Things You'll Need
Instructions
Connect the USB modem to your computer, as well as the data line, and plug in the power supply.
Ensure the modem is working properly on your computer and that you have an Internet connection. See the modem manufacturer for help with this.
Plug in the Ethernet crossover cable to both your computer and your PS3.
Go to Start->Control Panel->Network Connections and right click on the USB modems Internet connection.
Go to the advanced tab in the Modems connection properties window and click the box before "Allow other network users to connect through this computer's Internet connection."
Go to Settings->Network Settings->Internet Connection Settings and select "Yes" on the PS3. Follow the on screen instructions to connect your PS3 to the Internet connection.