In this work, we investigate the performance of polar codes with the assistance of feedback in communication systems. Although it is well known that feedback does not improve the capacity of memoryless channels, we show that the finite length performance of polar codes can be significantly improved as feedback enables genie-aided decoding and allows more flexible thresholds for the polar coding construction. To analyze the performance under the new construction, we then propose an accurate characterization of the distribution of the error event under the genie-aided successive cancellation (SC) decoding. This characterization can be also used to predict the performance of the standard SC decoding of polar codes with rates close to capacity.

翻译：在本工作中，我们研究了通信系统中借助反馈的极化码性能。虽然众所周知反馈无法改善无记忆信道的容量，但我们表明，由于反馈能够实现精灵辅助解码并为极化码构造提供更灵活的阈值，极化码的有限长性能可以得到显著提升。为分析新构造下的性能，我们随后提出了对精灵辅助逐次抵消解码下错误事件分布的精确刻画。该刻画也可用于预测速率接近容量的极化码标准逐次抵消解码的性能。