Performance Analysis of Relay based Molecular Communication with Depleted Molecule Shift Keying

Molecular communication (MC) is a new communication engineering paradigm where molecules are employed as information carriers. MC via diffusion is the most promising approach for the communication between nanomachines. Intersymbol interference (ISI) caused by the Brownian motion of diffusion molecules will seriously affected the reliability of communication. Meanwhile, with the increase of communication distance, the signal attenuation is serious, which leads to the decline of communication quality. In this paper, a decode-and-forward (DF) relay in diffusion-based molecular communication systems is proposed to improve communication quality, in which the depleted molecule shift keying (D-MoSK) coding is used to reduce ISI. The channel performance including the BER and capacity is analyzed. Meanwhile, the relationship among BER, capacity, and the key parameters, including the number of the released molecules, receiving radius, and relay position, is investigated. The simulation experiments show that the proposal D-MoSK coding can improve the communication reliability significantly, in which the performance gain can be maximized through optimizing the position of relay and the receiving radius.