Narrowband Power Research Articles

Design and FPGA Implementation of Signal Strength Measurement Techniques for Satellite Communication Systems

Communication receivers perform three major functions, frequency down conversion, IF demodulation and subcarrier demodulation. The functioning of a receiver is mainly controlled by input signal strength and relative dynamics. Signal strength is measured in terms of Signal to Noise ratio (SNR) and Carrier to Noise power density (C/No). Any measure of signal strength indirectly gives information about receiver performance for that period. Apart from this, SNR measurement in close loop with Phase Locked Loop (PLL) parameter forms the adaptive PLL system, which is one of the driving forces for this paper. The focus of this paper is to find suitable signal strength measurement techniques and their implementation for satellite communication systems. Signal to Noise Variance method (SNV) and Narrow band Wide band Power Ratio (NWPR) methods are considered based on the performance and realization aspects. All techniques require division, logarithm, and multiplication functions for their realization in hardware. CO-ordinate Rotation Digital Computer (CORDIC) algorithm is considered for realizing logarithm function. A comparison study is done for developed algorithm with Intellectual Property (IP) core. Developed SNR techniques are simulated for Binary Phase Shift Keying (BPSK) demodulator system and performance is evaluated for Additive White Gaussian Noise (AWGN). The paper describes the FPGA design and simulations of these techniques. Developed design is targeted to commercial and space qualified FPGA platforms. FPGA implementations results are compared with system level simulation results, and both are found to be satisfactory. Application of developed system in adaptive BPSK demodulator is also presented.

Controlled dispersive waves emission via swallowtail-type catastrophe pulses.

The dispersive waves (DWs) emission has emerged as an efficient way to extend the spectral range of a light source. However, the applications of the DWs are limited because of its narrowband and low power. It is crucial to find novel ways to manipulate the DWs radiation. We investigate a kind of catastrophe pulses, called swallowtail pulses, which can radiate DWs with broadband and high power. By exploiting the dependence of the temporal and spectral structure of swallowtail pulses on the initial control parameter within the catastrophe integral, we can effectively manipulate the emission of DWs in terms of resonant frequency and conversion efficiency. Furthermore, we observe that the swallowtail pulses can shed two solitons, and that both of them radiate DWs with different frequencies. In comparison to fundamental solitons, the minimum value of third-order dispersion required for the onset of DWs emission becomes significantly smaller for that of swallowtail pulses. The results of this study clearly reveal the impact of the inherent behaviors of swallowtail pulses on the DWs emission, which should be relevant for applications requiring broadband light sources and optical frequency combs based on the mechanism of DWs emission.

Optimal Passive Power Line Communication Filter for NB-PLC Applications

Narrowband Power Line Communication (NB-PLC) involves transmitting data by overlaying a high frequency low amplitude signal (ranging from 9 kHz to 500 kHz) onto the low-frequency high amplitude signal (50 Hz to 60 Hz) of the power grid. While using the existing power grid for communication is convenient, it was not originally designed for this purpose, leading to challenges such as conducted emissions and infrastructure constraints. To overcome these technical obstacles, power line filters (PLFs) are a viable solution. The results of our research work, focusing on the optimization of PLFs for NB-PLC to ensure their design fits the needed use case while avoiding over-engineering, are presented in this article. Our study concentrates specifically on the filtering of PLC signal and conducted emissions up to 500 kHz. Building upon a PLC PLF extensively discussed in our previous work—which blocks the PLC signal in the CENELEC-A frequency band regardless of its placement within the electrical installation, sometimes leading to over-engineering—this research aims to adapt the filter order and components for a variety of real scenarios in CENELEC-A, FCC, and ARIB frequency bands. By characterizing different filters, our work provides tailored solutions for these scenarios and serves as a framework for future filter designs in PLC applications.

Empirical Characterization of Non-Intentional Emissions generated by PV Installations

Non-Intentional Emissions (NIEs) generated by solar photovoltaic (PV) systems have significantly increased concerns about disturbances in the 9-150 kHz band of the lowvoltage distribution grid, which can lead to failures or cause thermal stress in the devices connected to the grid. Moreover, these emissions can cause interference in narrowband power line communications (NB-PLCs). This paper presents a characterization of emissions generated by different real PV systems. Specifically, measurement campaigns were carried out in isolated PV systems, which employed different panel configurations, as well as in a grid-connected system. The analysis of the NIEs allows the identification of the frequencies and amplitudes of the emissions, as well as the evaluation of the NIEs variation over time. In addition, the impedances of the PV systems were also measured to correlate impedance variations with emissions.

Emissions generated by electric vehicles in the 9-500 kHz band: Characterization, propagation, and interaction

Electric Vehicle Charging Processes (EVCPs), due to the involved power electronics with high-switching frequencies, generate high-amplitude emissions that could have a negative impact on Power Quality (PQ) and Narrowband Power Line Communications (NB-PLC) systems. In this context, this paper deals, first, with the frequency and time characterization of the disturbances generated by four EVCPs in the 9-500 kHz frequency range. The study is based on measurements carried out in a controlled Low Voltage (LV) grid. For this purpose, a novel procedure for the frequency and time characterization is proposed. The frequency characterization is based on the calculation of a set of parameters, which allows evaluating not only the amplitude of the disturbances in the frequency band under analysis, but also their spectral distribution. The time variability is characterized by means of a Fast Fourier Transform (FFT) analysis that leads to a simplified model to evaluate the time-dependent behavior of the disturbances, which shows a sub-cycle periodic pattern of the emissions in the frequency band of interest. Second, the propagation of the previously characterized emissions is analyzed, concluding that they propagate several meters through the LV grid. Although in most cases the disturbances are attenuated with distance, there might be resonances that lead to higher amplitudes at an electrical point distant from the source of the emissions. Finally, the influence of the simultaneous charging of several EVs is studied. The results show that, in general, the amplitudes correspond to the superposition of the individual disturbances, in addition to intermodulation products due to the switching frequencies of the inverters.As a conclusion, the high amplitude time-varying emissions, together with their capacity for propagation and interaction, are a matter to be analyzed due to their influence on PQ and their potential degradation of the performance of PLC in the frequency band from 9 kHz to 500 kHz.

Characterization of Non Intentional Conducted Emissions Up to 500 kHz in Urban Environment

The current interest in Europe to extend the frequency range for Narrowband Power Line Communications up to 500 kHz requires a thorough characterization of the non intentional emissions in this frequency range. This paper presents results of field measurements carried out in a dense urban environment, where the electrical devices are quite numerous and located at a short distance from the smart meters, and therefore, the effects of the non-intentional emissions on Smart Grids communications may be noticeable. In the study, spectral and time characterization of the recorded data was performed according to CISPR specifications, and then compared to recommended limits for non-intentional emissions in this frequency range. Results show that the levels of the emissions above 150 kHz may exceed the recommended limits for spurious emissions in the frequency band, mainly near the smart metering devices, due to the nearness of different types of electrical devices connected to the grid. This work demonstrates the need of characterizing the non-intentional emissions up to 500 kHz for the proper performance of future Smart Grid applications in this frequency range.

The Environmental Impacts of Radio Frequency and Power Line Communication for Advanced Metering Infrastructures in Smart Grids.

In the neighborhood area network (NAN), the advanced metering infrastructure (AMI) enables a bidirectional connection between the smart meter (SM) and the data concentrator (DC). Sensors, such as smart meter nodes or environmental sensor nodes, play a crucial role in measuring and transmitting data to central units for advanced monitoring, management, and analysis of energy consumption. Wired and wireless communication technologies are used to implement the AMI-NAN. This paper delves into a novel approach for optimizing the choice of communication medium, air for radio frequency (RF) or power lines for power line communication (PLC), between the SM and DC in the context of the AMI-NAN. The authors methodically select the specific technologies, RF and NB-PLC (narrowband power line communication), and meticulously characterize their attributes. Then, a comparative analysis spanning rural, urban, and industrial settings is conducted to evaluate the proposed method. The overall reliability performance of the AMI-NAN system requires a packet error rate (PER) lower than 10%. To this end, an efficient approach is introduced to assess and enhance the reliability of NB-PLC and RF for AMI-NAN applications. Simulation results demonstrate that wireless communication is the optimal choice for the rural scenario, especially for a signal-to-noise ratio (SNR) lower than 25 dB. However, in urban environments characterized by higher SNR values and moderately dense networks, NB-PLC gains prominence. In denser networks, it outperforms wireless communication, exhibiting a remarkable 10 dB gain for a bit error rate (BER) of 10-3. Moreover, in industrial zones characterized by intricate network topologies and non-linear loads, the power line channel emerges as the optimal choice for data transmission.

The Ionospheric Exploration Based on TJU#01 Meteorological Microsatellite Mission: Initial Results

AbstractThe global navigation satellite system radio occultation technique is achieving increasing significance and extensive promotion in the remote sensing of near‐earth atmosphere, climate, and ionosphere in recent three decades. Nowadays, many communities become interested in developing commercial mode in occultation measurement by launching massive nano‐ or cube satellite constellations at low costs. The TJU#01 is the first meteorological satellite of Tianjin Yunyao Aerospace Technology Co., Ltd. which was successfully launched into space on 7 December 2021. The occultation antenna onboard the satellite is able to probe both the ionosphere and atmosphere at multi‐frequencies including GPS, GLONASS, and BEIDOU systems. The microsatellite applies the same occultation antenna to receive both the atmospheric and ionospheric occultations at 100 and 1 Hz respectively. 100 Hz narrow band power and wide band power data are downloaded to the ground to generate high‐rate signal‐to‐noise ratio (SNR) series and applied to ionospheric scintillation exploration. In this paper, the primary parameters of the satellite and occultation antenna are introduced, as well as the ionospheric data processing methodologies. The initial ionospheric products of TJU#01 are evaluated after one‐month in orbit. The TJU#01 results have a good agreement with the co‐located ground ionosonde data and COSMIC‐2 observations. The new satellite and its follow‐on missions have great capabilities and potentials in the ionospheric and space weather researches.

A review on the empirical characterization of the low voltage distribution grid as a communication channel for power line communications

The electrical grid was not designed for the transmission of communication signals, which are affected by impedance variations, attenuation, and Non-Intentional Emissions (NIEs) in their propagation through the Low Voltage (LV) distribution grid. For this reason, the characterization of the electrical grid as a transmission medium is of vital importance for the correct development of Power Line Communications (PLC) technologies and the optimization of the opportunities offered by the LV distribution grid as a communication infrastructure. This paper deals with the state-of-the-art, challenges to be faced and future work of the characterization based on field trials in real scenarios. First, the features of Narrowband Power Line Communications (NB-PLC) and Broadband Power Line Communications (BB-PLC) technologies are outlined, including a brief comparison between the already developed NB-PLC protocols and providing an overview of the evolution of BB-PLC. Then, the parameters to be measured on the characterization of the LV grid are described, in addition to including the particularities and problems of the measurement systems designed for this aim. Finally, the state of the art and future work concerning the characterization of the outdoor LV grid as a transmission medium based on field trials are gathered.

Development of post-anesthesia care unit delirium is associated with differences in aperiodic and periodic alpha parameters of the EEG during emergence from general anesthesia - results from a prospective observational cohort study.

Intraoperative alpha-band power in frontal electrodes may provide helpful information about the balance of hypnosis and analgesia and has been associated with reduced occurrence of delirium in the post-anesthesia care unit (PACU). Recent studies suggest that narrow-band power computations from neural power spectra can benefit from separating periodic and aperiodic components of the EEG. This study investigates if such techniques are more useful in separating patients with and without delirium in the PACU at the group level as opposed to conventional power spectra. Intraoperative EEG recordings of 32 patients who developed perioperative neurocognitive disorders (PACU-D) and 137 patients who did not (noPACU-D) were considered in this post-hoc secondary analysis. We calculated power spectra using conventional methods and applied the "fitting oscillations & one over f" (FOOOF) algorithm to separate aperiodic and periodic components to see if the EEG signature is different between groups. At the group level, noPACU-D and PACU-D patients presented with significantly higher alpha-band power and a broadband increase in power, allowing a "fair" separation based on conventional power spectra. Within the first third of emergence, the difference in median absolute alpha-band power amounted to 8.53dB (AUC:0.74[0.65;0.82]), reaching its highest value. In relative terms, the best separation was achieved in the second third of emergence with a difference in medians of 7.71% (AUC:0.70[0.61;0.79]). AUC values were generally lower towards the end of emergence with increasing arousal. Increased alpha-band power during emergence in noPACU-D patients can be traced back to an increase in oscillatory alpha activity and an overall increase in aperiodic broadband power. Although differences between PACU-D and noPACU-D patients can be detected relying on traditional methods, the separation of the signal allows a more detailed analysis. Together this may enable clinicians to detect patients at risk for PACU-D early in the emergence phase.

Interference Level Detector with PCB HDI Rogowski coil for PLC Narrow-Band Applications.

This article presents and discusses the structure, principle of operation, and operational properties of a newly developed interference level detector (ILD) designed to measure conducted supraharmonic disturbances (1-150 kHz) in the power grid and to assess the effectiveness of narrow-band Power Line Communication (PLC) transmission, especially in the PRIME technology. The usability assessment was made on the basis of the validation and the results of tests carried out in a low-voltage network with non-linear loads. Appropriate practical conclusions were then formulated.

Proposals for Updated EMC Standards and Requirements (9–500 kHz) for DC Microgrids and New Compliance Verification Methods

This paper is aimed at making new proposals for developing future Electro-Magnetic Compatibility (EMC) standards tailored to DC microgrids in a frequency range between 9 and 500 kHz. In particular, new EMC proposals are made to reduce Electro-Magnetic Interference (EMI) with arc hazard detection and narrowband power line communication (PLC). To achieve this, first, arc detection requirements, PLC standards and existing EMC standards are reviewed. Next, new proposals are made to specify EMC requirements for equipment in DC microgrids in terms of conducted emission, immunity (9–500 kHz) and minimum impedance requirement (>40 kHz). The minimum impedance requirement is a new type of requirement and the relevant compliance testing method is developed. The new EMC proposals also distribute frequency bands to support arc detection and narrowband PLC. Then, to show the feasibility and advantage of proposed EMC codes, this paper develops a new arc detection method, which relies on only measuring the arc noise voltage (40–100 kHz) in a single point of the grid and does not need one or more current measurements. A total of three test cases are presented to show the feasibility of the arc detection method and the significance of having an EMC minimum impedance requirement. The executed tests for this paper also show that new EMC proposals are feasible and promising for DC microgrids. This concept and approach are the major novelties of this paper. The specific EMC threshold levels for conducted noise, immunity, and impedance within a frequency range between 9 and 500 kHz will need to be further fine-tuned based on the microgrid application parameters and further gathering of experimental data.

Passive Power Line Communication Filter Design and Benchmarking Using Scattering Parameters

NB-PLC (narrowband power line communication) is a method of data communication that involves superimposing a relatively high-frequency signal (9 kHz to 500 kHz), which contains data, onto the power grid’s low frequency (50 to 60 Hz) signal. While using the existing power grid as a transmission medium is convenient, the power grid was not designed for this purpose, leading to challenges such as conducted emissions and infrastructure limitations. To overcome these technical challenges, passive filters are necessary. This article presents the design, simulation (using scattering parameters), and evaluation of an NB-PLC filter by comparing it to commercially available filters. Our proposed design and benchmarking methods enable the accurate prediction of the filter’s behavior in field conditions. After comparing our filter with commercially available filters, we observed that it exhibits superior characteristics. Specifically, our filter has the best insertion loss versus frequency, achieved three times higher attenuation at 50 kHz (−130 dB) compared to the best commercially available filter (−40 dB), and has a power consumption of 0.6 W, which is comparable to the most power-efficient commercial filter (0.5 W). Additionally, our filter has the second best input and output impedance of 3.6 Ω within the frequency range of 35–95 kHz.

Precise Clock Synchronization Strategy of Power Distribution Field Network Based on HPLC Communication

In order to improve clock synchronization precision of the power distribution field network, a power distribution field network with high‐speed power line broadband carrier communication is designed, and a step‐by‐step precision clock synchronization strategy is developed based on modified timing‐sync protocol for sensor networks. In the strategy, the clock of the central node is calibrated in real‐time as the master clock of the field network by the communication master station through the long‐distance communication network, the time and frequency deviations of the clocks of each node in the network are accurately monitored using the broadcast mechanism and the network time base of the carrier communication, and the clock frequency is gradually amended by re‐calibrating the clock temperature compensation coefficient of the node so that the clock of the node is synchronized step‐by‐step within a clock synchronization cycle. The clock synchronization performances of the field network are tested in the laboratory and jobsite, and test results show that the clock synchronization accuracy of the field network is within ± 0.23 s/24 h, which is 28% higher than that of the power distribution field network based on narrowband power line carrier, and these phenomena of time gap or time repetition are avoided in the clock synchronization process. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Spectral current density and responsivity scaling for Fourier transform photocurrent spectroscopy.

We propose and experimentally verify a methodology to scale arbitrary units to photocurrent spectral density (A/eV) in Fourier transform Photocurrent (FTPC) spectroscopy. We also propose the FTPC scaling to responsivity (A/W), provided a narrow-band optical power measurement is available. The methodology is based on an interferogram waveform consisting of a constant background and interference contribution. We also formulate conditions that have to be met for correct scaling. We experimentally demonstrate the technique on a calibrated InGaAs diode and weak responsivity, long response time SiC interdigital detector. We identify a series of impurity-band and interband transitions in the SiC detector and slow mid-gap to conduction band transitions.

A narrow‐band overmoded rectangular waveguide filter for high‐power microwaves (HPMs)

AbstractAn overmoded rectangular waveguide filter with the advantages of narrowband and high power is presented in this paper. The transmission efficiency of each mode in the filter is analyzed based on mode‐matching techniques and optimized by combining it with the calculation method. Due to the overmoded waveguide and direct coupling topology, the designed structure has characteristics of narrowband and high power. The overall size of the proposed filter is only 17.45 × 36.20 × 126.67 mm3 (0.54λ0 × 1.12λ0 × 3.93λ0, λ0 is the wavelength of the center frequency in free space). The test results match well with the simulated ones and they both show that the transmission efficiency of TE10 mode is higher than 99.77%. Meanwhile, the proposed filter achieves 1% fractional bandwidth and 134.5 kW power capacity, which reveals that the filter has both narrow‐band and high‐power characteristics. The designed filter would be an attractive candidate for HPM systems.

Performance Analysis of Orthogonal Multiplexing Techniques for PLC Systems with Low Cyclic Prefix Length and Symbol Timing Offset.

This paper investigates the degradation caused by interference resulting from cyclic prefix violation and symbol timing offset in narrowband power line communication systems. In this sense, it presents a unified formulation from which Hermitian symmetric orthogonal frequency division multiplexing (HS-OFDM), orthogonal chirp division multiplexing (OCDM), single-carrier cyclic prefix (SCCP), and orthogonal time-frequency division multiplexing (OTFDM) can be easily derived. The paper then provides closed-form expressions for quantifying the aforementioned interference in the presence of a frequency domain equalizer. The numerical analyses exhibit the performances of these schemes under various data communication conditions, such as the availability of channel state information, the presence or absence of interference, modeling of additive noise as a white or colored Gaussian random process, frequency domain equalizer type, and the use of bit and power allocation techniques. The closed-form expressions and performance analyses regarding achievable data rate and bit error probability provide guidance for dealing with distinct constraints in narrowband power line communication (PLC) systems using the HS-OFDM, OCDM, SCCP, or OTFDM scheme. Lastly, the unified formulation and results obtained motivate the design of multi-scheme transceivers.

Smart Utilities IoT-Based Data Collection Scheduling

The Internet of Things is an ecosystem that connects billions of smart devices, meters, and sensors. These devices and sensors collect and share data for use and evaluation by organizations in different industry sectors. Humans may use the IoT to live and work more intelligently and gain total control over their lives. Consequently, IoT can be used to connect devices and integrate them with new digital technologies for customers. On the other hand, smart utility companies in the electric, gas, and water sectors need to deliver services more efficiently and analyze their operations in a way that can help optimize performance, detect growing problems in real time, and initiate fixes to avoid unplanned service interruptions. Building actual smart metering networks is costly and time-consuming. Therefore, in this paper, a new Smart Utilities Traffic Scheduling Algorithm (SUTSA) is proposed. To minimize the system complexity, the model is based on narrowband power line communication, in which a wired hidden network sends data across power lines. A simulation is performed using OPNET Modeler 14.5 to evaluate the proposed model. The results proved that the proposed model is highly scalable and achieves full network-bandwidth utilization in different situations based on different application requirements.

Design and Research of Channel Circuit Based on Broadband Power Line Carrier

In order to effectively improve the anti-attenuation, anti-noise and anti-impedance change capabilities of the low-voltage narrowband power line carrier communication unit, reduce the carrier signal coupling attenuation, and highly fidelity signal power encoded and modulated by the carrier chip, an improved high-speed power line carrier communication transceiver circuit is designed. Using 303.13kHz~357.81kHz as sub-carrier signal frequency can effectively avoid the random noise generated by high-power power electronic equipment and household appliances below 35kHz. At the same time, to prevent the frequency crosstalk of power line carrier products with 270kHz and 421kHz as the center frequency, the Y-coupling capacitor and sixth order Butterworth band-pass filter circuit are used to design the signal receiving and transmitting circuit of the communication unit to isolate unwanted signals. The experimental simulation of the designed circuit is carried out on the circuit simulation software Multisim 12. The results show that the designed power line carrier communication transceiver circuit can effectively control the signal coupling attenuation within 4dB, and the filtering of unwanted signals can also reach 41.7dB, which has good application value.

A Notch Filter-Based Coupling Circuit for UNB and NB PLC Systems

This paper introduces an analog notch filtering-based coupling circuit for receivers in ultra-narrowband and narrowband power line communication systems, which are connected to low-voltage electric power grids. It is composed of a twin-T notch analog filter, which is responsible for imposing a significant attenuation on the main frequency (i.e., f0∈{50,60} Hz) in cascade with an elliptic low-pass analog filter, designed with a 3 dB cut-off frequency of fc≫f0. For f0=60 Hz and fc=2 MHz, the prototype of the analog notch filtering-based coupling circuit attains attenuation values of 22 dB and less than 2 dB at the main frequency and in the rest of the frequency bandwidth, respectively, when practical scenarios are considered. Lastly, it shows that the analog notch filtering-based coupling circuit is more effective than a typical capacitive coupling circuit when frequencies lower than 3 kHz are considered for data communication and sensing purposes.