By using the PCI card EW-7711ln from Edimax the PC can be extended by 802.11n WiFi support.
Although the PCI card is recognized by the Linux kernel automatically:
03:02.0 Network controller: Ralink corp. RT3060 Wireless 802.11n 1T/1R
additional configuration is necessary to use the hardware.
Ubuntu tries to control the card via the module rt2800, which will fail with the following error message:
phy0 -> rt2800pci_mcu_status: Error - MCU request failed, no response from hardware
Instead, the module rt3562sta has to be used. This module is not part of the kernel yet and has to be compiled and installed by hand. First step is to blacklist the loading of the wrong modul in the file /etc/modprobe.d/blacklist.conf:
blacklist rt2800pci blacklist rt2800usb blacklist rt2x00lib blacklist rt2x00pci blacklist rt2x00usb
The source code drivers (RT3062) can be found at the Edimax Homepage of the card.
Compilation of the driver is explained in detail at http://www.x-fish.org/blog/1201061/Linux:_Edimax_EW-7711In_unter_Linux_Mint_12/.
After compilation the kernel module can be loaded by the command modprobe:
sudo modprobe rt3562sta