SDR (transmitter and receiver)

[hodahussein]

sdr transmitter

Now in my research I plan to put general view for SDR system (transmitter and receiver ) requirements in order to implement it on fpga.
I imagine that the receiver can be receive at least two different signals e.g FM and QBSK using single front end antenna. so what is the Challenges ?
thus from where I start?
what is first steps in the correct direction to implement SDR?

really I need to your recommendation and your Proposals

 

[eltonjohn]

sdr+transmitter

I will recomend starting with GNU radio ..there are supported fpga plataforms where you can see the soft interfaces and FPGA and the DAC and ADC sections.Also plenty of resources for the RF front end sections