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Design and Implementation of Adaptive Multi-Tap Analog Interference Canceller

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2019年第3期18卷 1698-1706页

作者： Zhang, Liyuan Ma, Meng Jiao, Bingli Peking Univ Sch Elect Engn & Comp Sci Beijing 100871 Peoples R China

Due to the severity of self-interferences, analog interference canceller is an essential part of a full duplex radio system. As the self-interference can potentially be even much stronger than the received signal, it must be meritoriously suppressed before analog-to-digital conversion. This paper is aimed to provide an optimal radio frequency domain multi-tap interference cancellation design. To this end, the following two key problems are addressed: the hardware design problem and the adaptive weight adjusting problem. For optimal hardware design, a trade-off between widening effective delay range and maximizing the minimum cancellation capability is formulated. The principles and guidelines for optimal solution and hardware parameter design are derived. We also formulate adaptive weight adjusting as a multi-dimensional optimization problem, which is proved to be non-convex while adjusting the attenuators and phase shifters independently. By using a coordinate transformation technique, it is then converted into a convex optimization problem, and a convergent iterative algorithm based on the gradient descent method is applied to obtain the global optimum. The hardware implementation and experimental results substantiated the effectiveness of the proposed principles and algorithms.

关键词： Full-duplex self-interference cancellation convex optimization problem iterative algorithm

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Synchronous full-field measurement of temperature and deformation based on separated radiation and reflected light

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OPTICS AND LASERS IN ENGINEERING 2019年第May期116卷 94-102页

作者： Tang, Yunlong Yue, Mengkun Fang, Xufei Feng, Xue Tsinghua Univ Dept Engn Mech AML Beijing 100084 Peoples R China Tsinghua Univ Ctr Mech & Mat Beijing 100084 Peoples R China

Optical method has been playing an important role in measuring temperature and deformation at elevated temperatures. Here we propose a simple and effective iterative algorithm to realize accurate and simultaneous measurement of the full-field temperature and deformation of specimens subjected to flame heating at temperatures up to 1000 degrees C. The algorithm separates the optical images of specimen surface into radiant and reflected parts. The radiant part is used to calculate the full-field temperature by an improved two-color method, and the reflected part is used to obtain the deformation of the specimen surface based on high-temperature digital image correlation method. Experimental validation shows that the proposed method can effectively eliminate the mutual interference between the radiation and reflected light, displaying great potential for synchronous measurement of temperature and deformation with sufficient accuracy by using one camera.

关键词： iterative algorithm Synchronous temperature and deformation measurement Separation of radiation and reflected light Two-color method

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Parameter estimation for a special class of nonlinear systems by using the over-parameterisation method and the linear filter

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INTERNATIONAL JOURNAL OF SYSTEMS SCIENCE 2019年第9期50卷 1689-1702页

作者： Chen, Mengting Ding, Feng Lin, Rongming Alsaedi, Ahmed Hayat, Tasawar Jiangnan Univ Sch Internet Things Engn Minist Educ Key Lab Adv Proc Control Light Ind Wuxi Jiangsu Peoples R China Qingdao Univ Sci & Technol Coll Automat & Elect Engn Qingdao 266061 Shandong Peoples R China King Abdulaziz Univ Dept Math Jeddah Saudi Arabia Nanyang Technol Univ Coll Engn Sch Mech & Aerosp Engn Singapore Singapore

This paper studies the parameter estimation issues of a special class of nonlinear systems (i.e. bilinear-in-parameter systems) utilising the measurement input-output data. The estimation idea is based on the data filtering technique and the over-parameterisation method to represent the system as a linearly parameterised form. Then, by means of the filtered model and the noise model, a filtering based over-parameterisation generalised extended gradient iterative (F-O-GEGI) algorithm is developed for estimating all the parameters. For purpose of improving the precision of parameter estimation, a filtering based over-parameterisation generalised extended least squares iterative (F-O-GELSI) algorithm is derived by formulating and minimising two separate criterion functions. By these foundations, the F-O-GEGI algorithm and the F-O-GELSI algorithm with finite measurement data are presented. The simulation example is provided to test and compare the presented approaches.

关键词： Bilinear-in-parameter system parameter estimation filtering technique iterative algorithm over-parameterisation

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Generalized Attitude Determination with One Dominant Vector Observation

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2019年第4期42卷 885-893页

作者： Crassidis, John L. Cheng, Yang Univ Buffalo State Univ New York Dept Mech & Aerosp Engn Amherst NY 14260 USA Mississippi State Univ Dept Aerosp Engn Mississippi State MS 39762 USA

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Fast algorithms for Designing Complementary Sets of Sequences Under Multiple Constraints

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IEEE ACCESS 2019年 7卷 50041-50051页

作者： Wu, Zhong-Jie Xu, Tian-Liang Zhou, Zhi-Quan Wang, Chen-Xu Harbin Inst Technol Sch Elect & Informat Engn Harbin 150001 Heilongjiang Peoples R China Harbin Inst Technol Sch Informat Sci & Engn Weihai 264209 Peoples R China

Complementary sets of sequences (CSSs) are widely used in many applications, such as active sensing and wireless communication. The construction of CSS has attracted considerable attention over the past few decades. In this paper, efficient and comprehensive computational algorithms for CSS design are proposed. We seek to minimize complementary integral sidelobe level (CISL) under multiple constraints, including unimodular, peak-to-average power ratio, discrete phase, and spectrum compatible constraint. The task of CSS design can be formulated as solving a nonconvex constraint optimization problem. As this problem is difficult to tackle directly, we resort to the general majorization-minimization (MM) method. By utilizing the inherent algebraic structure of the objective function, we construct the majorizing function via two consecutive applications of the MM method and obtain a closed-form solution by a couple of FFT operations at each iteration. The relationship between MM-based algorithms and derivative-based algorithms is revealed. Our algorithms are more flexible and widely applicable, and the numerical experiment results demonstrate the effectiveness and superiority over the existing state-of-art algorithms.

关键词： Waveform design complementary set of sequences correlation iterative algorithm majorization-minimization

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Optimal power allocation for energy-efficient full-duplex cognitive relay networks under primary interference

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IET COMMUNICATIONS 2019年第19期13卷 3317-3325页

作者： Poornima, S. Babu, A. V. Natl Inst Technol Dept Elect & Commun Engn Calicut Kerala India

This study investigates optimal power allocation (OPA) for maximising the energy efficiency (EE) of dual-hop underlay full-duplex cognitive relay network, under the influence of interference from primary source. The OPA for the EE optimisation is constrained on the maximum transmit power of the secondary nodes and the interference threshold power which can be tolerated at the primary destination. The authors convert the initial non-convex optimisation problem to a concave fractional programming form and propose an iterative algorithm using parametric transformation to find the OPA vector. Further, they prove that the point of convergence of the proposed iterative algorithm is a Karush-Kuhn-Tucker point of the initial non-convex problem. They numerically demonstrate the EE improvement achieved by the proposed algorithms over equal power allocation strategy.

关键词： relay networks (telecommunication) optimisation concave programming cognitive radio energy conservation convex programming iterative methods optimal power allocation energy-efficient full-duplex cognitive relay networks primary interference energy efficiency dual-hop underlay full-duplex cognitive relay network primary source maximum transmit power interference threshold power primary destination nonconvex optimisation problem concave fractional programming form iterative algorithm OPA vector nonconvex problem equal power allocation strategy

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Thermal-mechanical coupling buckling analysis of porous functionally graded sandwich beams based on physical neutral plane

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COMPOSITES PART B-ENGINEERING 2019年 168卷 236-242页

作者： Liu, Yijie Su, Shengkai Huang, Huaiwei Liang, Yingjing Guangzhou Univ Sch Civil Engn Guangzhou 510006 Guangdong Peoples R China South China Univ Technol Sch Civil Engn & Transportat Guangzhou 510640 Guangdong Peoples R China

Porosity of functionally graded materials (FGMs) is usually aroused by fabrication defects. It had been proven that the porosity has a significant influence on the static responses of their structures, but the effects of porosity on buckling behaviors are still worth investigating. To reveal these effects, the thermal-mechanical coupling buckling issue of a clamped-clamped porous FGM sandwich beam is investigated in this paper by employing the high-order sinusoidal shear deformation theory. The modified Voigt mixture rule is used to approximate the temperature-dependent material properties of porous FGMs. The physical neutral plane of FGM sandwich beams is taken into account to reflect the actual condition of the structures and simplify the calculation. The thermal environments are considered as uniform, linear and nonlinear temperature rises, and both the temperature independent and temperature-dependent material properties are discussed in order to justify the importance of the thermal-mechanical coupling effect. An iterative algorithm is used to solve the thermal-mechanical coupling critical buckling temperature. The present theoretical results are verified by comparing with the literature and ABAQUS results, and the effects of porosity, the physical neutral plane, gradient index, material temperature dependence, sandwich structural parameters are discussed. Results show that for buckling issue excluding the pre-buckling deformation effect, considering either the physical neutral plane or the geometrical middle plane of FGM beams would produce alike critical buckling temperatures. With the rise of porosity, the critical temperature increases greatly, which is quite different from the changing rule observed in the buckling issue of inplane-loaded porous FGM plates in literature. The beam with a smaller face-to-core ratio is more sensitive to the change in porosity. Moreover, to improve the thermal buckling load of FGM beams, ceramic constituents with the lower the

关键词： Functionally graded materials Thermal buckling Porosity iterative algorithm Coupling

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Speckle-reduced holographic beam shaping with modified Gerchberg-Saxton algorithm

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OPTICS COMMUNICATIONS 2019年 433卷 44-51页

作者： Pang, Hui Liu, Wenjing Cao, Axiu Deng, Qiling Chinese Acad Sci Inst Opt & Elect Chengdu 610209 Sichuan Peoples R China

Holographic laser beam shaping using a spatial light modulator can provide flexible adaptation of the intensity profile. However, speckle noise exists in the shaped beams, which reduces the beam quality seriously. In this paper, a new method is proposed to implement noise reduced flat-top beam shaping. The Gerchberg-Saxton (GS) algorithm with special spherical initial phase profile is adopted to calculate the phase-only hologram. When the spherical phase distribution is properly selected, the speckle free flat-top beam with high diffraction efficiency and low root-mean-square error can be obtained. Both simulations and experiments are performed to verify the feasibility of the proposed method. The comparison with the conventional GS algorithm using a random initial phase distribution is also carried out.

关键词： Laser beam shaping Computer holography iterative algorithm

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An Efficient Normal-Error iterative algorithm for Line Triangulation

An Efficient Normal-Error Iterative Algorithm for Line Trian...

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15th International Conference on Advanced Concepts for Intelligent Vision Systems (ACIVS)

作者： Zhang, Qiang Wu, Yan Liu, Ming Jiao, Licheng Xidian Univ Sch Elect Engn Xian 710071 Peoples R China Xidian Univ Minist Educ China Key Lab Intelligent Percept & Image Understanding Xian 710071 Peoples R China

ISBN: (纸本)9783319028958;9783319028941

In this paper, we address the problem of line triangulation, which is to find the position of a line in space given its three projections taken with cameras with known camera matrices. Because of measurement error in line extraction, the problem becomes difficult so that it is necessary to estimate a 3D line to optimally fit measured lines. In this work, the normal errors of measured line are presented to describe the measurement error and based on their statistical property a new geometric-distance optimality criterion is constructed. Furthermore, a simple iterative algorithm is proposed to obtain suboptimal solution of the optimality criterion, which ensures that the solution satisfies the trifocal tensor constraint. Experiments show that our iterative algorithm can achieve the estimation accuracy comparable with the Gold Standard algorithm, but its computational load is substantially reduced.

关键词： Line triangulation Normal error iterative algorithm Suboptimal solution

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Extending BiCG and BiCR methods to solve the Stein tensor equation

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COMPUTERS & MATHEMATICS WITH APPLICATIONS 2019年第12期77卷 3117-3127页

作者： Xu, Xiangjian Wang, Qing-Wen Shanghai Univ Dept Math Shanghai 200444 Peoples R China Nantong Univ Sch Sci Nantong 226019 Jiangsu Peoples R China

The biconjugate gradients (BiCG) and biconjugate residual (BiCR) methods are attractive ways for solving nonsymmetric linear system Ax = b. In this paper, the BiCG and BiCR methods are extended to solve the high order Stein tensor equation. The convergent properties of the developed iterative algorithms are studied. Numerical examples are provided to confirm the theoretical results, which demonstrate that the proposed algorithms are effective and feasible for solving the Stein tensor equation. (C) 2019 Elsevier Ltd. All rights reserved.

关键词： Stein tensor equation Biconjugate gradients (BiCG) method Biconjugate residual (BiCR) method iterative algorithm k-mode product

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