scholarly journals On the Outage Capacity of Transdermal Optical Wireless Links with Stochastic Spatial Jitter and Skin-Induced Attenuation

Photonics ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 553
Author(s):  
George K. Varotsos ◽  
Konstantinos Aidinis ◽  
Hector E. Nistazakis
Keyword(s):  
New Technology ◽  
Outage Capacity ◽  
Optical Wireless ◽  
Technical Literature ◽  
Implantable Medical Devices ◽  
Optical Wireless Communications ◽  
Pointing Error ◽  
Living Body ◽  
High Data ◽  
Data Rates

The tremendous development of both optical wireless communications (OWC) and implantable medical devices (IMDs) has recently enabled the establishment of transdermal optical wireless (TOW) links that utilize light waves to transfer information inside the living body to the outside world and conversely. Indeed, numerous emerging medical applications such as cortical recording and telemetry with cochlear implants require extremely high data rates along with low power consumption that only this new technology could accommodate. Thus, in this paper, a typical TOW link is investigated in terms of outage capacity which is a critical performance metric that has so far not been evaluated for such wireless systems in the open technical literature. More precisely, an outage capacity analysis is performed considering both skin-induced attenuation and stochastic spatial jitter, i.e., pointing error effects. Analytical expressions and results for the outage capacity are derived for a variety of skin channel conditions along with varying stochastic pointing errors which demonstrate the feasibility of this cross-field cooperation. Lastly, the corresponding simulation outcomes further validate our suggestions.

scholarly journals Transdermal Optical Wireless Links with Multiple Receivers in the Presence of Skin-Induced Attenuation and Pointing Errors

Computation ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 33 ◽  
Author(s):  
Varotsos ◽  
Nistazakis ◽  
Aidinis ◽  
Jaber ◽  
Rahman
Keyword(s):  
High Speed ◽  
Optical Signal ◽  
Optical Wireless ◽  
Implantable Medical Devices ◽  
Optical Wireless Communications ◽  
Pointing Error ◽  
High Data ◽  
Modulation Format ◽  
Pointing Errors ◽  
Mathematical Expressions

The last few years, the scientific field of optical wireless communications (OWC) has witnessed tremendous progress, as reflected in the continuous emergence of new successful high data rate services and variable sophisticated applications. One such development of vital research importance and interest is the employment of high speed, robust, and energy-effective transdermal optical wireless (TOW) links for telemetry with implantable medical devices (IMDs) that also have made considerable progress lately for a variety of medical applications, mainly including neural recording and prostheses. However, the outage performance of such TOW links is significantly degraded due to the strong attenuation that affects the propagating information-bearing optical signal through the skin, along with random misalignments between transmitter and receiver terminals, commonly known as pointing error effect. In order to anticipate this, in this work we introduce a SIMO TOW reception diversity system that employs either OOK or more power-effective L-PPM schemes. Taking into account the joint impact of skin-induced attenuation and non-zero boresight pointing errors, modeled through the suitable Beckmann distribution, novel closed-form mathematical expressions for the average BER of the total TOW system are derived. Thus, the possibility of enhancing the TOW availability by using reception diversity configurations along with the appropriate modulation format is investigated. Finally, the corresponding numerical results are presented using the new derived theoretical outcomes.

scholarly journals Underwater Optical Wireless Communications with Chromatic Dispersion and Time Jitter

Computation ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 35 ◽  
Author(s):  
Roumelas ◽  
Nistazakis ◽  
Stassinakis ◽  
Volos ◽  
Tsigopoulos
Keyword(s):  
Wireless Communications ◽  
Communication Systems ◽  
Chromatic Dispersion ◽  
Mathematical Expression ◽  
Optical Wireless ◽  
Optical Wireless Communications ◽  
Time Jitter ◽  
High Data ◽  
Data Rates ◽  
Very High

The obsolete communication systems used in the underwater environment necessitates the development and use of modern telecommunications technologies. One such technology is the optical wireless communications, which can provide very high data rates, almost infinite bandwidth and very high transmission speed for real time fast and secure underwater links. However, the composition and the optical density of seawater hinder the communication between transmitter and receiver, while many significant effects strongly mitigate the underwater optical wireless communication (UOWC) systems’ performance. In this work, the influences of chromatic dispersion and time jitter are investigated. Chromatic dispersion causes the temporal broadening or narrowing of the pulse, while time jitter complicates the detection process at the receiver. Thus, the broadening of the optical pulse due to chromatic dispersion is studied and the influence of the initial chirp is examined. Moreover, the effect of the time jitter is also taken into consideration and for the first time, to the best of our knowledge, a mathematical expression for the probability of fade is extracted, taking into account the influence of both of the above-mentioned effects for a UOWC system. Finally, the appropriate numerical results are presented.

scholarly journals Time and Spatial Jitter Influence on the Performance of FSO Links with DF Relays and OC Diversity over Turbulence Channels

Photonics ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 318
Author(s):  
Panagiotis J. Gripeos ◽  
Hector E. Nistazakis ◽  
Andreas D. Tsigopoulos ◽  
Vasilis Christofilakis ◽  
Evgenia Roditi
Keyword(s):  
Critical Factor ◽  
Weather Conditions ◽  
Optical Wireless Communications ◽  
Time Jitter ◽  
Diversity Techniques ◽  
High Data ◽  
Mathematical Expressions ◽  
Data Rates ◽  
Turbulence Effect ◽  
The Many

FSO communication is a viral technology among optical wireless communications, gathering the interest of both researchers and manufacturers. This is because of the many advantages associated with FSO communication, including high data rates, reliability, safety, and economy. However, there are several unavoidable drawbacks that shadow the performance of FSO systems. For example, atmospheric turbulence is a well-known problem related to the weather conditions of the channel, which causes the scintillation effect. Also, spatial jitter due to pointing errors is a critical factor of the link’s performance, caused by occasional misalignments between the transmitter and the receiver. Moreover, time jitter is another limiting agent that deteriorates the total throughput, inducing bit stream misdetections, caused by the arrival of out-of-sync pulses. All three effects have been exhaustively studied and many statistical models and interesting solutions have been proposed in the literature to estimate their magnitude and compensate for their impact. In this work, the turbulence effect was treated by Málaga distribution, the spatial jitter effect was regulated by the non-zero boresight model, and the time jitter effect was modeled by the generalized Gaussian distribution. Various modulation schemes were studied, along with DF multi-hop and optimal combining diversity techniques at the receiver’s end. New, accurate mathematical expressions of average BER performance have been obtained, and valuable conclusions were drawn thanks to the presented numerical results.

scholarly journals Hybrid NOMA-Based ACO-FBMC/OQAM for Next-Generation Indoor Optical Wireless Communications Using LiFi Technology

2021 ◽  
Author(s):  
Hamis Hesham ◽  
Tawfik Ismail
Keyword(s):  
Filter Bank ◽  
Data Transfer ◽  
Average Power ◽  
Optical Wireless ◽  
Optical Wireless Communications ◽  
Transfer Rates ◽  
High Data ◽  
Filter Bank Multicarrier ◽  
Great Availability ◽  
Multi Access

Abstract The light fidelity (LiFi) has been successfully used to achieve high data transfer rates, high security, great availability, and low interference. In this paper, we propose a LiFi system consisting of a combination of non-orthogonal multi-access (NOMA), asymmetrically-clipped optical (ACO) and filter bank multicarrier (FBMC) techniques combined with offset quadrature amplitude modulation (OQAM). The paper also applies a $\mu$-law companding approach for a high peak to average power ratio (PAPR) reduction of the FBMC/OQAM scheme. The combination of NOMA, ACO-FBMC/OQAM, and $\mu$-law companding allows a significant increase in throughput and a significant reduction in non-served users. An appropriate algorithm is developed considering two scenarios, maximize the throughput and minimize the number of blocked (non-served) users. The results show that the throughput of the system can be increased by $1.8$ compared to FBMC and OFDM. Furthermore, the proposed system reduces the number of blocked users below $10\%$, while the system can provide $30\%$ or $60\%$ in case only the FBMC or OFDM is used, respectively.

scholarly journals Underwater Optical Wireless Communications: Overview

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2261 ◽  
Author(s):  
Giuseppe Schirripa Spagnolo ◽  
Lorenzo Cozzella ◽  
Fabio Leccese
Keyword(s):  
Wireless Communications ◽  
Wireless Communication ◽  
Single Photon ◽  
Green Light ◽  
Low Latency ◽  
Optical Wireless Communication ◽  
Optical Wireless ◽  
Optical Wireless Communications ◽  
Data Rates ◽  
Absorption Window

Underwater Optical Wireless Communication (UOWC) is not a new idea, but it has recently attracted renewed interest since seawater presents a reduced absorption window for blue-green light. Due to its higher bandwidth, underwater optical wireless communications can support higher data rates at low latency levels compared to acoustic and RF counterparts. The paper is aimed at those who want to undertake studies on UOWC. It offers an overview on the current technologies and those potentially available soon. Particular attention has been given to offering a recent bibliography, especially on the use of single-photon receivers.

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