迭代检测算法在比特交织编码调制系统中的比较研究

Comparative Study of Iterative Decoding for Bit-interleaved Coded Modulation

迭代检测技术不仅局限于在传统的级联码系统中的应用,还可用于解决现代数字通信中的许多检测/译码问题。随着Turbo码的出现,人们对迭代译码算法进行深入研究,并提出一些简化译码算法。比特交织编码调制及迭代检测(bitinterleaved coded modulation with iterative decoding,BICM-ID)是一种高效数据传输系统。比特交织和迭代译码是BICM-ID系统具有卓越性能的关键因素,译码算法的选择不仅影响接收机的性能,也决定了系统的复杂度。文中研究迭代译码算法对BICM-ID系统性能的影响,分析各种译码算法的计算复杂度。仿真结果表明log-APP算法有好的性能同时复杂度也高,简化的译码算法能降低译码器的复杂度,但会带来一定的性能损失;随着信道条件的改善,算法简化带来的性能损失也随之减小。

The iterative can also be applied to many processing techniques are not limited to traditional concatenated coding schemes and detection/decoding problems in modern digital communications. With the emergence of turbo code, the iterative decoding algorithm is investigated deeply and some simplified implementations are provided. Bit-interleaved coded modulation with iterative decoding scheme. The bit-wise interleaving and iterative decoding are where the choice of iterative decoding algorithm affects both the system. This paper investigates the effect of the iterative （BICM-ID） is a bandwidth efficient transmission critical to the high performance of BICM-ID system, the performance of the receiver and the complexity of decoding algorithms on the performance of BICM-ID with the analysis of the decoding complexity. Simulation results demonstrate that the a posteriori probability algorithm in the log domain （log-APP） has a better performance with a higher decoding complexity while the simplified implementations have a lower decoding complexity but with some performance degradation and the degradation due to the simplification of the decoding algorithm is decreased with the increase of the signal-to-noise ratio.