IF Frequency Of QPSK Modulator

We are implementing direct qpsk modulator in fpga. Our data rate is 60 Mbit per sec . In digital , we must make I=I(0)*Sin(2*pi*f*t) and Q=Q(0)*Cos(2*pi*f*t). (f is frequency)

Our question is that what is the value of f ? 

2. If we want to inteface fpga with AD9787  (DAC) for converting I , Q to analog , what is our sampling frequency ? 

regards