I use These for work and personal gear from Wilson electronics. I use their mobile solution in a few trucks and have eliminated the dropped calls and data ot getting through.
http://www.wilsonelectronics.com/
The mobile one I use does all technologies out right now CDMA and GSM. 2G/3G/4G and LTE. you get a 50db gain on send and receive ....
http://www.wilsonelectronics.com/sto...5/38/mobile-4g
I also use for work the following for a building that has a lot of dead space due to it beaning on the extreme edges of all cell towers.
http://www.wilsonelectronics.com/sto...y-ag-pro-quint
Check out some of their other gear and you might find a good fit for your situation.
I have a mobile solution in my house. All I needed was a grower supply to replace the car supply. Just leave the phone near it and answer when it rings.
Hope this helps.
Just getting an antenna does not fix the db problem and you still need an amp.