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h Research
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RESEARCH
Main achievements of the project
The Distrim@ges project (competitive cluster Images
and Networks) began in 2006. It includes numerous
industrial partners and concerns video broadcasting
via the internet (DVB-IP). Our contribution is the study
of iterative decoding of the channel code and of the
code at application level.
The thesis of Samar Changuel was defended on 26th
June 2008 and dealt with decoding of RS produced
codes. The first part deals with the association of RS
turbo codes to high order modulations. The second
part concerns the decoding of RS product codes on
erasure channel. This work was carried out within
the framework of an external research contract from
Orange Labs on the decoding of RS codes.
In his first year of PhD studies, Andrej KABAT studied
the soft decoding of high error correction RS codes
RS (255,239,17) which is present in numerous
standards. Two new algorithms with good
complexity/performances ratios were proposed. The
second part dealt with « Network Coding » in
wireless communication. A new solution patented in
April2008 and based on turbo codes was validated for
this thesis. An article was submitted to IEEE
Transactions on Communications ain October 2008.
Work on the frame synchronisation(code words),
using coding equations, lead to a first patent [3] and
a PhD student (Rodrigue IMAD) was recruited in
spring 2006. Initial results concern theoretic
performances of the algorithm of frame
synchronisation. Afterwards the algorithm was
generalised to include frequency synchronisation and
phase synchronisation.
Amin Zribi began a thesis jointly with ENIT (Tunisia) in
2006. His work concerns the joint source/channel
decoding for image transmission. During the first
year he studied the techniques of decoding VLC codes
(Variable Length Codes) using the trellis method and
he established the performances of an iterative
decoding of a convolutional code and a VLC code. In
2008, we developed a new soft decoding algorithm
for VLC codes. This is of low complexity compared to
the trellis method and has equivalent performance
levels.
symbols in time and on antennae was established [2].
Two articles were presented at conference.
Cyrine LASHINI began a thesis jointly with ENIT
(Tunisia) in 2007 on low-complexity video encoding.
The compression, techniques used currently (MPEG)
were conceived within a framework of lowcomplexity
broadcasting. For new mobile video
applications the complexity constraints at encoder
level. A first possibility is to associate distributed
source coding and turbo codes.
In 2008, Hyeunseuk YOO began a thesis on the
reduction of the peak signal of encoded OFDM
modulations. The solution studied used the
properties of error-correcting codes and led to a
patent in June 2008 [4].
Publications
Articles in peer-review journals
[1] Raphaël Le Bidan, Camille Leroux, Christophe Jégo, Ramesh
Pyndiah, Patrick Adde. Reed-Solomon turbo product codes for
optical communications : from code optimization to decoder
design. EURASIP journal on wireless communications and
networking, april 2008, vol. 2008, pp. 1-14
[2] Massinissa Lalam, Karine Amis Cavalec, Dominique Leroux.
Space-time error correcting codes. IEEE transactions on wireless
communications, May 2008, vol. 7, n° 5, pp. 1472-1476
Patents
[3] Ramesh Pyndiah, Andrzej Michal Kabat, Karine Amis Cavalec,
Frédéric Guilloud. Procédé de transmission d'un signal numérique
entre au moins un émetteur et au moins un récepteur, mettant en
oeuvre au moins un relais, produit programme et dispositif relais
correspondant. Propriété Institut Télécom ; Télécom Bretagne.
02/04/2008
[4] Ramesh Pyndiah. Procédé et dispositif de transmission d'un
signal multiporteuse réduisant le rapport puissance moyenne,
procédé et dispositif de réception, programmes et signal
correspondants. Propriété Institut Télécom ; Télécom Bretagne.
10/06/2008 26 p.
In 2007, Mohamad Sayed Hassan began a thesis on
the space-time error correcting codes as a follow-up
to the thesis of Massinissa LALAM defended in 2006.
An initial result on the increase of space-time
diversity by optimisation of the distribution of
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