The University of Southampton
University of Southampton Institutional Repository

Extrinsic information transfer charts for characterizing the iterative decoding convergence of fully parallel turbo decoders

Ngo, H.A., Maunder, Robert G. and Hanzo, Lajos (2015) Extrinsic information transfer charts for characterizing the iterative decoding convergence of fully parallel turbo decoders IEEE Access, 3, pp. 2100-2110. (doi:10.1109/ACCESS.2015.2494861).

Record type: Article


Fully parallel turbo decoders (FPTDs) have been shown to offer a more-than-sixfold processing throughput and latency improvement over the conventional logarithmic Bahl–Cocke–Jelinek–Raviv (Log-BCJR) turbo decoders. Rather than requiring hundreds or even thousands of time periods to decode each frame, such as the conventional Log-BCJR turbo decoders, the FPTD completes each decoding iteration using only one or two time periods, although up to six times as many decoding iterations are required to achieve the same error correction performance. Until now, it has not been possible to explain this increased iteration requirement using an extrinsic information transfer (EXIT) chart analysis, since the two component decoders are not alternately operated in the FPTD. Hence, in this paper, we propose a novel EXIT chart technique for characterizing the iterative exchange of not only extrinsic logarithmic likelihood ratios in the FPTD, but also the iterative exchange of extrinsic state metrics. In this way, the proposed technique can accurately predict the number of decoding iterations required for achieving iterative decoding convergence, as confirmed by the Monte Carlo simulation. The proposed technique offers new insights into the operation of FPTDs, which will facilitate improved designs in the future, in the same way as the conventional EXIT charts have enhanced the design and understanding of the conventional Log-BCJR turbo decoders

PDF 07322183.pdf - Version of Record
Available under License Other.
Download (8MB)

More information

Accepted/In Press date: 21 October 2015
Published date: 10 November 2015


Local EPrints ID: 383511
PURE UUID: a2cda5a3-3123-41da-8997-f9e68d29d267
ORCID for Robert G. Maunder: ORCID iD

Catalogue record

Date deposited: 16 Nov 2015 08:55
Last modified: 17 Jul 2017 20:12

Export record



Author: H.A. Ngo
Author: Robert G. Maunder ORCID iD
Author: Lajos Hanzo

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton:

ePrints Soton supports OAI 2.0 with a base URL of

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.