常规信号的循环谱(代码部分)_GreenSim
计算信号循环谱的函数:
这个函数用来计算数字调制信号的循环谱图,结果存放在sxf中,surf和shading interp这两个函数配合使用就可以得到信号的循环谱图,M一般取64,N取2048。需要注意的是,数字信号要保留一定的载频,不能是基带信号。
function sxf=MyCS_density(s,M,N)
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spe_s = fft(s,N);
k = N/2-M;
sxf = zeros(2*k+1,4*k+1);
for ff = -k:k;
计算信号循环谱alpha截面的函数:
这个函数用来计算数字调制信号的alpha截面图,结果存放在sxf_amp中,参数的设置和上一个函数一样,需要注意的是ff参数必须是数字频率。这个函数非常简洁也非常有用,尤其是在设计基于循环谱的参数估计和调制识别算法中,一般用这个函数。
function sxf_amp = MyCSalpha_imag_density(s,M,N,ff)
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spe_s = fft(s,N);
spe_s=spe_s./2;
k = N/2-M;
sxf_amp = zeros(1,2*k+1);
for alpha=0:1:k-abs(ff))
end
计算信号循环谱f截面的函数:
这个函数和上一个函数用法差不多,主要在设计参数估计和调制识别算法中使用。
function sxf_amp = MyCSf_imag_density(s,M,N,alpha)
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spe_s = fft(s,N);
spe_s=spe_s./2;
k = N/2-M;
sxf_amp = zeros(k+1,1);
for ff = 0:k-abs(alpha/2);
end