Silence-Based Multi-Type Hybrid Transmission Scheme for Mobile Molecular Communication System

In this work, we consider a three-dimensional slow diffusive heterogeneous media-based mobile molecular communication (MC) system, with the communicating devices as point transmitters and passive spherical-shaped receiver nanomachines (NMs). For the considered slow diffusive MC system, we propose a time-varying stochastic diffusivity-based model for communicating devices and information-carrying molecules, and we characterize the mobile MC channel by the channel impulse response (CIR) and derive its mean. For the considered slow and stochastic diffusivity-based mobile MC system, we propose a novel silence-based multi-type hybrid transmission scheme, which combines communication through silence (CtS) with molecular shift keying (MoSK) and concentration shift keying (CSK) and we derive the closed-form expression for the average probability of error. For the slow diffusive environment, we compare the proposed transmission scheme with the position and concentration-based run-length aware, MoSK, and CSK transmission schemes. For the proposed silence-based multi-type hybrid and considered position and concentration-based run-length aware transmission schemes, we design their respective maximum likelihood (ML) threshold detectors. The proposed scheme outperforms and shows robust behavior in the presence of inter-symbol interference.