I'll try explaining as best i can, since i don't know all the tech terms =P
1. open your web browser
2. in the url, type
http://192.168.1.1
3. input username and password
4. go to the wireless tab
5. uder that, go to basic wireless settings
6 set Wireless configuration to manual
7. under radio band, select wide 40MHz channel
8. Make sure SSID Broadcast is enabled (default should be on)
9. leave the rest default
10. Save settings
This should widen your signal so you can be further away and still connect. However, if you are able to connect but keep getting dropped, see if there's another router in the area. If there is, there may be interferrence with each signal, move on to 11.
11. Change wide channel, this could be any number
12. change Standard channel, this could be either
13. save settings
This is the trial and error part since you'll be searching for an open channel that someone else may not be on so don't lose hope here! Hope that was helpful and understandable, if not, i'll try to explain better.