exa5_18.m

新版Matlab 7辅助信号处理技术与应用

%--------------------------------------------------------------------------
% exa060601_fir1.m,   for example 6.6.1;
% to test fir1 and to design highpass FIR filter;
%-------------------------------------------------------------------------

load chirp       % loads y and Fs
window= chebwin(35,30);
b = fir1(34,0.48,'high',window);
yfilt = filter(b,1,y);
[Py,fy] = pburg(y,10,512,Fs); % 滤波器前信号频谱
[Pyfilt,fyfilt] = pburg(yfilt,10,512,Fs); % 滤波器后信号频谱
plot(fy,10*log10(Py),'.',fyfilt,10*log10(Pyfilt));
grid on
ylabel('幅度(dB)'); 
xlabel('频率(Hz)');
legend('滤波前的线性调频信号','滤波后的线性调频信号')