I am a little confused after my lecture today. My professor started off with explaining what inter symbol interference (ISI) is and he ended the lecture talking about the different types of digital modulations out there.
I am now confused with how these two actually come together, or is it two different topics that have no connection?
Is ISI about sending digital signals in a wire? Does ISI come into play when doing lets say QPSK? I thought the symbol signal sent in QPSK is just a sin signal. or it uses this ISI?