I was toying around with the rfft() of the SHARC 21369 with a digital sinewave data. After the rfft(), the complex number is then converted to magnitude by rfft_mag(). The signal is been conditioned by a kaiser window with beta of 18.
The question is, after the conversion the noise floor of the signal is around -150 dBFS, when i do the same process on the same data with matlab it yielded -200 dBFS.
So is this the limiation of the rfft() function? as the function only accept float type but not long double type.
Anyone experience this before?
I have attached the signal file. Sampling rate of 48 kHz if you are wondering about it.