Total Signal Power Research Articles

High speed broadband light spatial laser system with hybrid linear/parabolic/measured indexed multimode optical fibers performance signature

Abstract This work clarified various multimode fiber configurations with spatial continuous wave lasers based different coding configurations for high speed fiber systems. The optimum lighted power form after linear index multimode fibers versus spectral wavelength is clarified. The optimum lighted form power after parabolic index multimode fibers versus spectral wavelength is demonstrated. The max lighted form power after measured index multimode fibers versus spectral wavelength is illustrated. Optimum lighted form signal power variations after linear index multimode fibers versus time are demonstrated. The max optimum form signal band form power after parabolic index multimode fibers versus time is indicated. The max optimum lighted signal power after measured index multimode fibers versus time is clarified. Total lighted signal power form after linear index multimode fibers is demonstrated. The total lighted signal power form after parabolic index multimode fibers is clarified. Total lighted power signal form after measured index multimode fibers is clarified. Max optimum signal electrical power form amplitude after PIN photodetector based various index multimode fibers is simulated and studied. Total lighted base form power against MMF length for different proposed optical multimode fibers is studied. Signal base band per noise form ratio against MMF length for different base proposed band optical multimode fibers is demonstrated. Total signal form electrical band power against MMF length for different proposed optical multimode fibers is observed. Max Q base band factor form against MMF length for different base band proposed lighted multimode fibers is clarified.

Deep-Learning-Enabled Direct Detection With Reduced Computational Complexity and High Electrical-Spectral-Efficiency

Complex-valued double-sideband (CV-DSB) direct detection (DD) is a promising solution for high capacity and cost-sensitive data center interconnects, since it can reconstruct the optical field as a homodyne coherent receiver while does not require a costly local oscillator laser. In a carrier-assisted CV-DSB DD system, the carrier occupies a large proportion of the total optical signal power but bears no information. Reducing the carrier to signal power ratio (CSPR) can improve the information-bearing signal power and thus maximize the achievable system performance. Recently, we have proposed and demonstrated a deep-learning-enabled DD (DLEDD) scheme to reconstruct the full-field of the CV-DSB signal. In the DLEDD scheme, the optical CV-DSB signal was detected by a dispersion-diversity receiver and then recovered by a deep convolutional neural network (CNN). Nevertheless, the computational complexity of the deep CNN is the main obstacle to the application of the DLEDD scheme. In this paper, we demonstrate a 50-GBaud CV-DSB 32-ary quadrature amplitude modulation (32-QAM) signal transmission over 80-km single-mode fiber with ∼64% computational-budget reduction in the field reconstruction. This is achieved by using 1×1 convolutions to attain a sparse dimensionality (in particular the number of channels) of the deep CNN. To the best of our knowledge, we achieve the highest electrical spectral efficiency of 7.07 b/s/Hz per polarization per wavelength for a CV-DSB DD receiver without requiring a sharp-roll-off optical filter.

Extended L-band 4-Core Er/Yb co-doped fiber amplifier based on 1018 nm cladding pumping.

The extended L-band 4-core Er/Yb co-doped fiber and amplifier (MC-EYDFA) is first proposed and demonstrated, to the best of our knowledge, for space division multiplexing combined with wavelength division multiplexing application. The fiber core co-doped with Er/Yb/P is adopted for bandwidth expansion, and the long wavelength extends to 1625 nm. Numerical simulations further show that efficient amplification and higher saturation power are achieved with the 1018 nm cladding pumping. Based on the integrated 4-core fiber amplifier, an average gain of ∼22 dB covering 1575-1625 nm is experimentally obtained with a 4 W pump power and a 3 dBm total signal power, and the max core-dependent gain (CDG) variation is measured to be 1.7 dB.

Constant Power Psychoacoustic Spectrum Optimization for Loudness and Sharpness with Application to Vehicle Interiors

<div>Sound quality assessments are an integral part of vehicle design. Especially now, as manufacturers move towards electrification, vehicle sounds are fundamentally changing. By improving the quality of the interior sounds of a vehicle, consumers’ subjective evaluation of it can be increased. Therefore, the field of psychoacoustics, which is the study of human perception of sound, is broadly applicable here. In fact, the perceived quality of a sound signal is influenced by several psychoacoustic indicators, including loudness, sharpness, and roughness. Of particular utility is identifying in advance how to distribute audible frequency content in a way that optimizes psychoacoustic metrics as this can help automotive engineers obtain specific design targets that optimize vehicle noise, vibration, and harshness (NVH).</div> <div>In this article, a novel modified gradient-based optimization technique (MGOT) is developed to optimize psychoacoustic loudness and sharpness. The new technique is applied to identify targeted adjustments to a measured vehicle interior sound signal that keep the signal energy constant but reduce loudness and/or sharpness. The MGOT numerically approximates the objective function gradient for small changes in the signal power distribution for which constant overall signal power is maintained. These gradient calculations identify power spectrum one-third octave band trades that minimize a sound signal metric that is a weighted sum of loudness and sharpness while conserving the total signal power. A trade consists of a reduction of power content from a one-third octave band designated as a source together with a simultaneous addition of that power to another receiver one-third octave band. In the MGOT, a one-third octave band that is at any time identified as a source can never later become a receiver of power. The MGOT results and execution times are compared with two widely available general-purpose optimization routines (a standard gradient-based optimizer and a “genetic,” non-gradient optimizer) are used to achieve identical optimization objectives. In comparison to existing optimization techniques, MGOT is found to identify spectrum modifications that produce a superior minimization of the objective function for comparable or even reduced execution times. The resultant sound spectrum modifications can guide vehicle structural or calibration design recommendations that realize a preferred frequency distribution for enhancing the vehicle driving experience.</div>

PERFORMING AN ANALYSIS OF ARRAY WAVEGUIDE (AWG) MULTIPLEXER BASED ON AN OPTICAL NETWORK

Rapid advances in optical technology have created potential solutions for enabling high capacity networks. The main problem in optical communication in the Ministry of Communication at the Republic of Iraq is dedicating a small bandwidth for each user. Most of the previous works have focused on modifying the characteristics of Array Waveguide Multiplexer (AWG) in the designing level. However, designing of optical communication is expensive which makes these efforts unpractically. Therefore, to develop multi-target communication over the current infrastructure, this paper investigates the performance of the AWG at the components level. In the beginning, an analysis is performed of an AWG at data rates of (8×40Gb/s, over 242.5km fiber optic link) with minimum system impairments. The presence of (Passive/Active) components is taken into considerations. The evaluation is performed using Optisystem software simulation package. By adopting (4.0402dBm) total input signal power, the simulation has achieved (0.3545dBm) total output signal power, (-3.6856dbm) total gain, (1.4248dBm) total output noise, and the average power is (-6.4255dBm). Furthermore, the transmission rates are successfully transmitted delivered in a low-cost infrastructure. Moreover, with the presence of multiple users on a single link, the transmission is performed with a high rapidity in addition to a minimum error. Consequently, the simulations can be applied to the existing fiber communication networks with ultimate reduction of the cost and operational expenditure for the overall network system.

Nonlinear wavelength conversion cross phase modulation in fiber systems based on directly modulated laser measured

Abstract This study has clarified the simulation of the nonlinear cross phase modulation (CPM) performance signature in optical fiber telecommunication systems. We have been clarified the max Q factor in relation to Cross phase shift modulation for the previous models and proposed model. The optimum optical power varied with spectral time and wavelength variation that is simulated for 90° cross phase shift modulation. Optimum total optical and electrical signal power is demonstrated for 90° Cross phase shift modulation. The max signal quality factor and min BER are assured for various degrees based on cross phase shift modulation. In addition to the optimum signal quality factor is emphasized for 90° Cross phase shift modulation.

High-efficiency cladding-pumped 4-core erbium-doped fiber with a pedestal for space division multiplexing amplification.

A cladding-pumped 4-core erbium-doped fiber (4C-EDF) with a pedestal structure has been firstly, to the best of our knowledge, proposed and fabricated for space division multiplexing (SDM) amplification. The numerical simulation shows that the index-raised pedestal around the fiber core can improve power conversion efficiency (PCE) by enhancing pump power usage. Compared with conventional 4C-EDF, the 4C-EDF with a pedestal has a gain improvement of 4.5 dB and a PCE enhancement of 91.8%, according to the experimental results (pedestal fiber: 9.55%, conventional fiber: 4.98%). For a 6 dBm total input signal power at L-band and a 7.8 W pump power at 976 nm, the pedestal 4C-EDF shows an average gain of 25 dB and an average noise figure (NF) of 6.5 dB over all cores in the wavelength range of 1570.41 nm to 1610.87 nm. The core-to-core gain variation is less than 2 dB.

Lightweight and Robust Chatter Detection Algorithms for Milling

Most machining processes suffer from self-excited chatter vibrations that destroy the work surface and affect machine tool’s health. Therefore, accurate and timely detection of chatter vibrations is critical for productivity and longevity of the manufacturing equipment. This paper presents two different chatter detection algorithms for milling process by monitoring power spectrum of the vibration signal measured on the machine. Firstly, a real-time suitable computationally efficient approach is presented, which computes total spectral power of the vibration signal using time-domain variance operator and forced vibration power using moving Fourier transform. Power spectrum of chatter vibration is then evaluated by deducting the forced vibration component from the total signal power. The second method is based on Principal Component Analysis (PCA), which extracts the dominant harmonics of the measured vibration signal. Forced and chatter vibration harmonics are then clustered and labeled to evaluate the forced and chatter vibration powers based on their eigenvectors and eigenvalue magnitudes. For both methods, the power ratio (PR) is used to detect chatter. Once PR exceeds 0.5, chatter starts to dominate whole process, and it is detected. Both algorithms are experimentally tested in machining flexible workpieces. Results show that although both methods perform well on detecting chatter timely, computationally efficient algorithm gives false alarms for flexible workpiece while PCA based algorithm provides more robust chatter detection.

Effects of Central and Peripheral Fatigue on Impact Characteristics during Running.

Fatigue and impact can represent an injury risk factor during running. The objective of this study was to compare the impact transmission along the locomotor system between the central and peripheral fatigued states during running. Tibial and head acceleration as well as shock attenuation in the time- and frequency-domain were analyzed during 2-min of treadmill running in the pre- and post-fatigue state in eighteen male popular runners (N = 18). The impact transmission was measured before and after a 30-min central fatigue protocol on the treadmill or a peripheral fatigue protocol in the quadricep and hamstring muscles using an isokinetic dynamometer. The time-domain acceleration variables were not modified either by peripheral or central fatigue (p > 0.05). Nevertheless, central fatigue increased the maximum (p = 0.006) and total (p = 0.007) signal power magnitude in the high-frequency range in the tibia, and the attenuation variable in the low- (p = 0.048) and high-frequency area (p = 0.000), while peripheral fatigue did not cause any modifications in the frequency-domain variables (p > 0.05). Furthermore, the attenuation in the low (p = 0.000)- and high-frequency area was higher with central fatigue than peripheral fatigue (p = 0.003). The results demonstrate that central fatigue increases the severity of impact during running as well as the attenuation of low and high components.

Deep-learning-enabled high-performance full-field direct detection with dispersion diversity.

Data center interconnects require cost-effective photonic integrated optical transceivers to meet the ever-increasing capacity demands. Compared with a coherent transmission system, a complex-valued double-sideband (CV-DSB) direct detection (DD) system can minimize the cost of the photonic circuit, since it replaces two stable narrow-linewidth lasers with only a low-cost un-cooled laser in the transmitter while maintaining a similar spectral efficiency. In the carrier-assisted DD system, the carrier power accounts for a large proportion of the total optical signal power. Reducing the carrier to signal power ratio (CSPR) can improve the information-bearing signal power and thus the achievable system performance. To date, the minimum required CSPR is ∼7 dB for all the reported CV-DSB DD systems having electrical bandwidths of approximately half of baud rates. In this paper, we propose a deep-learning-enabled DD (DLEDD) scheme to recover the full optical field of the transmitted signal at a low CSPR of 2 dB in experiment. Our proposal is based on a dispersion-diversity receiver with an electrical bandwidth of ∼61.0% baud rate and a high tolerance to laser wavelength drift. A deep convolutional neural network enables accurate signal recovery in the presence of a strong signal-signal beat interference. Compared with the conventional method, the proposed DLEDD scheme can reduce the optimum CSPR by ∼8 dB, leading to a significant signal-to-noise ratio improvement of ∼5.8 dB according to simulation results. We experimentally demonstrate the optical field reconstruction for a 28-GBaud 16-ary quadrature amplitude modulation signal after 80-km single-mode fiber transmission based on the proposed DLEDD scheme with a 2-dB optimum CSPR. The results show that the proposed DLEDD scheme could offer a high-performance solution for cost-sensitive applications such as data center interconnects, metro networks, and mobile fronthaul systems.

Cascaded stages of parametric optical fiber amplifiers with Raman fiber amplifiers for upgrading of telecommunication networks through optical wireless communication channel

Abstract This paper contains a main model which concludes a two optical fiber cable along 70 km and with Parametric/Raman amplifiers with a result of total power 0.781 dBm that computed by the optical power meter which is located before the receiver part and the second optical fiber channel, a total power −44.186 dBm at the end of model which is computed by the electrical power meter visualizer, and a max. Q factor 2.548 computed by the BER analyzer. The suggested model has outlined some updates on the previous model to improve the results so that the results are increased at the same length as the following: total power of optical signal becomes 10.039 dBm, total power of electrical signal becomes 0.624 dBm, and the max. Q factor becomes 9.60787.

One Wire Is always Better

The efficiency of transmitting electrical energy from tree phase source is very complicated and expensive. In the same time, it is known that active electrical energy is transmitted from a source to a load and does not come back to the source. If this is so, then why in all electrical devices and systems for transmission of electricity, one uses more than one wire? “It is shown that any electrical system can be made using a one-wire method”. The main results were received by several inventions that allow to change three wires line to one wire. The important contribution of the work is refinement calculation of the total power of a three-phase signal. It is showed that in proposed one wire system, the wire transmits a power more than in each wire in three-phase system. The cost of the electrical energy transmitting system can be reduced, also can be improved and the use of the renewable electrical energy can be sped up.

Parameter estimation with a spinning multimode waveform model

Gravitational waves from compact binary coalescence sources can be decomposed into spherical-harmonic multipoles, the dominant being the quadrupole ($\ell=2, m=\pm2$) modes. The contribution of sub-dominant modes towards total signal power increases with increasing binary mass ratio and source inclination to the detector. It is well-known that in these cases neglecting higher modes could lead to measurement biases, but these have not yet been quantified with a higher-mode model that includes spin effects. In this study, we use the multi-mode aligned-spin phenomenological waveform model IMRPhenomHM to investigate the effects of including multi-mode content in estimating source parameters and contrast the results with using a quadrupole-only model (IMRPhenomD). We use as sources IMRPhenomHM and hybrid EOB-NR waveforms over a range of mass-ratio and inclination combinations, and recover the parameters with IMRPhenomHM and IMRPhenomD. These allow us to quantify the accuracy of parameter measurements using a multi-mode model, the biases incurred when using a quadrupole-only model to recover full (multi-mode) signals, and the systematic errors in the IMRPhenomHM model. We see that the parameters recovered by multi-mode templates are more precise for all non-zero inclinations as compared to quadrupole templates. For multi-mode injections, IMRPhenomD recovers biased parameters for non-zero inclinations with lower likelihood while IMRPhenomHM recovered parameters are accurate for most cases, and if a bias exists, it can be explained as a combined effect of observational priors and (in the case of hybrid-NR signals) waveform inaccuracies. For cases where IMRPhenomHM recovers biased parameters, the bias is always smaller than the corresponding IMRPhenomD recovery, and we conclude that IMRPhenomHM will be sufficiently accurate to allow unbiased measurements for most GW observations.

ВПЛИВ ФОТОСТИМУЛЯЦІЇ НА ФУНКЦІОНАЛЬНИЙ СТАН ГОЛОВНОГО МОЗКУ ЛЮДИНИ

The study found that during the test with photostimulation, both in the presence of the phenomenon of reproduction of the rhythm of light flicker, and in its absence, the brain shows a pronounced reaction, as evidenced by significant changes in total bioelectric signal power in the cerebral hemispheres (CH). In the absence of the reaction of assimilation of the rhythm of light flicker in the subjects in most cases there is a decrease in the total signal strength in the CH. In the presence of a reaction of assimilation of the rhythm of light flicker, when the EEG visually observes oscillations that coincide with the frequency of the stimulus, the total signal strength in the hemispheres can both increase and decrease. At the same time, the largest increase in signal strength of individual rhythms during photostimulation is not always observed at the stimulation frequency. The results of the study suggest that the phenomenon of brain reproduction of the rhythm of light flicker observed on the EEG during photostimulation, and a decrease or increase in the total power of the bioelectric signal in the CH, are different physiological phenomena. This may mean that the absence of a response to the assimilation of the rhythm of light flicker during photostimulation is a more physiological response of the brain to the stimulus than the presence of such a reaction. This conclusion gives reason to believe that the presence of assimilation of the rhythm of light flicker at any of the frequencies during the test with photostimulation, and even more so, the presence of the 2nd and 3rd harmonics, is a manifestation of brain pathology. This approach to the evaluation of the sample with photostimulation correlates with the results of the test "with the eye open", which is also used to determine the reactivity of the human brain by exposure to the visual analyzer.

Energy-Efficient and Low-Latency Massive SIMO Using Noncoherent ML Detection for Industrial IoT Communications

To enable ultrareliable low-latency wireless communications required in the Industrial Internet of Things, in this paper we develop an energy-based modulation [i.e., non-negative pulse amplitude modulation (PAM)] constellation design framework for noncoherent detection in massive single-input multiple-output (SIMO) systems. We consider that one single-antenna transmitter communicates to a receiver with a large number of antennas over a Rayleigh fading channel, and the receiver decodes the transmitted information at the end of every symbol. For such an SIMO system with non-negative PAM modulation, we first propose a fast noncoherent maximum-likelihood decoding algorithm and derive a closed-form expression of its symbol error probability (SEP). We then enhance the system energy efficiency by finding the optimal PAM constellation that minimizes the exact SEP subject to a total signal power constraint for such a system with an arbitrary number of receiver antennas, signal-to-noise ratio (SNR), and constellation size. Furthermore, the closed-form upper and lower bounds on the optimal SEP are derived. Based on these bounds, the exact expression for coding gain of the dominant term of the SEP is presented for such an optimal massive SIMO system. We also present an asymptotic SEP expression at a high SNR regime and the approximate diversity gain of the system. Simulation results for the proposed optimal PAM constellation validate the theoretical analysis, and show that our presented optimal constellation attains significant performance gains over the currently available minimum-distance-based constellation systems.

On the LoRa Modulation for IoT: Waveform Properties and Spectral Analysis

An important modulation technique for Internet of Things (IoT) is the one proposed by the LoRa allianceTM. In this paper we analyze the M-ary LoRa modulation in the time and frequency domains. First, we provide the signal description in the time domain, and show that LoRa is a memoryless continuous phase modulation. The cross-correlation between the transmitted waveforms is determined, proving that LoRa can be considered approximately an orthogonal modulation only for large M. Then, we investigate the spectral characteristics of the signal modulated by random data, obtaining a closed-form expression of the spectrum in terms of Fresnel functions. Quite surprisingly, we found that LoRa has both continuous and discrete spectra, with the discrete spectrum containing exactly a fraction 1/M of the total signal power.

266.1-Tbit/s Transmission Over 90.4-km 6-Mode Fiber With Inline Dual C+L-Band 6-Mode EDFA

We demonstrate a 6-mode and 580-wavelength multiplexed transmission with an inline C+L-band 6-mode erbium-doped fiber amplifier (6M-EDFA). This is the first demonstration of amplified transmission with a C+L-band few-mode EDFA. The 6M-EDFA is designed with an extremely wide erbium-doping profile to cover all spatial modes with population inversion uniformly, thus, suppressing differential modal gain within 5.6 dB in both C-band (1535-1563 nm) and L-band (1574-1602 nm) for the total input signal power of +3 dBm. As a transmission line, we use an 11.3-km 6-mode 19-core fiber and connect eight cores of the fiber to emulate transmission fiber spans. Although the transmission line includes additional losses of fan-in/fan-out devices for the connection between cores, transmission over 90.4 km is successfully demonstrated. The total capacity and spectral efficiency reach 266.1 Tb/s and 36.7 bit/s/Hz, respectively.

Energy minimizing associate fractal functions

The object of this paper is twofold. First, a basic question on fractal function from the perspective of numerical analysis, namely, how to evaluate a Fractal Interpolation Function (FIF) at a prescribed point is addressed by an appeal to a series expansion for FIF. Second is related to the notion of $$\alpha $$ -fractal function, which we call associate fractal function, in the field of fractal approximation. We provide strategies for effective choices of scaling parameters in the associated fractal function. To this end, we minimize some functionals, such as square integral, which represents the total energy or power of a continuous-time signal and Holladay functional, which approximates the total bending energy.

Analyzing the robustness of an array of wireless access points to mobile jammers

We present an approach for measuring the vulnerability of a wireless network. Our metric, n-Robustness, measures the change in a network’s total signal strength resulting from the optimal placement of n jammers by an attacker. Toward this end, we develop a multi-period mixed-integer programming interdiction model that determines the movement of n jammers over a time horizon so as to minimize the total signal strength of users during a sustained jamming attack. We compared several solution approaches for solving our model including a Lagrangian relaxation heuristic, a genetic algorithm, and a stage decomposition heuristic. We tested our approach on a wireless trace dataset developed as part of the Wireless Topology Discovery project at the University of California San Diego. We found that the Lagrangian approach, which performed best overall, finds a close-to-optimal solution while requiring much less time than solving the MIP directly. We then illustrate the behavior of our model on a small example taken from the dataset as well as a set of experiments. Through our experiments we conclude that the total signal power follows a sigmoid curve as we increase the number of jammers and access points. We also found that increasing access points only improves network robustness initially; after that the benefit levels off. In addition, we found that the problem instances we considered have an n-Robustness of between 39 and 69%, indicating that the value of the model parameters (e.g., number of jammers, number of time periods) has an effect on robustness.

176-21: Divergent patterns of atrial ECG organization during catheter ablation of persistent atrial fibrillation revealed by adaptive harmonic frequency schemes

Introduction: We hypothesized that organization indices based on the analysis of atrial ECG harmonic components may help identify patients (pts) with persistent AF (pAF) unresponsive to pulmonary vein isolation (PVI) and left atrial (LA) ablation. Using adaptive harmonic frequency tracking schemes, we computed on the atrial ECG: 1) the variance of the phase difference (aPD) between the dominant frequency (DF) and the 1st harmonic (H1), and 2) the organization index (AOI) defined as the ratio of the power of the DF and H1 over the total power of the unprocessed atrial signal as measures of AF regularity. Methods: In 34 consecutive pts (61±7 y, pAF duration: 19±11 m), PVI and LA ablation were performed until AF termination. 40-sec ECG time series devoid of QRST were recorded at baseline (BL), after PVI (end_PVI) and at the end of LA ablation (end_ABL). APD and AOI were estimated on leads V1 and V6b (placed on the pts back). Results: pAF was terminated within the LA in 68% (23/34 LT - left terminated) of the pts, while 32% (11/34 NLT - not left terminated) did not. The figure shows that: 1) LT pts displayed higher AOI values at BL indicative of greater atrial ECG organization that increased significantly (p<0.05 for V1 and V6b) during LA ablation as opposed to NLT pts, and 2) NLT pts displayed higher APD values at BL indicative of greater atrial ECG disorganization that decreased during LA ablation, but did not reach LT pts values. Conclusion: Estimation of the level of organization of atrial ECG based on adaptive harmonic schemes appears as promising tools for the measure of pAF complexity and prediction of procedural outcome.