An Inter-Symbol Interference Model for Diffusion-Based Molecular Communication With Reversible Absorption Receiver

Inter-symbol interference (ISI) is a fundamental source of performance degradation in diffusive molecular communication channels. Comprehensive study and modeling of the ISI phenomenon is crucial in better understanding the behavior and performance of molecular communication systems. In this work, a novel, realistic ISI model is proposed, where the probability distribution of the ISI in a three-dimensional fluid environment with a spherical receiver is derived. A reversible reaction mechanism is considered to model the reception process, which involves the reactions of the information molecules to activate the receptors on the receiver surface, and to reverse back to the environment. The ISI distribution is derived, and is shown to converge to a Gaussian model for very short transmission intervals. Numerical simulations, based on the proposed model, show the impact of the time-slot duration, and the reverse reaction rate on the bit error rate performance.