Energy efficient ISI mitigation for communication via diffusion

Molecular communication (MC) aims to develop a promising bio-inspired communication paradigm for nanotechnology, in which molecules are used to encode, transmit, and receive information. One of the main challenges in MC is the intersymbol interference (ISI) caused by the nature of the diffusion channel. The most popular solution to reduce the effects of ISI in MC is to keep the symbol duration as long as possible and reduce the number of molecules that can be received in subsequent symbol durations. On the other hand, a long symbol duration leads to a very low data rate, even for very short distances. Furthermore, due to the size of the nano-scale machines, production of energy becomes an essential problem. In this paper, an ISI mitigation technique for diffusion-based molecular communication channels, titled Molecular Transition Shift Keying (MTSK) is proposed in order to increase the data rate via suppressing the negative impact of the ISI on communication quality. MTSK employs multiple molecule types and the energy efficient extended version of MTSK with power adjustment (MTSK-PA) makes use of the residual molecules in the channel to reduce the ISI that would otherwise contribute to the ISI. It is shown via computer simulations that both MTSK and MTSK-PA outperforms the standard modulation techniques proposed in the literature.