decode

this code determine the music spectrum

关于matlab的几个实例和若干教程，国外写的(Several instances of matlab and tutorial written abroad)

采用matlab对平面四杆机构进行运动分析,并输出图像.(Using MATLAB to analyse the motion of planar four bar mechanism, and the output image)

本matlab程序对滚动轴承的外圈进行了分析研究，与正常情况下的做对比，可以发现故障的位置，进一步的对比还要再做研究。(The matlab program analysis, and under normal circumstances, the contrast of rolling bearing outer ring, you can find the location of the fault, further comparison should also do research.)

仿真BPSK、QPSK、GMSK等基本调制方式。(Simulation BPSK, QPSK, GMSK modulation scheme.)

在一个移动通信系统中，发射信号是一个未调制的音频x(t)=cos(2πft)，其中f=f0+fi。设标称载波为f0=1GHz，并设fi =512Hz。假定移动用户在一个繁忙的高速公路上距离基站l公里处的地方，从开始从每小时60公里的速度开始，其速度（在0.01秒的时间间隔内测量）以1/2的概率随机的增加或减少1/10公里每小时。试仿真移动用户在这2s的时间间隔内所接收到的信号(及其频谱)。接收信号可以表示为： y(t)=a(t)Cos[2π(fo+f1)(t-△t)] 式中 △(t)=d(t)/c 且 a(t)=k/d2(t) 在上面的表达式中d(t)是在t时刻基站与移动用户的距离，c是光速，△(t)是传播延迟，而a(t)是信号在t时刻的衰减，并假设在这2s内a(t)是一个常数。利用复低通等效模型来进行仿真。(In a mobile communication system, the transmitted signal is an unmodulated audio x (t) = cos (2πft), where f = f0+ fi. Let nominal carrier of f0 = 1GHz, and set fi = 512Hz. Assume that mobile users on a busy motorway station l kilometers place, starting the beginning of 60 kilometers per hour, the speed (measured in 0.01 second interval) to increase the probability of a random 1/2 or reducing 1/10 km/h. Simulation test signal which the mobile subscriber in the 2s time intervals of the received (and its spectrum). The received signal can be expressed as: y (t) = a (t) Cos [2π (fo+ f1) (t- △ t)] Where △ (t) = d (t)/c And a (t) = k/d2 (t) In the above expression, d (t) at time t is a base station and a mobile user s distance, c is the speed of light, △ (t) is the propagation delay, and a (t) is the attenuation of the signal at time t, and assuming that 2s within a (t) is a constant. Using complex low-pass equivalent model for emulation.)

说明：  经验小波变换（EWT）的编写程序，自动划分滤波器组(Wavelet transform (EWT) programming, automatic division of filter)

A/D convertor, PCM, quantization

仿真了转台目标，并进行了R-D算法仿真。 (Simulation of the turntable-goal and the RD algorithm simulation.)

CDMA下行解调的MatLab程序，完成下行信号的解扩。(CDMA downlink demodulation process MatLab)