JPEG_CODING

这是我学习时候，我的课本上的课后习题，我把他整理出来！希望大家能有所收益！(This is my study, my after-school textbook exercises, I took him out of order! Hope that we can get any benefit!)

matlab开发环境下的谱减法算法，主要用在了作者的语音增强算法当中(development environment under matlab spectral subtraction algorithm, mainly used in the author)

利用matlab模拟菲涅尔全息何用傅里叶变换实现单射光衍射(The use of the matlab simulation Fresnel holographic What Fourier transform single shot-ray diffraction)

傅 立叶变换是数字信号处理领域一种很重要的算法。要知道傅立叶变换算法的 意义，首先要了解傅立叶原理的意义。傅立叶原理表明：任何连续测量的时序或 信号，都 可以表示为不同频率的正弦波信号的无限叠加。而根据该原理创立的 傅立叶变换算法利用直接测量到的原始信号，以累加方式来计算该信号中不同正 弦波信号的频 率、振幅和相位。 (The goals for the course are to gain a facility with using the Fourier transform, both specific techniques and general principles, and learning to recognize when, why, and how it is used. Together with a great variety, the subject also has a great coherence, and the hope is students come to appreciate both. )

例3：分析占空比为ta的矩形脉冲频谱 T=1 时间窗大小 ta=0.5 占空比 N=256 t=linspace(-T,T,N) ts=2*T/N fs=1/ts (x=zeros(1,N) x(N/2-round(N/2*ta):N/2+round(N/2*ta))=ones(1,2*round(N/2*ta)+1) y=fft(x,N) figure plot(t,x) title([ 时域信号图 占空比为 ,num2str(ta)]) axis([-T T-0.2 1.2]) xlabel( t /s ) figure subplot(211) f=linspace(-fs/2,fs/2,N) plot(f,abs(fftshift(y))/N) title([ 矩形脉冲双边谱 脉冲时间t=[- ,num2str(ta*T), , ,num2str(ta*T), ] ]) xlabel( f /Hz ) )

说明：  matlab，实现永磁同步电机调速。pid控制(matlab，pmsm，PID controller)

Phase-shift keying (PSK) is a modulation process whereby the input signal, a binary PCM waveform, shifts the phase of the output waveform to one of a fixed number of states. The demodulation process can be divided into three major subsections, as shown by Figure 4. First, since the incoming waveform is suppressed carrier in nature, coherent detection is required. The methods by which a phase-coherent carrier is derived from the incoming signal are termed, carrier recovery, and will be covered first.

GA优化BP很详细的注释，而且里面加载了实际应用的例子效果很明显(GA optimization of BP very detailed notes, and which examples of practical application loading effect is obvious)

huffman tree in matlab

说明：  运用matlab程序，分析实现数值的插值与拟合功能(Realize the interpolation and fitting of numerical value)