Modulation Techniques for Molecular Communication via Diffusion

By interconnecting nanomachines and forming nanonetworks, the capacities of single nanomachines are expected to be enhanced, as the ensuing information exchange will allow them to cooperate towards a common goal. Nowadays, systems normally use electromagnetic signals to encode, send and receive information, however, in a novel communication paradigm, molecular transceivers, channel models or protocols use molecules. This article presents the current developments in nanomachines along with their future architecture to better understand nanonetwork scenarios in biomedical applications. Furthermore, to highlight the communication needs between nanomachines, two applications for nanonetworks are also presented: i) a new networking paradigm, called the Internet of NanoThings, that allows nanoscale devices to interconnect with existing communication networks, and ii) Molecular Communication, where the propagation of chemical compounds like drug particles, carry out the information exchange.

Download Full-text

ARFIS: Adaptive-Receiver-Based Fuzzy Inference System for Diffusion- Based Molecular Communications

Current Nanoscience ◽

10.2174/1573413715666190625114949 ◽

2020 ◽

Vol 16 (2) ◽

pp. 280-289

Author(s):

Ghalib H. Alshammri ◽

Walid K. M. Ahmed ◽

Victor B. Lawrence

Keyword(s):

Fuzzy Inference System ◽

Fuzzy Inference ◽

Detection Threshold ◽

Learning Rule ◽

Optimal Number ◽

Molecular Communication ◽

Inference System ◽

Detection Scheme ◽

Adaptive Receiver ◽

Detection Schemes

Background: The architecture and sequential learning rule-based underlying ARFIS (adaptive-receiver-based fuzzy inference system) are proposed to estimate and predict the adaptive threshold-based detection scheme for diffusion-based molecular communication (DMC). Method: The proposed system forwards an estimate of the received bits based on the current molecular cumulative concentration, which is derived using sequential training-based principle with weight and bias and an input-output mapping based on both human knowledge in the form of fuzzy IFTHEN rules. The ARFIS architecture is employed to model nonlinear molecular communication to predict the received bits over time series. Result: This procedure is suitable for binary On-OFF-Keying (Book signaling), where the receiver bio-nanomachine (Rx Bio-NM) adapts the 1/0-bit detection threshold based on all previous received molecular cumulative concentrations to alleviate the inter-symbol interference (ISI) problem and reception noise. Conclusion: Theoretical and simulation results show the improvement in diffusion-based molecular throughput and the optimal number of molecules in transmission. Furthermore, the performance evaluation in various noisy channel sources shows promising improvement in the un-coded bit error rate (BER) compared with other threshold-based detection schemes in the literature.

Download Full-text

Visible Light Driven Degradation of Terephthalic Acid: Optimization of Energy Demand by Light Modulation Techniques

Journal of Photocatalysis ◽

10.2174/2665976x01999200731185927 ◽

2020 ◽

Vol 01 ◽

Author(s):

Diana Sannino ◽

Vincenzo Vaiano ◽

Olga Sacco ◽

Nicola Morante ◽

Luca De Guglielmo ◽

...

Keyword(s):

Visible Light ◽

White Light ◽

Terephthalic Acid ◽

Kinetic Constant ◽

Fixed Bed ◽

Light Modulation ◽

Photocatalytic Reactor ◽

Sinusoidal Modulation ◽

Photocatalytic System ◽

Modulation Techniques

Aims: The aim of this work was to investigate the impact of light modulation parameters on the degradation of terephtalic acid, an organic model pollutant, within a heterogeneous photocatalytic system under visible light. For this purpose, a fixed bed photocatalytic reactor, irradiated by white-light LEDs matrix controlled by a system for light dimming, was used. The bed consisted of a nitrogen-doped titania photocatalyst deposited on polystyrene pellets. Background: Wastewater containing TPA can be treated into conventional aerobic biological units. However, the mineralization of TPA is slow and inefficient and its presence influences negatively the biodegradation efficiency because this pollutant inhibits microbial growth. Nowadays innovative technologies named advanced oxidation processes (AOPs), such as heterogeneous photocatalysis with UV and visible light, ozonation, Fenton oxidation have gained popularity for effective organic destruction of TPA from wastewater. The heterogeneous photocatalytic oxidation process of the TPA under visible light is the most advantageous process in terms of both fixed and operating costs. Objective: In this work the successful application of light modulation techniques to degradation of TPA using a photocatalytic system with supported visible active photocatalysts (N-doped TiO2) immobilized on polystyrene pellets was reported. In particular, sinusoidal lighting has been used analyzing the influence of the period of oscillation and the amplitude of the light modulation on the reaction kinetics, in such a way as to minimize the times and energy costs for the process. Methods: To evaluate the influence of light modulation on the efficiency of the TPA removal, a discontinuous system composed by a Recirculating Photocatalytic Fixed Bed Reactor (RPFBR) irradiated by a matrix of white light LEDs was used. The flat geometry of photoreactor guarantees the efficient excitation of photocatalyst. An amount of 250 mL of aqueous solution with initial TPA concentration of 12.5 ppm was applied in the photocatalytic tests lasting 180 min of irradiation fixed or sinusoidal modulated. Results: The results show that the variation of the oscillation period of the sinusoidal modulation has a relevant influence on the photodegradation of TPA and a maximum value of the apparent kinetic constant, 0.0045 min-1 is found when the period of oscillation is 0.24 s. The sinusoidal modulation with optimal amplitude is that with current between 50-200 mA, that shows the highest value of the apparent kinetic constant, equal to 0.0046 min-1. The optimal sinusoidal modulation, as a consequence is with current between 50-200 mA and period of 0.24 s. From the data collected from the tests, it is possible to evaluate the energy cost necessary to obtain the reduction of 90% of the terephthalic acid in 1 m3 of polluted water for each modulation (E E/O ), and compare these values with other tests for TPA degradation reported in the literature. The internal comparison and with the three systems of literature showed the optima sinusoidal modulation of LEDs matrix permits a strong reduction the electrical energy consumption. Conclusion: Photocatalytic tests have demonstrated the improvement of the process energy efficiency using the light modulation technique . A further confirmation of the advantage of light modulation was obtained by comparing the energy costs required for the abatement of 90% of the terephthalic acid in 1m 3 of the photocatalytic system. Finally, a mathematical model for photocatalytic degradation of terephthalic acid within the recirculating fixed bed photocatalytic reactor, irradiated by white-light LEDs was developed.

Download Full-text

On the Distribution of Molecules for Diffusion Based Molecular Communication System

2019 10th International Conference on Computing, Communication and Networking Technologies (ICCCNT) ◽

10.1109/icccnt45670.2019.8944756 ◽

2019 ◽

Author(s):

Gaurav Sharma ◽

Ajay Singh

Keyword(s):

Communication System ◽

Molecular Communication

Download Full-text