As 100-Gb/s coherent systems based on polarization- division multiplexed quadrature phase shift keying (PDM-QPSK), with aggregate wavelength-division multiplexed (WDM) capacities close to 10 Tb/s, ...are getting widely deployed, the use of high-spectral-efficiency quadrature amplitude modulation (QAM) to increase both per-channel interface rates and aggregate WDM capacities is the next evolutionary step. In this paper we review high-spectral-efficiency optical modulation formats for use in digital coherent systems. We look at fundamental as well as at technological scaling trends and highlight important trade-offs pertaining to the design and performance of coherent higher-order QAM transponders.
•A new four dimensional fractional-order dynamical system with no equilibrium points is proposed and the corresponding numerical solution based on the Adomian decomposition method is given.•The ...system exhibits three initial offset boosting behaviors that are conservative, quasi-conservative, and dissipative, respectively.•The system was implemented by the digital signal processor (DSP) platform.
In this study, a new fractional-order chaotic system is proposed based on the Adomian decomposition method (ADM). The system is proved to have no equilibrium point, so the system has hidden nonlinear characteristics. Furthermore, the initial-offset boosting behavior can be observed from this system. When the system parameters are fixed and the initial value changes, the evolution of the conservative, quasi-conservative, and dissipative phase trajectory boosts are analyzed in detail by numerical simulations, such as phase diagrams, mean values of the state variables, bifurcation diagrams, and dynamical distribution maps. These dynamic behaviors also indicate that the system has striking hidden multistability. Although some chaotic systems with initial-offset boosting behavior has been previously reported, it should be noted that this non-equilibrium fractional-order chaotic system with three types of offset-boosted control of initial value is the first to build and study. Finally, a circuit implementation on a digital signal processor (DSP) demonstrates the validity of the numerical analysis and the physical implementability of the system.
Very large scale integration is a process of integrating hundreds of thousands of transistors or devices into a single chip. VLSI can be categorized into two fields Frontend and Backend. Digital VLSI ...design falls under the Frontend design. Multiplication is an arithmetic operation important for the Digital Signal Processing (DSP) and for processors. Multiplier is the main hardware block for the digital circuit. More than 70% of the applications in a digital circuit are either addition or multiplication. As these operations dominates most of the execution time so we need fast multipliers. The overall objective of a good multiplier is to have high speed, low power consumption unit, less area. Vedic multipliers are the fast multipliers and occupy less area. They are based on the Vedic mathematics sutra "Urdhava-Triyakbhyam" . The paper contain a high speed multipliers and use of different adder structures.
Owing to a change in the scope of physics research, the AMBER spectrometer at CERN is undergoing an update on its instrumentation and trigger strategy for the data acquisition system. One of the key ...updates is the adoption of a free-running and trigger-less operation, which differs from the predecessor of AMBER, COMPASS, by working in a continuous mode but in an event-based triggered way.
In this article, we present a multichannel data-acquisition platform developed in line with the next generation of trigger-less and free-running data acquisition systems. The platform is based on a pre-existing Mezzanine Sampling ADC board for the analog-to-digital conversion and a Xilinx Zynq Ultrascale+ System on Module for online real-time data processing. We also present the evaluation of the system operating in continuous mode, taking data from a 25-element electromagnetic calorimeter prototype with a muon beam, during the first AMBER pilot run. The acquired data were used for noise and pulse shape studies required for the design of the algorithms for lossless compression and data feature extraction needed for trigger-less operation.
We propose a novel two-stage blind carrier phase recovery scheme tailored for probabilistically shaped QAM. Our algorithm is based on modifying the classic Viterbi&Viterbi (V&V) and maximum ...likelihood (ML) phase estimators by optimizing the blind decisions over the received symbols taking into account the probability distribution of the received signal. Our technique improves the standard V&V+ML in all conditions and outperforms the state-of-the-art blind phase search (BPS) algorithm for a constellation entropy ≤ 4. At the same time our implementation preserves the low complexity of standard V&V+ML. This results in a remarkable reduction in complexity of up to a factor thirty compared to BPS.
In recent years, there has been an increase in the amount of pharmaceutical medication contamination of water sources. They are extremely difficult to detect since they are only present in trace ...amounts. In the presented study, the extraction method of dispersive solid phase was paired with HPLC as an easy, effective, and developed approach for preconcentration and measurement of desipramine drug, a depression medication, in aqueous and urine samples with nanomagnetic chitosan/β-cyclodextrin. The sorbent was produced from magnetic nanoparticles of (Fe3O4) in chitosan substrate modified with β-cyclodextrin (βCD) for increasing porosity, and then it was distinguished by several methods, containing X-ray diffraction, infrared spectroscopy, vibrating sample magnetometry, energy dispersive X-ray analysis, and field emission scanning electron microscopy. The significant elements affecting extraction effectiveness are optimized as pH, ionic strength of the solution, amount of adsorbent, the type of elution solvent, temperature and time adsorption, and elution solvent volume (in a multivariate method with the help of the Design Expert program). The results show the very good performance of this technique. The calibration curve of the method is a range of linear of 2–50 μg/L. The detection limit of the method is 0.39 μg/L, the 2.50% relative standard deviation in the method, and the correlation coefficient is 0.98. The maximum adsorbent capacity was recorded at 59.98 mg g−1.
•The environmentally friendly porous adsorbent for preconcentration of desipramine drug.•Extraction of trace desipramine in aqueous and urine samples.•Response Surface Methodology for optimization effective factors of extraction.
Hydrogen energy shows promise as a renewable energy source for various applications like battery and electric vehicle charging stations, as well as grid connections. However, high current ripple from ...fuel cells (FCs) and inadequate voltages for grid use pose challenges. This study presents a novel solution using neural fuzzy network control in a high-gain DC-DC boost converter to address these issues. The suggested converter charges in parallel and discharges in series, minimizing the current ripple range in the fuel cell network. Additionally, the switch-capacitor cell efficiently increases the output voltage.
In this study, a Neuro-fuzzy system with 9 rules is trained meticulously over 50 epochs using hybrid optimization and grid partition methods, achieving a low training error of 0.045 with 522,064 samples. The neural fuzzy network, employing the weighted average method for Defuzzification, produces duty cycle values from 0.02 to 0.5 in response to input signals. Additionally, an innovative Space Vector Pulse Width Modulation (SVPWM) approach within the inverter circuit enhances voltage generation precision and power quality for grid delivery, notably reducing current ripple and ensuring stable power supply. This combined with the neural fuzzy network in the converter efficiently converts hydrogen energy into AC voltage for seamless grid integration, revolutionizing boost converter efficiency and advancing hydrogen energy utilization across various energy sectors.
Coherent detection offers high spectral efficiency and receiver sensitivity, but digital signal processing (DSP)-based coherent receivers may be prohibitively power hungry for data centers even when ...optimized for short-reach applications, where fiber propagation impairments are less severe. We propose and evaluate low-power DSP-free homodyne coherent receiver architectures for dual-polarization quadrature phase shift keying (DP-QPSK) for inter- and intradata center links. We propose a novel optical polarization demultiplexing technique, for DP-QPSK and higher-order modulation formats, with three cascaded phase shifters driven by marker tone detection circuitry. We consider carrier recovery based on either optical or electrical phase-locked loops (PLLs). We propose a novel multiplier-free phase detector based on XOR gates, which exhibits less than 0.5 dB power penalty relative to a conventional Costas loop phase detector. We also study the relative performance of homodyne DP-differential QPSK, for which carrier phase recovery is unnecessary. Our proposed DSP-free architectures exhibit ~1 dB power penalty at small chromatic dispersion compared to their DSP-based counterparts. We estimate conservatively that the high-speed analog electronics of an electrical PLL-based coherent receiver consume nearly 4 W for 200 Gbit/s DP-QPSK, assuming a 90-nm complementary metal-oxide semiconductor process.
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