Bit error rate analysis of molecular communication via diffusion

Abstract

Conveying information between two entities across any distance has always been a considerate issue in our fast growing society. Digital communication has brought a drastic change to this matter of concern in ways that were beyond imagination a long time ago. However, our present radio frequency (RF) digital communication breaks down when the size of devices is reduced to small scales of nanometer to micrometer. To overcome this obstacle, molecular communication has been proposed recently for communication between nano-scale devices. It is a biologically inspired process and is based on chemical signaling. The study of molecular communication from an engineering perspective is important because communication between tiny devices will unlock a scope of futuristic possibilities like micro, nano-scale robotics, self-repairing machines, nanomedicines, artificial immune systems, etc. In addition to providing a solution for communication problems at smaller levels, molecular communication is advantageous in areas of infrastructure monitoring, robotics, etc., that can give rise to new applications in smart cities and disaster prone areas such as search and rescue.Molecular communication takes place in a different manner as compared to traditional RF communication. Moreover, with distant nodes, a relay node can be introduced in between the two basic nodes to ensure the reliability of a communication system. The work in this thesis presents the performance analysis of a relay-based system model of molecular communication via diffusion. The relaying scheme implemented is decode-and-forward (DF) relaying. Specifically, we investigate the DF relaying with erasure detection at relay node that has not been analyzed previously. With erasure detection at the relay node, the probability of incorrect detection reduces to certain extent. We present the system and channel modeling by considering the appropriate scenarios. We then evaluate the system performance by conducting bit error rate analysis at the destination node for various parameters. We observe that the impact of introducing erasure detection has a remarkable effect. The error propagation from the relay node reduces drastically and thereby offers the overall improvement in performance of the system.