62,558 research outputs found
Maximum Likelihood Detection for Cooperative Molecular Communication
In this paper, symbol-by-symbol maximum likelihood (ML) detection is proposed
for a cooperative diffusion-based molecular communication (MC) system. In this
system, a fusion center (FC) chooses the transmitter's symbol that is more
likely, given the likelihood of the observations from multiple receivers (RXs).
We propose three different ML detection variants according to different
constraints on the information available to the FC, which enables us to
demonstrate trade-offs in their performance versus the information available.
The system error probability for one variant is derived in closed form.
Numerical and simulation results show that the ML detection variants provide
lower bounds on the error performance of the simpler cooperative variants and
demonstrate that majority rule detection has performance comparable to ML
detection when the reporting is noisy.Comment: 7 pages, 4 figurs. This work has been accepted by the IEEE ICC 201
Anti-ISI Demodulation Scheme and Its Experiment-based Evaluation for Diffusion-based Molecular Communication
In diffusion-based molecular communication (MC), the most common modulation technique is based on the concentration of information molecules. However, the random delay of molecules due to the channel with memory causes severe inter-symbol interference (ISI) among consecutive signals. In this paper, we propose a detection technique for demodulating signals, the increase detection algorithm (IDA), to improve the reliability of concentration-encoded diffusion-based molecular communication. The proposed IDA detects an increase (i.e., a relative concentration value) in molecule concentration to extract the information instead of detecting an absolute concentration value. To validate the availability of IDA, we establish a real physical tabletop testbed. And we evaluate the proposed demodulation technique using bit error rate (BER) and demonstrate by the tabletop molecular communication platform that the proposed IDA successfully minimizes and even isolates ISI so that a lower BER is achieved than the common demodulation technique
Decision-Feedback Detection for Bidirectional Molecular Relaying with Direct Links
In this paper, we consider bidirectional relaying between two diffusion-based
molecular transceivers (bio-nodes). As opposed to existing literature, we
incorporate the effect of direct diffusion links between the nodes and leverage
it to improve performance. Assuming network coding type operation at the relay,
we devise a detection strategy, based on the maximum-likelihood principle, that
combines the signal received from the relay and that received from the direct
link. At the same time, since a diffusion-based molecular communication channel
is characterized by high inter-symbol interference (ISI), we utilize a decision
feedback mechanism to mitigate its effect. Simulation results indicate that the
proposed setup incorporating the direct link can achieve notable improvement in
error performance over conventional detection schemes that do not exploit the
direct link and/or do not attempt to mitigate the effect of ISI
On the Impact of Transposition Errors in Diffusion-Based Channels
In this work, we consider diffusion-based molecular communication with and
without drift between two static nano-machines. We employ type-based
information encoding, releasing a single molecule per information bit. At the
receiver, we consider an asynchronous detection algorithm which exploits the
arrival order of the molecules. In such systems, transposition errors
fundamentally undermine reliability and capacity. Thus, in this work we study
the impact of transpositions on the system performance. Towards this, we
present an analytical expression for the exact bit error probability (BEP)
caused by transpositions and derive computationally tractable approximations of
the BEP for diffusion-based channels with and without drift. Based on these
results, we analyze the BEP when background is not negligible and derive the
optimal bit interval that minimizes the BEP. Simulation results confirm the
theoretical results and show the error and goodput performance for different
parameters such as block size or noise generation rate.Comment: This paper has been submitted to IEEE Transactions on Communication
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
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