Linux Atheros madwifi driver

# apt-get update && apt-get upgrade
# apt-get install build-essential libssl-dev linux-headers-`uname -r` subversion
$ svn checkout http://svn.madwifi-project.org/madwifi/trunk/ madwifi-ng
# cat >> /etc/modprobe.d/blacklist.conf << END

#Remove To Install MadWIFI Drivers
blacklist ath9k
blacklist ath5k
END

# cd madwifi-ng
# make && make install
#echo ath_hal >> /etc/modules
#echo ath_pci >> /etc/modules

Reference :
WifiDocs/Driver/Atheros - Community Ubuntu Documentation