Abstract:The high time resolution of ultra-wide-band (UWB) signals facilitates very precise position estimation in indoor scenarios. This paper reviews the problem of position estimation in UWB systems, beginning with an overview of the characteristics of the UWB positioning system. This overview is followed by the fundamentals of positioning. Two key challenges are issued which are the problem of UWB signal sampling and the problem of TOA estimation. Compressive Sensing theory is applied to solve these problems and research results are given. Finally, a real-time precise location system for business is described.

Abstract:In order to improve the performance of the Generalized Cross Correlation (GCC) method for time delay estimation, a new arithmetic which combined with GCC and Second Correlation has been proposed. The main process of the new arithmetic is as the GCC method except that the signals are auto-correlated and inter-correlated before the weighting processing. Simulation tests indicated that its performance of anti-interference and precision is better than GCC. To verify the proposed method, the artificially triggered lightning data was processed, which proved the new arithmetic could be competent to the lightning radiation source location and increase the location accuracy effectively.

Abstract:The luminance components of the input color images are processed with nonsubsampled Contourlet transform (NSCT). The decision map is attained by fusing the high frequency coefficients through the scheme of Synthesis Image Coefficient Value Select Maximum (SI-CVSM). Then the decision map is verified by consistency verification and is used to select the RG,B components simultaneously. Experiment results show that the proposed algorithm avoids color distortion caused by fusion algorithms in RGB space model. At the same time this method is only the luminance component integration, thereby reducing the computational complexity. The fused image, which not only retains the important information existing in the input color images, but also improves the detail expression, is more adaptive to the vision of human beings. The integration method is also applied to gray-scale multi-focus image integration in this paper, and the practice shows it is pretty effective.

Abstract:According to shortcoming of Wavelet and Contourlet in the applicatiopn of SAR image denoising, taking advantage of wavelet and contourlet, the proposed method was complemented by wavelet transform in conjunction with directional filter banks. First, the proposed method derived wavelet coefficients of entry image by wavelet transform, then reconstructed the image only by lowpass coefficients and after processing it can derived a highpass subband, afterwards to partition the highpass subband into multi-direction subbands by direction filter banks. Last we adapt Bayesian maximum aposteriori probability(MAP) estimation to estimate these multi-direction subbands. The experimental results show that the proposed method can restrain the speckle noise effectively at the same time it can keep the Radiated characteristics of even region very well, it also can keep edge information effectively and avoid artifacts. Futhermore the highpass subband image of the proposed method contains more texture, it is beneficial to extract edge feature of image.

Abstract:To further improve the ability that the Direct Sequence Spread Spectrum System restrains the narrowband interference, the paper realized adaptive threshold suppressing the narrowband interference basing on wavelet packet transformation. Through analyzing the power spread of the DS signal in wavelet packet transform, the thesis sets the adaptive threshold to orientate and reject the narrow-band interference. And the problem that the threshold is hard to settle is resolved. The adaptive threshold can quickly track and accurately locate the contaminate subsidiary-band, and be adaptive for the interference changing. Finally, the results of simulation demonstrate that the anti-jamming ability of the DSSS was further improved by the threshold algorithm.

Abstract:Based on Teager-Kaiser(TK) power estimating operator, the novel coexisting narrow band interference(NBI) detecting algorithm for Ultra-wideband(UWB) communication is proposed in this paper. The novel algorithm can estimate the central frequency of NBI accurately by adding the standard frequency signal to the TK disposing branch and using the discrepancy frequency information provided by the TK computation. The mathematic model and simulation analysis for the novel algorithm are made in this paper. The simulation results show that the measuring NBI frequency function can be finished efficiently. Furthermore, the novel algorithm can leave out the analog mixer used widely in typical frequency measuring system and reduce the deposing complexity evidently, which can provide the important reference for development of adaptive anti–jamming technology and cognitive technology for UWB communications.

Abstract:To compensate the ISI of 16APSK over satellite channels, equalization is needed before demodulation and decoding. Conventional receivers execute equalization, demodulation and decoding independently. This paper applies Wiener equalization to BICM satellite system and proposes an associated processing algorithm for 16APSK over memory non-linearity satellite channels. The algorithm join soft-decision feedback decoding, iterative Wiener equalization and weighting likelihood information together, which deeply excavates the inherent relevance between information. Therefore, an associated processing among equalization, demodulation and decoding is achieved to compensate the nonlinear distortion of 16APSK. Simulation results show that the algorithm is validity and gets better performance.

Abstract:A novel cooperative diversity scheme based on irregular low density parity check code(LDPC) design is proposed in this paper, and three different relay protocols of one user and one relay numerical results of bit error rate and outage probability for the quasi-static rayleigh fading channels are also presented by theoretical derivation and system simulation. Compare and analysis the bit error performance and outage probability simulation graphs of two-users multi-relays using coded cooperation strategy.results that through integrating with irregular LDPC and cooperative MIMO,bit error rate and outage probability decreased greatly.the performance improved significantly.

Abstract:A new non-orthogonal decomposition method of random signal is proposed in this paper. This approach find the feature space of the signal by transform the second-order statistics of the observation data at first. And then do the non-orthogonal decomposition of the signal according to the practical factors that affect the signal to obtain the decomposition results which is more realistic and easy to deal with. Through this decomposition, a random signal can be

Abstract:When the Extend Kalman Filter (EKF) is applied in the aircraft attitude estimation, two defects exist: one is computational complexity; the other is large linearization error. Aiming at these problems, Central Difference Kalman Filter (CDKF) based on Stirling interpolation formulation is applied to the low-cost aircraft attitude estimation system which is of less accurate and high noisy sensors. First, the nonlinear mathematic model of aircraft attitude based on quaternion is established, then CDKF is used for attitude estimation.Experimental results with real flying data show that CDKF is superior to the commonly used EKF method. The algorithm not only improves the attitude estimation precision and stability greatly, but also avoids the computing burden of Jacobian matrices. In addition, it is more simple and easier to implement.

Abstract:For the characteristics of limited nodes energy in wireless sensor networks, how to improve the rate of energy utilization and lengthen the lifetime of WSN is a problem that every WSN researchers need to face. It is also the puzzle which should be solved in the WSN development process. Therefore, this paper introduced the Data Integration algorithm into Wireless Sensor Networks. By removing redundant information in sensor nodes the data flow of network is reduced, thus the energy consumption of the network is reduced, and the goals of improving energy utilization rate and lengthening lifetime of network achieve at the same time. In this paper the research foundation was the tree structure WSN. The paper analysis and research the energy consumption of network before and after Data Integration, and give the corresponding energy consumption mode. Followed by the ways of computer simulation and experimental data monitoring, the paper prove the Data Integration is effective in reducing energy consumption of network, and have certain practical value.

Abstract:There are several nonlinear filters, such as hard limiter, clipper and hold puncher in traditional digital receivers which only focus on larger amplitude in time domain and without any considerations for actual statistical characteristics of noises. α stable distribution is a non-Gaussian model, which can be adopted to describe the “heavy-tailed” noise well. But there is no closed form expression of the probability density function (PDF) of α stable distribution model except for several special values, which is inconvenient to use. Firstly Cauchy Gaussian Model (CGM), which has specific expressions of PDF, is adopted to approximate α distribution model. Then Gaussianization filter is formulated by estimated PDF, which is special for different value of α. At last simulation results indicate that this filter is better than traditional nonlinear filters.

Abstract:Build the resource requirement plane by the normalized bandwidth requirement and normalized signal to noise ratio，overall resource efficiency measure method is put forward based on the bandwidth efficiency and energy requirement，the method is taken into the multiple-input multiple-output (MIMO) system，overall resource efficiency of the MIMO is analyzed system under a different number of transmit and receive antennas，different modulation and detection algorithm. To conclusion that MIMO system the efficiency of the overall resources than the traditional single-input single-output (SISO) system overall resource with high efficiency. When the number of transmit antennas is fixed，MIMO system resource efficiency increases with the increase of the number of receiving antenna; Using M-ary quadrature amplitude modulation (MQAM) overall resource efficiency is higher than that of employing M-ary phase shift keying (MPSK)，and the overall resource efficiency improve with the increase of M. Maximum likelihood detection (MLD) is the optimal detection algorithm，which overall efficiency of resources relatively high. The above conclusions verify the validity of the algorithm，the overall resource efficiency measure provide an important basis for applied to other system as well as new detection algorithm.

Abstract:To solve the low accuracy of fire situation assessment, fire alarm and fire source localization during fire detection in the lager room for the regular fire monitoring system due to fire monitoring node isolation, a fire detection and localization algorithm for the large place based on wireless sensor network is proposed in this paper. The artificial neural network is firstly trained by fire data from the wireless sensor node, and the artificial neural network with fuzzy decision is then used to estimate and decide the fire situation. The limited space smoke diffusion model and gas temperature diffusion model are applied to locate fire source and measure the coverage of fire, and it is possible to assess fire situation more accurately in large room, which can provide more information for firefighters to take measures to extinguish fire. The simulation results show that not only single node fire alarm based on neural network has high fire alarm probability but also total fire detect wireless sensor network has high accuracy about fire situation assessment and high accuracy about fire source localization. Theory analysis and experimental results show that the fire detection and localization algorithm is feasible.

Abstract:To improve the performance of Compressed Video Sensing (CVS), a multi-hypothesis based hierarchical reconstruction method is proposed. In the presented framework, the key frame in Group of Picture (GOP) is first reconstructed independently. Afterwards, reconstruction level is allocated for each non-key frame, following which the reconstruction is processed from the lowest level to the highest one. When reconstructing a non-key frame, block by block reconstruction is processed. The temporal data set in reference frames and spatial data set in current frame are taken as multi-hypothesis (MH) for current block, followed by solving the Total Variation Minimization (TVmin) problem to reconstruct the prediction residual. The final reconstructed image is formed by adding the prediction residual to the prediction value. Experimental results show that compared with the existing method, the proposed one can get higher Peak Signal to Noise Ratio (PSNR) up to about 3.2dB at the same sampling rate.

Abstract:To improve the statistical monitoring performance of complex chemical process, a new statistical process monitoring and fault identification method having the character of nonlinear which based on kernel independent component analysis (KICA) and kernel fisher discriminant analysis (KFDA) is proposed. KICA is used to establish the normal operating conditions and identify the fault. If a fault occurs, the nuclear fisher discriminant vector and feature vector F of the process data are extracted from the Fisher subspace. Thus, the batch normal or not can be detected by comparing distance with the predefined threshold. Comparing the present discriminant vector and the optimal discriminant vector of fault in historical data set, the similar degree can be identified. According to the similar degree, the perform fault can be diagnosed. The results of simulating demonstrate that the proposed method can efficient in detecting and diagnosing the malfunctions，with more accurate result.

Abstract:When the signal frequency locates in the area near the midpoint of two neighboring discrete frequencies, the performance of IIN algorithm is poor. But when the signal frequency is near the discrete frequency, the performance of Rife algorithm is poor. A new algorithm called R-IIN algorithm is presented. Firstly, the signal frequency is approximately estimated using Rife algorithm.Secondly, move the signal frequency to the area near the discrete frequency. Finally, the frequency is estimated by IIN algorithm. Simulation results show the performance of R-IIN is better than M-Rife[4] and one iteration of IIN[8] algorithm, and close to IIN of two iterations.

Abstract:The noise is one of the main factors affecting edge detection of the image. Various morphology operations can remove the noise effectively, and the study of algorithms using morphology to detect the edge of the image with noise is widely concerned in recent years. In order to improve the accuracy of edge detection and reduce the effect of noise on the image edge detection. An improved algorithm of morphology to resist the noise is proposed, using two different structure elements for edge detection. For the image with the salt and pepper noise, the improved algorithm can filter the noise effectively, the improved image is more smooth and clear outline. The edge location is accurate and the detail characteristics of the edge is well retained. The experiment results show that the algorithm has better anti-noise capacity, and the objective evaluation and visual effect are good. Meanwhile, the algorithm has certain practicality and feasibility.

Abstract:Research on performance test method of GNSS anti-jamming receiver is very important to improve the safety and reliability of satellite navigation system under actual application environment. This paper presents an improved test method of GNSS anti-jamming receiver by expanding the viewing angle range of analog signal based on microwave chamber, the method realizes multiple output of satellite signal and dynamic simulation of interference signal. Compared with the traditional test method, which are signal output of satellite signal and static simulation of interference signal, the method proposed in the paper can approximate the external reality test environment, which improves the accuracy of anti-jamming receiver performance test. Finally, through the digital simulations, the influence on anti-jamming receiver test brought by the angle of interference source and signal source and simulation error of signals is also analyzed.

Abstract:Aiming at the spectrum sensing demand under low SNR environment of cognitive radio (CR) users, a cooperative spectrum sensing algorithm based on truncated sequential probability radio test (SPRT) is proposed. Each cooperative radio user counts the number of sampling points, while its energy value is greater than the preset threshold in every field by sectionally processing the signal sequences they received, and then upload them to the fusion center as local test statistics, which reduces the overhead of control channel effectively. By introducing De Moivre-Laplace theorem and central limit theorem, the local test statistics of intrasegment approximate Gaussian distribution, which greatly simplifies the theoretical deduction and calculative process of likehood ratio function subsequently. Performance analysis and simulation results show that under the same conditions of detection performance, the proposed algorithm reduces the spectrum sensing time largely compared with the conditional energy detection.

Abstract:In this paper, we propose an online motor imagery detect algorithm including Electroencephalography (EEG) preprocessing, common spatial patterns feature extraction?, SVM classification, and threshold mechanism. In designing the light wireless switch hardware module, we develop the light switch system controlled by EEG. Participants can use their brain waves to remote control the light turn on, turn off , which especially provide a new direct communication channel for patients suffering from Amyotrophic Lateral Sclerosis(ALS) with the nature. Five healthy subjects participated in the training experiment and online experiment, the experimental results show that: after a specific training procedure, participants can effectively control the light switch system with an average accuracy of 90% and an average time of 4 seconds for each single command.

Abstract:Considering the problem which the artificial bee colony is inclined to fall into local optimum. Firstly, the onlooker bees′ number is doubled, the roulette wheel selection mechanism is adopted to update with its half to keep evolution along the high concentration of nectar sources; and the roulette wheel selection mechanism of the reverse with others is used to maintain population diversity. Secondly, employed bees is transformed corresponding to all the nectar sources which the times of counter without updating is greater than the threshold value into scout bees, then are these nectar sources updated. Finally, the center position of nectar sources is calculated which are gotten after each iteration, a new solution is produced in the neighborhood that is formed by the center position and every nectar source, then compared thevalues of fitness to choose optimum. Experiments show that the improved colony algorithm not only has better convergence precision and good robustness, but also increases the chance of the algorithm to jump out of local optimum, enhances the ability of search, and has a better optimization performance.