can we know, which field of communications are you looking for. For basic communications, i feel simon haykins book, communications system 4th edition is good. however, beginners might have a little difficulty in understanding.
a lot of equations to in the book.
As per your requirment, like u said a lot of equations, for u Proakis is THE BEST book.But if u r in this for the first time , then u will require BP Lathi's Digital Communication then it would be easy to go through Proakis.