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Constructing quantum error correcting code via logic function

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Science china(information Sciences) 2010年第3期53卷 515-523页

作者： ZHONG ShuQin, MA Zhi & XU YaJie zhengzhou institute of information engineering, university of information engineering of china, zhengzhou 450002, china zhengzhou institute of information engineering University of Information Engineering of China

We present a systematic way to construct p-ary quantum error correcting codes using logic functions. As a consequence, for a given function with APC distance d′ 2, we can construct quantum codes with parameters ((n, K, d))p and gain a lower bound of K for all 2 d d′. The basic states of the constructed quantum codes can be stated and the sufficient conditions for saturating quantum Singleton bound are also discussed. We give quantum codes [[5, 1, 3]]p with p prime, [[6, 0, 4]], [[6, 2, 3]]p with p > 2 prime and [[2n, 2n - 2, 2]] as examples constructed in this way.

关键词： quantum error-correcting code logic states APC distance

Array errors active calibration algorithm based on instrumental sensors

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Science china(information Sciences) 2011年第7期54卷 1500-1511页

作者： WANG Ding & WU Ying institute of information engineering,information engineering university,zhengzhou 450002,china institute of information engineering Information Engineering University

The array mutual coupling,gain-phase errors and sensor position errors would significantly degrade the performance of high-resolution direction of arrival (DOA) estimation *** at the combined influences of the above three array errors,a kind of active calibration algorithm is presented with the help of instrumental sensors in this ***,the integrated effects of the three array errors are shown to be equivalent to angularly dependent gain-phase ***,a non-linear least square (LS) optimization model for the three array errors is established through an auto-calibration algorithm using auxiliary sensors,and the corresponding resolving algorithms of the LS optimization problem are given according to the different models of array errors ***,the parameter estimation uniqueness of the proposed algorithms is analyzed in detail and an improvement strategy is ***,the effectiveness of the novel algorithm is validated by simulations.

关键词： array calibration array errors mutual coupling effect gain-phase errors sensor position errors instrumental sensors

Array errors active calibration algorithm and its improvement

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Science china(information Sciences) 2010年第5期53卷 1016-1033页

作者： WANG Ding & WU Ying institute of information engineering, information engineering university, zhengzhou 450002, china institute of information engineering Information Engineering University

The combined effects of mutual coupling, gain and phase errors, and sensor position errors have great negative impact on the direction-finding performance of the MUSIC algorithm. This paper investigates the calibration of the array errors induced by the three errors. Based on the array errors calibration algorithm (algorithm 1) presented by See, two improved array error-calibrating algorithms are presented. One (algorithm 2) uses the sparseness of mutual coupling matrix, and the other (algorithm 3) utilizes more special structures of mutual coupling matrix. Although the three algorithms have the same computation mode and theoretical framework, the latter two algorithms have much higher precision than the former one, as more properties of mutual coupling matrix are utilized in the two algorithms, and if the array manifold is uniform linear array or uniform circular array, algorithm 3 could have more obvious advantages. On the other hand, the three algorithms can be generalized to the situation when the calibration source azimuths have deviations. The three extended algorithms can not only calibrate the array errors, but also offset the deviations of calibration source azimuths simultaneously. Finally, the performances of the three algorithms are compared both in the absence and presence of the deviations of calibration source azimuths. Many simulation experiments demonstrate that the estimation precision of array errors can be obviously improved if more properties of mutual coupling matrix are effectively used.

关键词： array calibration mutual coupling gain and phase error sensor position errors complex symmetric banded Toeplitz matrix complex symmetric circular matrix sparse matrix

A single observer location method under the scatter signals position disturbance situation:the constraint total least square method

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Science china(information Sciences) 2011年第1期54卷 146-152页

作者： YANG TianChi1,YU ChaoQun2,WANG TianPeng1 & JIN Liang1 1National Digital Switching System engineering and Technological Research Center, zhengzhou 450002,china 2surveying and mapping College of information engineering university, zhengzhou 450002,china National Digital Switching System engineering and Technological Research Center surveying and mapping College of information engineering university

A target position can be estimated using position information from scattered signals in the nonline-of-sight propagation environment in a single observer location *** is always an error in the final estimated result of the position obtained using scatter signals because measurement noise is *** reduce the total error of the system,we propose a method of converting the problem of optimizing location into a one of solving the extremes of the *** the problem of how to solve the extremes of the constraints is converted into an unconstrained problem by using the constrained total least squares(CTLS) ***,the Newton iteration method is used to obtain the optimized *** results also verify the capability of this method.

关键词： scatter position disturbing VOCTLS single observer location Newton iteration

National 2000' GPS control network of china

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Progress in Natural Science:Materials International 2007年第8期17卷 983-987页

作者： Yang Yuanxi~(1**) Tang Yingzhe~1 Chen Chuanlu~2 Wang Min~3 Zhang Peng~4 Wang Xiaorui~2 Song Lijie~5 Zhang Zusheng~6 (1.Xi'an Research institute of surveying and mapping,Xi'an 710054,china 2.Geodetic Data Processing Center,Xi'an 710054,china 3.Center of Earthquake Analysis and Prediction,china Seismological Bureau,Beijing 100036,china 4.National Geomatics Center of china,Beijing 100044,china 5.institute of surveying and mapping,zhengzhou university of information engineering,zhengzhou 4.0052,china 6.First Crustal Deformation Monitoring Center,china Seismological Bureau,Tianjin 300180,china) Xi'' an Research institute of surveying and mapping Xi'' an 710054 China Geodetic Data Processing Center Xi'' an 710054 China Center of Earthquake Analysis and Prediction China Seismological Bureau Beijing 100036 China National Geomatics Center of china Beijing 100044 China institute of surveying and mapping Zhengzhou University of Information Engineering Zhengzhou 450052 China First Crustal Deformation Monitoring Center China Seismological Bureau Tianjin 300180 China

An accurately unified national GPS network with more than 2500 stations,named"National 2000' GPS Control Net- work",signed the epoch 2000.0,has been established by integrating the existing six nationwide GPS networks of china set up by differ- ent departments with different *** paper presents the characteristics of the existing GPS networks,summarizes the strategies in the integrated adjustment of the GPS network,including functional model,stochastic model as well as the adjustment principle modifi- *** modifying the adjustment strategies according to the characteristics of the existing GPS networks and under the support of the IGS stations,the accuracy of the integrated national GPS network is greatly *** datum differences among the sub networks disappear,the systematic error influences are weakened,and the effects of the outliers on the estimated coordinates and their variances are *** is shown that the average standard deviation for the horizontal component is smaller than 1.0 cm,the vertical component is smaller than 2.0 cm,and the three-dimensional (3-D) position of geocenter coordinates is smaller than 3.0 *** exterior checking ac- curacy for the 3-D position is averagely better than 1.0 cm.

关键词： GPS control network adjustment systematic errors robust estimation variance component estimation coordinate system

Decoy-state quantum key distribution for the heralded pair coherent state photon source with intensity fluctuations

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Science china(information Sciences) 2010年第12期53卷 2485-2494页

作者： ZHOU Chun, BAO WanSu & FU XiangQun institute of Electronic Technology, The PLA information engineering university, zhengzhou 450004, china institute of Electronic Technology The PLA Information Engineering University

This paper characterizes two important properties of the photon number distribution of the heralded pair coherent state (HPCS) photon source. The formula of secret key generation rates for the decoy-state quantum key distribution with intensity fluctuation source is proved to hold true for the HPCS photon source. By numerical simulations, we show that the three-intensity decoy-state protocols for the HPCS photon source is efficiently getting close to the ideal decoy-state method. Moreover, we find that the HPCS source is more robust against intensity fluctuation than the weak coherent photon (WCP) source, but less stable than the heralded single photon source (HSPS).

关键词： quantum key distribution decoy states heralded pair coherent state intensity fluctuations

The GPS-gravimetry boundary value problem

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Science china Earth Sciences 2005年第3期48卷 398-405页

作者： YU Jinhai1,2 & ZHANG Chuanding2 1. institute of Geodesy and Geophysics of Chinese Academy of Sciences, Wuhan 430077, china 2. zhengzhou information engineering university, zhengzhou 4.0052, china institute of Geodesy and Geophysics of Chinese Academy of Sciences Wuhan China zhengzhou information engineering university Zhengzhou China

How to determine the earth’s external gravity field with the accuracy of O(T2) by making use of GPS data and gravity values measured on the earth’s surface is dealt with in this paper. There are two main steps: to extend these measured values on the earth’s surface onto the reference ellipsoid at first and then to seek for the integral solution of the external Neumann problem outside the ellipsoid. In addition, the corresponding judging criteria of accuracy to solve the GPS-gravity boundary value problem are established. The integral solution given in the paper not only contains all frequency-spectral information of the gravity field with the accuracy of O(T 2), but is also easily computed. In fact, the solution has great significance for both theory and prac- tice.

关键词： Neumann boundary value problem, integral solution, gravity disturbance.

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A NEW METHOD OF FREQUENCY-HOPPING(FH) SIGNAL DETECTION

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Journal of Electronics(china) 2011年第4期28卷 468-473页

作者： Zeng Yu Liu Xueqian Li Ou(information and engineering university,information and engineering institute,zhengzhou 450002,china) information and engineering institute Information and Engineering University Zhengzhou China zhengzhou China

A new Frequency-Hopping(FH) signal detection method is *** from pre-vious methods which need to monitor the total band,it can monitor part of the band and decrease the range of the *** to this method,a new detection model is set and the computation formulas of the detection probability and false-alarm probability are *** parameters of a VHF radio are used to prove the validity of the *** results show that this method can de-crease the range of the bandwidth and detect the FH signal with some penalty on the SNR and signal loss.

关键词： Frequency-Hopping(FH) Detection Monitor Interception Channelized radiometer

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The gravitational gradient tensor’s invariants and the related boundary conditions

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Science china Earth Sciences 2010年第5期53卷 781-790页

作者： YU JinHai1,2,3 & ZHAO DongMing4 1 College of Earth Science, Graduate university of Chinese Academy of Sciences, Beijing 100049, china 2 institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan 430077, china 3 State Key Laboratory of Astronautic Dynamics, Xi’an 710043, china 4 zhengzhou institute of surveying and mapping, zhengzhou 4.0052, china College of Earth Science Graduate University of Chinese Academy of Sciences Beijing China institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan China State Key Laboratory of Astronautic Dynamics Xi’an China zhengzhou institute of surveying and mapping Zhengzhou China

Here we report new approaches of recovering the Earth gravitational field from GOCE (Gravity field and steady-state Ocean Circulation Explorer) gradiometric data with the help of the gradient tensor’s invariants. Our results only depend on GOCE satellite’s position and gradiometry, in other words, they are completely independent of the satellite attitude. First, starting from the invariants, linearization models are established, which can be referred as the general boundary conditions on the satellite’s orbit. Then, the spherical approximation expressions for the models are derived, and the corresponding solving methods for them are discussed. Furthermore, considering effects of J2-term, the spherical approximation models are improved so that the accuracies of the boundary conditions can be theoretically raised to O ( J 2/2 T), which is approximately equivalent to O(T2). Finally, some arithmetic examples are constructed from EGM96 model based on the derived theories, and the computational results illustrate that the spherical models have accuracies of 10-7 and the order recovering the gravitational field can reach up to 200, and the models with regard to effect of J2-term have accuracies of 10-8 and the order can reach up to 280.

关键词： the Earth’s gravitational field gravitational gravidiometry tensor’s invariant

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