Performance analysis of diffusion-based decode-and-forward relay with depleted molecule shift keying

The distance-decay effect of molecular signals makes communication range a major challenge for diffusion-based Molecular Communication(MC).To solve this problem,the intermediate nano-machine is deployed as a relay between the transmitter and its intended receiver nano-machines.In this work,we employ the Depleted Molecule Shift Keying(D-MoSK) to model a Decode-and-Forward(DF) relay communication scheme.The closed-form expression of Bit Error Rate(BER) for the concerned DF relay with D-MoSK is derived.Meanwhile,the maximum a posteriori probability,minimum error probability,and maximum likelihood schemes are formulated for data detection.The relationships between BER and other key parameters,including the number of released molecules,receiving radius,and relay position,are investigated in detail.Simulation results show that the proposed scheme can improve communication reliability significantly.Moreover,the performance gain can be maximized by optimizing the position of the relay and the receiving radius.