Asymptotically Good Convolutional Codes

New Convolutional Code Constructions and a C lass of Asymptotically Good T ime-Varying Codes

New convolutional code constructions and a class of asymptotically good time-varying codes

A Gallager-Tanner construction based on convolutional codes

Generalized low density codes are built by applying a Tanner-like construction to binary recursive systematic convolutional codes. The Gallager-Tanner construction is restricted to 2 levels only. We describe the structure of a GLD code and show how to compute its ensemble performance. We also prove that RSC based GLD codes are asymptotically good. A parity-check interpretation of turbo codes is...

HIGH - RATE BINOMIAL CONVOLUTIONAL CODES by Ph . PIRET

A construction is described of high-rate RS-like convolutional codes, and a lower bound is given on their free distance. These codes can be used to construct asymptotically good binary convolutional codes. 1. Introduetion I~ a preceding report 4), a class of RS-like convolutional codes was introduced. These codes were obtained only for length n, rate R = kln and constraint length 'll related by...

On classes of convolutional codes that are not asymptotically catastrophic

Denote by w 0 the minimum average weight per edge over all nonzero cycles in the state diagram for a convolutional code, and assume that a technique is available for generating canonical parity-check matrices for codes with increasing degree m. The obtained class of codes is asymptotically catastrophic if w 0 approaches zero for large m. In this paper we prove the existence of convolutional cod...