improve PI model

多径无线信道在时域的建模仿真，很有参考价值(Multi-path wireless channel modeling in the time domain simulation of great reference value)

This is also related to shift keying mod technique.....it is also very helpfull for the biggner who want to do digital mod techniques.........

simple laboratory problem volved by matlab 2

首先对采样信号进行傅里叶变换，计算出功率谱或幅值谱，然后用功率谱或者幅值谱的数据，计算每一个中心频率的带宽内数据的平均值。(Firstly, Fourier transform is applied to the sampled signal to calculate the power spectrum or amplitude spectrum, and then the average value of the data within the bandwidth of each center frequency is calculated by using the power spectrum or amplitude spectrum data.)

code for averaging,ORing,ANDing images

通信原理基于Matlab的计算机仿真教程:北京邮电大学出版社，一本很好的教材(Communication theory of computer simulation based on Matlab tutorial: Beijing University of Posts and Telecommunications Press, a very good textbook)

关于自适应控制，经过仿真证明可以用，而且比较准确，值得一看。(it is good )

单旋翼固定尾迹分析。可用来进行简单的旋翼拉力、功率的计算(Single fixed rotor wake analysis. Rotor can be used for simple tension, the calculation of power)

说明：  matlande 灰色关联度 算法实现，精品(Gray Relational matlande algorithm, products)

xlsx2csv Transform sheets in xlsx file to csv files