Boot any (current) live cd, open a terminal window, become root and enter
open a browser, navigate to http://kmuto.jp/debian/hcl/index.rhtmlx
, and copy-paste the output of the command there. This will give you a list of all recognized devices and the drivers you need for them (as module names). Look for an entry containing "wlan", "wireless", "wifi" or "atheros". I think the modules for atheros cards are called "ath*". If you find a module name, check with your distro which package you need to install. If the website output contains no trace of anything "atheros", your card might be not supported by linux at all, unfortunately. Also make sure that it is not disabled in BIOS.