Generally speaking, you should not put any institution as your affiliation unless you are currently based there, or did the work while you were based there. In this case, unless you did the research while at Linkoping, you should not give Linkoping as your affiliation.
See, for example, this discussion.
If it helps, it's worth remembering that the "affiliation" is in many ways an "address" - it evolved out of simply giving an address at which you could be contacted, and some journals still refer to it this way. It's not unknown in some fields for independent researchers to give their home address, but it's perhaps more common just to say "independent".
If you have no current affiliation, you can simply say "Independent researcher", or similar, and leave it at that (adding an email address is good, if not asked for elsewhere in the paper).