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We demonstrate 100-Gbaud on-off-keying (OOK) transmission driven at a low voltage using an electro-optic (EO) polymer modulator combined with a silicon Mach-Zehnder interferometer waveguide. Various types of organic- and polymer-based modulators have been reported to perform efficient EO modulation and high-speed data transmission at over 100 Gbaud. However, there are critical concerns regarding the practical application of polymer devices in terms of environmental stability. In particular, long-term thermal storage and stability during operation require improvements before EO polymer modulators can be applied in practical systems. We have developed an EO polymer with enhanced thermophysical stability and used it to fabricate an efficient EO polymer modulator. In this study we extend our earlier work on high-speed EO polymer modulators by performing fiber-link 100-Gbaud OOK transmission at various operating temperatures. A thermal stability test revealed that the EO polymer modulator can survive high-temperature exposure up to 110°C. Error-free signal transmissions over a distance of 2.0 km was successfully demonstrated with a driving voltage of 1.9 Vpp and a bit error rate below the 7% overhead forward error correction threshold. The driving voltage, bandwidth, bit error rate, and fiber-link performance of the device are presented.

An 800-MHz OOK transmitter for short-range Internet-of-Things (IoT) applications is presented in this letter. The OOK transmitter utilizes a microelectromechanical system (MEMS)-based RF oscillator for carrier frequency generation, leading to a hardware- and power-efficient architecture. The transmitter is implemented in a 180-nm CMOS process and delivers −12.4-dBm output power. The power consumption of the MEMS oscillator is only 0.24-mW with 126.3-dBc/Hz phase noise at 100-kHz offset and a figure-of-merit (FoM) of 210.5 dB due to the optimized high- $Q$ aluminum nitride (AlN) piezoelectric MEMS resonator. The transmitter can provide a 120-Mb/s data rate of OOK modulation with an energy efficiency of 5 pJ/bit by directly switching ON/OFF the power amplifier (PA). The 175-ns startup time of the MEMS-based oscillator can support very heavy duty-cycle transmitter operation, leading to ultralow average power consumption of 50 nW.

Photomultiplier tube (PMT) receiver is a promising solution for long-distance underwater wireless optical communication (UWOC) due to its characteristics of high gain, low noise, and large receiver area. However, the complex underwater environment leads to the dynamic change of the received optical intensity and impacts the stability and reliability of UWOC system using PMT. In this work, the bandwidth limitation and performance degradation of UWOC system caused by PMT saturation is experimentally observed and characterized for various optical intensity and PMT gain. A low-cost, high-integrated, and small-volume receiver control system and relevant adaptive control strategy are proposed to improve the stability and reliability of UWOC system by dynamically adjusting the received optical power and PMT gain according to the detected optical signal. The experiment results show that the dynamic range of UWOC received optical power can be extended to 68 dB (−63 dBm∼5 dBm) for 100 Mbit/s OOK modulation based UWOC system.

We consider optical camera communication (OCC) between a camera receiver with optical lenses and distributed transmitters. This article investigates the features of an OCC system when the periods of reception and transmission are slightly different from each other. We describe a received light signal model for the OCC system with on-off keying and regard the received signals generated from a probability distribution of a Gaussian mixture model. We obtain the parameters of the probability distributions by applying a variational Bayesian inference method and utilize them for channel estimation. In addition, we define cost functions and minimize them to demodulate the transmitted bit sequences. The demodulation procedure uses a maximum-likelihood sequence detection method, which can be implemented by the Viterbi algorithm and estimates a synchronization parameter by minimizing the cost functions. Our new demodulation method requires neither synchronization devices nor training sequences for estimating the parameters. Moreover, the receiver does not need the precise transmission period, which is difficult to know in advance in practical situations because of the frequency tolerance of the clock generator in the transmitter. To validate our developed method, we conducted numerical simulations and compared the results with those from an oracle estimator that knows the parameters other than the bit sequence in advance. We also experimented in a real setup situation, and the results show the efficiency of our developed method.

The energy efficiency of an inductive wireless power transfer (WPT) system will deviate from the possible peak value if the magnetic coupling of the transmitter and receiver coils or the load resistance changes. To achieve maximum-efficiency tracking regardless of coupling or load changes, on – off keying (OOK) modulation is used. However it has the issue of large surge current in the circuits during OOK modulation. The current overshoots of a series–series (SS) compensated WPT system at the startup stage might be much higher than the rated current. The current overshoots not only increase the stress on the power switch devices but also cause high voltage spikes across the windings and the resonant capacitors which is a challenge for insulation design. A soft-start scheme is proposed to address the current overshoot problem. The principle of the soft-start scheme can be essentially applied to WPT systems with different compensation topologies. The experimental results of a 3.3-kW prototype verify that the proposed soft-start scheme effectively suppress the current overshoots.

In this study, a symmetric polarization-division-multiplexing (PDM) wavelength-division-multiplexing passive optical network (WDM-PON) with fiber to the extension (FTTE) architecture is presented and investigated. The proposed PON can also avoid the Rayleigh backscattering (RB) interference noise. Here, each WDM wavelength can produce 25 Gbit/s on-off keying (OOK) and 10 Gbit/s OOK modulation channels simultaneously in x- and y-polarizations (Polx and Poly) through PDM method for 25 and 105 km single-mode fiber (SMF) transmissions without dispersion compensation. The measured minimal power budget of 25 and 10 Gbit/s downstream and upstream signals are 29 and 35.1 dB and 29.8 and 31.5 dB, respectively, at the forward error correction (FEC) target. Therefore, the proposed PDM WDM-PON architecture can not only offer symmetric 35 Gbit/s downstream and upstream connections by the dual-polarized wavelength, but also can avoid the RB-induced interference noise. In addition, the presented dual-polarized downstream signal also can provide information security in physical layer, when the unauthorized user occupies unlawfully.

A comprehensive study on the optical characteristics and high-speed transmission performance of a hexagonally arrayed seven-core fiber supporting both multimode transmission at 850 nm and quasi-single mode transmission at 1310 and 1550 nm are presented. We investigated its optical and transmission characteristics such as inter-crosstalk, modal bandwidth, chromatic dispersion, and misalignment tolerance. The results show that the multicore fiber (MCF) has a high bandwidth at 850 nm while remaining a comparable performance with standard single-mode fiber (SSMF) at 1310 and 1550 nm. The worst inter-core crosstalk is less than −43 dB over a 10 km-long MCF connected with a pairwise fan-in/fan-out devices. The minimum effective modal bandwidth of 8.44 GHz $\cdot$ km is achieved with the MCF for multimode operation, while the chromatic dispersion of the MCF at 1550 nm only increases by 7% compared with that of SSMF. In experiment, we successfully performed the 7 × 25 Gb/s multimode transmission over a 300 meter-long MCF at 850 nm and quasi-single mode transmission over a 12.4 and 10 km-long fiber at 1310 and 1550 nm, respectively, with an OOK modulation format. There was no obvious degradation observed when all cores operated simultaneously. Moreover, we carried out 7 × 50 Gb/s PAM4 transmission over a 300 meter-long and 10 km-long MCF at 850 and 1310 nm, respectively, as well as 7 × 40 Gb/s PAM4 transmission over a 10 km-long MCF at 1550 nm. A BER which is well below the forward error correction (FEC) threshold (5 $\times\, 10^{-5}$ ) was reached for different MCF links.

The Bit Error Rate (BER) of the diffusive molecular communication (DMC) systems employing on-off keying (OOK) modulation. We also analyze the BER of the OOK-modulated DMC systems with inter- symbol interference cancellation (ISIC). Our main motivation is to introduce alternative tools for analyzing and efficiently computing the BER of the DMC systems without or with ISIC. Specifically, for the OOK-modulated DMC systems without ISIC, we first derive an exact BER expression based on the Poisson modeling of DMC systems. Then, the Gaussian- and Gamma-approximation approaches are introduced to approximate the discrete Poisson distribution, and based on the approximation approaches, the corresponding BER expressions are derived.

In this paper, we propose, design and evaluate the performance of an angle diversity transmitter (ADT) to achieve high data rate multi-user indoor visible light communication (VLC) systems. Our pro...

A novel architecture for the On Off Keying (OOK) modulator with high gain and high data rate power amplifier (PA) operating at 11.6 GHz IBM 0.18-µm RF CMOS technology is presented for a X-band passive RFID tag. Currently used low frequency switching techniques such as multiplexers were not functioning in the high frequency X-band architectures. In this novel approach OOK modulator with power amplifier, a CMOS switch was used to transmit ‘1’ and ‘0’ coming from the digital signal unlike in the existing low frequency architectures. Both the load and driver in this proposed PA were class A operation supplied by a single ended 1.83V source. The important design considerations include output power, 1 dB compression point and linearity. The fabricated results of the amplifier have a 1 dB compression point of 1.2 dBm and input power of 5.19 dBm at 9.2 GHz.

In this work we study the non-linear effects through the analysis of the operating results of three alloptical 3R regeneration (re-amplifying, re-shaping and re-timing) under the effects of cross-phase modulation (XPM) and four-wave mixing (FWM), being a system with hybrid modulation and two other communication systems with modulation on-off keying (OOK) with return to zero (RZ) and non-return to zero (NRZ) coding. The main part of the 3R regeneration system proposed here is a Mach-Zehnder interferometer (MZI) composed of an acousto optical filter (AOF) and a highly nonlinear photonic crystal fiber (HNL-PCF), so the system proposed here was named 3R-MZIAOF regenerator. The comparison of the system results occurred through the variation of the input power variation from -10 dBm to 10 dBm for the link length of 121.3 km and transmission rate 10 Gbps. The results showed that the regeneration 3R scheme OOK-NRZ with AOF presented excellent values of bit error rate (BER) equal to 10-21 and quality factor (Q-Factor) equal to 9.4, when compared to a system with OOK-NRZ 3R regeneration and hybrid modulation.

Free space optical communication (FSO) system has remarkably gained importance of late due to the various advantages associated with it. However, before deployment of FSO communication system, an understanding of the laser beam scintillation due to the atmospheric as well as other weather-induced losses need to be understood. This paper mainly focuses on simulative performance analysis of an FSO system under rain conditions using Optisystems commercial software and rainfall data. Thus, the available models which are the Suriza, Carbonnea, Japan and Samir models were used to determine the rainfall-induced attenuation for a given rainfall rate. Unlike in the previous articles that only used on off keying as the modulation scheme at the transmitter, we have used modified duobinary return to zero (MDRZ) modulation. Further, to improve the MDRZ-based FSO performance in rain conditions, we have used the single-input multiple-output (SIMO) concept with equal gain combining (EGC) at the receiver and again proved that the improvement in BER, Q factor and received optical power suggests that MDRZ-based SIMO FSO communication results in a remarkable improvement.

Ambient backscatter which utiliees the ambient radio-frequency signals to enable transmissions between battery-less devices has attracted considerable attention in academia and industry. This study addresses the questions of full-duplex (FD) and self-interference cancellation (SIC) for ambient backscatter which adopts dual-antenna structure to achieve persistent information transmission and energy harvesting. The authors construct the physical-layer network coding (PNC) mapping principle of on–off keying in the dual-antenna structure and propose the PNC-based FD algorithm to eliminate the self-interference in the information domain. Furthermore, the bit-error-ratio and throughput performances are analysed under conventional half-duplex mode and the proposed FD mode, respectively. In order to facilitate system complexity and reduce power consumption, they design a hardware prototype to achieve SIC which consists of low-power passive analogue components. Numerical results are provided to confirm the theoretical studies. Circuit simulations demonstrate that the circuit is commendably consistent with the design concept.

We propose and experimentally demonstrate a simple and elegant modulation format shifting (MFS) scheme by continuously changing the modulation formats between OOK and Manchester signal for optical camera communication (OCC) using a commercially available mobile phone. Leveraging the MFS scheme, extra data bits are delivered without reducing the pixel width of each bit, resulting in higher transmitted data rate. Meanwhile, multi-thresholding scheme is proposed for modulation format identification and signal decoding at the receiver. The experimental results demonstrate that the proposed MFS scheme can achieve a data rate of 8.16 Kbps with the bit error rate (BER) of $2.9\times 10^{-3}$ at the illuminance of 400 lux. In addition, compared with conventional OOK modulation, MFS scheme can remarkably improve the BER performance at the same data rate.

In this letter, a 24-GHz high-isolation ON–OFF keying (OOK) modulator with reduced input impedance variation in a 65-nm CMOS technology is proposed. A modified magnetic coupled triple-cascode configuration with a series inductor and two shunt transistors, which can simultaneously improve the ON/OFF isolation and reduce the input return loss variation between the ON- and OFF-states, is designed and analyzed for the first time. Based on this configuration, the OOK modulator achieves a 45.7-dB ON/OFF isolation and maintains better than 10-dB return loss for both the ON- and OFF-states. In addition, a data rate of 3.3 Gbps is achieved.

In medical treatment, healthcare and home appliances, the demand for Internet of Things (IoT) services is increasing in urban areas. However, in fading environments of urban area, the existing IoT communication system can degrade severely. The purpose of this paper is to develop a new IoT communication technology that improves communication performance in fading channels. IoT communication systems are aiming at low power long distances. In addition, the amount of data transmission is small due to the service requirements. To achieve this goal, existing IoT communication modems are designed with narrowband signals. However, narrowband signals may cause performance degradation in a frequency selective fading channel environments in urban area. In this paper, we propose a split channel two tone OOK (SC-TT-OOK) that implements on-off keying (OOK) using two tones. Unlike the existing OOK by using one tone, SC-TT-OOK uses spaced two tones to improve communication performance in fading channels. The conventional OOK method has a similar characteristic to that of the existing IoT modems with a narrow bandwidth spectrum. The proposed SC-TT-OOK is OOK using two separated tones. Since the proposed modulation uses two tones, it requires twice the frequency resources of the conventional OOK. However, if the frequencies of the two tones are sufficiently spaced apart, frequency diversity gain can be achieved in the frequency selective fading channels, and communication reliability can be improved in urban environments. The proposed SC-TT-OOK is examined through computer simulation. The simulation results show that the proposed scheme outperforms the conventional scheme in the frequency selective fading channel. Therefore, the proposed method can be used as an alternative technique for IoT modem in urban environments.

Intercore crosstalk (ICXT) impaired weakly-coupled multicore fiber (MCF) systems using on-off keying (OOK) and direct-detection (DD) are experimentally assessed. The stochastic properties of the received bit amplitudes that depend on the relative propagation delay (skew) between two cores of the MCF and on the OOK bit-rate are discussed. For low skew×bit-rate ( $ 1): (i) the received amplitude of bits 0 or 1 of the interfered core are mainly characterized by two possible levels; (ii) when the short-term average crosstalk (STAXT) power increases (decreases), the fluctuations of the received amplitudes of bits 1 and 0 become larger (lower). For high skew×bit-rate ( $>>$ 1): (i) the received amplitudes of bits 0 and 1 present a noise-like behaviour; (ii) larger fluctuations of the received amplitudes of the OOK signal may not occur only for high STAXT powers. For both low and high skew×bit-rate, it is shown that the histogram of the received amplitudes of bits 1 or 0, and the histogram of the mean and variance of these amplitudes are reasonably well characterized by Gaussian distributions. Experimental results suggest that the rule of thumb to design emerging MCF applications with higher ICXT tolerance is to use cores with skew much longer than the symbol period.

The major drawback of the conventional chaotic ON–OFF keying (COOK) scheme is that the transmitted signal energy is not constant due to the non-periodic nature of the chaotic sequences. These chaotic sequences increase the amount of noise present in the received signal and degrade the system performance under multipath fading channel conditions. Moreover, in COOK scheme, the optimum threshold for symbol detection depends on the Signal to Noise Ratio (SNR) available at the detector input. In this paper, a noise reduction COOK scheme is proposed for improved performance. In this scheme, for transmitting binary bit ‘1’ $$\frac{\beta }{R}$$ distinct chaotic samples are generated and each sample is repeated R times to get a required spreading sequence length of β and no signal is being transmitted during binary bit ‘0’. For demodulation of the transmitted data, each of the R identical samples are averaged, correlated with itself and summed over the bit duration $$T_{b}$$ where $$T_{b} = \frac{\beta }{R}T_{c}$$ to recover the transmitted data. The averaging operation over R identical samples reduces the effect of noise present in the received signal and improves the performance of the system over noisy channels. Closed form expression for bit error rate (BER) of the proposed NR-COOK system is derived and analyzed under multipath fading channel and are validated through simulation results to demonstrate performance improvement over conventional non coherent schemes.

In this paper, a novel two dimensional (2D) wavelength/time (W/T) optical code division multiple access (OCDMA) code with zero cross-correlation property to minimize multiple access interface (MAI) is addressed. The code is constructed using various features of two different one-dimensional codes, i.e., multi-diagonal code and prime hop code referred as multi-diagonal prime hopping (MDPHC) code. The proposed 2D W/T MDPHC code is generated using java software version 8.1, which is found to be optimal. In this paper, the code complexity of the proposed 2D code is also derived. In addition to the novel 2D code design, security provision at the photonic layer of the OCDMA network is also addressed by transmitting the data through a novel encrypted circuit in order to prevent attacks by an eavesdropper. In this work, the proposed encryption circuit is integrated with the proposed 2D (W/T) MDPHC OCDMA encoder to enhance the overall security performance. The proposed model is validated using optisystem software version 14. Robustness of the proposed technique against different types of attacks such as ciphertext-only attack, known plain text attack, chosen plaintext attack, energy detection attack in on off keying optical code division multiple access, Brute-force search attack is investigated theoretically. Bit error rate is also estimated for different fiber distances.

This paper presents a G-band on-off -keying transmitter and a G-Band receiver in 65-nm bulk CMOS process. The proposed transmitter includes a high-efficiency push–push voltage-controlled oscillator (VCO) with body-bias and a switch-based modulator using the folded coupled-line topology. The benefits of the folded coupled-line in switch design are theoretically analyzed and proved. The receiver utilized a topology based on envelope detector and inverter-chain-based output buffer. The standalone VCO demonstrates a peak dc-RF efficiency of 4.1% at 209 GHz with 1.02 dBm output power. The switch-based modulator performs a minimum insertion loss of 1.6 dB with isolation better than 21 dB. The transmitter exhibits a maximum output power of −0.04 dBm at 208 GHz with 3% efficiency and a phase noise of −84.9 dBc at 1-MHz offset. The transmitter and receiver achieve 7.5-Gb/s errorless [bit error rate (BER) < 1 × 10−12] data rate with 1.73 pJ/b energy efficiency and 9 Gb/s with 1 × 10−4 BER in loop-back test. The results of both the transmitter/receiver and standalone components show competitive performances at the frequency over 200 GHz among the designs in CMOS process.

This paper presents a new on–off keying modulation circuit for a Class-E power transmitter used in high-data-rate wireless links used for powering medical implants. A circuit technique is proposed to keep the current of the RF choke of the power transmitter constant, while the transmitter turns on and off. This allows the transmitter to quickly turn on and off. To prove the feasibility of the proposed circuit, a wireless power and data transfer link based on the proposed circuit was designed and implemented. At a carrier frequency of 2.5 MHz, the measured data rate was 625 kbps, which means that a data-rate-to-carrier-frequency ratio of 25% has been achieved. The power transfer efficiency and the power delivered to the load, with a 2.37-μH transmitter coil and a 1.4-μH receiver coil separated by a 1.0-cm air gap, were measured to be 21% and 80 mW, respectively. The measured bit error rate of the link was less than 10−5.

In this paper, we propose a novel mode division multiplexing (MDM) based FSO transmission system incorporating polarization shift keying (PolSK) to enhance the information carrying capacity of the system. Using numerical simulations, we report the transmission of two independent 40 Gbps information signals using distinct Laguerre Gaussian modes up to an FSO transmission reach of 90 km under the influence of clear environmental conditions using the proposed system. Further, the influence of different environmental conditions such as rain, haze, and fog on the performance of the proposed link using bit error rate as performance metrics has also been investigated in this paper. Also, we report a comparative analysis of PolSK and on–off keying modulation formats in the proposed MDM-FSO link under the same environmental conditions. The simulation results show that under different weather conditions, PolSK based MDM-FSO transmission system demonstrates better performance.

The practical development of WUSN would benefit numerous applications, including online infrastructure monitoring, earthquake warning systems, and agricultural automation. However, stateof- the-art RF electromagnetic wireless systems are ineffective for communicating through-soil, due to extreme signal path losses from absorption and scattering in soil, even though the typical data requirements for such applications are modest, ranging from tens to hundreds of bps. In contrast, elephants, rodents and a wide variety of insects use acoustic waves for communicating through-soil, suggesting the viability of soil as a communication channel, and of acoustic waves as carriers. In this article, we demonstrate how soil can be used as a communication medium for wireless acoustic digital communication over distances up to 50 m at 20 bps data rates. By leveraging a physical model of the soil channel derived from its identified characteristics, then employing QPSK and OOK modulation and sparse decision feedback equalization schemes, and exploiting well-coupled and matched acoustic sources, wireless digital communication was successful in both laboratory and field experiments, illustrating the viability of sending application- specific data, ranging from binary sensor readings to low-resolution images.

Run-length limited (RLL) codes can facilitate reliable data transmission and provide flicker-free illumination in on-off keying-modulated visible light communication (VLC) systems. This letter proposes new RLL codes that can decrease error and achieve desirable brightness levels with high throughput. The flicker control and free distance of the proposed rate 2/3 RLL codes are extensively described. Extensive simulations evaluated the proposed RLL codes in forward error correction (FEC)-uncoded and FEC-coded VLC systems, demonstrating that the proposed RLL codes offer superior error performance when compared with rate 1/2 Miller and enhanced Miller codes.

In this study, we built a single photon avalanche diode (SPAD) receiver based underwater wireless optical communication (UWOC) system. The bit error rate (BER) and signal-to-noise ratio (SNR) performance of UWOC with different distances and data transmission rates were obtained. Based on the water attenuation coefficient of 0.12 m-1, a series of neutral density (ND) filters were exploited to attenuate the light output power from the blue laser diode (LD) to simulate the long distance UWOC. The maximum estimated distances of 144 m and 117 m with corresponding BERs of 1.89 × 10-3 and 5.31 × 10-4 at data transmission rates of 500 bps and 2 Mbps were acquired in UWOC system using on-off keying (OOK) modulation scheme, respectively. Furthermore, we compared the differences between free-space and underwater channels, and a divergence angle of ~1.02 mrad was measured experimentally at a distance of 50 m in the free space. The long UWOC distances obtained in this study partly benefit from high sensitivity SPAD, the small laser divergence angle and low light attenuation. This study provides an approach to achieve long distance UWOC using SPAD.

Free space optical (FSO) communication technology has become increasingly advanced with capabilities of high speed, high capacity, and low power consumption. However, despite the great potential of FSO, its performance is limited in a turbulent atmosphere. Atmospheric turbulence causes scintillation in the FSO propagated signals, leading to an increase in the bit error rate (BER) performance of the recovered signals at the receiver. In this paper, we demonstrate that the use of deep learning (DL) detection methods could overcome these limitations. We present a new detection method of on-off keying (OOK) modulated signals by using different models of DL over different strength FSO turbulent channels, without the need for prior knowledge of the parameters of the channel. The demonstrated DL decoders improve the performance of the FSO turbulent channel and decrease the power consumption. Moreover, the demonstrated DL models also work faster than maximum likelihood (ML) methods with perfect channel estimation decoders, with even slightly better performance because of the turbulence, thus enabling realization of FSO over turbulent atmospheric channels.

This study investigates the performance of scintillation mitigation for linear polarization shift on-off keying (LPS-OOK) transmission in free-space optical (FSO) communications. Scintillation effect is a critical issue for FSO communication in vertical links. The LPS-OOK signal with orthogonal linear x- and y-polarizations for bits ‘1’ and ‘0’ is modulated and transmitted from the transmitter end. The bits ‘1’ and ‘0’ suffer the scintillation effect in turbulence channel. Based on the orthogonal polarization characteristics of LPS-OOK, linear polarizer (LP) is used to mitigate the scintillation effect on bit ‘0’ by blocking its polarization without the distortion of bit ‘1’. Further, owing to the nonlinear gain characteristics of logarithmic amplification, it is used to equalize the intensity fluctuation of bit ‘1’. Finally, the equalized LPS-OOK is distinguished using fixed threshold decision (FTD) instead of a complex symbol-by-symbol estimation of adaptive threshold. The performance of the proposed technique was verified experimentally for various degrees of the turbulence channel. A Mach–Zehnder modulator (MZM)-based turbulence channel simulator was adopted to accommodate turbulence-induced scintillation effect. The experimental results confirmed that the proposed technique that employed FTD has an improved bit-error-rate (BER) performance compared with that of OOK that employed an adaptive threshold decision (ATD) under various degrees of turbulence channels.

This letter presents the design of a 120-GHz wireless link. The link incorporates a 28-nm CMOS ON–OFF keying transceiver with on-chip antennas to launch the mm-wave signal into a flexible dielectric fiber. The flexible fiber is connected to a 3D-printed high-gain lens proposed to overcome the high free-space path loss to achieve a 15-dBm EIRP. The receiver consists of a low-noise amplifier with 24.9 dB of voltage gain and covers 42-GHz BW−3dB. An efficient self-mixing envelope detector demodulates the amplified signal back to baseband. Using the proposed flexible fiber and wireless topology, a data rate of 11 Gb/s is demonstrated and distance of 1 m is reached with a power consumption

Recent years have witnessed the conceptualization and development of light-to-camera communication (LCC). Various innovative modulation schemes are designed for throughput improvement. Nevertheless, the fundamental limits of LCC itself are still unknown from a theoretical perspective. In this paper, we present the LCC channel model to shed light on a question: how to improve the system performance under identical conditions of transmitting/receiving device and modulation scheme. We reveal the channel parameters of LCC that affect the formation of the signal layer and provide a design guideline for increasing the symbol rate. Moreover, we improve the demodulation performance by sampling judging points from the separated signal layer instead of detecting the widths of bands in capture images. To enhance the signal-to-noise ratio, we propose a short-time linear regression algorithm to filter out the noise from the signal layer. We build a hardware prototype with the simple ON-OFF keying to demonstrate the proposed channel model under various experiment settings. The results show that the system throughput reaches 8.2 kbps with a symbol rate of 25 kBd. We believe our techniques for symbol rate increasing and demodulation improvement can help other LCC systems improve their performance.

In the paper, we propose and design a ring-topology wavelength-division-multiplexing (WDM) access network for long-reach signal transmission. Here, the new central office (CO) and optical network unit (ONU) modules are designed to construct the ring-based architecture for symmetric data connection. Thus, the Rayleigh backscattering (RB) beat noise can be prevented due to the unidirectional downstream and upstream signal connections. In the demonstration, eight WDM wavelengths with 10 Gbit/s on-off keying (OOK) modulation are applied to serve as the symmetric downstream and upstream traffic through 105 km fiber connection without dispersion compensation. In addition, the minimum power budgets of 33.8, 36.1 and 35.4 dB among the eight WDM wavelengths can be obtained at the back-to-back (BtB), 51 and 105 km fiber links, respectively, under the forward error correction (FEC) target.

In latest years, the number of gadgets and apps relying on wireless communication hasexploded, resulting in major changes in people's lifestyles. To manage this increase inconnectivity, several advanced techniques are planned with 5G standards, while trying tominimize the negative impact of power consumption. Light-Fidelity (Li-Fi) technology, alsoreferred to as visible light communication (VLC), is an alternate solution to this problem. This isa novel visible light data transmission system that, like Wi-Fi, employs light-emitting diodes andlaser light sensors as a high-speed communication medium. In terms of wireless communication,Li-Fi outperforms Wi-Fi. It has a better capacity in terms of bandwidth in the visible area anddoes not cause radio frequency interference communications. It should also be mentioned that LiFi allows for user mobility and multi-user access. The combined infrared and visible lightspectrums are nearly 2600 times larger than the whole 300 GHz radio waves band.The primary goal of this thesis is to focus on the modulation of high frequency light toencode and transmit information with an interest in the security aspect in the case of computerattacks. Our contribution consists in proposing a new solution based on the differentenvironments in order to guarantee dependability of data processing and transmission in a contextof mobility and quality of service. The proposed architecture ensures the authenticity andconfidentiality of data transmitted through the light signal and can be implemented in differentsectors such as schools, airports and airplanes., Ces derniers temps, le nombre de gadgets et d'applications reposant sur la communicationsans fil a explosé, entraînant des transformations considérables dans le style de vie des gens.Pour gérer cette augmentation de connectivité, plusieurs techniques avancées sont prévues avec les normes 5G, tout en essayant de minimiser l’impact négatif de la consommation d’énergie.Une solution alternative pour surmonter ce problème est la technologie Light-Fidelity (Li-Fi) ou communication par lumière visible (VLC). Il s'agit d'un nouveau modèle de transmission de données en lumière visible qui utilise des diodes électroluminescentes et des capteurs de lumière laser comme moyen de communication à haut débit, similaire au Wi-Fi. Le Li-Fi est une meilleure alternative au Wi-Fi en matière de communication sans fil. Il a une plus grandecapacité en termes de bande passante dans la région visible et ne perturbe pas les communications qui utilisent la gamme de radiofréquences. On note aussi que le Li-Fi supporte la mobilité des utilisateurs et l'accès multi-utilisateurs. La taille du spectre infrarouge et de la lumière visible ensemble équivaut à approximativement 2600 fois la taille de l'ensemble du spectre de fréquence radio de 300 GHz.L’objectif de cette thèse est centré sur la modulation de lumière à haute fréquence pourencoder et envoyer des informations en s’intéressant à l’aspect sécurité dans le cas des attaques informatiques. Notre contribution consiste à proposer une nouvelle solution basée sur les différents environnements afin d’assurer une fiabilité de traitements et de transmissions des données dans un contexte de mobilité et de qualité de service. L’architecture proposée assure l’authenticité et la confidentialité des données transmises à travers le signal lumineux et peut-être mise en œuvre dans différents secteurs telle que les écoles, les aéroports et les avions.