Channel Characterization of Diffusion-Based Molecular Communication With Multiple Fully-Absorbing Receivers

Abstract

In this paper an analytical model is introduced to describe the impulse response of the diffusive channel between a pointwise transmitter and a given fully-absorbing (FA) receiver in a molecular communication (MC) system. The presence of neighbouring FA nanomachines in the environment is taken into account by describing them as sources of negative molecules. The channel impulse responses of all the receivers are linked in a system of integral equations. The solution of the system with two receivers is obtained analytically. For a higher number of receivers the system of integral equations is solved numerically. It is also shown that the channel impulse response shape is distorted by the presence of the neighbouring FA interferers. For instance, there is a time shift of the peak in the number of absorbed molecules compared to the case without interference, as predicted by the proposed model. The analytical derivations are validated by means of particle based simulations.

Localizing the Unknown Receiver in a Diffusive SIMO Molecular Communication System

“…In this section, we show the estimator's performance in localizing the unknown receiver. Simulation system parameters are taken from [10] and are reported in Tab. I.…”

“…Receivers can count the number of molecules absorbed as they hit the receivers' surface. The FA characteristic introduces a coupling effect among the receivers' observations that can be interpreted as a reduction of molecules from the environment [10]. Thus, we need to consider the reciprocal impact to study the number of molecules absorbed by each receiver.…”

“…As shown in [10], the coupling effect among the FA receivers can be modelled by introducing the concept of the negative point source. The negative source position is described by the barycenter that can be associated with each FA receiver.…”

“…The barycenter is defined as the spatial average of molecules that hit the surface of each receiver according to the geometry of the problem. We can write the absorption rate of each receiver in a SIMO scenario as [10…”

“…In order to find the number of molecules absorbed by each receiver, it is required to integrate and solve (4). The time domain closed-form solution of (4) for more than two receivers has not been derived yet, while the numerical solution is shown in [10].…”