Hi wronghorizon,
Thanks, I did manage to solve the non-zero problem by using higher resolution.
Now I'm trying to introduce complex multiplier in between the FFT and IFFT in order to control the output by modifying the original DSP BUilder FFT/IFFT Unity Gain Example (using multiply add module). Since I'm using a constant muliplier of 1 and 0 for each of the complex multiplier respectively, I'm expecting the same result as through, i.e. non-zero real and zero imag output as before.
The problem now, I'm not getting the same result and both output are of the same magnitude with funny shapes. Do you have any idea? I'm attaching the new simulation together with this entry.
Regards,
wimax