How Much Space Is Needed Between Reception Tables I Need A Clandestine Method Of Boosting Wifi Reception At Work.?

I need a clandestine method of boosting wifi reception at work.? - how much space is needed between reception tables

Where I work, WiFi is installed on the part of the history of 4, the building is relatively small. No wifi in the first floor. I am on the third floor. There is a large open space in the middle of the building, directly behind the door where I work, maybe 13 meters away, where the USB on my desktop from first to fourth floor. With a netbook, you can not receive any comments, sometimes up to 52% signal building. I still have ENUWI-N IEEE 802.11b / g, IEEE 802.11n Draft 2.0 USB 2.0 Adapter Wireless 802.11n data rates of up to 300 Mbps. It is a wall a hundred years of marriage, perhaps 18 cm thick between me and the open space that makes it impractical by drilling. I run a USB cable from your computer and put it inside on a ledge above the door, and perhaps by placing a thin piece of wood and drilling on the outer edge of the door. Is there a secret method to try to boost the signal. The strainer, coffee cans or ideas would be strange, because people regularly come into the office cd, including the responsible person, thanks. For suggestionsons or links.