Narrowband Power Line Communication Research Articles

Bottom-up single-wire power line communication channel modeling considering dispersive soil characteristics

This paper investigates the influence of frequency-dependent soil conductivity and permittivity on narrowband and broadband power line communication (PLC) channel modeling using transmission line theory. For narrowband PLC channels, the variation of the transfer function H(f) of a single overhead wire over a finitely conducting ground due to frequency-dependent soil parameters is minimal for low-resistivity soils, but more relevant for high-resistivity soils in the upper frequency range. For broadband PLC channels, H(f) strongly depends on the soil model for frequencies below 10MHz or so, but is relatively insensitive to this parameter at higher frequencies. The average channel attenuation is more affected by soil model and soil parameters than the achievable data rate. Also, the voltage definition assumed in the derivation of the per-unit-length parameters of the line has little influence on the results. A comparison between different formulations traditionally used in PLC channel modeling indicates that the admittance associated with a finitely conducting ground should not be neglected in the modeling of broadband PLC channels.

Gaussian Approximation-Based Lossless Compression of Smart Meter Readings

Automation metering services, load forecasting, and energy feedback are among the great benefits of smart meters. These meters are usually connected using Narrowband power line communication to transmit the collected waveform readings. The huge volume of these streams, the limited-bandwidth, energy, and required storage space pose a unique management challenge. Compression of these streams has a significant opportunity to solve these issues. Therefore, this paper proposes a new lossless smart meter readings compression algorithm. The uniqueness is in representing smart meter streams using few parameters. This is effectively achieved using Gaussian approximation based on dynamic-nonlinear learning technique. The margin space between the approximated and the actual readings is measured. The significance is that the compression will be only for margin space limited points rather than the entire stream of readings. The margin space values are then encoded using burrow-wheeler transform followed by move-to-front and run-length to eliminate the redundancy. Entropy encoding is finally applied. Both mathematical and empirical experiments have been thoroughly conducted to prove the significant enhancement of the entropy (i.e., almost reduced by half) and the resultant compression ratio (i.e., 3.8:1) which is higher than any known lossless algorithm in this domain.

Application-Layer Approach for Efficient Smart Meter Reading in Low-Voltage PLC Networks

This paper presents an efficient method for data acquisition and automatic meter reading (AMR) system from smart electric meters (SM) using power-line communications (PLC) networks. A PLC network uses existing electrical wiring to simultaneously carry both data and electric power. However, since the transmission medium in a PLC network is not designed for high quality data transfer, its efficiency in carrying out AMR applications is limited. The PLC network’s traffic load is significantly affected both by the routing algorithm and the polling ordering of the SM. This paper suggests two novel smart polling algorithms based on application layer approach. The proposed algorithms demonstrate efficient utilization of both proactive and reactive routing protocols for AMR applications in narrowband PLCs networks. The benefit of the proposed approach is demonstrated for the two most common protocols, the routing protocol for low-power and lossy networks and the lightweight on-demand ad hoc distance-vector routing protocol.

Narrowband Modeling of Single-Wire Earth Return Distribution Lines

The implementation of powerline communication (PLC) on single-wire earth return (SWER) grids requires high-frequency earth path characterization. The empirical determination of these characteristics is not practical for large grids. Analytical expressions may be used to estimate the high-frequency characteristics of earth paths; however, this paper shows that this approach can lead to errors when modeling line-to-earth path PLC channels. Therefore, a hybrid empirical/analytical earth path characterization method, based on heuristic correlations of measurement results with a lossy capacitor model, is hereby proposed. Further measurements on an experimental SWER line using two types of conductors were carried out. The results indicate that narrowband PLC implementation on SWER grids is feasible, and that conductors with similar size and material composition may have similar high-frequency characteristics, regardless of the construction method used. The proposed earth path characterization method was verified by comparing measurements with simulations of frequency-dependent analytical and constant parameter hybrid, per-unit SWER transmission line models.

A New Low Cost Coupling System for Power Line Communication on Medium Voltage Smart Grids

This paper proposes and verifies the performance of an innovative and low cost coupling system for power line communication (PLC) on medium voltage (MV) smart grids. The coupling system makes use of the capacitive divider of the voltage detecting systems (VDSs) to inject and receive the PLC signal. VDS are usually already installed in the MV switchboards of the major electrical manufacturer all over the world according to IEC 61243–5. VDS are used to detect the presence of the mains voltage to guarantee personnel safety. An interface circuit has been developed to be connected between the PLC transceiver and the VDS socket. In this way, the PLC signal can be coupled to the MV network without installing a dedicated MV coupler, thus avoiding the related costs of the coupler, the installation, and the temporary service interruption. The innovative device is able to couple digitally modulated narrowband PLC signals with modulation rate up to 19.2 kbit/s. In this paper, first a description of the proposed solution is reported. Second, its communication performance has been tested in laboratory. Finally, different tests have been carried out in two MV smart grid real installations under normal operation, i.e., in the presence of the mains voltage.

Secure Sum-Rate-Optimal MIMO Multicasting Over Medium-Voltage NB-PLC Networks

We propose a multiple-input multiple-output orthogonal frequency-division multiplexing transceiver for narrowband power-line communication applications in multi-user medium-voltage multicasting networks. The 3-phase medium-voltage multicasting network is modeled as a 2-input/3-output multiple-input multiple-output frequency-selective channel over the 3–500 kHz frequency band. We design the optimal spatial precoder, spatial power allocation, and frequency bit loading profile which maximize the sum-rate of the multicasting groups. In addition, we propose two schemes to secure data transmission through the two-group multicasting network. The first scheme secures the network when the eavesdropper is a user in one of the two multicasting groups and, hence, its channel state information is known at the transmitter. The second scheme secures the multicasting network from external passive eavesdroppers and, hence, the channels between the transmitter and the eavesdroppers are assumed to be unknown at the transmitter. The secrecy rate is evaluated for both scenarios.

Efficient network coding techniques for time constrained multicast narrowband power line communications

SummaryNowadays, power line communication (PLC) technology is receiving a renewed attention in many application fields. In particular, PLC is quite attractive for what concerns novel paradigms as smart microgrid systems and smart buildings. This paper deals with a proposal of a PLC scheme that efficiently allows multicast services based on the use of an efficient network coding (NC) scheme. Furthermore, an analytical approach is outlined to pursue the performance optimization of the proposed solution. Finally, the good behavior of the proposed NC approach is highlighted by presenting performance comparisons with the classical NC alternative.

NB-PLC channel: Estimation of periodic impulsive noise parameters and mitigation techniques

Narrowband Power Line Communication (NB-PLC) plays a key role in the deployment of smart grid, since it is a widely spread technology for smart grid applications and systems, like the Advanced Metering Infrastructure (AMI) system. In this paper, we study the characteristics of the NB-PLC channel and noise. A method is proposed to estimate the occurrence and duration of the dominant category of noise, the periodic impulsive noise, which greatly degrades the signal quality. A technique is proposed to mitigate the noise effect, with the use of Luby Transform (LT) codes. The proposed scheme exploits the features of the dominant noise on the NB-PLC channel and mitigates its effect especially in highly noisy environments. An estimation algorithm of the burst time occurrence and its duration is introduced. The system can estimate these parameters with an accuracy in the range of 10−4 and it can work even without channel state information. The proposed scheme is compared to two popular NB-PLC technologies, namely the PRIME and G3-PLC, whereas the results show that it can be very effective under severe noise conditions.

First and Second-Order Semi-Hidden Fritchman Markov models for a multi-carrier based indoor narrowband power line communication system

The realization of a Semi-Hidden Fritchman Markov models (SHFMMs) for power line communication (PLC) channel is only practicable if combined with efficient algorithms for learning and inference. This article thus reports First and Second-Order SHFMMs for the bit error pattern at the output of an Orthogonal Frequency Division Multiplexing based system for in-home narrowband PLC applications. Accurate SHFMMs have been derived for a residential and laboratory environment using the efficient iterative Baum–Welch algorithm. The log-likelihood ratio plots, the error-free run distribution plots, the mean square error and Chi-Square (χ2) test validates the accuracy of the derived models. The reliability and accuracy of resulting models are confirmed by a close match between the measured bit error sequences and the model generated bit error sequences. The estimated Second-Order SHFMMs have been validated to be superior to the First-Order models, although at the expense of more computational complexity. Resulting models assist designers to speed up and facilitate the process of designing and evaluating novelties for PLC systems.

Impulsive Noise Characterization in Narrowband Power Line Communication

Currently, narrowband Power line communication (PLC) is considered an attractive communication system in smart grid environments for applications such as advanced metering infrastructure (AMI). In this paper, we will present a comprehensive comparison and analysis in time and frequency domain of noise measured in China and Italy. In addition, impulsive noise in these two countries are mainly analyzed and modeled using two probability based models, Middleton Class A (MCA) model and α stable distribution model. The results prove that noise measured in China is rich in impulsive noise, and can be modeled well by α stable distribution model, while noise measured in Italy has less impulsive noise, and can be better modeled by the MCA model.

Top-down random channel generator for the narrowband power line communication

This paper proposes a random channel generator for the narrowband power line communication (PLC). Based on the top-down approach, an analytical formulation with a limited set of parameters is established for the PLC channel transfer function in the frequency band below 500 kHz. Then, the extracted parameters deduced from measurements are fitted with proper distribution functions. The top-down random channel generator is validated through the comparison between measured and generated channels in terms of time–frequency characterization metrics, especially the average channel attenuation, the root mean square (RMS) delay spread and the coherence bandwidth. Obtained results show the good agreement between the proposed modeled channels and the experimental ones with very close mean values and distributions of the main metrics.

On-field evaluation of the performance of IP-based data transmission over narrowband PLC for smart grid applications

One of the current efforts for the grid modernization is the deployment of Advanced Metering Infrastructure systems. Regarding AMI technologies, NarrowBand PLC is one of the most spread technologies worldwide. While current AMI deployments based on NB-PLC focus on metering applications, this work addresses the operation of IP over NB-PLC for Smart Grid applications. IP is a well-established standard that might become the key enabler for the interoperability amongst numerous applications for the Smart Grid. In this scenario, on-field measurements become essential to test the coexistence of AMI systems and data transmission beyond metering applications. This paper analyses the configurations and parameters that affect the performance of IP over PRIME such as the number of nodes in the subnetwork, switching levels and transport layer protocols, among others. Results show that the topology of the subnetwork plays a key role for the resulting data rates and provide a meaningful contribution towards the implementation of new applications over NB-PLC based on IP data transmission.

Railway Sign Power Line As Transmission Medium for Narrowband PLC

Abstract This work shows transmission parameters of specific power line, which is control cable used for supplying a railway sign. Two transmission parameters are considered, namely: attenuation and characteristic impedance, these two secondary parameters are calculated from primary parameters i.e. R, L and C. Primary parameters and their components were calculated if they depended on the frequency or were taken from producers notes. Analysis was done for the frequency in range from 50 kHz up to 100 kHz. Two types of cables were analysed, as extreme cases, first with the 1 mm2 solid conductors cable and second with the 1.5 mm2 19 strands conductors. Knowing the PLC modem transmission parameters together with the transmission parameters of the railway sign power line it is possible to calculate the capabilities of the communication system e. g. distance or maximum bit rate.

Cyclostationary Noise Mitigation for SIMO Powerline Communications

The cyclostationary noise in low-voltage narrowband powerline communications (NB-PLC) severely degrades the communication reliability. In this paper, we adopt single-input multi-output (SIMO) transmission to enhance the reliability of NB-PLC. Considering the SIMO receiver structure, we exploit the NB-PLC noise cyclostationarity and the high spatial correlations across multiple receive phases to design practical and efficient noise mitigation techniques. In particular, we propose two time-domain frequency-shift (FRESH) filtering-based cyclostationary signal recovery techniques with different performance and complexity levels. The proposed time-domain-based FRESH filtering techniques minimize the mean-squared error in estimating the orthogonal frequency division multiplexing (OFDM) information signal in the time-domain. The FRESH filtering exploits the cyclic auto-correlation of both the NB-PLC noise and the OFDM information signal in addition to their cyclic cross-correlation across the receive phases. Moreover, we propose a frequency-domain-based cyclostationary noise mitigation technique that minimizes the mean-squared error in estimating the OFDM information signal in the frequency-domain. The proposed frequency-domain-based technique exploits the cyclostationarity of the noise to estimate its power spectral density as well as the cross-correlation, per frequency subchannel, over multiple stationary noise temporal regions. Our proposed SIMO NB-PLC noise mitigation techniques are shown via simulation results conducted using noise field measurements to achieve considerable performance gains over single-input single-output techniques. In addition, we show that our proposed techniques achieve considerable performance gains over the conventional SIMO maximal-ratio-combiner designed assuming stationary noise.

Design of active power filter for narrow-band power line communications

In power line communication (PLC), couplers such as coupling transformers and band-pass matching coupling circuits are usually required for coupling, band-pass filtering, and impedance matching. However, the cost and size of transformers prevent them from being an economic and compact solution for PLC couplers. In addition, passive band-pass matching coupling circuits need accurate impedance matching and possibly incur power losses. In this paper, a 6th order multiple feedback (MFB) active power filter with the minimum number of components was designed for narrow-band PLC, which has high input impedance and low output impedance, allowing outstanding performance in main voltage isolation, suppressing the current-harmonics and compensating the reactive power simultaneously. Finally, simulations were conducted in the range of 95 kHz-125 kHz (CENELEC “B-band”), which confirmed that the new filter met the CENELEC requirements for transmission and disturbance levels.

Equalization of Narrowband Indoor Powerline Channels for High Data Rate OFDM Communications

In this paper, the well known Zadeh’s series representation of a linear periodically time varying system is exploited to develop linear equalization techniques for narrowband powerline communications based on orthogonal frequency division multiplexing. Numerical and experimental results referring to the band 200–500 kHz evidence that a coherent receiver exploiting the proposed equalizers can significantly outperform both its counterpart based on conventional channel estimation/equalization techniques and differential detection with a limited complexity. This leads to the conclusion that a coherent receiver incorporating the proposed equalization techniques represents a technically appealing solution for narrowband high data rate powerline communications in indoor scenarios.

Correction to “On the Capacity of Narrowband PLC Channels”

In [1] , the first equation in Theorem 2 on page 1195 contains an error, where $\rho $ should be replaced with $N_{0} \cdot \rho $ .

Smart Grid Applications for a Practical Implementation of IP over Narrowband Power Line Communications

Currently, Advanced Metering Infrastructure (AMI) systems have equipped the low voltage section with a communication system that is being used mainly for metering purposes, but it can be further employed for additional applications related to the Smart Grid (SG) concept. This paper explores the potential applications beyond metering of the available channel in a Power Line Communication-based AMI system. To that end, IP has been implemented over Narrow Band-Power Line Communication (NB-PLC) in a real microgrid, which includes an AMI system. A thorough review of potential applications for the SG that might be implemented for this representative case is included in order to provide a realistic analysis of the potentiality of NB-PLC beyond smart metering. The results demonstrate that existing AMI systems based on NB-PLC have the capacity to implement additional applications such as remote commands or status signals, which entails an added value for deployed AMI systems.

Reed solomon inner-convolutional outer concatenated code with error-erasure decoding for narrowband and broadband power line communications

Reed solomon inner-convolutional outer concatenated code with error-erasure decoding for narrowband and broadband power line communications

Impact of the control-command process in a photovoltaic conversion chain on the power line channel transfer function in the narrowband PLC frequency range

Impact of the control-command process in a photovoltaic conversion chain on the power line channel transfer function in the narrowband PLC frequency range