This is not a new idea. Actually, this idea has been thought about before and dismissed. The researchers referenced propose using millisecond radio pulsars for navigation. This is a poor idea from an engineering standpoint because it requires having a large collecting area of radio dishes in order to get an apporpriate signal level.
A better idea, which is currently being researched, and was suggested four years ago (at least the earliest I recall it being mentioned) was using x-ray pulsars, which require much smaller collecting area. See for example
this thesis on the subject.