Can't install new linux kernel even after squeeze-backports

I'm trying to upgrade my kernel version from 2.6.32 to 3.2.0.0. When I try:

sudo apt-get install linux-image-3.16.0-4-amd64

I get the following error message:

 linux-image-3.16.0-4-amd64 : Depends: linux-base (>= 3~) but 2.6.32-48squeeze6 is to be installed
                              Recommends: firmware-linux-free (>= 3~) but it is not going to be installed
                              Recommends: irqbalance but it is not going to be installed
                              Breaks: initramfs-tools (< 0.110~) but 0.98.8 is to be installed

I read that the problem has to do with having two kernel versions at once, so I tried the squeeze backports option. After adding the line:

deb http://ift.tt/1khhgJC squeeze-backports main contrib non-free

to my /etc/apt/sources.list, and running the following command:

sudo apt-get install -t squeeze-backports linux-image-3.16.0-4-amd64

I get the same error message as above. Can someone explain to me what the problem is, and how I would proceed to install the new kernel?