Having a background with Matlab, now I am working on QPSK transceiver in Gnuradio.
I have a question for understanding RRC filter parameters in Gnuradio.
Let's take an RRC interpolation filter in the transmitter. There are parameters for sample rate and for symbol rate. Suppose my sample rate is 32 kHz (typical default value) and for the symbol rate I put 8 kHz. Isn't it obvious that interpolation is 4, so I have 4 samples per symbol. My question is why is there a dedicated parameter for interpolation? What function will it have? What would be the difference if instead of 4 in the field interpolation, I put 128?
Best regards.