The Minimum Distance of Turbo-Like Codes

Combinatorial Analysis of the Minimum Distance of Turbo Codes

Combinatorial analysis of the minimum distance of turbo codes

In this paper, new upper bounds on the maximum attainable minimum Hamming distance of Turbo codes with arbitrary — including the best — interleavers are established using a combinatorial approach. These upper bounds depend on the interleaver length, on the code rate and on the scramblers employed in the encoder. Examples of the new bounds for particular Turbo codes are given and discussed. The ...

Upper bound on the minimum distance of turbo codes

An upper bound on the minimum distance of turbo codes is derived, which depends only on the interleaver length and the component scramblers employed. The derivation of this bound considers exclusively turbo encoder input words of weight 2. The bound does not only hold for a particular interleaver but for all possible interleavers including the best. It is shown that in contrast to general linea...

Distance upper bounds and true minimum distance results for Turbo-Codes designed with DRP interleavers

Stewart Crozier received his B.Sc. degree in applied mathematics and engineering from Queen's University, Kingston, Canada in 1979. He received his M.Eng. and Ph.D. degrees in systems engineering from Carleton University, Ottawa, Canada in 1983 and 1990 respectively. He is currently a research scientist with the Communications Research Centre, Ottawa, Canada. His primary research interests are ...

A distance spectrum interpretation of turbo codes

The performance of Turbo codes is addressed by examining the code’s distance spectrum. The ‘error floor’ that occurs at moderate signal-to-noise ratios is shown to be a consequence of the relatively low free distance of the code. It is also shown that the ‘error floor’ can be lowered by increasing the size of the interleaver without changing the free distance of the code. Alternatively, the fre...