4,507 research outputs found
Optimal Detection for Diffusion-Based Molecular Timing Channels
This work studies optimal detection for communication over diffusion-based
molecular timing (DBMT) channels. The transmitter simultaneously releases
multiple information particles, where the information is encoded in the time of
release. The receiver decodes the transmitted information based on the random
time of arrival of the information particles, which is modeled as an additive
noise channel. For a DBMT channel without flow, this noise follows the L\'evy
distribution. Under this channel model, the maximum-likelihood (ML) detector is
derived and shown to have high computational complexity. It is also shown that
under ML detection, releasing multiple particles improves performance, while
for any additive channel with -stable noise where (such as
the DBMT channel), under linear processing at the receiver, releasing multiple
particles degrades performance relative to releasing a single particle. Hence,
a new low-complexity detector, which is based on the first arrival (FA) among
all the transmitted particles, is proposed. It is shown that for a small number
of released particles, the performance of the FA detector is very close to that
of the ML detector. On the other hand, error exponent analysis shows that the
performance of the two detectors differ when the number of released particles
is large.Comment: 16 pages, 9 figures. Submitted for publicatio
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
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