oW should coded communication be approached? Is it about prob- H ability
theorems and bounds, or about algorithms and structures? The traditional
course in information theory and coding teaches these together in one
course in which the Shannon theory, a probabilistic the- ory of
information, dominates. The theory's predictions and bounds to
performance are valuable to the coding engineer, but coding today is
mostly about structures and algorithms and their size, speed and error
performance. While coding has a theoretical basis, it has a practical
side as well, an engineering side in which costs and benefits matter. It
is safe to say that most of the recent advances in information theory
and coding are in the engineering of coding. These thoughts motivate the
present text book: A coded communication book based on methods and
algorithms, with information theory in a necessary but supporting role.
There has been muchrecent progress in coding, both inthe theory and the
practice, and these pages report many new advances. Chapter 2 cov- ers
traditional source coding, but also the coding ofreal one-dimensional
sources like speech and new techniques like vector quantization. Chapter
4 is a unified treatment of trellis codes, beginning with binary
convolu- tional codes and passing to the new trellis modulation codes.