The University of Southampton
University of Southampton Institutional Repository

Joint Iterative Decoding of Trellis-Based VQ and TCM

Joint Iterative Decoding of Trellis-Based VQ and TCM
Joint Iterative Decoding of Trellis-Based VQ and TCM
A joint video and channel coded system employing an iteratively decoded serial concatenation of a Vector Quantization (VQ) based video codec and a Trellis-Coded Modulation (TCM) scheme is proposed. The video codec imposes VQ-induced code constraints, which may be completely described by a trellis structure, which is employed as the basis for optimal minimum mean-squared-error VQ-encoding and -decoding. In the latter case, the Bahl-Cocke-Jelinek-Raviv (BCJR) algorithm is employed to facilitate the iterative exchange of soft information between the VQ and TCM decoder. An error-free video reconstruction quality is supported using 16-level Quadrature Amplitude Modulation (16QAM) based TCM for transmission over Rayleigh-fading channels at a Signal-to-Noise Ratio (SNR) per bit of 5.25 dB. This value is within 1.29 dB of the Rayleigh channel’s capacity at our system’s effective bandwidth-efficiency of 2 bits/s/Hz. Owing to its ability to exploit the VQ-induced code constraints during iterative decoding, the joint video and channel coding approach is found to consistently outperform the Shannonian source and channel separation philosophy. This is achieved at the cost of a 1.6 times higher computational complexity. Finally, the convergence of the iterative decoder is investigated with the aid of a novel so-called EXtrinsic Information Transfer (EXIT) chart.
video, vector quantization, VQ, variable length coding, VLC, iterative decoding, EXIT chart, serial concatenation, joint source and channel coding, trellis, BCJR, Viterbi, MMSE, soft
1327-1336
Maunder, R. G.
76099323-7d58-4732-a98f-22a662ccba6c
Kliewer, J.
e500e56d-f2d2-45df-8962-56274e41a1a1
Ng, S. X.
e19a63b0-0f12-4591-ab5f-554820d5f78c
Wang, J.
dc08532d-c8db-4f40-83ae-f5abf4acc068
Yang, L.-L.
ae425648-d9a3-4b7d-8abd-b3cfea375bc7
Hanzo, L.
66e7266f-3066-4fc0-8391-e000acce71a1
Maunder, R. G.
76099323-7d58-4732-a98f-22a662ccba6c
Kliewer, J.
e500e56d-f2d2-45df-8962-56274e41a1a1
Ng, S. X.
e19a63b0-0f12-4591-ab5f-554820d5f78c
Wang, J.
dc08532d-c8db-4f40-83ae-f5abf4acc068
Yang, L.-L.
ae425648-d9a3-4b7d-8abd-b3cfea375bc7
Hanzo, L.
66e7266f-3066-4fc0-8391-e000acce71a1

Maunder, R. G., Kliewer, J., Ng, S. X., Wang, J., Yang, L.-L. and Hanzo, L. (2007) Joint Iterative Decoding of Trellis-Based VQ and TCM IEEE Transactions on Wireless Communications, 6, (4), pp. 1327-1336.

Record type: Article

Abstract

A joint video and channel coded system employing an iteratively decoded serial concatenation of a Vector Quantization (VQ) based video codec and a Trellis-Coded Modulation (TCM) scheme is proposed. The video codec imposes VQ-induced code constraints, which may be completely described by a trellis structure, which is employed as the basis for optimal minimum mean-squared-error VQ-encoding and -decoding. In the latter case, the Bahl-Cocke-Jelinek-Raviv (BCJR) algorithm is employed to facilitate the iterative exchange of soft information between the VQ and TCM decoder. An error-free video reconstruction quality is supported using 16-level Quadrature Amplitude Modulation (16QAM) based TCM for transmission over Rayleigh-fading channels at a Signal-to-Noise Ratio (SNR) per bit of 5.25 dB. This value is within 1.29 dB of the Rayleigh channel’s capacity at our system’s effective bandwidth-efficiency of 2 bits/s/Hz. Owing to its ability to exploit the VQ-induced code constraints during iterative decoding, the joint video and channel coding approach is found to consistently outperform the Shannonian source and channel separation philosophy. This is achieved at the cost of a 1.6 times higher computational complexity. Finally, the convergence of the iterative decoder is investigated with the aid of a novel so-called EXtrinsic Information Transfer (EXIT) chart.

PDF ToW042007.pdf - Version of Record
Download (508kB)

More information

Published date: April 2007
Keywords: video, vector quantization, VQ, variable length coding, VLC, iterative decoding, EXIT chart, serial concatenation, joint source and channel coding, trellis, BCJR, Viterbi, MMSE, soft
Organisations: Southampton Wireless Group

Identifiers

Local EPrints ID: 264077
URI: http://eprints.soton.ac.uk/id/eprint/264077
PURE UUID: d9059e57-26fc-4072-ae4e-29f07ed504a1
ORCID for R. G. Maunder: ORCID iD orcid.org/0000-0002-7944-2615
ORCID for S. X. Ng: ORCID iD orcid.org/0000-0002-0930-7194
ORCID for L.-L. Yang: ORCID iD orcid.org/0000-0002-2032-9327
ORCID for L. Hanzo: ORCID iD orcid.org/0000-0002-2636-5214

Catalogue record

Date deposited: 23 May 2007
Last modified: 18 Jul 2017 07:39

Export record

Contributors

Author: R. G. Maunder ORCID iD
Author: J. Kliewer
Author: S. X. Ng ORCID iD
Author: J. Wang
Author: L.-L. Yang ORCID iD
Author: L. Hanzo ORCID iD

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.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

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.

×