ISI-aware channel code design for molecular communication via diffusion

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.In molecular communication via diffusion, information molecules diffusing in the environment are subject to Brownian motion. Due to probabilistic propagation, the arrival of the molecules at the receiver is spread in time, leading to the reception of some molecules belonging to the previous symbol(s) during the upcoming symbol duration. Known as inter-symbol interference (ISI), this problem has been extensively studied in the literature by applying a large spectrum of techniques, mostly inspired by approaches in the wireless communication domain, including channel coding techniques. Unfortunately, many known channel codes do not perform well in the molecular communications domain since the diffusion channel features a significant memory component. In this paper, novel methods for channel coding by incorporating the effect of ISI in the design of the channel codes for the molecular diffusion channel are proposed. The results show that the proposed methods provide significant improvements in performance in terms of the codeword error rate.Postprint (author's final draft

Error performance analysis of diffusive molecular communication systems with on-off keying modulation

In this paper, we analyze the bit error rate (BER) of the diffusive molecular communication (DMC) systems employing on-off keying (OOK) modulation. We also analyze the BER of the OOK-modulated DMC systems with inter-symbol interference cancellation (ISIC). Our main motivation is to introduce alternative tools for analyzing and efficiently computing the BER of the DMC systems without or with ISIC. Specifically, for the OOK-modulated DMC systems without ISIC, we first derive an exact BER expression based on the Poisson modeling of DMC systems. Then, the Gaussian- and Gamma-approximation approaches are introduced to approximate the discrete Poisson distribution, and based on the approximation approaches, the corresponding BER expressions are derived. Furthermore, in order to reduce the computation complexity imposed by long ISI, we propose the Monte-Carlo, simplified Poisson, simplified Gaussian and the simplified Gamma approaches for BER computation. In the context of the OOK-modulated DMC systems with ISIC, we consider both the Poisson and Gaussian-approximation approaches for BER analysis. Again, exact and approximate BER expressions are derived under the Poisson, Gaussian-approximation, simplified Poisson and simplified Gaussian approaches. Finally, the considered approaches are compared and validated by a range of performance results obtained from evaluation of the derived expressions or by simulations. Our studies show that the alternative approaches are in generaleffective for providing near-accurate BER estimation