Performance Analysis of Reversible Binding Receptor Based Decode-and-Forward Relay in Molecular Communication Systems

Molecular communication (MC) allows nano-machines to communicate and cooperate with each other in a fluid environment. The diffusion-based MC is easily constrained by the transmit distance due to the severe attenuation of molecule concentrations. In this letter, we present a decode-and-forward relay strategy for the reversible binding receptor in the diffusion-based MC system. The time-varying spatial distribution of the information molecules based on the reversible association and dissociation between ligand and receptor at the surface of receiver is characterized. An analytical expression for the evaluation of expected error probability is derived, and the key factors impacting the performance are exploited. Results show that the proposal can improve the performance significantly with a constant molecular budget, in which the performance gain can be maximized through optimizing the position of the relay nodes and the number of molecules assigned to the source nodes.