You could always perhaps re-position your router within your home to get maximum coverage. Also, most routers have a setting for the range they are transmitting. Try to make sure that is set to maximum.
As for your device itself, you can always try more complicated root/patch fixes for especially difficult problems. However, I'd recommend trying everything else possible before doing that.
I agree with ArmageddonX. Without root, I don't think you can do much about the wifi reception problem. However, if you are a so-called risk-lover, you can root your phone, flash a custom ROM and a new radio to see if it improves things.