Universal source controlled channel decoding with nonsystematic quick-look-in turbo codes
IEEE Transactions on Communications
Performance bounds and codes design criteria for channel decoding with a-priori information
IEEE Transactions on Wireless Communications
Optimized concatenated LDPC codes for joint source-channel coding
ISIT'09 Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3
IEEE Transactions on Communications
Performance bounds and distance spectra of variable length codes in turbo/concatenated systems
IEEE Transactions on Communications
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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 extrinsic 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 outperforms tandem coding schemes for bit error rates smaller than 10-4, while enjoying a lower system complexity.