptive control Feedback Transmitter power

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Channel Estimation for space-time block coded OFDM Systems using Few Received Symbols 7

Channel Estimation for Space-Time Block Coded OFDM Systems u...

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7th International Joint Conference on Pervasive and Embedded Computing and Communication Systems (PECCS)

作者： Zhang, Biling Yuan, Yipu Yu, Jung-Lang Hsu, Wei-Ting Huang, Yu-Jie Beijing Univ Posts & Telecommun Sch Network Educ Beijing 100876 Peoples R China Quanzhou Normal Univ Coll Phys & Informat Engn Quanzhou 362000 Peoples R China Fu Jen Catholic Univ Dept Elect Engn New Taipei 24205 Taiwan

ISBN: (纸本)9789897582660

A novel subspace channel estimation is proposed for space-time block coded (STBC) multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems. Considering the zero-padding technique, the signal model of the STBC-OFDM system is first studied. The major drawback of the subspace method is the slow convergence which requires a large number of received symbols to compute the noise subspace. The repetition index scheme is developed here to increase the number of equivalent received symbols. Using the space-time coding property, the forward-backward method is presented to improve the convergence speed further. Moreover, the repetition index scheme transforms the white noise into non-white one. The noise prewhitening technique is proposed to reduce the non-white noise effect. Computer simulations show the effectiveness of the proposed forward-backward method and noise prewhitening technique.

关键词： space-time block code Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing Subspace Channel Estimation Forward-backward Method Noise Prewhitening Technique

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Performance analysis of space-time block codes in Nakagami-m keyhole channels with arbitrary fading parametersa

Performance analysis of space-time block codes in Nakagami-<...

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IEEE International Conference on Communications (ICC 2008)

作者： Zhao, Hongzhi Gong, Yi Guan, Yong Liang Li, Shaoqian Univ Elect Sci & Technol China Natl Key Lab Commun Chengdu 610054 Peoples R China Nanyang Technol Univ Position & Wireless Technol Ctr Sch Elect & Elect Engn Singapore Singapore

ISBN: (纸本)9781424420742

In certain multiple-input multiple-output (MIMO) fading environments, the offered channel capacity can be very low even when the MIMO channels are uncorrelated;this effect has been termed as keyhole or pinhole effect. In this paper, we present rigorous error rate analysis of orthogonal space time block codes in Nakagami-m keyhole channels with arbitrary fading parameters. Using a moment-generation-function based approach, we provide the exact expressions of symbol error rate. Furthermore, the closed-form asymptotic expressions are derived, based on which one can easily quantify the diversity gain of the considered system with arbitrary m-fading parameters while existing methods in literature fail to do so. Simulation results are also provided to verify our analytical results.

关键词： space-time block code Rayleigh fading keyhole MIMO symbol error rate diversity gain

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Performance Analysis of Orthogonal space-time block codes Over Nakagami-? (Hoyt) MIMO RFID Backscattering Channels

Performance Analysis of Orthogonal Space-time Block Codes Ov...

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作者： Yasmin Hisham Tawfiq Qabbani Al-Quds University

学位级别：硕士

Radio frequency identification (RFID) is an automatic identification technology which utilizes radio-frequency electromagnetic fields to identify objects carrying tags in the reading range of a reader. Such identification over a wireless channel doesn't necessitate the tag and the reader being in physical contact or line-of-sight (LOS) aligned. This preferable feature of sending identification data wirelessly may adversely affect the performance of the RFID system, because even when LOS path exists, heavy small-scale fading may still be present due to indoor operation, a cluttered reader environment, and the inhomogeneous nature of the tagged object. To mitigate this fading problem and increase the read reliability, space-time block coding (STBC) for multiple-input multiple-output (MIMO) RFID systems is suggested and employed. In this thesis, a performance analysis of orthogonal space-time block codes (OSTBC) in passive MIMO RFID system is conducted. More particularly, the conditional moment-generating function (MGF) approach is employed to analyse the performance of OSTBC over Nakagami- (Hoyt) MIMO RFID backscattering channels. New exact and asymptotic closed-form symbol error rate (SER) expressions are derived for the case of two and four reader-receiving antennas. The diversity order that the system can achieve is found to be, where is the number of tag antennas, and the performance of this channel is found to be more sensitive to the channel condition (the parameter) of the forward link than that of the backscattering link. A good agreement with previous published studies was observed for the special case that the Hoyt fading covers.

关键词： backscattering cascaded structure Nakagami-(Hoyt) fading radiofrequency identification multiple-input multiple-output symbol error rate diversity gain space-time block code

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A comparative study of ultra-massive MIMO intelligent receivers with adversarial robustness and energy efficiency for 6G applications

Results in Engineering

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Results in Engineering 2025年 26卷

作者： Pushkar Nidagundi Advesh Darvekar Malik Amber Ramesh R School of Electronics Engineering Vellore Institute of Technology Chennai Tamil Nadu 600127 India

Ultra-Massive Multiple Input Multiple Output (UM-MIMO) systems are pivotal for 6G wireless networks, enabling unprecedented data rates and spectral efficiency. However, optimizing these systems requires a careful balance between energy efficiency, spectral efficiency, and Bit Error Rate (BER) performance. This paper proposes a novel Taguchi-based optimization framework that systematically fine-tunes power allocation, modulation schemes, and space-time coding parameters, reducing computational complexity by up to 85 % compared to exhaustive search. The approach integrates advanced technologies including UM-MIMO, cognitive radio, and Artificial Intelligence (AI)-based detection to enhance robustness against adversarial attacks. Simulation results demonstrate that the optimized Minimum Mean Square Error (MMSE) detector achieves up to 95 % reduction in Bit Error Rate (BER) compared to Zero-Forcing (ZF) in small-to-medium UM-MIMO configurations (2 × 2 to 32 × 32), as shown in Tables (4 and 5), while maintaining computational feasibility. For ultra-massive configurations (256 × 256 to 1024 × 1024), optimized ZF offers the best trade-off between performance and energy efficiency. The Taguchi method yields up to 40 % improvement in energy efficiency while maintaining near-perfect BER. Practical implications of massive power consumption, system complexity, and execution time are discussed, alongside a comparative analysis with recent neural network and genetic algorithm optimizations. Limitations of simulation-based evaluation and a plan for experimental validation are also presented. The findings establish deployment guidelines for mission-critical versus energy-sensitive 6G applications.

关键词： UM-MIMO: Ultra-massive multiple input multiple output BER: Bit error rate SNR: Signal-to-noise ratio AWGN: Additive white Gaussian noise ZF: Zero-forcing UM-MIMO Ultra-Massive Multiple Input Multiple Output BER Bit Error Rate SNR Signal-to-Noise Ratio AWGN Additive White Gaussian Noise ZF Zero-Forcing MMSE Minimum Mean Square Error ML Maximum Likelihood BPSK Binary Phase Shift Keying QPSK Quadrature Phase Shift Keying QAM Quadrature Amplitude Modulation STBC space-time block code OSTBC Orthogonal space-time block code AI Artificial Intelligence CNN Convolutional Neural Network 6G Sixth Generation

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Subspace Channel Identification for Multiuser MIMO STBC-OFDM Systems

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CIRCUITS SYSTEMS AND SIGNAL PROCESSING 2019年第9期38卷 4115-4140页

作者： Yuan, Yipu Zhang, Biling Yu, Jung-Lang Fu Jen Catholic Univ Grad Inst Appl Sci & Engn New Taipei Taiwan Quanzhou Normal Univ Coll Phys & Informat Engn Quanzhou Fujian Peoples R China Beijing Univ Posts & Telecommun Sch Network Educ Beijing Peoples R China Xidian Univ State Key Lab Integrated Serv Networks Xian Shaanxi Peoples R China Fu Jen Catholic Univ Dept Elect Engn New Taipei Taiwan

This paper investigates the subspace channel identification for multiple-input multiple-output zero-padded orthogonal frequency-division multiplexing systems with space-time block code and virtual carriers (VCs). We first develop a new subspace channel identification model when the VCs exist. Then, two schemes, the forward-backward method and the repetition index scheme (RIS), are developed to generate many times equivalent symbols and then to enhance the performance of the subspace channel identification. With these methods, more accurate subspace channel identification can be obtained by using only a few received blocks. Further, the noise pre-whitening technique is investigated to decrease the nonwhite noise effect caused by the RIS scheme. We also provide complexity analyses of the proposed methods. With the acceptable computational cost, the proposed methods significantly improve the performances of the channel identification and the equalization. Simulations are carried out to demonstrate the effectiveness of the proposed methods.

关键词： space-time block code MIMO-OFDM Virtual carriers Subspace channel identification Forward-backward method Repetition index scheme Noise pre-whitening technique

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Adaptive Filtering Techniques using Cyclic Prefix in OFDM Systems for Multipath Fading Channel Prediction

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CIRCUITS SYSTEMS AND SIGNAL PROCESSING 2016年第10期35卷 3595-3618页

作者： Kohli, Amit Kumar Kapoor, Divneet Singh Thapar Univ Dept Elect & Commun Engn Patiala 147004 Punjab India

This paper presents adaptive channel prediction techniques for wireless orthogonal frequency division multiplexing (OFDM) systems using cyclic prefix (CP). The CP not only combats intersymbol interference, but also precludes requirement of additional training symbols. The proposed adaptive algorithms exploit the channel state information contained in CP of received OFDM symbol, under the time-invariant and time-variant wireless multipath Rayleigh fading channels. For channel prediction, the convergence and tracking characteristics of conventional recursive least squares (RLS) algorithm, numeric variable forgetting factor RLS (NVFF-RLS) algorithm, Kalman filtering (KF) algorithm and reduced Kalman least mean squares (RK-LMS) algorithm are compared. The simulation results are presented to demonstrate that KF algorithm is the best available technique as compared to RK-LMS, RLS and NVFF-RLS algorithms by providing low mean square channel prediction error. But RK-LMS and NVFF-RLS algorithms exhibit lower computational complexity than KF algorithm. Under typical conditions, the tracking performance of RK-LMS is comparable to RLS algorithm. However, RK-LMS algorithm fails to perform well in convergence mode. For time-variant multipath fading channel prediction, the presented NVFF-RLS algorithm supersedes RLS algorithm in the channel tracking mode under moderately high fade rate conditions. However, under appropriate parameter setting in 2x1 space-time block-coded OFDM system, NVFF-RLS algorithm bestows enhanced channel tracking performance than RLS algorithm under static as well as dynamic environment, which leads to significant reduction in symbol error rate.

关键词： Orthogonal frequency division multiplexing space-time block code Cyclic prefix Multipath fading Kalman filter Least mean square Recursive least squares algorithm Channel estimation

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