User`s guide

IFFT
5-233
Input and Output Characteristics
The following table describes all valid block input types, their corresponding
outputs, and the dimension along which the block computes the IDFT.
Note For M-by-N and length-M inputs, M must be a power of two. To work
with other input sizes, use the Zero Pad block to pad or truncate the length-M
dimension to a power-of-two length. To get valid outputs, you must correctly
set the
Input is in bit-reversed order parameter to indicate the ordering of
the block input. When the input is conjugate symmetric and you want to get a
real-valued output, set the Input is conjugate symmetric parameter.