Repeat-punctured turbo trellis-coded modulation.
Loading...
Date
2010
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Ever since the proposal of turbo code in 1993, there has been extensive research carried out
to improve both the performance and spectrum efficiency. One of the methods used to
improve the spectrum efficiency was to combine turbo code with a trellis-coded modulation
scheme, called turbo trellis-coded modulation (TTCM). The scheme is used in various
applications such as deep-space communication, wireless communication and other fields.
It is a well established fact that an increase in an interleaver size of a TTCM system results in
an improved performance in the bit error rate (BER). In this thesis repeat-punctured turbo
trellis-coded modulation (RPTTCM) is proposed. In RPTTCM, the effect of repeat-puncture
is investigated on a TTCM system, repetition of the information bits increases the interleaver
size, followed by an appropriate puncturing scheme to maintain the respective code rate. The
TTCM and RPTTCM systems are simulated in an Additive White Gaussian Noise (AWGN)
channel. To understand how the RPTTCM scheme will perform in a wireless channel, the
Rayleigh flat fading channel (with channel state information known at the receiver) will be
used. The BER performance bound for the TTCM scheme is derived for AWGN and
Rayleigh flat fading channels. Thereafter repeat-punctured is introduced into the TTCM
system. The BER performance bound is then extended to include repeat-puncturing. The
performances of the TTCM and RPTTCM systems are then compared. It was found that the
RPTTCM system performed better at high signal-to-noise ratio (SNR) in both AWGN and
Rayleigh flat fading channels. The RPTTCM scheme achieved a coding gain of
approximately 0.87 dB at a BER of for an AWGN channel and 1.9 dB at a BER of
for a Rayleigh flat fading channel, for an information size of N=800.
Description
Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2010.
Keywords
Trellis-coded modulation., Modulation (Electronics), Theses--Electronic engineering.