Simulation Study and Analysis of Diffusive Molecular Communications With an Apertured Plane

Abstract

Molecular communication via diffusion (MCvD) is a method of achieving nano-and micro-scale connectivity by utilizing the free diffusion mechanism of information molecules. The randomness in diffusive propagation is the main cause of inter-symbol interference (ISI) and the limiting factor of high data rate MCvD applications. In this paper, an apertured plane is considered between the transmitter and the receiver of an MCvD link. Either after being artificially placed or occuring naturally, surfaces or volumes that resemble an apertured plane only allow a fraction of the molecules to pass. Contrary to intuition, it is observed that such topology may improve communication performance, given the molecules that can pass through the aperture are the ones that take more directed paths towards the receiver. Furthermore, through both computer simulations and a theoretical cost function named signal-to-interference and noise amplitude ratio (SINAR), it is found that the size of the aperture imposes a trade-off between the received signal power and the ISI combating capability of an MCvD system, hinting to an optimal aperture size that minimizes the bit error rate (BER). In addition, it is shown that the optimal aperture size is affected by the location of the aperture and the bit rate. Lastly, the paper analyzes the effects of a radial offset in the placement of the apertured plane, and finds that a reduction in BER is still in effect up to a certain offset value. Overall, our results imply that apertured plane-like surfaces may actually help communication efficiency, even though they reduce the received signal power.Index Terms-Molecular communication via diffusion, nanonetworks, apertured plane, inter-symbol interference, bit error rate.