I'm running Arch Linux and I use netctl for my wifi, but for some reason it keeps dropping every 5 minutes, especially fast if I don't use the internet for 5 seconds it seems. I have a USB wifi stick (ASUS USB-N13 11n).
I run netctl restart and it works again for a few minutes.
My netctl edit looks like this:
Description='Automatically generated profile by wifi-menu' Interface=wlp0s18f2u3 Connection=wireless Security=wpa ESSID=<wifiname> IP=dhcp Key=<password>