Hi All, My question is as follows. When calculating an N-point IFFT with the inputs conjugate symmetric (real output), this can be performed using a single N/2-point IFFT and some pre and post processing. Is there any method to do this (use a single N/2-point IFFT) with half the inputs set to zero instead of the complex conjugate? (and thus getting the complex analytic output instead of the real output?) Thanks, Nadav This message was sent using the Comp.DSP web interface on www.DSPRelated.com

# Efficient Calculation of Complex Analytic IFFT

Started by ●May 11, 2005

Reply by ●May 11, 20052005-05-11

nadavf wrote: > Is there any method to do this (use a single N/2-point IFFT) with half the> inputs set to zero instead of the complex conjugate? (and thus getting the > complex analytic output instead of the real output?) > > Thanks, NadavI won't call it impossible ... but I doubt it. Look at the inverse operation that would be possible if that were true. It would be equivalent to zero-padding a length N sequence to size 2N and doing a 2N fft on it for the cost of a 1N fft. In other words, you'd get the increased/interpolated frequency resolution for free. -- Mark