I am currently trying to generate a psk modulated carrier with gnu radio.
Attach is an image of my flow graph.
As can be seen I am generating a bit stream using the Random Source module and implementing the modulation using the Constellation Modulator module. I then Low Pass Filter it and move forward to the conversion from baseband to passband generating Fc +- Fbb. I would like to utilize a bandpass filter to deal with the lower carrier frequency. It seems though when I implement the filter I still see both of the carrier frequency.
Why is this? I can't wrap my head around it.
EDIT: I figured out my bandpass filter question. All I had to do was set the FIR Type in the filter to "Complex->Complex(Complex Taps)(Decim)" from "Complex->Complex(Real Taps)(Decim)"
Now for the bandwidth question...
This is is fairly general question (I am assuming), but how does one define bandwidth in this context?
Typically BW with PSK is established at BB with the highest frequency component representing the BW.