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blind Interference Suppression Scheme by Eigenvector Beamspace CMA Adaptive Array with Subcarrier Transmission Power Assignment for Spectrum Superposing

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IEICE TRANSACTIONS ON COMMUNICATIONS 2015年第6期E98B卷 1050-1057页

作者： Maruta, Kazuki Mashino, Jun Sugiyama, Takatoshi NTT Corp NTT Access Network Serv Syst Labs Yokosuka Kanagawa 2390847 Japan NTT Corp NTT Network Innovat Labs Yokosuka Kanagawa 2390847 Japan Kogakuin Univ Tokyo 1638677 Japan

This paper proposes a novel blind adaptive array scheme with subcarrier transmission power assignment (STPA) for spectrum superposing in cognitive radio networks. The Eigenvector Beamspace Adaptive Array (EBAA) is known to be one of the blind adaptive array algorithms that can suppress inter-system interference without any channel state information (CSI). However, EBAA has difficulty in suppressing interference signals whose Signal to Interference power Ratio (SIR) values at the receiver are around 0 dB. With the proposed scheme, the ST intentionally provides a level difference between subcarriers. At the receiver side, the 1st eigenvector of EBAA is applied to the received signals of the subcarrier assigned higher power and the 2nd eigenvector is applied to those assigned lower power. In order to improve interference suppression performance, we incorporate Beamspace Constant Modulus algorithm (BSCMA) into EBAA (E-BSCMA). Additionally, STPA is effective in reducing the interference experienced by the primary system. Computer simulation results show that the proposed scheme can suppress interference signals received with SIR values of around 0 dB while improving operational SIR for the primary system. It can enhance the co-existing region of 2 systems that share a spectrum.

关键词： adaptive array Subcarrier Transmission Power Assignment (STPA) blind algorithm Eigenvector Beamspace Adaptive Array (EBAA) Constant Modulus algorithm (CMA) spectrum superposing

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Splicebuster: a new blind image splicing detector

Splicebuster: a new blind image splicing detector

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IEEE International Workshop on Information Forensics and Security(WIFS)

作者： Cozzolino, Davide Poggi, Giovanni Verdoliva, Luisa Univ Naples Federico II DIETI Naples Italy

ISBN: (纸本)9781467368025

We propose a new feature-based algorithm to detect image splicings without any prior information. Local features are computed from the co-occurrence of image residuals and used to extract synthetic feature parameters. Splicing and host images are assumed to be characterized by different parameters. These are learned by the image itself through the expectation-maximization algorithm together with the segmentation in genuine and spliced parts. A supervised version of the algorithm is also proposed. Preliminary results on a wide range of test images are very encouraging, showing that a limited-size, but meaningful, learning set may be sufficient for reliable splicing localization.

关键词： Image forensics forgery detection and localization local image descriptors blind algorithm

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Mixed-Domain Adaptive blind Correction of High-Resolution Time-Interleaved ADCs

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ETRI JOURNAL 2014年第6期36卷 894-904页

作者： Seo, Munkyo Nam, Eunsoo Rodwell, Mark Sungkyunkwan Univ Coll Informat & Commun Engn Suwon South Korea ETRI Components & Mat Res Lab Taejon South Korea Univ Calif Santa Barbara Dept Elect & Comp Engn Santa Barbara CA 93106 USA

blind mismatch correction of time-interleaved analog-to-digital converters (TI-ADC) is a challenging task. We present a practical blind calibration technique for low-computation, low-complexity, and high-resolution applications. Its key features are: dramatically reduced computation;simple hardware;guaranteed parameter convergence with an arbitrary number of TI-ADC channels and most real-life input signals, with no bandwidth limitation;multiple Nyquist zone operation;and mixed-domain error correction. The proposed technique is experimentally verified by an M = 4 400 MSPS TI-ADC system. In a single-tone test, the proposed practical blind calibration technique suppressed mismatch spurs by 70 dB to 90 dB below the signal tone across the first two Nyquist zones (10 MHz to 390 MHz). A wideband signal test also confirms the proposed technique.

关键词： Analog-to-digital conversion mismatch blind algorithm adaptive technique

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One-Shot blind CFO and Channel Estimation for OFDM With Multi-Antenna Receiver

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2014年第15期62卷 3799-3808页

作者： Zhang, Weile Yin, Qinye Wang, Wenjie Gao, Feifei Xi An Jiao Tong Univ Key Lab Intelligent Networks & Network Secur Minist Educ Xian 710049 Shaanxi Peoples R China Tsinghua Univ Tsinghua Natl Lab Informat Sci & Technol Dept Automat State Key Lab Intelligent Technol & Syst Beijing 100084 Peoples R China

In this paper, we design a new blind joint carrier frequency offset (CFO) and channel estimationmethod for orthogonal frequency-division multiplexing (OFDM) with multiantenna receiver. The proposed algorithm requires only one received OFDM block and thus belongs to the category of one-shot estimation methods. Other advantages of the proposed algorithm include 1) it supports fully loaded data carriers and is thus spectral efficient;2) the channel from the transmitter to each receive antenna can be blindly estimated with only a scaling ambiguity;and 3) the algorithms outperforms the existing methods. Moreover, we derive the Cram r-Rao Bounds (CRB) of joint CFO and channel estimation in closed forms. Numeral results not only show the effectiveness of the proposed algorithm but also demonstrate its closed performance to CRB.

关键词： blind algorithm carrier frequency offset (CFO) channel estimation multi-antenna one-shot estimation orthogonal frequency division multiplexing (OFDM)

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blind Adaptive Arrays with Subcarrier Transmission Power Assignment for Spectrum Superposing

Blind Adaptive Arrays with Subcarrier Transmission Power Ass...

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Asia-Pacific Microwave Conference Proceedings

作者： Maruta, Kazuki Mashino, Jun Sugiyama, Takatoshi NTT Corp NTT Access Network Serv Syst Labs 1-1 Hikarino Oka Yokosuka Kanagawa 2390847 Japan NTT Corp NTT Network Innovat Labs Yokosuka Kanagawa 2390847 Japan

ISBN: (纸本)9784902339314

This paper proposes an extension scheme of blind adaptive arrays for spectrum superposing in cognitive radio networks. Though Maximal Ratio Combining (MRC) and Power Inversion (PI) are known as one of the blind adaptive array algorithms, MRC strongly receives a desired signal when SIR (at the antenna input)>0dB while PI appropriately suppresses interference signal when SIR<0dB. With the proposed method, the secondary transmitter intentionally provides a level difference between subcarriers. At the receiver side, MRC is applied to the received signals of subcarrier assigned higher power and PI is applied to ones assigned lower power. Computer simulation results show that the proposed scheme can suppress interference around SIR=0dB while improving operational SIR for the primary system over 5dB. Our initial study revealed the validity of the proposed scheme for spectrum superposing.

关键词： Adaptive Array Subcarrier Transmission Power Assignment blind algorithm Maximal Ratio Combining (MRC) Power Inversion (PI) Spectrum Superposing

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Splicebuster: a new blind image splicing detector

Splicebuster: a new blind image splicing detector

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IEEE International Workshop on Information Forensics and Security

作者： Davide Cozzolino Giovanni Poggi Luisa Verdoliva DIETI University Federico II of Naples

ISBN: (纸本)9781467368032

We propose a new feature-based algorithm to detect image splicings without any prior information. Local features are computed from the co-occurrence of image residuals and used to extract synthetic feature parameters. Splicing and host images are assumed to be characterized by different parameters. These are learned by the image itself through the expectation-maximization algorithm together with the segmentation in genuine and spliced parts. A supervised version of the algorithm is also proposed. Preliminary results on a wide range of test images are very en-couraging, showing that a limited-size, but meaningful, learning set may be sufficient for reliable splicing localization.

关键词： Image forensics Forgery detection and localization Local image descriptors blind algorithm

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blind Compensation for Phase Noise in OFDM Systems over Constant Modulus Modulation

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IEEE TRANSACTIONS ON COMMUNICATIONS 2012年第3期60卷 620-625页

作者： Lee, Myung-Kyu Lim, Seung-Chan Yang, Kyeongcheol Pohang Univ Sci & Technol POSTECH Dept Elect Engn Pohang 790784 Kyungbuk South Korea

A blind algorithm is proposed in order to compensate for the phase noise resulting from imperfect oscillators in orthogonal frequency-division multiplexing (OFDM) systems over constant modulus modulation. In the proposed algorithm, one received OFDM symbol is partitioned into subblocks in the time domain and the phase noise over each subblock is approximated as its time-average. Under the approximation, the squared magnitude of the channel gain multiplied by the data symbol at each subcarrier is shown to be expressed in terms of these time-averages and the discrete Fourier transform (DFT) coefficients of the received samples at each subblock with zero padding. Based on the relation, the proposed algorithm compensates for the phase noise without pilot symbols. Numerical results show that the proposed algorithm outperforms conventional algorithms as well as it requires lower computational complexity.

关键词： Orthogonal frequency-division multiplexing (OFDM) system phase noise compensation blind algorithm constant modulus modulation

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A Novel blind Polarization Demultiplexing algorithm Based on Correlation Analysis

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JOURNAL OF LIGHTWAVE TECHNOLOGY 2011年第9期29卷 1258-1264页

作者： Gong, Chen Wang, Xiaodong Cvijetic, Neda Yue, Guosen Columbia Univ Dept Elect Engn New York NY 10027 USA NEC Labs Amer Inc Princeton NJ 08540 USA

We propose a novel correlation-based blind polarization demultiplexing technique for coherent optical communication systems. The basic procedure involves the blind estimation of various channel parameters through correlation analysis, and resolving ambiguities using pilot symbols. In a 56 Gb/s/polarizaton multiplexing transmission system employing quadrature phase-shift keying, for both symbol-rate sampling and double symbol-rate sampling, the proposed algorithm achieves the same performance as that of the receiver with known channel parameters and significantly outperforms the constant modulus algorithm.

关键词： blind algorithm correlation analysis polarization demultiplexing polarization division multiplexing

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Two blind algorithms of MMSE Filter Based on Second-Order Statistics in MIMO Systems with Multiple Interferences

Two Blind Algorithms of MMSE Filter Based on Second-Order St...

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2011年无线通信与信号处理国际会议(WCSP 2011)

作者： Bo Hu Xu Wang Tao Yang Fan He Rueywen Liu E.E. Dept. of Fudan University Shanghai 200433 China University of Notre Dame Notre Dame IN USA

In this paper, we consider an MIMO system with multiple interferences. The minimum mean-square error (MMSE) criterion is the best trade off between the rejection of interference and the preservation of user signal in terms of bit error rate (BER). The solution of MMSE filter is known but it requires channel state information which is to be estimated by pilot signals. The estimation tends to be inaccurate or time consuming when the interferences are large. As such, an accurate blind algorithm under heavy interferences would be an attractive alternative approach. In this paper two blind algorithms are presented, one for strong signal and one for strong interferences. The deviation of the mean-square error (MSE) between the ideal MMSE filter and the estimated MMSE filter by the blind algorithms are shown by simulation to be within 0.001.

关键词： Autocorrelation function MMSE filter blind algorithm Linear MIMO system

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Hybrid Time/Frequency Domain Compensator for RF Impairments in OFDM Systems

Hybrid Time/Frequency Domain Compensator for RF Impairments ...

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22nd IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)

作者： Kiayani, Adnan Anttila, Lauri Zou, Yaning Valkama, Mikko Tampere Univ Technol Dept Commun Engn FI-33101 Tampere Finland

ISBN: (纸本)9781457713484

I/Q signal processing based communication systems suffer from analog front-end (FE) imperfections such as in-phase and quadrature-phase (I/Q) imbalance and carrier frequency offset (CFO). These impairments are commonly encountered in all practical implementations, and severely degrade the obtainable link performance. Moreover, orthogonal frequency division multiplexing (OFDM)-based systems are particularly sensitive to radio frequency (RF) impairments. In this paper, we analyze the impact of transmitter and receiver I/Q imbalance together with channel distortion and CFO error on an ideal transmit signal, and propose low-complexity DSP algorithms and compensation structure for coping with such imperfections. Based on our proposed estimation/compensation structure, we are able to decouple the impairments and process them individually with rather low-complexity. More specifically, we first apply a blind algorithm for receiver I/Q imbalance compensation, followed by an efficient time domain CFO estimator and compensator. The transmitter I/Q imbalance and channel are then equalized jointly, in the frequency domain, with maximum-likelihood (ML) or zero-forcing (ZF) schemes, respectively. The applied algorithms are either blind working without aid of any training symbol or use only one OFDM symbol for impairments estimation, providing an efficient alternative solution with reduced complexity. The computer simulation results indicate a close to ideal performance of ZF scheme, and sugget that additional performance improvement due to frequency diversity can be obtained when ML estimation technique is employed.

关键词： CFO error Channel estimation Estimation I/Q signal processing based communication system Joints ML estimation OFDM OFDM modulation OFDM symbol OFDM system OFDM-based system RF impairment Radio transmitters Receivers ZF scheme analog front-end imperfection blind algorithm carrier frequency offset channel distortion communication complexity diversity reception estimation-compensation structure frequency diversity frequency domain compensator in-phase imbalance link performance low-complexity DSP algorithm maximum likelihood estimation maximum-likelihood scheme orthogonal frequency division multiplexing quadrature-phase imbalance radio frequency impairment radio receivers radio transmitters receiver I/Q imbalance time domain CFO estimator time domain compensator transmitter I/Q imbalance wireless channels zero-forcing scheme

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