www.gusucode.com > dsp 案例源码程序 matlab代码 > dsp/SingleSidedAmplitudeSpectrumOfASignalExample.m
%% Single-Sided Amplitude Spectrum Of a Signal % Find frequency components of a signal in additive noise. %% % *Note*: This example runs only in R2016b or later. If you are using an % earlier release, replace each call to the function with the equivalent % |step| syntax. For example, myObject(x) becomes step(myObject,x). Fs = 800; L = 1000; t = (0:L-1)'/Fs; x = sin(2*pi*250*t) + 0.75*cos(2*pi*340*t); y = x + .5*randn(size(x)); % noisy signal hfft = dsp.FFT('FFTLengthSource', 'Property', ... 'FFTLength', 1024); Y = hfft(y); %% % Plot the single-sided amplitude spectrum plot(Fs/2*linspace(0,1,512), 2*abs(Y(1:512)/1024)); title('Single-sided amplitude spectrum of noisy signal y(t)'); xlabel('Frequency (Hz)'); ylabel('|Y(f)|');