On the Performance of the Modulation Methods in Time-varying Molecular Communication Channels

Molecular communication via diffusion (MCvD) is a new research area that considers the communication using messenger molecules in a diffusive fluidic channel. In this area, various modulation methods have been proposed to overcome the problems in the channel, especially the inter symbol interference (ISI). However, these methods are generally considered and tested for the channels that do not change over time. On the other hand, most of these methods require the channel state information (CSI) and a change in the channel may degrade performance. In this paper, performances of modulation methods proposed in the literature are examined over time-varying channels. According to the presented simulation results, adaptive methods should be adopted for time-varying channels to maintain high performance.