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Fast-Converging Constant Modulus algorithm with Variable Step Size for Multibeam Massive MIMO

IEICE TRANSACTIONS ON COMMUNICATIONS 2022年第10期E105B卷 1154-1161页

作者： Nishimori, Kentaro Maruta, Kazuki Hiraguri, Takefumi Shiomi, Hidehisa Niigata Univ Fac Engn Niigata 9502102 Japan Tokyo Univ Sci Dept Elect Engn Tokyo 1258585 Japan Nippon Inst Technol Fac Engn Saitamaken 3458501 Japan Osaka Univ Ctr Quantum Informat & Quantum Biol Toyonaka 5600043 Japan

Multibeam massive multiple-input multiple-output (MIMO) configuration has been proposed that selects high-power beams in an analog part and uses a blind algorithm, such as the constant-modulus algorithm (CMA), in the digital part. The CMA does not require channel state information. However, when least-squares CMA (LS-CMA) is applied to a quadrature amplitude modulation signal whose amplitude changes, the interference cancellation effect decreases as the modulation order increases. In this paper, a variable-step-size-based CMA (VS-CMA), which modifies the step size of the steepest-descent CMA, is proposed as a blind adaptive algorithm to replace LS-CMA. The basic performance of VS-CMA, its success in cancelling interference, and its effectiveness in multibeam massive MIMO transmission are verified via simulation and compared with other blind algorithms such as independent component analysis, particularly when the data smoothing size is small.

关键词： constant modulus blind algorithm variable step size multi-beam massive MIMO QAM

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Pre- Calibration Techniques for Transmitter-Side RF Imbalance and Spectrum Distortion 95

Pre- Calibration Techniques for Transmitter-Side RF Imbalanc...

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IEEE 95th Vehicular Technology Conference: (VTC-Spring)

作者： Deng, Juinn-Horng Prasad, Pavan Vatal Shankar Huang, Wei-Cheng Ku, Meng-Lin Yuan Ze Univ Dept Elect Engn 135 Yuan Tung Rd Chungli Taiwan Natl Cent Univ Dept Commun Engn 300 Zhong Da Rd Chungli Taiwan

ISBN: (数字)9781665482431

ISBN: (纸本)9781665482431

In this paper, we study the cascaded pre-calibration techniques to overcome the coexisting problems of RF IQ imbalance (IQI) and RF spectrum distortion, which can improve the performance of a single package mmWave IC. The calibration techniques are designed separately. We first pre-compensate the IQI effect by using a single-tone signal with a blind algorithm to estimate the impairment parameters and calculate the precalibration weighting coefficients. After that, we adopt quadrature wideband training sequences to estimate the RF distorted responses and calculate the pre-calibration filters via the deconvolution techniques. The above calibration schemes are realized in the digital pre-processing domain and can perform better than the conventional RF calibration circuit design. Both the computer simulation results and the mmWave software defined radio (SDR) platform measurement results confirm that the proposed techniques can pre-calibrate the cascaded RF IQI and RF spectrum distortion problems.

关键词： Separated calibration procedures RF IQ imbalances RF spectrum distortion digital pre-calibration blind algorithm deconvolution technique mmWave software defined radio platform.

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Mathematical Model for an Autonomous Vehicle to Fulfill the Closed Area 6

Mathematical Model for an Autonomous Vehicle to Fulfill the ...

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6th International Conference on Imaging, Signal Processing and Communications (ICISPC)

作者： Namngam, Kampanat Chitsakul, Pakkinee Satthamsakul, Sutham King Mongkuts Inst Technol Ladkrabang KMITL Dept Math Sch Sci Bangkok Thailand King Mongkuts Inst Technol Ladkrabang KMITL Sch Engn Dept Instrumentat & Control Engn Bangkok Thailand

ISBN: (纸本)9781665454803

This research presents the mathematical model to roam an autonomous vehicle in a closed region with minor coincident areas. This model is blind algorithm, no literature that concern on mathematical model. It is essential for agricultural technology, for example, shoveling soil for planting, spraying liquid fertilizer, harvesting agricultural products, to control the movement of the vehicle with the redundant path is as less as possible is benefited to decrease the working hours and also the burning oil and more for cost-saving without any expensive hardware. The almost wholly filled farmland depends on the shape, the size of the area, and the vehicle dimension.

关键词： mathematical model low-cost autonomous vehicle blind algorithm quadrilateral

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blind-based demodulation scheme for virtual massive MIMO systems

Blind-based demodulation scheme for virtual massive MIMO sys...

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International Symposium on Antennas and Propagation (ISAP)

作者： Takahashi, Sota Watanabe, Issei Nishimori, Kentaro Taniguchi, Ryotaro Murakami, Tomoki Niigata Univ Ikarashi Grad Sch Sci & Technol Nishi Ku Ikarashi 2 Nocho 8050 Niigata 9502181 Japan NTT Corp Access Network Serv Syst Labs 1-1 Hikari No Oka Yokosuka Kanagawa 2390847 Japan

ISBN: (纸本)9784885523267

In beyond-fifth-generation (B5G) networks, massive multiple-input-multiple-output (MIMO) systems using a large number of base station antennas have attracted significant attention. As the number of antennas increases, the hardware scale of massive MIMO systems is complicated. In recent years, a virtual massive (VM)-MIMO system which performs MIMO transmission by using virtual antenna arrays creating a single antenna element has been investigated. In this paper, we propose a blind-based demodulation scheme for a VM-MIMO system to cancel the interference with oversampling. In our proposed scheme, as a signal whose level is less than a certain power threshold cannot be used in the high-order modulation scheme with oversampling, we apply filtering wherein signals with the noise power level are removed. Through this procedure, multi-level modulation signals can be utilized in VM-MIMO. Moreover, our simulation evaluations show that the bit error rate improves considerably by using our proposed scheme on the uplink commutation environment including up to ten users.

关键词： Virtual Massive MIMO blind algorithm Unsynchronous sampling

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Noisesniffer: a Fully Automatic Image Forgery Detector Based on Noise Analysis 9

Noisesniffer: a Fully Automatic Image Forgery Detector Based...

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9th International Workshop on Biometrics and Forensics (IWBF)

作者： Gardella, Marina Muse, Pablo Morel, Jean-Michel Colom, Miguel Univ Paris Saclay Ctr Borelli CNRS ENS Paris Saclay Gif Sur Yvette France Univ Republica Fac Ingn IIE Montevideo Uruguay

ISBN: (纸本)9781728195568

Images undergo a complex processing chain from the moment light reaches the camera's sensor until the final digital image is delivered. Each of these operations leave traces on the noise model which enable forgery detection through noise analysis. In this article we define a background stochastic model which makes it possible to detect local noise anomalies characterized by their number of false alarms. The proposed method is both automatic and blind, allowing quantitative and subjectivity-free detections. Results show that the proposed method outperforms the state of the art.

关键词： image forensics automatic forgery detection noise residual blind algorithm

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Semi-blind Adaptive Beamforming Based on Constant Modulus algorithm for Smart Antennas

Semi-Blind Adaptive Beamforming Based on Constant Modulus Al...

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4th International Conference on Information, Cybernetics and Computational Social Systems (ICCSS)

作者： Zhao, Yue Ai, Bo Liu, Yiru Fei, Dan Li, Dapeng Beijing Jiaotong Univ State Key Lab Rail Traff Control & Safety Beijing 100044 Peoples R China Beijing Engn Res Ctr High Speed Railway Broadband Beijing 100044 Peoples R China Univ Jinan Sch Informat Sci & Engn Jinan 250022 Shandong Peoples R China ZTE Corp Shenzhen Peoples R China

ISBN: (纸本)9781538632574

Adaptive beamforming plays an important role in smart antenna systems. Nonblind adaptive algorithm utilizes the known training sequence to update the weights of antenna array at the cost of low transmission efficiency. Without sending training sequences, blind adaptive algorithm is a solution to implement beamforming and increase the transmission efficiency. Two classic blind algorithms are studied, namely constant modulus (CM) algorithm and Least squares-constant modulus (LS-CM) algorithm. Considering the advantages of the nonblind and blind algorithms, a semi-blind adaptive beamforming based on CM algorithm is proposed in this paper. Simulation results indicate it has comparable performance compared with nonblind adaptive algorithm, while it only needs the training sequence in the first iteration.

关键词： beamforming adaptive blind algorithm

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Constant Modulus and Kurtosis based blind Adaptive Array Interference Suppression: Comparisons and New Approach 18

Constant Modulus and Kurtosis based Blind Adaptive Array Int...

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18th International Symposium on Communications and Information Technologies (ISCIT)

作者： Maruta, Kazuki Nishimori, Kentaro Ahn, Chang-Jun Chiba Univ Grad Sch Engn Chiba Japan Niigata Univ Grad Sch Sci & Technol Niigata Japan

ISBN: (纸本)9781538684580

This paper presents performance comparison of interference suppression on blind adaptive array algorithms. Co-channel interference becomes more extensive due to frequency resource exhaustion and small cell deployment which had been triggered by mobile traffic explosion. Multi-antenna signal processing is an effective means for such co-channel interference suppression. Strict approach is to utilize a priori information of channel state by estimating it via known training sequences. It gratuitously consumes radio resource and thus overhead inflates according to the increase of interference source to be suppressed. In addition, training sequence cannot be shared between wireless communication systems employing different transmission schemes. Here we focus on blind adaptive array where any channel estimation is not required. algorithms of interest in this study are based on constant modulus and independent component analysis (ICA) criteria. We present fundamental observation of their interference suppression performance compared in terms of modulation order, number of interference sources, and degree of freedom, then derive the most stable approach using ICA incorporated with beamspace pre-processing.

关键词： Adaptive array blind algorithm Interference suppression Constant modulus Independent component analysis

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blind adaptive carrier phase recovery for QAM systems

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DIGITAL SIGNAL PROCESSING 2016年 49卷 65-85页

作者： Abrar, Shafayat Zerguine, Azzedine Nandi, Asoke K. COMSATS Inst Informat Technol Islamabad 44000 Pakistan King Fahd Univ Petr & Minerals Dhahran 31261 Saudi Arabia Brunel Univ London Uxbridge UB8 3PH Middx England Tongji Univ Shanghai 200092 Peoples R China

This paper provides a study of adaptive phase recovery in quadrature amplitude modulation (QAM) based communication systems. Here, we modify the traditional fourth-power phase recovery algorithm (FP-PRA) to propose three improved algorithms, and analyze their performances in the presence of additive white Gaussian noise, phase noise, frequency-offset, and inter-symbol interference. We demonstrate that it is possible to obtain the optimal values of step-sizes (or loop-gains) in closed-form in the presence of phase noise and/or frequency-offset. In particular, we discuss two methods to improve FP-PRA. The first method involves utilizing the idea of partitioning the QAM constellation into QPSK-like and not-QPSK-like annular regions. The phase synchronizer is allowed to update only when a derotated QAM symbol lies in QPSK-like region;otherwise, the update process is stopped. The second method exploits an evolving idea of QAM-to-QPSK transformation, and uses transformed symbols to estimate phase mismatch. We provide a new interpretation of this transformation method and relate it to the quadrant-wise centroid of the rotated constellation. Furthermore, we discuss the feasibility of this method for both square and cross-QAM, and, identify and verify numerically the existence of false-locks in the case of cross-QAM. To the best of our knowledge, the ideas of constellation partitioning and constellation transformation have not appeared earlier in the context of adaptive phase recovery. We discuss adaptive blind estimation of optimal step-sizes in the presence of phase noise and frequency-offset. Finally, we discuss the modification of the proposed stochastic gradient methods to transform them into batch processing algorithms so as to make them more suitable for higher data rate systems. Numerical experiments indicate that the proposed algorithms can outperform the traditional FP-PRA algorithm for a number of practical QAM sizes under different mismatch conditions, and that o

关键词： Adaptive receiver design blind algorithm Carrier phase recovery Quadrature amplitude modulation Quadrature phase shift keying Mean square deviation

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Joint blind Compensation of Inter-Block Interference and Frequency-Dependent IQ Imbalance

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IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES 2016年第1期E99A卷 196-198页

作者： Zhang, Xi Miyajima, Teruyuki Ibaraki Univ Grad Sch Sci & Engn Hitachi Ibaraki 3168511 Japan Ibaraki Univ Coll Engn Hitachi Ibaraki 3168511 Japan Toppan Printing Co Ltd Tokyo Japan

In this letter, we propose a blind adaptive algorithm for joint compensation of inter-block interference (IBI) and frequency-dependent IQ imbalance using a single time-domain equalizer. We combine the MERRY algorithm for IBI suppression with the differential constant modulus algorithm to compensate for IQ imbalance. The effectiveness of the proposed algorithm is shown through computer simulations.

关键词： blind algorithm inter-block interference IQ imbalance time-domain equalization

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blind Phase Tracking algorithm for FBMC Receivers 12

Blind Phase Tracking Algorithm for FBMC Receivers

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12th International Symposium on Wireless Communication Systems (ISWCS)

作者： Dore, Jean-Baptiste Berg, Vincent CEA Leti Minatec 17 Rue Martyrs F-38054 Grenoble 9 France

ISBN: (纸本)9781467365406

Non synchronous random access is envisaged for sporadic traffic to limit the amount of the exchanged signaling messages. Burst data transmission is commonly used in wireless communication systems. Each burst begins with a preamble which is used to synchronize the receiver. When the initial estimation of the Carrier Frequency Offset is coarse, and/or the burst duration is relatively long, a phase tracking algorithm is required to track any residual phase during the payload transmission. In this paper we investigate a blind phase tracking algorithm for Filter Bank Multicarrier waveforms. Different algorithms are described and evaluated. A comparison with state of the art algorithms is discussed. Finally we describe an algorithm based on sign statistics that outperforms the state of the art algorithms while reducing the complexity.

关键词： FBMC blind algorithm Carrier frequency offset Phase tracking

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