Lakhasly

This paper examines the history of channel coding, progressing from Shannon's 1948 theorem and Hamming codes to modern capacity-approaching codes. The focus is on advancements improving performance relative to complexity, especially for the AWGN channel. It explains why algebraic block codes fell short of achieving the Shannon limit, and details the development of crucial predecessors to today's high-performance codes: convolutional codes, concatenated codes, and other probabilistic methods. The paper concludes with a brief overview of practical applications.

Starting from Shannon’s celebrated 1948 channel coding theorem, we trace the evolution of channel coding from
Hamming codes to capacity-approaching codes. We focus on the contributions that have led to the most significant
improvements in performance vs. complexity for practical applications, particularly on the additive white Gaussian
noise (AWGN) channel. We discuss algebraic block codes, and why they did not prove to be the way to get to the
Shannon limit. We trace the antecedents of today’s capacity-approaching codes: convolutional codes, concatenated
codes, and other probabilistic coding schemes. Finally, we sketch some of the practical applications of these codes.