Abstract
A novel method for approximating the optimal max* operator used in Log- MAP decoding of turbo and turbo trellis-coded modulation (TTCM) codes is proposed being derived from a well-known inequality, which has not been published before. The max* operation is generalized, for the first time, and performed on n > 2 rather than n = 2 arguments, as it is the conventional approach. Complexity comparisons reveal a significant reduction in the number of operations required per decoding step for the proposed approximation, as compared with the optimal Log-MAP algorithm. Performance evaluation results are presented for both turbo and TTCM codes, showing the near optimal performance of the novel approximation method in both the additive white Gaussian noise (AWGN) and uncorrelated, i.e. fully interleaved, Rayleigh fading channels.
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This work was supported by the European Commission in the framework of the FP7 Network of Excellence in Wireless COMmunications NEWCOM++ (contract no. 216715).
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Papaharalabos, S., Sybis, M., Tyczka, P. et al. Novel Generalized max* Approximation Method for Simplified Decoding of Turbo and TTCM Codes. Wireless Pers Commun 69, 373–386 (2013). https://doi.org/10.1007/s11277-012-0578-6
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DOI: https://doi.org/10.1007/s11277-012-0578-6