In this letter, we introduce an efficient method for estimating weight distributions of polar codes and polarization-adjusted convolutional (PAC) codes. Based on a recursive algorithm of computing the weight enumerating functions of polar cosets, this method focuses on two key objectives: accurately determining the number of low-weight codewords and quickly approximating the distribution of high-weight codewords. Simulation results demonstrate that this hybrid method maintains competitively low complexity while effectively achieving the objectives.

翻译：本文介绍了一种高效估计极化码和极化调整卷积（PAC）码权重分布的方法。该方法基于计算极余弦权重枚举函数的递归算法，聚焦于两个关键目标：精确确定低权重码字的数量，以及快速逼近高权重码字的分布。仿真结果表明，这种混合方法在有效实现目标的同时，保持了具有竞争力的低复杂度。