matlab

基于小波变换的数字水印算法matlab代码，含有各种攻击的效果对比，对做毕设的同学应该有帮助。(Digital Watermarking Based on Wavelet Transform algorithm matlab code, containing a variety of attacks on the effect of contrast on the Bi-based students should do help.)

说明：  编了一个用C++程序实现BP网络的异或问题。(compiled a C program BP network problems or differences.)

多维标度变换是应用广泛的无线传感器网络定位算法(Multi-Dimensional Scaling)

说明：  WLS的电力系统状态估计，能够迅速完成节点迭代(WLS state estimation of power system that can quickly complete node iterator)

1、验证窗函数 N 变化时，验证其频谱主瓣副瓣比、主瓣宽度的变化。 a)矩形窗函数的 N 变化时，验证其其频谱主瓣副瓣幅度比基本不会发生变化， 而主瓣宽度将会变窄。这说明，当用矩形窗函数设计滤波器时，增大 N 不能使 得阻带衰减减小，但能够减小过渡带。 b)再选取其他的窗如 hamming/hanning 窗，验证当 N 变化时，其频谱主瓣宽 度变化、主瓣副瓣比值变化情况。 2、用窗函数法设计线性相位 FIR 低通，通带截止频率 wp=0.5PI, 阻带截止频率 ws=0.6PI, 阻带衰减不小于 40dB,通带衰减不大于 3dB. a)选取 Hanning,Hamming 窗查看设计出来的 FIR 的过渡带宽和阻带衰减是否 满足要求，二者有什么不同。 b)使用 hamming 窗，将窗长增大 1 倍，设计 FIR。验证同样的窗函数类型 (hamming)，不同窗长度时，设计出来的 FIR 的过渡带宽和阻带衰减都有什么变 化。 3、不使用 Matlab 系统函数得到上一项指标的低通，并与上一项结果比较。 4 用窗函数法设计线性相位 FIR 高通，通带截止频率 wp=0.8PI, 阻带截止频率 ws=0.7PI, 阻带衰减不小于 30dB,通带衰减不大于 3dB.(An actual filter is implemented using the truncated unit impulse response sequence of the ideal filter. For the ideal low pass filter, the unit impulse response h, N, D () is intercepted by a length of N, and the length is The N sequence H (n), when intercepted, guarantees causality and linear phase requirements for the filter. In order to reduce the Gibbs effect, the H (n) window is added, and the appropriate window function is selected to ensure the stopband attenuation and Transition zone requirement. Note that the sidelobe of the window function affects the stopband attenuation of the filter, and the main lobe width affects the filter Transition bandwidth.)

功率谱反演法对大气湍流的数值模拟，分为均匀采样和非均匀采样两种(Numerical simulation of the power spectral inversion of atmospheric turbulence, uniform sampling and divided into two kinds of non-uniform sampling)

说明：  用差分方法计算带时变系数的波动方程,界面可视。(simulate the wave functions with time-varying coefficients)

OFDM Modulation and Demodulation

代码里有很完整的注释和解释，是小学期课程设计的题目，预报误差法参数辨识-松弛的思想，微分方程组数值解方法，添加噪声处理。(Code, there are very complete notes and explanations Is the topic of the elementary school stage curriculum design, Prediction Error Method for Parameter Identification- the idea of relaxation, Numerical solution of differential equations method, Add noise processing.)

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