Hi I have exactly same problem as Intel Dual BandWireless-AC 3168 does not work on Ubuntu 16.04
I am new and I dont have 50 reputaion to comment on the question.
When I run
sudo add-apt-repository ppa:canonical-kernel-team/ppa
it shows
ERROR: '~canonical-kernel-team' user or team does not exist.
Error: 'ppa:canonical-kernel-team/ppa' invalid
I am connected to the internet already. Is there another way to get kernel 4.8?