I am very much a newbie to electronics, so I hope some one can help me out here. I want to design and implement a full duplex , digital walky talky. The hardest thing for me in the project is the data transfer between two devices. I wish to have a range of atleast 1-2 km, but i don't know which frequency to use or what modulation to use ( I am adamant about the data being digital and not analogue ) . I would obviously prefer an ic for the modulation. the data input to the modulator should preferably be parallel(8 bit) , but if not feasible i don't mind serial either. I am also not quite sure how do i actually put the output from the modulator 'on air' .

Oh and for now i am ignoring legal issues of restricted freq . and i am not very sure of the data rate but the minimum i need is that enough for decent voice transmision ( i hope you understand my non technical lingo)

I also think that it is not required for the ic to handle any protocols , as i have a microcontroller which would handle everything.

 

Welcome Jinal,
While your interest is appreciable, perhaps you are to be VERY cautious on license and Legal issues. If you are In India, you need to approach Dept of Telecom (wireless planning) for necessary approvals, before you could start any Transmission.
Otherwise, you will be at risk , in the present days of remote blasts and all! be vary cautious please. It is not pure technology or Engineering issue.

__________________
Regards,
Sarma.