I have built a QPSK modulator, but I have some doubts about the Baseband
Shaping Filter. The Baseband Filter is a "SRRC Digital Filter" with cutoff
at Nyquist / 2 with selectable roll-off. In my project roll-off is 0.35.
Example (SAT):
27500 Msymb/s ---> Nyquist Frequency is 55000 Mhz (for I and Q) --->
cutoff
Frequency 27500 Mhz.
May need to interpolate at least 2 ? Is right ? It is necessary to
interpolate in all ways ?
How many taps used for filtering ?
What window of approximation it up for the calculation of taps filter ?
Thanks in advance.
Kappa.
