1,647 research outputs found
Modeling and Simulation of Molecular Communication Systems with a Reversible Adsorption Receiver
In this paper, we present an analytical model for the diffusive molecular
communication (MC) system with a reversible adsorption receiver in a fluid
environment. The widely used concentration shift keying (CSK) is considered for
modulation. The time-varying spatial distribution of the information molecules
under the reversible adsorption and desorption reaction at the surface of a
receiver is analytically characterized. Based on the spatial distribution, we
derive the net number of newly-adsorbed information molecules expected in any
time duration. We further derive the number of newly-adsorbed molecules
expected at the steady state to demonstrate the equilibrium concentration.
Given the number of newly-adsorbed information molecules, the bit error
probability of the proposed MC system is analytically approximated.
Importantly, we present a simulation framework for the proposed model that
accounts for the diffusion and reversible reaction. Simulation results show the
accuracy of our derived expressions, and demonstrate the positive effect of the
adsorption rate and the negative effect of the desorption rate on the error
probability of reversible adsorption receiver with last transmit bit-1.
Moreover, our analytical results simplify to the special cases of a full
adsorption receiver and a partial adsorption receiver, both of which do not
include desorption.Comment: 14 pages, 8 figures, 1 algorithm, submitte
Molecular Signal Modeling of a Partially Counting Absorbing Spherical Receiver
To communicate at the nanoscale, researchers have proposed molecular
communication as an energy-efficient solution. The drawback to this solution is
that the histogram of the molecules' hitting times, which constitute the
molecular signal at the receiver, has a heavy tail. Reducing the effects of
this heavy tail, inter-symbol interference (ISI), has been the focus of most
prior research. In this paper, a novel way of decreasing the ISI by defining a
counting region on the spherical receiver's surface facing towards the
transmitter node is proposed. The beneficial effect comes from the fact that
the molecules received from the back lobe of the receiver are more likely to be
coming through longer paths that contribute to ISI. In order to justify this
idea, the joint distribution of the arrival molecules with respect to angle and
time is derived. Using this distribution, the channel model function is
approximated for the proposed system, i.e., the partially counting absorbing
spherical receiver. After validating the channel model function, the
characteristics of the molecular signal are investigated and improved
performance is presented. Moreover, the optimal counting region in terms of bit
error rate is found analytically.Comment: submitted to Transactions on Communication
Channel Model of Molecular Communication via Diffusion in a Vessel-like Environment Considering a Partially Covering Receiver
By considering potential health problems that a fully covering receiver may
cause in vessel-like environments, the implementation of a partially covering
receiver is needed. To this end, distribution of hitting location of messenger
molecules (MM) is analyzed within the context of molecular communication via
diffusion with the aim of channel modeling. The distribution of these MMs for a
fully covering receiver is analyzed in two parts: angular and radial
dimensions. For the angular distribution analysis, the receiver is divided into
180 slices to analyze the mean, standard deviation, and coefficient of
variation of these slices. For the axial distance distribution analysis,
Kolmogorov- Smirnov test is applied for different significance levels. Also,
two different implementations of the reflection from the vessel surface (i.e.,
rollback and elastic reflection) are compared and mathematical representation
of elastic reflection is given. The results show that MMs have tendency to
spread uniformly beyond a certain ratio of the distance to the vessel radius.
By utilizing the uniformity, we propose a channel model for the partially
covering receiver in vessel-like environments and validate the proposed model
by simulations
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