mingmingbaibai

一种基于matlab的数字水印的仿真的实现。(Digital Watermarking Based on the simulation matlab implementation.)

M序列发生器函数，使用m文件实现，2至7级寄存器，主要分为两个部分。第一部分主要负责输入，输出，第二部分是M序列发生函数(M sequence generator function, 2-7 registers, divided into two parts. The first part is mainly responsible for the input, output, and the second part is the sequence generating function M)

首先根据短训练字的特性进行相关运算，进行信号到达检测，当检测到相关值大于门限一定次数后，认为有信号到达。然后根据长训练字的特性，进行相关运算，进行OFDM符号FFT窗口起始位置的估计。估计出FFT窗口的位置后，先在时域进行小频偏的估计，将两个长训练字进行小频偏补偿后，进行FFT运算，根据FFT运算的结果进行整数倍频偏的估计。这些参数估计完成后，就可以进行数据解调了。先对数据部分进行完整的频偏补偿，然后根据估计的FFT窗口位置进行FFT运算得到频域的数据，进行解调。然后在对应于导频的子载波位置上提取出导频信息，根据导频信息估计出剩余定时误差以及剩余的信道响应误差，将误差量送入环路进行跟踪。当收到所有数据后，重新回到信号到达检测状态，进行下一次信号到达的检测和信号接收。(First, according to the characteristics of the short training word correlation operation, the signal reaching the detector, when the detected correlation value is greater than the threshold after a certain number of times that a signal arrives. And then the characteristics of long training word, the correlation operation for the FFT window starting position of an OFDM symbol estimate. The estimated position of the FFT window, the first small frequency offset in the time domain estimation, the two long training word small frequency offset compensation, the FFT operation, the FFT result of the operation for integer frequency offset estimate. These parameter estimation is completed, the data can be demodulated on. The first portion of the data for a complete frequency offset compensation, and based on the estimated FFT window position of the FFT operation to obtain frequency domain data, demodulated. Then corresponding to the position of the pilot subcarriers are extracted on pilot inform)

本程序可以简单地求出两个信号之间的相位差，操作简单(This procedure can be simply the phase difference between the two signals is obtained, simple operation)

inveter modelling ,..DC voltage is converted to AC voltage by help of MOSFET

通信系统仿真原理与无线应用书中matlab源程序(Communication System Simulation Principle and wireless applications matlab source book)

同步在数字接收机的解调中非常重要，本程序详细描述了用平方定时算法描述的符号同步算法，(Time square Algorithm Symbol synchronization )

信号处理，用这个Matlab的程序可以处理信号。(filter signal)

说明：  MATLAB中的图像放大基于数字图像处理（最近邻）(MATLAB image magnification of based on digital image processing (the))

混沌吸引子，有logistic,有lonez等(Chaotic attractor, there are logistic, etc. have lonez)