I am doing simulation of FMCW radar. I am applying signal processing chain on raw radar data. Here in the code below, I am taking
fft of data and plotting it. Moreover, I am doing zero padding by multiplying the signal length by 1000. I should be getting beat frequency at 2.020 MHz instead I am getting at 2.019MHz. There is something little probelem but I do not know what.
Is it the correct way for Zero padding? Moreover, am I defining frequency axes correctly? Thanks everyone in advance
% second-order butterworth [b, a] = butter(2, [w1 w2], 'bandpass'); load('fb2030'); % loading the data x = fb2030(30,:); % filtering y_filt = filter(b,a,x); % filtering the received signal nfft = length(y_filt)*1000; %%%% Zero Padding res = fft(y_filt,nfft)/ nfft; % normalizing the fft f = fs/2*linspace(0,1,nfft/2+1); % choosing correct frequency axes res = res(1:nfft/2+1); % amplitude of fft(taking the half length of nfft) figure,plot(f,2*abs(res)); xlabel('Frequency in MHz');ylabel('amp')