Research And Improvement Of Molecular Communication Transmission Technology Based On Molecular-concentration Shift Keying

Molecular communication is different from traditional electromagnetic wave communication in many aspects.Therefore,the existing communication means cannot be directly used.It is necessary to study its communication technologies according to the characteristics of molecular communication itself.Among the various communication modes of molecular communication,molecular communication based on free diffusion is the most concerned at present.Due to the random walk of molecules,inter-symbol interference(ISI)will occur in the molecular communication system based on free diffusion.Especially when the more symbols are sent,the more ISI will accumulate.In addition,in many molecular communication scenarios,the channel state is difficult to obtain and is not suitable for the use of high complexity coherent signal detection algorithms.This paper mainly studies ISI mitigation technology and incoherent signal detection technology in molecular communication based on free diffusion.The specific work of this paper is as follows:Firstly,as on off keying(OOK)is the foundation of many modulation schemes such as binary Molecular-Concentration Shift Keying(MCSK),this paper first elaborates on the theoretical modeling process of OOK modulation schemes.Then the expressions of bit error rate and channel capacity of OOK in some detection modes,such as maximum likelihood detection,adaptive threshold detection(ATD),are derived.Secondly,aiming at the ISI problem,this paper proposes a further ISI mitigation scheme on the basis of MCSK and derives the formula of its bit error rate and channel capacity.In order to verify the theoretical derivation,this article uses a particle-based simulation framework to simulate the channel response of the system.The consistency between the theoretical and simulation channel responses verifies the correctness of the basic simulation framework code written.Furthermore,based on this framework,this paper proposes a simulation framework based on MCSK modulation,obtaining the simulation error rates of MCSK and the proposed further ISI mitigation scheme,and verifying the theoretical derivation.In addition,this paper also analyzes the impact of some system parameters on communication performance.The simulation and numerical results show that the proposed ISI mitigation scheme effectively reduces ISI and improves communication performance.Thirdly,in response to the difficulties in obtaining the state of molecular communication channels and the high complexity of traditional non coherent detection,inspired by the ATD and utilizing the inherent characteristics of MCSK,this paper proposes a non-coherent detection scheme based on MCSK modulation.The performance of using ATD scheme for MCSK and the proposed non-coherent detection scheme based on MCSK were studied and derived in the paper.Subsequently,the paper compared the bit error rates of MCSK using these two non-coherent detection methods,and validated the theoretical derivation using the simulation framework based on MCSK modulation proposed in the paper.The simulation and numerical results indicate that the non-coherent detection scheme proposed in this paper based on the inherent characteristics of MCSK is more suitable than the ATD scheme for noncoherent detection of MCSK.