Get A/D-conversor data

Dear colleagues,

I use the RTL-SDR (Software-Defined Radio) dongle to get a specific radio signal, but I realize that using a simple A/D conversor would be better, in terms of hardware signal processing performance. I already have the amps, filters etc.

Indeed, I already have the A/D conversor hardware too. I want to send the digital data (bits) to a USB port, similar to what happens in the RTL-SDR (we get the data on a USB port).

The question is: how can I get, with Matlab, the data of a A/D-conversor in a USB port? Please, which are the steps I must accomplish, is there some toolbox etc.

I really do not know how to begin...