Transmission Strategy for Simultaneous Wireless Information and Power Transfer with a Non-Linear Rectifier Model

Most studies determining data rate or power conversion efficiency (PCE) of simultaneous wireless information and power transfer (SWIPT) focus on ideal models for the non-linear energy harvester, or focus on simplified waveforms that carry no information. In this paper, we study SWIPT using realistic waveforms and a measurement-based energy harvesting model. For a special class of multisine waveforms carrying only information in the phase, we analyze PCE as a function of waveform design, including the impact of pre-equalization to mitigate wireless channel distortion. A balanced pre-equalizer that trades off between the peak-to-average power ratio (PAPR) and signal to noise ratio, maximizing the total PCE is proposed. The impact on the information rate of the analyzed waveforms is also presented. The results show that balanced pre-equalizers can improve the total PCE more than three times within 5% rate loss compared to the pre-equalizer that solely maximizes the signal PAPR or the capacity using the same transmit power. We also show that the maximum normalized PCE is increased by a factor of two by only allowing phase modulation to ensure the PAPR of one symbol, compared to traditional modulation schemes that carry information in both phase and amplitude to maximize spectral efficiency.

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MEASUREMENTSBASEDEVALUATION OF PATHLOSSEXPONENTS IN URBAN OUTDOORENVIRONMENTS

International Journal of Advanced Research ◽

10.21474/ijar01/12556 ◽

2021 ◽

Vol 9 (03) ◽

pp. 72-79

Author(s):

Akohoule Alex ◽

◽

Bamba Aliou ◽

Kamagate Aladji ◽

Konate Adama ◽

...

Keyword(s):

Mobile Networks ◽

Average Power ◽

Path Loss ◽

Wireless Channel ◽

Propagation Model ◽

Strong Impact ◽

Efficient Design ◽

Path Loss Exponent ◽

Outdoor Environments ◽

The Impact

In wireless networks, propagation models are used to assess the received power signal and estimate the propagation channel. These models depend on the pathloss exponent (PLE) which is one of the main parameters to characterize the propagation environment. Indeed, in the wireless channel, the path loss exponent has a strong impact on the quality of the links and must therefore be estimated with precision for an efficient design and operation of the wireless network. This paper addresses the issue of path loss exponents estimation for mobile networks in four outdoor environments. This study is based on measurements carried out in four outdoor environments at the frequency of 2600 MHz within a bandwidth of 70 MHz. It evaluates the path loss exponent, and the impact of obstacles present in the environments. The parameters of the propagation model determined from the measurements show that the average power of the received signal decreases logarithmically with the distance. We obtained path loss exponents values of 4.8, 3.53, 3.6 and 3.99 for the site 1, site 2, site 3 and site 4, respectively. Clearly the density of the obstacles has an impact on the path loss exponents and our study shows that the received signal decrease faster as the transmitter and receiver separation in the dense environments.

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Parametric Analysis of Self-Phase Modulation in Single-Tone RoF System

Journal of Optical Communications ◽

10.1515/joc-2018-0101 ◽

2018 ◽

Vol 0 (0) ◽

Author(s):

Namita Kathpal ◽

Amit Kumar Garg

Keyword(s):

Phase Modulation ◽

Parametric Analysis ◽

Effective Area ◽

Fiber System ◽

Long Distance ◽

Single Tone ◽

Self Phase Modulation ◽

Linear Effect ◽

Non Linear ◽

The Impact

Abstract Self-phase modulation (SPM) is one of the major non-linear effect in single-tone radio over fiber system which limits the long-distance transmission as it leads to the broadening of pulse spectrum. In this paper, the mathematical and parametric analysis was carried out to understand the origination and upgradation of SPM and based on results achieved, a rigorous evaluation has been conducted to decrease the impact of SPM. The effect of SPM has been evaluated in terms of optical spectrums, eye diagrams, eye-opening and Q-factor by utilizing four important parameters specifically launched power, fiber effective area, bit rate and fiber attenuation using OptiSystem simulator which reveals insight information for the elimination of non-linear effects.

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Anti-Jamming Performance Simulation of PN-LFM Combined Ranging System

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.462-463.159 ◽

2013 ◽

Vol 462-463 ◽

pp. 159-164

Author(s):

Zhe Feng Ding

Keyword(s):

Phase Modulation ◽

Cross Correlation ◽

Detection System ◽

Average Power ◽

Performance Simulation ◽

Random Code ◽

Range Resolution ◽

Phase Code ◽

Fractal Noise ◽

The Impact

The pseudo-random binary-phase code phase modulation and linear frequency modulation (PN-LFM) combined ranging system is a new detection system, which has proven to be powerful capacity in range resolution, velocity resolution and maximum range measurable without ambiguity. In this paper, we study the anti-jamming performance of the new ranging system, especially in the fractal stochastic noise environments. We analyze the impact mechanism of fractal noise on the PN-LFM detection system, and simulate the output of correlating detection. The cross correlation function, power spectrum function and average power of pseudo random signal and fractal noise are deduced, compared with the impact of white noise on the pseudo code detection system. Simulation shows that PN-LFM combined ranging system possess powerful anti-jamming capacity, and performs better in the fractal noise environment than Pseudo random code phase modulation system.

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Waveform Impact on Wireless Power Transfer Efficiency using Low-Power Harvesting Devices

Electrical Control and Communication Engineering ◽

10.2478/ecce-2019-0013 ◽

2019 ◽

Vol 15 (2) ◽

pp. 96-103 ◽

Cited By ~ 1

Author(s):

Janis Eidaks ◽

Anna Litvinenko ◽

Arturs Aboltins ◽

Dmitrijs Pikulins

Keyword(s):

Low Power ◽

Conversion Efficiency ◽

Average Power ◽

Wireless Power Transfer ◽

Directional Antennas ◽

Power Transfer ◽

Wireless Power ◽

Power Harvesting ◽

The Impact ◽

Multicarrier Signals

AbstractThe paper addresses the impact of peak-to-average power ratio (PAPR) and spectrum of the waveform, as well as load resistance on the performance of low-power harvesting device in a real-life wireless power transfer (WPT) scenario. In the current study, a combination of the classic voltage doubler circuit for RFDC conversion and premanufactured device for DC-DC conversion is used. For the investigation of conversion efficiency and harvesting device performance, three types of waveforms are used: single tone, multicarrier signals with low PAPR and multicarrier signal with high PAPR. In order to generate high-PAPR signal, subcarriers with the same amplitude and phase are summed, whereas for generation of low PAPR signal the phases of the subcarriers are chosen pseudo-randomly. Over-the-air transmission in 865 MHz ISM band is made using directional antennas and all multicarrier waveforms have equal 5 MHz bandwidth. To evaluate the performance of harvesting device and conversion efficiency, the average voltages at the input and output of the RF-DC converter as well as at the output of the DC-DC converter with corresponding input and load impedance are measured. The experiments have shown that the employed multicarrier signals can greatly improve the performance of harvesting device during WPT under certain conditions, which are discussed in the paper.

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Machine Learning Based Device Simulation Using Multi-variable Non-linear Regression to Assess the Impact of Device Parameter Variability on Threshold Voltage of Double Gate-All-Around (DGAA) MOSFET

2020 IEEE 2nd International Conference on Circuits and Systems (ICCS) ◽

10.1109/iccs51219.2020.9336608 ◽

2020 ◽

Author(s):

Sandeep Moparthi ◽

Chandan Yadav ◽

Gopi Krishna Saramekala ◽

Pramod Kumar Tiwari

Keyword(s):

Machine Learning ◽

Linear Regression ◽

Threshold Voltage ◽

Device Simulation ◽

Double Gate ◽

Device Parameter ◽

Non Linear ◽

The Impact

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Non-Parametric Generalized Additive Models as a Tool for Evaluating Policy Interventions

Mathematics ◽

10.3390/math9040299 ◽

2021 ◽

Vol 9 (4) ◽

pp. 299

Author(s):

Jaime Pinilla ◽

Miguel Negrín

Keyword(s):

Linear Regression ◽

Regression Models ◽

Linear Trend ◽

Generalized Additive Models ◽

Additive Models ◽

Linear Regression Models ◽

Non Linear ◽

Nonlinear Trends ◽

The Impact ◽

Non Parametric

The interrupted time series analysis is a quasi-experimental design used to evaluate the effectiveness of an intervention. Segmented linear regression models have been the most used models to carry out this analysis. However, they assume a linear trend that may not be appropriate in many situations. In this paper, we show how generalized additive models (GAMs), a non-parametric regression-based method, can be useful to accommodate nonlinear trends. An analysis with simulated data is carried out to assess the performance of both models. Data were simulated from linear and non-linear (quadratic and cubic) functions. The results of this analysis show how GAMs improve on segmented linear regression models when the trend is non-linear, but they also show a good performance when the trend is linear. A real-life application where the impact of the 2012 Spanish cost-sharing reforms on pharmaceutical prescription is also analyzed. Seasonality and an indicator variable for the stockpiling effect are included as explanatory variables. The segmented linear regression model shows good fit of the data. However, the GAM concludes that the hypothesis of linear trend is rejected. The estimated level shift is similar for both models but the cumulative absolute effect on the number of prescriptions is lower in GAM.

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Does agricultural intensification cause tipping points in ecosystem services?

Landscape Ecology ◽

10.1007/s10980-021-01321-8 ◽

2021 ◽

Author(s):

Stephen C. L. Watson ◽

Adrian C. Newton ◽

Lucy E. Ridding ◽

Paul M. Evans ◽

Steven Brand ◽

...

Keyword(s):

Ecosystem Services ◽

Agricultural Intensification ◽

Spatial Dynamics ◽

Policy Option ◽

List Type ◽

Tipping Points ◽

Software Models ◽

Non Linear ◽

Study Interval ◽

The Impact

Abstract Context Agricultural intensification is being widely pursued as a policy option to improve food security and human development. Yet, there is a need to understand the impact of agricultural intensification on the provision of multiple ecosystem services, and to evaluate the possible occurrence of tipping points. Objectives To quantify and assess the long-term spatial dynamics of ecosystem service (ES) provision in a landscape undergoing agricultural intensification at four time points 1930, 1950, 1980 and 2015. Determine if thresholds or tipping points in ES provision may have occurred and if there are any detectable impacts on economic development and employment. Methods We used the InVEST suite of software models together with a time series of historical land cover maps and an Input–Output model to evaluate these dynamics over an 85-year period in the county of Dorset, southern England. Results Results indicated that trends in ES were often non-linear, highlighting the potential for abrupt changes in ES provision to occur in response to slight changes in underlying drivers. Despite the fluctuations in provision of different ES, overall economic activity increased almost linearly during the study interval, in line with the increase in agricultural productivity. Conclusions Such non-linear thresholds in ES will need to be avoided in the future by approaches aiming to deliver sustainable agricultural intensification. A number of positive feedback mechanisms are identified that suggest these thresholds could be considered as tipping points. However, further research into these feedbacks is required to fully determine the occurrence of tipping points in agricultural systems.

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Interphotoreceptor coupling: an evolutionary perspective

Pflügers Archiv - European Journal of Physiology ◽

10.1007/s00424-021-02572-9 ◽

2021 ◽

Author(s):

Lorenzo Cangiano ◽

Sabrina Asteriti

Keyword(s):

Visual Information ◽

Signal To Noise Ratio ◽

Electrical Coupling ◽

Physiological Role ◽

Cellular Processes ◽

Contact Points ◽

Highly Sensitive ◽

The Many ◽

The Impact

AbstractIn the vertebrate retina, signals generated by cones of different spectral preference and by highly sensitive rod photoreceptors interact at various levels to extract salient visual information. The first opportunity for such interaction is offered by electrical coupling of the photoreceptors themselves, which is mediated by gap junctions located at the contact points of specialised cellular processes: synaptic terminals, telodendria and radial fins. Here, we examine the evolutionary pressures for and against interphotoreceptor coupling, which are likely to have shaped how coupling is deployed in different species. The impact of coupling on signal to noise ratio, spatial acuity, contrast sensitivity, absolute and increment threshold, retinal signal flow and colour discrimination is discussed while emphasising available data from a variety of vertebrate models spanning from lampreys to primates. We highlight the many gaps in our knowledge, persisting discrepancies in the literature, as well as some major unanswered questions on the actual extent and physiological role of cone-cone, rod-cone and rod-rod communication. Lastly, we point toward limited but intriguing evidence suggestive of the ancestral form of coupling among ciliary photoreceptors.

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The Improvement on the Performance of DMD Hadamard Transform Near-Infrared Spectrometer by Double Filter Strategy and a New Hadamard Mask

Micromachines ◽

10.3390/mi10020149 ◽

2019 ◽

Vol 10 (2) ◽

pp. 149 ◽

Cited By ~ 1

Author(s):

Zifeng Lu ◽

Jinghang Zhang ◽

Hua Liu ◽

Jialin Xu ◽

Jinhuan Li

Keyword(s):

Near Infrared ◽

Signal To Noise Ratio ◽

Nonuniform Distribution ◽

Stray Light ◽

Spectral Energy ◽

Hadamard Transform ◽

Digital Micromirror Device ◽

Infrared Spectrometer ◽

Near Infrared Spectrometer ◽

The Impact

In the Hadamard transform (HT) near-infrared (NIR) spectrometer, there are defects that can create a nonuniform distribution of spectral energy, significantly influencing the absorbance of the whole spectrum, generating stray light, and making the signal-to-noise ratio (SNR) of the spectrum inconsistent. To address this issue and improve the performance of the digital micromirror device (DMD) Hadamard transform near-infrared spectrometer, a split waveband scan mode is proposed to mitigate the impact of the stray light, and a new Hadamard mask of variable-width stripes is put forward to improve the SNR of the spectrometer. The results of the simulations and experiments indicate that by the new scan mode and Hadamard mask, the influence of stray light is restrained and reduced. In addition, the SNR of the spectrometer also is increased.

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