Inter-symbol interference (ISI) limits reliability in diffusion-based molecular communication (MC) channels. We propose RLIM, a family of run-length-limited (RLL) codes that form fixed-size codebooks by minimizing the total number of 1-bits, increasing the per-symbol molecule budget under standard power normalizations and thus improving reliability. We develop a provably optimal linear-time greedy decoder that is equivalent to Viterbi decoding under a deterministic last-wins tie-break and has lower computational complexity; empirically, it outperforms first-wins and random Viterbi variants on RLL baselines. Extensive binomial and particle-tracking simulations show that RLIM achieves lower bit error rate (BER) than classical RLL and other prominent coding schemes across a broad range of scenarios.

翻译：码间干扰（ISI）限制了基于扩散的分子通信（MC）信道的可靠性。我们提出了RLIM，这是一类游程受限（RLL）码，其通过最小化总“1”比特数来构建固定大小的码本，从而在标准功率归一化下增加了每符号的分子预算，进而提升了可靠性。我们开发了一种可证明最优的线性时间贪婪解码器，该解码器在确定性的“最后获胜”平局决胜规则下等效于维特比解码，且具有更低的计算复杂度；实证表明，在RLL基线模型上，其性能优于“最先获胜”和随机变体的维特比解码器。大量的二项分布与粒子追踪仿真表明，在广泛的场景下，RLIM相比经典RLL及其他主流编码方案实现了更低的误码率（BER）。