how to solve this connection problem

Hi everyone.

So right now i have my tv and ps3 in my family room and its on the same level as my bedroom where i have my computer, modem and router. I have a wireless network in my house and thats how i play on my ps3 online. Now here is the problem. I am planning to move the tv and ps3 into the basement but the wireless signal is too week down there so i can play games online. How can i solve this problem? Can i extend the range of the router? Is there a way to set up a wired connection down their?

Thanks