arXiv subjects

Ozgur B. Akan

Publications and source records attributed to Ozgur B. Akan.

98 records · Page 6Linked to original sources

arXiv2020

Internet of Radars (IoR): Internet of RAdio Detectors And Rangers

The Internet of Things (IoT) are interconnected devices for exchanging information through sensors and actuators. One of the main physical sensors to understand the environment beyond the visible world is a radar. Basically, radars have always been a military tool to be used to investigate the environment. However, with the developing technology, radars have become more compact and affordable to use in a building, in a car, in a drone or even in a wristwatch. In the near future, radar-equipped IoT platforms will start to appear increasingly. For each IoT platform, dual use of spectrum with dual aperture is required for sensing and communicating when using conventional approaches. For the radar sensing IoT devices, the emission from the radar and communication circuitry is the main reason of the increase in energy consumption. Furthermore, an increasing number of radars emerges as congested spectrum, and RF convergence between radars and communication systems becomes more likely to present itself. Recent years, there have been numerous researches which propose using the one emission/waveform for perceiving the environment and sending information. They are often called as "Joint Radar-Communication (JRC)" systems. Due to the latest developments in JRC system designs, radar sensing IoT platforms now can be transformed into an "Internet of RAdio Detectors And Rangers (IoR)". In this article, we present a short survey on JRC technologies, possible application areas IoR applications and challenges and future research directions for enabling the concept of IoR.

eess.SP↗

arXiv2019

Channel Sensing in Molecular Communications with Single Type of Ligand Receptors

Molecular Communications (MC) uses molecules as information carriers between nanomachines. MC channel in practice can be crowded with different types of molecules, i.e., ligands, which can have similar binding properties causing severe cross-talk on ligand receptors. Simultaneous sensing of multiple ligand types provides opportunities for eliminating interference of external molecular sources and multi-user interference (MUI), and developing new multiple access techniques for MC nanonetworks. In this paper, we investigate channel sensing methods that use only a single type of receptors and exploit the amount of time receptors stay bound and unbound during ligand-receptor binding reaction to concurrently estimate the concentration of multiple types of ligands. We derive the Cramér-Rao Lower Bound (CRLB) for multi-ligand estimation, and propose practical and low-complexity suboptimal estimators for channel sensing. We analyze the performance of the proposed methods in terms of normalized mean squared error (NMSE), and show that they can efficiently estimate the concentration of ligands up to $10$ different types with an average NMSE far below $10^{-2}$. Lastly, we propose a synthetic receptor design based on modified kinetic proofreading (KPR) scheme to sample the unbound and bound time durations, and a Chemical Reaction Network (CRN) to perform the required computations in synthetic cells.

cs.ET↗

arXiv2019

Transmitter and Receiver Architectures for Molecular Communications: A Survey on Physical Design with Modulation, Coding and Detection Techniques

Inspired by Nature, molecular communications (MC), i.e., use of molecules to encode, transmit and receive information, stands as the most promising communication paradigm to realize nanonetworks. Even though there has been extensive theoretical research towards nanoscale MC, there are no examples of implemented nanoscale MC networks. The main reason for this lies in the peculiarities of nanoscale physics, challenges in nanoscale fabrication and highly stochastic nature of biochemical domain of envisioned nanonetwork applications. This mandates developing novel device architectures and communication methods compatible with MC constraints. To that end, various transmitter and receiver designs for MC have been proposed in literature together with numerable modulation, coding and detection techniques. However, these works fall into domains of a very wide spectrum of disciplines, including but not limited to information and communication theory, quantum physics, materials science, nanofabrication, physiology and synthetic biology. Therefore, we believe it is imperative for the progress of the field that, an organized exposition of cumulative knowledge on subject matter be compiled. Thus, to fill this gap, in this comprehensive survey we review the existing literature on transmitter and receiver architectures towards realizing MC amongst nanomaterial-based nanomachines and/or biological entities, and provide a complete overview of modulation, coding and detection techniques employed for MC. Moreover, we identify the most significant shortcomings and challenges in all these research areas, and propose potential solutions to overcome some of them.

cs.ET↗

arXiv2017

Fluorescent Troffer-powered Internet of Things: An Experimental Study of Electric-field Energy Harvesting

A totally new energy harvesting architecture that exploits ambient electric-field (E-field) emitting from fluorescent light fixtures is presented. A copper plate, 50 x 50 cm in size, is placed in between the ambient field to extract energy by capacitive coupling. A low voltage prototype is designed, structured and tested on a conventional ceiling-type 4-light fluorescent troffer operating in 50 Hz 220 V AC power grid. It is examined that the harvester is able to collect roughly 1.25 J of energy in 25 min when a 0.1 F of super-capacitor is employed. The equivalent circuit and the physical model of the proposed harvesting paradigm are provided, and the attainable power is evaluated in both theoretical and experimental manner. The scavenged energy is planned to be utilized for building battery-less Internet of Things (IoT) networks that are obliged to sense environmental parameters, analyze the gathered data, and remotely inform a higher authority within predefined periods.

physics.app-ph↗

arXiv2016

On the Capacity of Diffusion-Based Molecular Communications with SiNW FET-Based Receiver

Molecular communication (MC) is a bio-inspired communication method based on the exchange of molecules for information transfer among nanoscale devices. Although MC has been extensively studied from various aspects, limitations imposed by the physical design of transceiving units have been largely neglected in the literature. Recently, we have proposed a nanobioelectronic MC receiver architecture based on the nanoscale field effect transistor-based biosensor (bioFET) technology, providing noninvasive and sensitive molecular detection at nanoscale while producing electrical signals at the output. In this paper, we derive analytical closed-form expressions for the capacity and capacity-achieving input distribution for a memoryless MC channel with a silicon nanowire (SiNW) FET-based MC receiver. The resulting expressions could be used to optimize the information flow in MC systems equipped with nanobioelectronic receivers.

cs.ET↗

arXiv2016

On the 5G Wireless Communications at the Low Terahertz Band

Initiation of fourth generation (4G) mobile telecommunication system rollouts fires the starting pistol for beyond 4G research activities. Whereas technologies enhancing spectral efficiency have traditionally been the solution to data rate and network capacity increase demands, due to the already advanced techniques, returns of the even more complicated algorithms hardly worth the complexity increase any longer. In addition, surging number of connected devices now enables operative use of short-range communication methods. Also considering the recently approved standards for the 60 gigahertz (GHz) industrial, scientific and medical radio band, in this paper the transmission windows around 300 GHz is proposed to be utilized for the fifth generation wireless communication systems. Motivations for the low end of the terahertz (THz) band are provided in accordance with market trends, and standardization activities in higher frequencies are listed. Unified mathematical expressions of the electromagnetic wave propagation mechanisms in the low-THz band are presented. THz band device technologies are outlined and a complete survey of the state-of-the-art low-THz band circuit blocks which are suitable for mass market production is given. Future research directions are specified before the conclusion of the paper.

cs.NI↗

arXiv2016

On the Physical Design of Molecular Communication Receiver Based on Nanoscale Biosensors

Molecular communications (MC), where molecules are used to encode, transmit, and receive information, is a promising means of enabling the coordination of nanoscale devices. The paradigm has been extensively studied from various aspects, including channel modeling and noise analysis. Comparatively little attention has been given to the physical design of molecular receiver and transmitter, envisioning biological synthetic cells with intrinsic molecular reception and transmission capabilities as the future nanomachines. However, this assumption leads to a discrepancy between the envisaged applications requiring complex communication interfaces and protocols, and the very limited computational capacities of the envisioned biological nanomachines. In this paper, we examine the feasibility of designing a molecular receiver, in a physical domain other than synthetic biology, meeting the basic requirements of nanonetwork applications. We first review the state-of-the-art biosensing approaches to determine whether they can inspire a receiver design. We reveal that nanoscale field effect transistor based electrical biosensor technology (bioFET) is a particularly useful starting point for designing a molecular receiver. Focusing on bioFET-based molecular receivers with a conceptual approach, we provide a guideline elaborating on their operation principles, performance metrics and design parameters. We then provide a simple model for signal flow in silicon nanowire (SiNW) FET-based molecular receiver. Lastly, we discuss the practical challenges of implementing the receiver and present the future research avenues from a communication theoretical perspective.

cs.ET↗

arXiv2015

Modeling and Analysis of SiNW BioFET as Molecular Antenna for Bio-Cyber Interfaces towards the Internet of Bio-NanoThings

Seamless connection of molecular nanonetworks to macroscale cyber networks is envisioned to enable the Internet of Bio-NanoThings, which promises for cutting-edge applications, especially in the medical domain. The connection requires the development of an interface between the biochemical domain of molecular nanonetworks and the electrical domain of conventional electromagnetic networks. To this aim, in this paper, we propose to exploit field effect transistor based biosensors (bioFETs) to devise a molecular antenna capable of transducing molecular messages into electrical signals. In particular, focusing on the use of SiNW FET-based biosensors as molecular antennas, we develop deterministic and noise models for the antenna operation to provide a theoretical framework for the optimization of the device from communication perspective. We numerically evaluate the performance of the antenna in terms of the Signal-to-Noise Ratio (SNR) at the electrical output.

cs.ET↗