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Regularization by Multiple Dual Frames for Compressed Sensing Magnetic Resonance Imaging With Convergence Analysis

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IEEE/CAA Journal of Automatica Sinica 2023年第11期10卷 2136-2153页

作者： Baoshun Shi Kexun Liu School of information Science and Engineering Yanshan University the Hebei Key Laboratory of information transmission and Signal Processing Qinhuangdao 066004China IEEE

Plug-and-play priors are popular for solving illposed imaging inverse problems. Recent efforts indicate that the convergence guarantee of the imaging algorithms using plug-andplay priors relies on the assumption of bounded denoisers. However, the bounded properties of existing plugged Gaussian denoisers have not been proven explicitly. To bridge this gap, we detail a novel provable bounded denoiser termed as BMDual,which combines a trainable denoiser using dual tight frames and the well-known block-matching and 3D filtering(BM3D)denoiser. We incorporate multiple dual frames utilized by BMDual into a novel regularization model induced by a solver. The proposed regularization model is utilized for compressed sensing magnetic resonance imaging(CSMRI). We theoretically show the bound of the BMDual denoiser, the bounded gradient of the CSMRI data-fidelity function, and further demonstrate that the proposed CSMRI algorithm converges. Experimental results also demonstrate that the proposed algorithm has a good convergence behavior, and show the effectiveness of the proposed algorithm.

关键词： Bounded denoiser compressed sensing magnetic resonance imaging(CSMRI) dual frames plug-and-play priors regularization

Adaptive Neighboring Selection Algorithm Based on Curvature Prediction in Manifold Learning

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Journal of Harbin institute of Technology(New Series) 2013年第3期20卷 119-123页

作者： Lin Ma Cai-Fa Zhou Xi Liu Yu-Bin Xu Communication Research Center Harbin Institute of Technology Science and Technology on information transmission and Dissemination in Communication Networks Laboratory

Recently manifold learning algorithm for dimensionality reduction attracts more and more interests, and various linear and nonlinear,global and local algorithms are proposed. The key step of manifold learning algorithm is the neighboring region selection. However,so far for the references we know,few of which propose a generally accepted algorithm to well select the neighboring region. So in this paper,we propose an adaptive neighboring selection algorithm,which successfully applies the LLE and ISOMAP algorithms in the test. It is an algorithm that can find the optimal K nearest neighbors of the data points on the manifold. And the theoretical basis of the algorithm is the approximated curvature of the data point on the manifold. Based on Riemann Geometry,Jacob matrix is a proper mathematical concept to predict the approximated curvature. By verifying the proposed algorithm on embedding Swiss roll from R3 to R2 based on LLE and ISOMAP algorithm,the simulation results show that the proposed adaptive neighboring selection algorithm is feasible and able to find the optimal value of K,making the residual variance relatively small and better visualization of the results. By quantitative analysis,the embedding quality measured by residual variance is increased 45. 45% after using the proposed algorithm in LLE.

关键词： manifold learning curvature prediction adaptive neighboring selection residual variance

A Static Spectrum Aggregation Algorithm in Cognitive Radio System

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Journal of Harbin institute of Technology(New Series) 2013年第2期20卷 40-44页

作者： Cong Yin Xue-Zhi Tan Lin Ma Xiu-Hua Li Communication Research Center Harbin Institute of Technology Science and Technology on information transmission and Dissemination in Communication Networks Laboratory

Cognitive radio ( CR) is known as an intelligent technology allowing a secondary user ( SU) to occupy a primary user's ( PU's) band when it is idle. Appearance of the idle band may be contiguous or non-contiguous. In other words,the PU's band and the idle band are distributed alternately over the spectrum. Apparently the non-contiguous idle band cannot be fully utilized in this context. This paper proposes an algorithm to solve the problem of low utilization of the non-contiguous idle band and to increase the number of the SU who needs access to the spectrum by a static spectrum aggregation ( SSA) method combined with non-contiguous orthogonal frequency division multiplexing ( NC-OFDM) . The simulation results show that the SSA algorithm realizes at least 70% utilization of the idle band which provides access to the spectrum for as many as 30 SUs as expected.

关键词： cognitive radio static spectrum aggregation non-contiguous OFDM

Novel Pilot-aided Ridge Regression Channel Estimation for SC-FDE System on Time-varying Frequency Selective Fading Channel

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Journal of Harbin institute of Technology(New Series) 2013年第1期20卷 23-27页

作者： Xiu-Hua Li Lin Ma Xue-Zhi Tan Xin Liu Communication Research Center Harbin Institute of Technology Science and Technology on information transmission and Dissemination in Communication Networks Laboratory

A novel pilot-aided ridge regression (RR) channel estimation for SC-FDE system on time-varying frequency selective fading channel is derived. Previous least square (LS) channel estimation, which does not consider and utilize the influence of noise, has poor performance when the observed signal is corrupted abnormally by noise. In order to overcome the inherent disadvantage of LS estimation, the proposed RR estimation uses the influence of noise to get better performance. The performance of this new estimator is examined. The numerical results are presented to show that the new estimation improves the accuracy of estimation especially in low channel signal-to-noise ratio (CSNR) level and outperforms LS estimation. In addition, the proposed RR estimation can get the gains of about 1dB compared with LS estimation.

关键词： SC-FDE channel estimation least square ridge regression

Imaging a periodic moving/state-changed object with Hadamard-based computational ghost imaging

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Chinese Physics B 2022年第8期31卷 391-398页

作者： Hui Guo Le Wang Sheng-Mei Zhao institute of Signal Processing and transmission Nanjing University of Posts and TelecommunicationsNanjing 210003China College of information Engineering Fuyang Normal UniversityFuyang 236037China

We propose a method for imaging a periodic moving/state-changed object based on computational ghost imaging with Hadamard speckle patterns and a slow bucket detector, named as PO-HCGI. In the scheme, speckle patterns are produced from a part of each row of a Hadamard matrix. Then, in each cycle, multiple speckle patterns are projected onto the periodic moving/state-changed object, and a bucket detector with a slow sampling rate records the total intensities reflected from the object as one measurement. With a series of measurements, the frames of the moving/state-changed object can be obtained directly by the second-order correlation function based on the Hadamard matrix and the corresponding bucket detector measurement results. The experimental and simulation results demonstrate the validity of the PO-HCGI. To the best of our knowledge, PO-HCGI is the first scheme that can image a fast periodic moving/state-changed object by computational ghost imaging with a slow bucket detector.

关键词： ghost imaging periodic moving object periodic state-changed object Hadamard matrix

Simple and practical method of characterizing the parametric down-conversion source

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Chinese Physics B 2017年第11期26卷 83-88页

作者：王东伍娟赵良圆安雪碧银振强陈巍韩正甫王琴 Key Laboratory of Quantum information University of Science and Technology of China Synergetic Innovation Center of Quantum information & Quantum Physics University of Science and Technology of China institute of Signal Processing and transmission Nanjing University of Posts and Telecommunications

Parametric down-conversion（PDC） sources play an important role in quantum information processing, therefore characterizing their properties is necessary. Here we present a statistical model to assess the properties of the PDC source with certain distribution, such as the brightness and photon channel transmissions, we only need to measure the singles and coincidences counts in a few seconds. Furthermore, we validate the model by applying it to a PDC source generating highly non-degenerate photon pairs. The results of the experiment indicate that our method is more simple, efficient, and less time consuming.

关键词： parametric down-conversion brightness photon channel transmission

Full color ghost imaging by using both time and code division multiplexing technologies

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Chinese Physics B 2022年第11期31卷 316-323页

作者： Le Wang Hui Guo Shengmei Zhao institute of Signal Processing and transmission Nanjing University of Posts and Telecommunications(NUPT)Nanjing 210003China College of information Engineering Fuyang Normal UniversityFuyang 236037China

We propose a new full color ghost imaging scheme using both time and code division multiplexing *** the scheme,the speckle patterns of three colors(red,green and blue)are modulated with different time slots and *** light intensity is sampled by one bucket *** based on the modulated time slots and codes,we can effectively and simultaneously extract three detection component signals corresponding to three color components of objects from the sampling signal of the bucket ***,three component images resulting from the three component detection signals can be synthesized into a full color *** experimental results verify the feasibility of our scheme under the limit of the number of time slots and ***,our scheme reduces the number of bucket detectors and can realize high quality imaging even in a noisy environment.

关键词： ghost imaging time division multiplexing code division multiplexing full color imaging

Transmit Power Optimization for Relay-Aided Multi-Carrier D2D Communication

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Tsinghua Science and Technology 2018年第1期23卷 65-74页

作者： Muhammad Waqas Guftaar Ahmad Sardar Sidhu Tayyaba Jabeen Muhammad Afaq Ahmad Muhammad Awais Javed Department of Electrical Engineering COMSATS Institute of Information Technology (CIIT) Islamabad 44000 Pakistan transmission Department Pakistan Telecommunication Company Limited (PTCL) Islamabad 44000 Pakistan

In this paper, we consider the power optimization problem in Orthogonal Frequency Division Multiplexing （OFDM）-based relay-enhanced device-to-device （D2D） communication. In a single cell transmission scenario, dual- hop communication is assumed in which each D2D user re-uses the spectrum of just one Cellular User （CU）. In this work, we formulate a joint optimization scheme under a Decode-and-Forward （DF） relaying protocol to maximize the sum throughput of D2D and cellular networks via power allocation over different sub-carriers. The problem is thus transformed into a standard convex optimization, subject to individual power constraints at different transmitting nodes. We exploit the duality theory to decompose the problem into several sub-problems and use Karush-Kuhn- Tucker （KKT） conditions to solve each sub-problem. We provide simulation results to validate the performance of our proposed scheme.

关键词： device-to-device communication Orthogonal Frequency Division Multiplexing (OFDM) Decode-and-Forward (DF) relay transmission power optimization

Network Sorting Algorithm of Multi-Frequency Signal with Adaptive SNR

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Journal of Beijing institute of Technology 2018年第2期27卷 206-212页

作者： Xinyong Yu Ying Guo Kunfeng Zhang Lei Li Hongguang Li institute of information and Navigation Air Force Engineering UniversityXi'an 710077China Science and Technology on information transmission and Dissemination in Communication Networks Laboratory Shijiazhuang 050081China

An signal noise ratio（ SNR） adaptive sorting algorithm using the time-frequency（ TF）sparsity of frequency-hopping（ FH） signal is proposed in this paper. Firstly,the Gabor transformation is used as TF transformation in the system and a sorting model is established under undetermined condition; then the SNR adaptive pivot threshold setting method is used to find the TF single source. The mixed matrix is estimated according to the TF matrix of single source. Lastly,signal sorting is realized through improved subspace projection combined with relative power deviation of source. Theoretical analysis and simulation results showthat this algorithm has good effectiveness and performance.

关键词： frequency-hopping(FH) under-determined adaptive signal noise ratio(SNR) time-frequency(TF) signal source network sorting