I am currently operating in vhf band AND trying to detect frequencies using Fast Fourier transform thresholding method. While detection of multiple frequencies , i received spurs(May not appropriate word) in addition with original frequencies, Such as in case of f1,f2 that are incoming frequencies i also receive their sum f1+f2 and difference f1-f2.
i am trying to eliminate these using thresholding method but i can't differentiate them with real real frequency magnitudes. Please suggest me some method, or methodology to eliminate this problem
Input frequencies F1, F2 Expected frequencies F1,F2 Receive frequencies ,F1,F2,F1-F2,F1+F2