By the way, how did you plan to connect the receiver to the USB ?
I searched on the web about the usb, and I find some solutions. It could be very interesting, even for any other electronic project to have a serial to usb adapter for android. There is one, but it cost $30 + ship..it's too much.
I did a search a begining of the project and found the bluetooth the easiest solution, but now I'm more experienced.
A USB OTG cable should be all you need, but your device has to support OTG.