基于电力系统功率因数调节仪的一种电网电流基波分量的实时检测方法

提出了一种在电网电流畸变情况下依然适用的、基于FFT,IIR滤波算法的电网电流基波分量的实时检测方法。并用MATLAB和devpp进行了验证。理论分析表明:即使在电网电流剧烈变化时,这种方法仍然可以正常工作。该方法已应用在电力系统功率因数调节仪的研制中,用于计算电流基波。调节仪使用芯片ATmege128进行数据处理。结果证明了该方法的有效性和在工业应用中的适用性。     

基于DSP的MEMS陀螺去噪算法研究

作为惯导系统的重要传感器,陀螺仪的精度直接影响到导航定位的精确性,而随机噪声是影响其精度的重要因素.对随机漂移进行建模并在系统中加以补偿是提高陀螺及其导航系统精度的关键.本文对MEMS陀螺的信号进行分析,对高于通频带的噪声用切比雪夫低通滤波器进行滤波,对带内的噪声运用改进的中值滤波进行处理.DSP仿真结果表明,该方法能在保证实时性的情况下降低陀螺噪声误差对系统精度的影响,可以将信号的信噪比提高8 dB.     

线性相位数字滤波器的设计

针对经典数字滤波器设计方法的缺陷进行了分析,提出了利用现代数字滤波器技术设计具有线性相位特性的无限脉冲响应IIR数字滤波器的设计方法,并给出了具体的实现方案。     

A mathematical method to realize complex poles in a high-order passive switched-capacitor filter

A high-order discrete-time IIR low-pass with complex poles using charge sampling is presented in a single-stage structure by using a mathematical strategy. In comparison with the analog complex-poles G_m-C filters, the proposed filter consumes lower power and has good linearity, and all of the tunings are implemented only by capacitor sizes. The proposed filter is a seventh-order Butterworth, but this method can be generalized to implement other complex pole filters like Tchebyshev and Elliptic. Post-layout simulation results in 130-nm complementary metal-oxide-semiconductor (CMOS) show an IIP3 of +18 dBm and a noise figure of 5 dB. The filter has a rejection of more than 110 dB in its stop band and consumes 1.5 mW with a 1.6-V supply voltage, and circuit occupies an about 0.12 mm² of silicon.     

Massively parallel systolic‐array architectures for 2d IIR polyphase space–time plane‐wave beam digital filters

A systolic architecture has recently been proposed for implementing two‐dimensional infinite impulse response (IIR) space–time beam plane‐wave filters at a throughput of one‐frame‐per‐clock–cycle for such applications as real‐time broadband smart antennas. A novel polyphase systolic architecture is proposed here that further increases the throughput of these IIR beam filters, by a factor of M, to M‐frames‐per‐clock‐cycle, where M is the number of polyphases. The proposed method combines the polyphase approach, along with pipelining and look‐ahead optimization methods, to achieve frame sample frequencies that are several times higher than the clock‐cycle limit of the very large‐scale integration (VLSI) technology, thereby potentially allowing multi‐GHz frame sample frequencies using current custom VLSI circuits. The implementation of a field programmable gate array‐based real‐time prototype is described, tested and verified for the two‐phase case (M = 2) at a technology‐limited clock frequency of 50 MHz which corresponds to a throughput of 100 million‐frames‐per‐clock–cycle. Copyright © 2010 John Wiley & Sons, Ltd.     

基于自适应陷波器的科氏流量计信号频率跟踪新方法

为提高对科氏流量计信号频率随机缓慢变化的持续跟踪能力,以对格型ANF、简化格型ANF和基于SMM的新式ANF三种典型自适应陷波器的性能比较分析为基础,提出了一种科氏流量计信号频率跟踪新方法。该方法对频率、幅值和相位均随机游动变化的科氏流量计信号,首先采用新式ANF快速检测信号频率并作短时频率跟踪,待其收敛后简化格型ANF开始并行工作,在简化格型ANF收敛后取代新式ANF持续跟踪信号频率的变化。仿真结果表明,本文方法比格型ANF方法收敛速度更快、频率跟踪精度更高,比单一采用新式ANF方法计算更为简便,是一种科氏流量计信号处理的有效方法。     

“数字信号处理”的MATLAB应用研究

针对“数字信号处理”课程教学过程中出现的由于概念抽象、公式繁杂引起的学生对知识点理解肤浅的问题,在讲解过程中采用了矩阵实验室（MATLAB）编程技术,将数字信号处理的基本理论和处理方法用图形化演示方式表示出来。给出的实例和教学实践表明,该方法能够增强学生的理解能力,牢固掌握数字信号处理的理论知识和分析设计方法,提高了教学质量。     

A hybrid evolutionary dynamic neural network for stock market trend analysis and prediction using unscented Kalman filter

Stock market prediction is of great interest to stock traders and investors due to high profit in trading the stocks. A successful stock buying/selling generally occurs near price trend turning point. Thus the prediction of stock market indices and its analysis are important to ascertain whether the next day's closing price would increase or decrease. This paper, therefore, presents a simple IIR filter based dynamic neural network (DNN) and an innovative optimized adaptive unscented Kalman filter for forecasting stock price indices of four different Indian stocks, namely the Bombay stock exchange (BSE), the IBM stock market, RIL stock market, and Oracle stock market. The weights of the dynamic neural information system are adjusted by four different learning strategies that include gradient calculation, unscented Kalman filter (UKF), differential evolution (DE), and a hybrid technique (DEUKF) by alternately executing the DE and UKF for a few generations. To improve the performance of both the UKF and DE algorithms, adaptation of certain parameters in both these algorithms has been presented in this paper. After predicting the stock price indices one day to one week ahead time horizon, the stock market trend has been analyzed using several important technical indicators like the moving average (MA), stochastic oscillators like K and D parameters, WMS%R (William indicator), etc. Extensive computer simulations are carried out with the four learning strategies for prediction of stock indices and the up or down trends of the indices. From the results it is observed that significant accuracy is achieved using the hybrid DEUKF algorithm in comparison to others that include only DE, UKF, and gradient descent technique in chronological order. Comparisons with some of the widely used neural networks (NNs) are also presented in the paper.     

基于双线性变换法的IIR数字滤波器设计与matlab仿真

传统的数字滤波器设计使用繁琐的公式计算,尤其是设计高阶滤波器时工作量很人.利用matlab数字信号处理(dsp)工具箱(signal processing toolbox)可以快速有效的实现数字滤波器的设计与仿真.MATLAB软件的频谱分析和滤波器的分析设计功能很强,从而使数字信号处理变得十分简单.本文比较了设计IIR数字滤波器的两种方法,介绍了利用双线性变换法设计IIR滤波器的原理、步骤,并在matlab下进行了仿真.