Research On Modulation Method Of Molecular Communication Based On Diffusion Channel

Molecular Communication(MC)uses chemical signals to transmit information,which is considered as a new communication paradigm and a bridge between engineering biological nanomachines and natural biological nanomachines to realize information interaction.Modulation strategy in MCv D(Molecular Communication via Diffusion)is a new research field,which focuses on embedding information into chemical signals.At present,most modulation related research is based on the concentration,type,time and space of messenger molecules.However,due to the randomness and high delay of molecular movement in diffusion channels,The molecular communication system in the SISO(Single Input Single Output)scenario will be seriously affected by ISI(Inter Symbol Interference),and there will be serious ILI(Inter Link Interference)in the MIMO(Multiple Input Multiple Output)scenario.In view of the above scenarios,the thesis studies the modulation mechanism in the SISO and MIMO scenarios of molecular communication based on diffusion,and proposes the modulation scheme technology suitable for two different scenarios,which can effectively reduce the bit error rate and improve the reliability of the system.The main research contents and contributions of the thesis are as follows:According to the motion formula of the messenger molecule in the diffusion channel,the probability distribution of the messenger molecule from the transmitter to the receiver is calculated.Thus,the formula of the number of intersymbol interference(ISI)molecules received by the receiver in the SISO scenario based on the diffusion channel is further calculated and deduced,and extended to 2 × 2 MIMO scenario,further derive the formula of the number of molecules of inter-link interference(ILI)received by the receiver.A simple modulation and demodulation method is proposed for the molecular communication SISO communication system based on diffusion channel.It uses multiple messenger molecules to modulate,which can effectively reduce ISI and improve the transmission efficiency through simple mapping relationship.A novel modulation and demodulation method is proposed for the molecular communication MIMO communication system based on diffusion channel.It uses multiple messenger molecules to modulate,and designs modulation strategies based on the information between transmitters.With limited messenger molecular resources,it can not only effectively reduce ISI,but also alleviate ILI.Experimental analysis and simulation verification show that the modulation methods proposed in thesis for SISO and MIMO scenarios of diffusion molecular communication can effectively reduce the impact of interference,reduce the system error rate and improve the reliability compared with the existing modulation methods.