diode

Quadrature amplitude modulation (QAM) is a modulation scheme in which two sinusoidal carriers, one exactly 90 degrees out of phase with respect to the other, are used to transmit data over a given physical channel. One signal is called the I signal, and the other is called the Q signal. Because the orthogonal carriers occupy the same frequency band and differ by a 90 degree phase shift, each can be modulated independently, transmitted over the same frequency band, and separated by demodulation at the receiver. For a given available bandwidth, QAM enables data transmission at twice the rate of standard pulse amplitude modulation (PAM) without any degradation in the bit error ratio (BER).

matlab code embedding watermarking

FAST FOURIER TRANSFORM ALGORITHM To compute the coefficients in the discrete approximation

该程序模拟仿真QPSK传输系统，对通信系统学习有帮助。(Simulation program to realize QPSK transmission system)

在matlab界面上,用鼠标实现任意图形的绘制(just for plot figure using your mouse)

清华大学版matlab基础教程，内容详细，非常适合初学者。(This book,published by Qsinghua University Press concentrates on fundamental knowledge of matlab.It is helpful for beginners to get a general view of matlab.)

programme in matlab - aproximation 1D & 2D- using square root method

optisystem 色散补偿的例子，已经验证过，非常好用。(Optisystem dispersion compensation for example, has been verified, very good use.)

本程序主要通过仿真动态显示均匀平面电磁波中，磁场 Hz 的波阵面在自由空间（理想介质）中的传播。(The program primarily through dynamic simulation shows uniform plane wave, the magnetic field Hz wavefront in free space (ideal medium) in the transmission.)

In the rectangle packing problem, encoding schemes to represent the placements of rectangles are the key factors determining the efficiency of algorithms. SEQP AIR is one of the most sophisticated encoding sheme, which has been considered to have a small solution space