Rick Lyons on Using the Forward FFT Algorithm to Compute the IFFT
Instructor Rick Lyons has written a new post on his blog at DSP Related discussing ways that you can use an FFT algorithm to compute the IFFT.
If you need to compute inverse fast Fourier transforms (inverse FFTs) but you only have forward FFT software (or forward FFT FPGA cores) available to you, below are four ways to solve your problem.