Optimum 1-Step Majority-Logic Decoding of Binary Reed-Muller Codes
Hoang Ly, Emina Soljanin
TL;DR
The paper introduces the first one-step majority-logic decoder for binary Reed–Muller codes that applies uniformly to all $(r,m)$. By exploiting a geometric recovery-set structure tied to $ ext{EG}(m,2)$, it proves the decoder can correct up to $d_{ extmin}/4$ errors and up to $d_{ extmin}-1$ erasures, and it shows these limits are tight within the 1S-MLD paradigm. The approach generalizes Reed’s original algorithm into a parallel, single-step process and reveals deep connections between recovery-set geometry and coding-theoretic limits, including a new transversal theorem for truncated flats. These results offer a practical, low-latency decoding option for RM codes and point to extensions to more general code families.
Abstract
The classical majority-logic decoder proposed by Reed for Reed-Muller codes RM(r, m) of order r and length 2^m, unfolds in r+1 sequential steps, decoding message symbols from highest to lowest degree. Several follow-up decoding algorithms reduced the number of steps, but for a limited set of parameters, or at the expense of reduced performance, or relying on the existence of some combinatorial structures. We show that any one-step majority-logic decoder-that is, a decoder performing all majority votes in one step simultaneously without sequential processing-can correct at most d_min/4 errors for all values of r and m, where d_min denotes the code's minimum distance. We then introduce a new hard-decision decoder that completes the decoding in a single step and attains this error-correction limit. It applies to all r and m, and can be viewed as a parallel realization of Reed's original algorithm, decoding all message symbols simultaneously. Remarkably, we also prove that the decoder is optimum in the erasure setting: it recovers the message from any erasure pattern of up to d_min-1 symbols-the theoretical limit. To our knowledge, this is the first 1-step decoder for RM codes that achieves both optimal erasure correction and the maximum one-step error correction capability.
