Abstract:This paper investigates transmit beamforming optimization problem with per-cell power constraints for multi-cell downlink systems. A uplink-downlink duality under per-cell power constraints is established, based on the second-order statistics of the channel coefficients instead of instantaneous channel state information. And with the aid of this duality, a effective algorithm is proposed for the beamforming problem with per-cell power constraints.

Abstract:In this paper a robust AGC architecture is brought forward to solve the stability problem caused by short-time pulse interference; at the same time, it make the uncontaminated data best quantized. According the short-time characteristic of pulse, a new algorithm based on multiple observation is put forward, which can blank pulse interference effectively. The new method is very simple and can be processed in real time. It is shown by simulation and test result, the new method in this paper has good performance and low complexity, which can be applied to receiver design.

Abstract:Based on per user unitary and rate control (PU2RC), this study presents a multi-mode transmission scheme for the multi-user multiple-input multiple-output (MIMO) downlink systems with limited feedback. In the proposed scheme, the transmission mode, i.e., the number of data streams for simultaneous transmission, is adaptively chosen to maximize the ergodic sum rate of the system. Due to the difficulty in evaluating the ergodic sum rate, this paper derives an upper bound of the ergodic sum rate and uses it as the metric for transmission mode selection. Simulation results show that the proposed scheme achieves better ergodic sum rate performance than the conventional PU2RC scheme, especially when the number of users in the system is not so large or the signal-to-noise ratio is high.

Abstract:A method for signal processing of CMF based on DTFT algorithm with overlap Hanning windows is proposed. First, a new IIR adaptive notch filter is applied to filter the sensor output signals of CMF and calculate the frequency. Then the DTFT algorithm with overlap Hanning windows is introduced to calculate the real-time phase difference between two enhanced signals. With the frequency and phase difference obtained, the time interval between the two signals is calculated and then the mass flowrate is derived ultimately. The simulations and field test results show that the proposed method is efficient.

Abstract:In order to solve the problem of rapidly acquisition for weak signal in the Global Position System (GPS), a new improved weak signal acquisition algorithm is proposed which improves the past coherent and incoherent integral gain based on Fast Fourier Transform (FFT). The proposed method uses batch mode to improve capture gain adopting doppler compensation and improves signal accumulate time tolerance, and the method can further improve the signal capture sensitivity. Comparing with traditional algorithm the capture probability rises greatly and it has been proved fully by lots of simulation tests. Finally the method is implemented on FPGA.

Abstract:The design of cosine-modulated subband filter banks can be convertedto a high-dimension nonlinear optimization problem. The conventional iteration design method avoids the complicated solution. The conventional iteration design method controls the aliasing error relying on the stopband attenuation of filter banks, so that the orders of the designed filter banks are generally too high. A modified iteration design method for cosine-modulated filter banks (CMFB) is proposed in this paper. The new cost function consists of system response, stopband energy and the first aliasing factor which is added to eliminate the aliasing error more effectively. This cost function is formulated as a quadratic function whose minimum point can be obtained using a closed-form solution. The minimum point is approached by iteration in this algorithm which is simpler and more realizable than the direct optimization method. Simulation results demonstrate that this algorithm can design the subband filter banks with less aliasing error and shorter length, comparing with the conventional iteration design method.

Abstract:These years, modeling the process of Internet public opinions' evolution and trend forecasting based on that has become a hot topic. The existing short-term trend forecasting method ignores the variability of statistical properties of Internet public opinions’ evolution, which leads to a blind model selection, and the forecasting performance is poor. Therefore, this paper presents an adaptive evolution modeling method of Internet public opinions (AEMIPO). Firstly, this method tracks the statistical characteristics of the process of Internet public opinions' evolution dynamically, such as smoothness, periodicity and self-similarity. Then, by selecting ARMA, ARIMA, SARIMA and FARIMA, an alternative model bank is constructed. Finally, by making model selection rules, an appropriate model is selected to model and forecast the process of evolution adaptively. The experimental results show that compared with the existing methods, AEMIPO has higher forecasting accuracy and stability, and this method is more suitable for short-term modeling and trend forecasting of Internet public opinions’ evolution.

Abstract:For colored lighting and complex background facial video image, this article presents a skin color extraction algorithm based on CbCr-CgCr double Gaussian average degree of likelihood and inter-frame difference of I component in YIQ color space. This algorithm calculates the CbCr-CgCr double Gaussian average likelihood of facial video input image after preprocessing , roughly segments the average likelihood image by using the value of average likelihood and the value of I component, and then extracts the skin color region by combinating the skin coarse segmented image and I component inter-frame difference image. Experiment demonstrates that this algorithm has the good results of skin color extraction.

Abstract:By analysis of variable step size NLMS ( VSS-NLMS ) algorithms and compare their performances in far-talk and double-talk mode, an improvement is made on the NEW-NPVSS algorithm. The improved algorithm has better convergence in double-talk mode. Then a new variable step-size NLMS algorithm is put forward based on the filter coefficient gradient. When the filter coefficient of gradient is less than threshold value, fixed step-size is used in update the filter coefficients. Conversely, it stops updating the filter coefficients, and uses the coefficient in far-talk mode to replace the current coefficient. The simulation results show that the proposed algorithm has better convergence than the other variable step-size NLMS algorithms in far-talk mode, and has better convergence compared with the fixed step NLMS, SVSS in double-talk mode.

Abstract:A new algorithm based on one single snapshot is proposed for the instantaneity and decorrelation problems among Direction-Of-Arrival (DOA) estimation of signals on a ULA, which reconstructs a Toeplitz matrix using the correlation processed data vector. It is proved that the rank of this Toeplitz matrix has no relations with the coherency of the signals. Then accurate signal subspace and noise subspace can be acquired by performing eigenvalue decomposition of the matrix and the DOA of coherent and incoherent signals can be estimated combined with the subspace kind algorithms such as MUSIC and ESPRIT. This algorithm, without reducing the aperture of array, enhances the performances of DOA estimation under low SNR condition. Simulation results verify that the proposed algorithm is effective.

Abstract:Compared with the classical strap-down inertial navigation system and the rotating inertial navigation system in being, tri-unit rotating strap-down inertial navigation system has many advantages. Nevertheless, it brings some new problems to data acquisition. In view of the characteristic of this system, such as large amount of data, strong requirement on time synchronization, the impact of time asynchronization both between inertial sensors and between inertial sensors and gratings was analyzed in detail. At the same time, the corresponding solution project was given. In view of the phenomenon that temperature acquisition was disturbed by the rotation of motor easily, the causes were described concretely and relevant measures were taken as well. What’s more, a new communication between digital temperature sensor DS18B20 and DSP was designed in hardware. The result shows the data acquisition instrument comforts anticipative requirements and lay a good foundation for the coming out of high-precision, low-cost inertial navigation system.

Abstract:In the process of reconstructing super-resolution images by POCS algorithm, Image registration and initial estimation have important influence on the result of reconstruction.For solving the problem that the small block matching is liable to be interfered by noise and the big block matching can’t track the local moving objects accurately, a method to determine the spatial flatness of the image and divide the blocks according to the flatness of the image is provided.It can change the block size dynamically;As the initial estimation for the single frame is lack of enough information, we use all known low-resolution image to register the interpolated image.Then the initial estimation is generated by the optimal interpolation method.Experiments show that the improved matching algorithm reduces the influence of noise and local motion on block-matching accuracy and it’s also very sample.The new algorithm also improve the PNSR of the initial estimation and speeds up the convergence.

Abstract:In this paper, we study the signal coding and processing scheme of the STBC-SC-FDE systems with 2 transmit and 1 receive antenna over frequency-selective fading channels, and develop a least-squares channel frequency response estimation algorithm based on the input-output modal in frequency domain. We analyze the mean square error of the proposed algorithm, and get the result that the algorithm is not only able to achieve the minimum mean square error for channel estimation but also to make a communication system with a relative low peak-to-average power ratio by employing Chu sequences as its optimal training sequences. For SC-FDE systems, the proposed algorithm can save more computing resources than those algorithms that estimate channel impulse response firstly and then transfer it to frequency domain. In the end, the performance of the proposed algorithm is evaluated by Monte Carlo simulations.

Abstract:More efficient FFT algorithm is required in power quality analysis, while the traditional FFT algorithm have a greater time cost because of making butterfly in inverse-order. In order to boost real-time power quality analysis, this paper proposes a non-inversed order algorithm of FFT, which means much efficiency and space cost cuts. Compared with FFT algorithm supplied by matlab math library, the above algorithm realized in c language proved correct and highly efficient by simulation result.

Abstract:Normalization methods for the pre-process of gene chip are an important step.By studying normalization methods for gene chip,an improved algorithm is proposed in this paper.The improved algorithm has nearly effect to the robust Lowess normalization method, however our method spend less running time.The method is smoothed to the data points by locally weighted linear regression.Then kernel estimation is used for estimation of residue from smoothing estimation.Finally,scaling each data point on the plaid. Experimental results show that the algorithm is effective.

Abstract:This paper mainly discusses the key technology of connecting wireless sensor network with M2M platform-design and implementation of M2M gateway. Wireless sensor network (WSN) has many advantages such as independent ad hoc network and low power consumption. However, because of its feature of short distance communication, its application scope is limited. It is an inevitable trend in the development of wireless sensor networks that connecting WSN to M2M platform, while M2M gateway is the key technology to achieve the docking. Wireless sensor network M2M gateway use the embedded ARM9 processor S3C2440 as the core; CC2530 as the sink node to collecting data of WSN; GPRS module EM310 as the export of network data to docking the M2M platform server. The M2M gateway, which can connect WSN with M2M platform, can be widely used in a lot of practical application of Internet of Things with strong universality.

Abstract:In this paper, near-field microwave imaging system based on side-looking circular scanning is studied. It can solve the problem that the traditional turntable imaging system can not focus the targets with large angular rotation very well. The proposed system introduces not only the sparse sampling technique in frequency domain, but also the fast convolution algorithm in angular domain. The advantage of the proposed method is that it can obtain the high resolution image quickly. The resolution of the proposed method is deduced according to point spreading function. The sampling criterion is then presented in both frequency domain and angular domain. The proposed method is testified by both simulation results and experimental results. The results show that the proposed method can be used to acquire high quality and high resolution image.

Abstract:To enhance the accuracy of tamper localization and the performance of recovery, the paper proposes refining-localization-based image authentication and recovery scheme using iterative compensation mechanism. The authentication algorithm contains basic authentication and refining authentication. It fuses the twice authentication results and take some post-processing measures based on connected tampered region to obtain the accuracy authentication result. According to embedding capacity, the recovery scheme uses iterative compensation mechanism to recover the tampered pixels. Theoretical analysis and simulation results show that the proposed algorithm can improve the accuracy of tamper localization and the probability of recovering the tampered pixels.