Except from a x86 fix and two sound enhancements, Linux kernel 3.11.1 introduces only updated drivers, including USB, hwmon, and iSCSI. See the official announement.
Install / Upgrade Kernel 3.11.1
The DEB packages are available in Kernel PPA. Press Ctrl+Alt+T on your keyboard to open terminal. When it opens, run below commands to download them:
for 32-bit system:
wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.11.1-saucy/linux-headers-3.11.1-031101-generic_3.11.1-031101.201309141102_i386.deb wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.11.1-saucy/linux-headers-3.11.1-031101_3.11.1-031101.201309141102_all.deb wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.11.1-saucy/linux-image-3.11.1-031101-generic_3.11.1-031101.201309141102_i386.deb
for 64-bit system:
wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.11.1-saucy/linux-headers-3.11.1-031101-generic_3.11.1-031101.201309141102_amd64.deb wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.11.1-saucy/linux-headers-3.11.1-031101_3.11.1-031101.201309141102_all.deb wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.11.1-saucy/linux-image-3.11.1-031101-generic_3.11.1-031101.201309141102_amd64.deb
Once downloaded, both 32-bit & 64-bit run below command to install them:
sudo dpkg -i linux-headers-3.11.1*.deb linux-image-3.11.1*.deb
(Optional) To remove this kernel, run below command:
sudo apt-get purge linux-image-3.11.1*
Kernel PPA: http://kernel.ubuntu.com/~kernel-ppa/mainline/