Frequency domain to Time Domain using IFFT

Hello,

I have data in an Excel spreadsheet that is in terms of frequency and amplitude. I want to convert this to a signal as a function of time using an inverse Fourier transform. What script could I use to import this data and perform the ifft.

Thanks

[Walter Roberson]

Are the frequencies evenly spaced or irregularly spaced? If they are not evenly spaced in the file, is there an underlying even spacing but we should assume that any frequency not mentioned in the file has 0 amplitude?

Are the amplitudes complex valued? If so how are the complex numbers represented in the file? http://www.engineerexcel.com/complex-numbers-in-excel/

[Jack]

The frequencies are irregularly spaced over a spectrum of 500 MHz to 1.6GHz. The amplitudes are not complex valued

[Mohd Faisal Ansari]

Hello Sir, I have data in an Excel spreadsheet that is in terms of frequency and amplitude, how can I convert this into time domain curve?

waiting for response

Answer 1

[Walter Roberson]

You would need a non-uniform DFT. See https://www.mathworks.com/matlabcentral/fileexchange/25135-nufft--nfft--usfft