In diffusion-based molecular communication simple modulation techniques based on the concentration, type, or released time of molecules are commonly used. However, random delay of the diffused molecules in environment can cause some strong inter-symbol interference (ISI) among consecutive symbols. Due to the limited computational capabilities of nano-machines, sophisticated modulation and coding schemes cannot be used to resolve this issue . In this paper, we propose several new, yet simple, ISI-resistant coding schemes for diffusion-based communications over a one-dimensional noiseless channel. These schemes map the information bits into variable length codewords and place time-gaps between the consecutive codewords to mitigate ISI issue. Our analytical and simulation results indicate that the proposed schemes provide superior performances in terms of probability of error and throughput compared to the existing schemes.

在基于扩散的分子通信中，通常使用基于分子的浓度，类型或释放时间的简单调制技术。但是，环境中扩散的分子的随机延迟会在连续的符号之间引起强烈的符号间干扰（ISI）。由于纳米机器的有限计算能力，无法使用复杂的调制和编码方案来解决此问题。在本文中，我们为一维无噪声信道上基于扩散的通信提出了几种新的但简单的，抗ISI的编码方案。这些方案将信息比特映射到可变长度的码字中，并在连续的码字之间放置时间间隔以减轻ISI问题。