TELKOMNIKA Telecommunication, Computing, Electronics and Control
Efficient SOVA decoding and enhanced early termination mechanism based on new attenuation factors

TELKOMNIKA Telecommunication, Computing, Electronics and Control
Efficient SOVA decoding and enhanced early termination mechanism based on new attenuation factors

Attenuation factor
Early termination
SOVA
Turbo code

This paper proposes two attenuation factors (AF’s) to improve the performance of the soft-output Viterbi algorithm (SOVA) as well as to enhance the early termination mechanism in turbo decoding. The mean
square difference between the systematic bipolar coded symbols and the
a-posteriori information is used to estimate the first AF. The second AF is computed online for each iteration based on the correlation coefficient
between the extrinsic and a-priori information instead of intrinsic information as customary to calculate in literature. The second factor is used
in the early termination (ET) scheme which is practically useful to terminate iterations when there is no significant improvement is achieved. In addition, a method for offline computing the AF’s that cover a specific range of signal-to-noise power ratio is provided which results in a reduction of
utilization and latency estimates with a shallow degradation in performance. The results show that the proposed scheme outperforms the previous related works by about 0.2 dB at bit error rate (BER) of 10-5 using interleaver depth of 512 and reducing the average number of iterations (ANI) by about 3 iterations.

Ahmed A. Hamad, Hussain F. Jaafar, Hilal Al-Libawy

Universitas Ahmad Dahlan

April 2022

Sri Wahyuni

ISSN: 1693-6930

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