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

Asymptotically Good Convolutional Codes

In this paper, we construct new sequences of asymptotically good convolutional codes (AGCC). These sequences are obtained from sequences of transitive, self-orthogonal and self-dual algebraic geometry (AG) codes attaining the Tsfasman-Vladut-Zink bound. Furthermore, by applying the techniques of expanding, extending, puncturing, direct sum, the 〈u|u+ v〉 construction and the product code constru...

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...

A New Construction for Low Density Parity Check Convolutional Codes

Low density parity check (LDPC) block codes have been shown to achieve near capacity performance for binary transmission over noisy channels. Block codes, however, require splitting the data to be transmitted into frames, which can be a disadvantage in some applications. Convolutional codes, on the other hand, have no such requirement, and are hence well suited for continuous transmission. In [...

Structured LDPC convolutional codes

LDPC convolutional codes, also known as spatially coupled LDPC codes, have attracted considerable attention due to their promising properties. By coupling the protographs from different positions into a chain and terminating the chain properly, the resulting convolutional-like LDPC code ensemble is able to produce capacityachieving performance in the limit of large parameters. In addition, opti...