Hi My appologies if the question is too vague or sounds naive- I have read a number of papers(specially IEEE communication society journals) on synchronization issues in communication- frequency, time and phase sync. All these papers address the issue of synchronization in baseband and no reference is made to the AFC present in transciever chips (which in all probablity is controlled by baseband processor according to some algorithm) . On the other hand literature from receiver circuit perspective present approaches for synchronization in hardware by using AFC/PLL etc and this is performed on RF signal. Considering this, I have the following questions-
1) Is the baseband approach of frequency synchronization only of theroretical interest or are they actually used in products 2) Is the synchronization task perfomed in two stages? eg- first at RF/IF level and then remaining offset in baseband software
3) How is synchronization achieved in USRP- at daughterboard hardware or gnuradio software