Because it is not available via PPA, the needed deb packages of Kernel 3.18.1 are available via kernel.ubuntu.com. This installation should work on:
- Ubuntu 15.04 vivid vervet
- Ubuntu 14.10 Utopic Unicorn
- Ubuntu 14.04 Trusty Tahr (LTS)
- Linux Mint 17.1 Rebecca
- Linux Mint 17 Qiana
- Pinguy OS 14.04
- Elementary OS 0.3 Freya
- Elementary OS 0.2 Luna
- Peppermint Five
- Deepin 2014, LXLE 14.04
- Linux Lite 2.0
- Linux Lite 2.2
- and other Ubuntu derivative systems
More info can be found here.