This question already has an answer here:

I recently moved to Linux from OSx and in there I had mapped Caps lock to Ctrl+b. This was mostly done because of tmux.

How can I do this in Ubuntu 14?

There is a very comprehensive answer here how to remap keys: https://askubuntu.com/questions/296155/how-can-i-remap-keyboard-keys

But this doesn't cover a key combination like Ctrl+b. It only covers remaping a single key to another key.

marked as duplicate by Pandya, Jakuje, vonbrand, Anthon, garethTheRed Mar 5 '16 at 16:16

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