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Summary: IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, VOL. 5, NO. 5, MAY 2006 1065
Joint Source-Channel Turbo Coding
for Binary Markov Sources
Guang-Chong Zhu, Member, IEEE and Fady Alajaji, Senior Member, IEEE
Abstract-- We investigate the construction of joint source-
channel (JSC) Turbo codes for the reliable communication of
binary Markov sources over additive white Gaussian noise and
Rayleigh fading channels. To exploit the source Markovian
redundancy, the first constituent Turbo decoder is designed
according to a modified version of Berrou's original decoding
algorithm that employs the Gaussian assumption for the ex-
trinsic information. Due to interleaving, the second constituent
decoder is unable to adopt the same decoding method; so its
extrinsic information is appropriately adjusted via a weighted
correction term. The Turbo encoder is also optimized according
to the Markovian source statistics and by allowing different or
asymmetric constituent encoders. Simulation results demonstrate
substantial gains over the original (unoptimized) Turbo codes,
hence significantly reducing the performance gap to the Shannon
limit. Finally, we show that our JSC coding system considerably
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