Channel capacity analysis of a diffusion-based molecular communication system with ligand receptors

Summary Diffusion-based communication is one of the most dominating forms in the micrometer and nanoscale communications. Generally, information is coded in molecules that are released by a transmitter nanomachine, propagated via a diffusion-based channel, and then received by a receiving nanomachine (called receiver). The receiver considered in this paper is equipped with multiple ligand receptors. The molecular communication system in this paper is single hop and SISO. Namely, there is only a channel connecting a pair of transmitter and receiver. While most literature considers either the channel or the receptors, this paper proposes a channel model that takes into account both the diffusion-based channel and the ligand-based receiver. The channel capacity under such model is analyzed, which studies the impact of different parameters at both channel and the receiver on the performance of the molecular communication system. We establish a digital channel model based on the on-off keying and time slot scheme. A capacity expression is derived with consideration of the effects of the channel memory and ligand-receptor binding mechanisms. The numerical results show that the overall channel capacity is restricted by the physical parameters of diffusion channel and ligand receptors