Demodulation Methods For Timing-modulated Molecular Communication

Of growing interest,the nanoscale network is a frontier technology which is based on communications between nanoscale devices,or nano-machines.Strongly limited by available size,structure,and power,researchers have proposed the molecular communication to convey messages between nano-machines on the physical layer.Nano-machines in the molecular communication transmit information by emitting and absorbing typical molecules.With the development of molecular biology and nanotechnology,various molecular communication approaches have been designed to different application scenarios.Timing-modulated molecular communication,in which information is encoded by the release time of information molecules,has the advantage of its clear timing-based channel,uncomplicated communication processes and so on.There are also big challenges such as performance evaluation,intersymbol interference(ISI)to be solved.In this thesis,theoretical analysis and simulations are applied to discuss the channel parameter estimation and signal demodulation problems.Several estimation approaches,and researches on single-symbol detection and multi-symbol detection are presented.The main research work in this thesis are as follows:1.Timing-Based Channel Parameter EstimationChannel Parameters are very important to the modulation and demodulation of timing-based information on the molecules.The Moment Estimation(MME)and the Maximum Likelihood Estimation(MLE)are applied to the parameter estimation problem.Iterative algorithms are designed for the parameter estimation under the limited detection time conditions.2.Single-Symbol Detection in Timing-Modulated Molecular CommunicationIn the single-symbol timing-modulated molecular communication,the receiver isn’t affected by the ISI.The average detection and the order statistics detection are applied,their approximate thresholds and symbol error rates(SERs)are presented in this part.The conclusions are proven through both theoretical analysis and numerical simulation.3.Multi-Symbol Detection in Timing-Modulated Molecular CommunicationIn the multi-symbol timing-modulated molecular communication with ISI,the counting statistics are applied to describe the arrival conditions of information molecules.The greedy algorithm and the posterior probability iteration algorithm are used to decrease the complexity of the maximum a posterior(MAP)detection of the counting statistics.Furthermore,the influence of modulation parameters on the performance of multi-symbol detection are discussed.Thus,optimal modulation parameters are available from this research.