Information Theory, Coding and Cryptography

Chapter 8

Convolution Codes

8.1  INTRODUCTION

Convolution code is an alternative to block codes, where n outputs at any given time unit depend on k inputs at that time unit as well as m previous input blocks. An (n, k, m) convolution code can be developed with k inputs, n output sequential circuit, and m input memory. The memory m must be large enough to achieve low error probability, whereas k and n are typically small integers with k < n. An important special case is when k = 1, the information sequence is not divided into blocks and can be processed continuously. This code has several practical applications in digital transmission over wire and radio channels due to its high data rate. The improved version of this scheme in the association ...