改进的Turbo码自适应迭代译码算法及其性能仿真

获得优良的差错控制特性和多次迭代处理产生大的时间延迟是一对矛盾.为了有效解决这一问题,对Turbo码机理和迭代译码技术进行了深入研究,在此基础上,提出一种改进的自适应迭代译码算法.该算法的实质在于其新颖的译码迭代终止判决策略.通过使用译码器产生的尾比特进行错误检测并设计合适的最小迭代译码次数Imin,可以确保在较低的误码率情况下,有效地减少平均译码处理的迭代次数.计算机仿真以及对仿真结果的比较分析证明了这种改进的Turbo译码算法能够有效减少译码时间延迟.

Performance and Simulations of Improved Adaptive Iterative Decoding Algorithm of Turbo Codes

Increasing the number of iteration steps can decrease BER(bit error rate) but increase time-delay.A compromise is reached between the errors and time-delay, and an adaptive iterative decoding algorithm is improved through an investigation on the principle of turbo codes and iterative decoding technique,in which a novel strategy is introduced to determine when to terminate the iterative process.Using the tail bits generated from decoder to detect errors and designing properly the minimum number of iteration steps can efficiently reduce the average number of iteration steps with low BER.Computer simulation showed that the improved algorithm can efficiently decrease the time-delay.