If you check the Internet you will find many references to the driver for the RT2870 chip used in a USB. You might be able to find an RPM for the RT2800 group of chips(rt2800usb), either for CentOS or Redhat, if you don't already have it in your kernel.
I am not sure, but I believe that the RT2800 package for USB does now work. This is at least the case for the pci version. The package "rt2800pci" installs the driver with the needed Ralink firmware.
If that is the case, the post I linked to is no longer correct, but I gave it to you as a starting point