Performance Enhancement of SOVA Based Decoder in SCCC and PCCC Schemes

• 作者: Ahmed A. Hamad
• 来源期刊: 无线工程与技术(英文)
• 学科: 工学
• 关键词: Turbo Codes SOVA SCCC SCALING Factor EXIT
• 年，卷（期）: 2013,（1）
• 页码范围: 40-45
• 页数: 6页
• 分类号: TN91

摘要

This study proposes a simple scaling factor approach to improve the performance of parallel-concatenated convolutional code (PCCC) and serial concatenated convolutional code (SCCC) systems based on suboptimal soft-input soft-output (SISO) decoders. Fixed and adaptive scaling factors were estimated to mitigate both the optimistic nature of a posteriori information and the correlation between intrinsic and extrinsic information produced by soft-output Viterbi (SOVA) decoders. The scaling factors could be computed off-line to reduce processing time and implementation complexity. The simulation results show a significant improvement in terms of bit-error rate (BER) over additive white Gaussian noise and Rayleigh fading channel. The convergence properties of the suggested iterative scheme are assessed using the extrinsic information transfer (EXIT) chart analysis technique.