A Method to Reduce the Complexity of Computing the Complete Weight Distribution of Polar Codes
Zhichao Liu, Zhiming Ma, Guiying Yan
TL;DR
This work defines a new subgroup of LTA of decreasing monomial codes which can find more cosets with the same weight distribution and further reduces the complexity by proofing the group action on a coset set is transitive.
Abstract
The code spectrum of polar codes is crucial to the performance of polar codes. Based on the lower-triangular affine group (LTA) of decreasing monomial codes and the one-variable descendance (ovd) relation, we define a new subgroup of LTA which can find more cosets with the same weight distribution. Using this algebraic structure, we further reduce the complexity by proofing the group action on a coset set is transitive. Our method is an enhanced version of previous research, and the complexity of most cases can be reduced exceeding several times.
