The purpose of coding theory is the design of efficient systems for
the transmission of information. The mathematical treatment leads to
certain finite structures: the error-correcting codes. Surprisingly
problems which are interesting for the design of codes turn out to be
closely related to problems studied partly earlier and independently
in pure mathematics. In this book, examples of such connections are
presented. The relation between lattices studied in number theory and
geometry and error-correcting codes is discussed. The book provides at
the same time an introduction to the theory of integral lattices and
modular forms and to coding theory.
In the 3rd edition, again numerous corrections and improvements have
been made and the text has been updated.