wavelet2

对声音信号的LMS滤波，噪音为固定信噪比的高斯噪声(LMS filtering of sound signals, noise, Gaussian noise for a fixed signal to noise ratio)

this document a list of mathemtical forms

说明：  掌握矩阵和数组的一般操作，包括创建、保存、修改和调用等。学习矩阵和数组的加减运算与乘法。掌握对数组中元素的寻访与赋值，会对数组进行一般的操作。 (Master matrix and an array of general operations, including create, save, modify, and recalls. Learning addition and subtraction and multiplication of matrices and arrays. Mastery of the search and the assignment of elements in the array, the array will carry out general operations.)

差错控制编码技术是用来提高光纤通信系统质量和可靠性的主要手段。(Error control coding technique is used to improve the quality of optical fiber communication systems and the primary means of reliability.)

这是一个有关指纹识别的小程序，希望对初学者有所帮助！(This is a small program the fingerprint identification, want to be helpful for beginners!)

说明：  我编写的利用trous（多孔算法）实现小波变换，利用‘db4’小波函数分解两层，其中卷积运算采用频域的fft算法，给出了仿真信号的处理结果。(prepared by the use of trous (porous algorithm) to achieve wavelet transform, use 'db4' wavelet decomposition layers, which used convolution operators fft the frequency domain algorithm, given the signal processing simulation results.)

LS (Least Square) & LMMSE (Minimum Mean Square Error)

自适应滤波算法中的LMS算法，用于语音通信中的噪声抵消。(Adaptive filtering algorithm in the LMS algorithm for voice communications in noise canceling.)

Data Encryption by Matrix Multiplication We will only use numbers 0 to 26 for the encryptive mathematics operation. Numbers from 1 to 26 are for letters from A to Z and 0 is for all non-letter characters. To minimize usage of numbers, all letters are converted to upper case. The original message is converted to number array according to the ASCII table and minus 64. We partition whole array into blocks of 8 numbers. The last block may be added several zeros. Then multiply each block by the an 8x8 matrix A which is invertible in Z27 to get cipher data. The decryption is the same process except to use its inverse matrix B. For good visual reading, we convert all non-letter characters to under score for the decryption.

在相干通信中精确恢复眼图，使用正弦函数作为例子，经过欠采样后，对数据进行FFT变换后在进行精同步(After the restoration of coherent communications precise eye, using a sine function as an example, after subsampling, FFT transform data during fine synchronization)