what is the question exactly?
I can understand that:
you have a specification,(sensitivity, frequency, bandwidth, spectral mask, noise figure, SNR ...) and you want to design the receiver. First of all, you have to know what type of technology will be used. You have to be an idea about what knows the technology.
And you design the receiver, so you give the specifications for the LNA, mixer, LO, demodulator,.... and thinking about the antenna as well, you think about the filters and make a system simulation ( I recommend MATLAB for it). If the results are good ( so satisfy the original specifications), you design the circuits, and now you select the schematics for the components. So you select the original schematics due to the specifications and then you optimize them(and simulate the system), and then you design them physically. And when they are ready you simulate the system and if it's good then you make the circuits and then you test it. and if it's good, you will be very happy.