fourier_analysis

这是无线通信中两径模型的源代码，比较了不同增益对接收功率的影响，能直接运行。(This is a two-path model in wireless communications source code, compare the effects of different gain on the received power can be run directly.)

用平面波展开法计算二维声子晶体带隙,能量谱分析计算,合成孔径雷达（SAR)目标成像仿真。( Computation Method D phononic bandgap plane wave, Energy spectrum analysis and calculation, Synthetic Aperture Radar (SAR) imaging simulation target.)

正弦信号通过幅度调制（AM,DSB,SSB）所得到的时域波形及频域波形(AM,DSB,SSB waveforms in frequency- domain and Time domain)

说明：  超宽带无线电基础配套matlab代码，相当不错的。(Ultra-wideband radio infrastructure to matlab code)

this file have simple demodulation program for qpsk demodulation. it will give the bit of stream after demodulation of qpsk (quadrature phase shift keying) wave.

The (a) section of Figure 1 illustrates the Line Echo Canceller (LEC) residing in the access network where echoes occur. Other voice processing modules, such as Automatic Level Control (ALC) and Noise Reduction (NR), are shown merely for illustration purposes. On the terminal side, both acoustic and electrical echo can occur. If the voice terminal is a speaker telephone set with an open acoustical path from the speaker to the microphone, the effect of acoustical echo is combined with the effect of the network echo. Because there is only a miniscule delay between the electrical signal and its echo, the speaker/listener is exposed to an effect known as side tone. Typically, instead of mounting a LEC at the terminal, side tone circuitry is placed to control the amount of the returned energy. The (b) section of Figure 1 shows examples of echo canceller signals representing the following:

通过ZMNL方法，完成了对瑞丽杂波，威布尔杂波，对数正态分布杂波以及K杂波的建模仿真，并对功率谱以及杂波幅度概率分布进行分析仿真(By ZMNL method, completed the Ruili clutter, Weibull clutter, lognormal and K clutter clutter modeling and simulation, and the power spectrum and amplitude probability distribution clutter simulation analysis)

病态系统求解方法比较：龙格库塔4固定步长、变步长、吉尔法(Pathological system solving methods: Runge-Kutta 4 fixed step size, variable step size, Gill Law)

matlab code for digital modulations

Drools5 Drools5(Drools5 develop )