Power Line Communication Channel Model Research Articles

A comparison between autocorrelation- and crosscorrelation-based coarse frame synchronization schemes for OFDM-PLC systems

Orthogonal frequency division multiplexing (OFDM)-based Power-Line Communications (PLC) systems are vulnerable to synchronization errors, and the particularities of the PLC channel affect the performance of the synchronization process. In this context, this work is focused on the initial pilot symbol detection, presenting a comparison between autocorrelation- (AC) and crosscorrelation (CC)-based timing metrics, which include the most common preamble-based synchronization strategies. Two robust timing metrics are defined and the effect of multipath, Colored Background Noise (CBN) and Impulsive Noise (IN) is theoretically evaluated on each. A detailed analysis of the probability distributions of the timing metrics is performed and primary detection thresholds and lower bounds for the symbol detection probability are derived. Simulations of the OFDM-PLC system are performed in order to validate the analysis, considering a statistic PLC channel model and different noise sources. Results show that the CBN and IN significantly degrade the timing metrics behavior, and that the CC-based timing metric is more robust to this worsening, thus achieving a better synchronization performance than the AC-based timing metric.

A power‐line communication system employing median filtering for power control enhancement of wind generators

SummaryThe monitoring and control of renewable energy sources are extremely important to guarantee the operability of the system and the quality of the energy generated. Communication technologies play an important role in the success of these systems and, among them, power‐line communication (PLC) has shown itself to be a very promising and economically viable solution, as it uses the existing power infrastructure to transmit the monitoring and control information. In this context, this paper proposes a communication system based on the G3‐PLC standard associated with a median filter (MDF) to improve the robustness of the control operation of a wind power generation system (WPGS) composed of a doubly fed induction generator (DFIG) and a predictive controller. The MDF is employed to attenuate impulsive noise and distortions, caused by the degrading effects of the PLC channel, being possible to recover corrupted control information without the need to retransmit data packets. The complete system, that is, WPGS, G3‐PLC, and MDF, was modeled in a computational environment and analyzed over a realistic PLC channel model. Simulation results showed that the system is capable of operating with good quality, reducing latency, and enabling real‐time communication even under severe channel conditions.

High performance binary LDPC-coded OFDM systems over indoor PLC channels

Power line communication (PLC) technology is actually among the most renowned technologies for home environments due to their low-cost installation opportunities. In this study, the bit error rate (BER) performances of binary low-density parity check (LDPC) coded orthogonal frequency-division multiplexing (OFDM) systems have been considered over indoor PLC channels. Performances comparison of diverse soft and hard decision LDPC decoder schemes such as Min-Sum (MS), weighted bit flipping (WBF), gradient descent bit-flip (GDBF), noisy gradient descent bit-flip (NGDBF) and its few variants including the single-bit NGDBF (S-NGDBF), multi-bit NGDBF (M-NGDBF) and smoothed-multi-bit NGDBF (SM-NGDBF) decoders were examined in the modeled network. To evaluate the BER performance analyses three different PLC channel scenarios were generated by using new and more realistic PLC channel model proposal were also employed. All of the simulations performed in Canete’s PLC channel model showed that remarkable performance improvement can be achieved by using short-length LDPC codes. Especially, the improvements are striking when the MS or SM-NGDBF decoding algorithms are employed on the receiver side.

Performance Analysis of MIMO System over an In-home PLC Channel

Power line communication (PLC) system is an attractive technology for Smart Grid applications. One key benefit of PLC is its low installation cost because, in PLC technology, we do not need to install any extra cable to extend a network due to the accessibility to low voltage power network. Orthogonal frequency division multiplexing (OFDM) is widely used in PLC networks. Currently, Multiple Input Multiple Output (MIMO) technology is one of the processing techniques appropriate to PLC networks, allowing high data rate. In this work, the MIMO-OFDM system is established to provide better performance over the PLC system by providing communication links with substantial diversity and capacity. However, adapting MIMO to the PLC network involves solving several issues such as MIMO PLC channel modelling and optimisation of the modulation parameters. In this paper, we present measurements results of the transfer function and impulsive noise in the extended frequency range 2-100 MHz. In the simulation part, we evaluate the performance of the proposed receivers in 2×2 MIMO-PLC channels. It is shown that the minimum mean square error (MMSE) receiver can be one of the appropriate candidates for MIMO PLC channels due to its bite error rate (BER) characteristics under impulsive noise.

MAC Performance Analysis for Reliable Power-Line Communication Networks with ARQ Scheme.

Power-line communication (PLC) networks have been increasingly used for constructing industrial IoT (internet of things) and home networking systems due to their low-cost installation and broad coverage feature. To guarantee the transmission reliability, ARQ (automatic repeat request) scheme is introduced into the link layer of reliable PLC networks, which allows the retransmission of a data frame several times so that it has a higher probability to be correctly received. However, current studies of performance analysis for PLC MAC (medium access control) protocol (i.e., IEEE 1901) do not take into account of the impact of ARQ scheme. To resolve this problem, we propose an analytical model to investigate the MAC performance of IEEE 1901 protocol for reliable PLC networks with ARQ scheme. In the modeling process, we first establish a PLC channel model to reflect the impacts of PLC channel types (containing Rayleigh fading and Log-normal fading), additive non-Gaussian noise feature and ARQ scheme on data transmission at link layer. Next, we employ Renewal theory and Queueing dynamics to capture the transmission attempt behavior of executing IEEE 1901 protocol in the unsaturated environment with finite transit buffer size. On the basis of combining these two models, we derive the closed-form expressions of 1901 MAC metrics considering the influence of the ARQ scheme. Furthermore, we prove that the proposed analytical model has the convergence property. Finally, we evaluate the MAC performance of 1901 protocol for reliable PLC networks with ARQ scheme and verify the proposed analytical model.

Development of Top-Up And Bottom –Up Techniques for Assessment of Power Line Communication Channel Model

Power Line Communication (PLC) is the transfer of data and voice signals from one communication system to another over the electric power delivery network. However, with the advent of technology, human dependency on electricity and communication has grown beyond leaps and bounds. The power transmission line channel has not been designed with wired channel requirements for broadband applications and appears as a harsh environment for the low-power high-frequency communication signals. This study therefore evaluate the performance of PLC on power grid by simulating a practical multipath power line communication channel model using top-down and bottom-up approach. The statistical multipath parameters such as path arrival time, magnitude and interval for each category were analyzed. This is done over the frequency range of 100-300 kHz. The result shows that at 100 kHz, data can be transmitted up to 350 meters without signal distortions while for 300 kHz only 50 meters can be covered. In addition, signal attenuation with a distance of 2 km is about 0.2 of the original signal at 300 kHz and less at higher frequencies. The results in the time and frequency domains indicate that data transmission in PLC environment needs signal to be amplified at higher powers. Keywords : Power Line Communication, Power Grid, Transmission Line, Multipath Parameters, Channel Modelling, Top-Down Approach, Bottom-Up Approach. DOI : 10.7176/JNSR/9-16-03 Publication date : August 31 st 2019

A comparative simulation study of different decoding schemes in LDPC coded OFDM systems for NB-PLC channel

In this paper, we study the performance of Low density Parity Check (LDPC) coded orthogonal frequency-division multiplexing (COFDM) systems when they are applied on the short data block of a narrowband (NB) power line communications (PLC) channel. In the modelled system simulations have been performed using different code lengths. It is assumed that the channel has a multipath propagation with two different noise scenarios: AWGN background noise with and without the presence of impulsive noise. Performances of Various soft and hard decision LDPC decoder schemes such as belief propagation (BP), weighted bit flipping (WBF), improved weighted bit flipping (IWBF) and implementation-efficient reliability ratio based weighted bit flipping (IRRWBF) decoders were investigated. It has been shown for all simulations performed in PLC channel model showed that remarkable performance improvement can be achieved by using short-length LDPC codes. Especially, the improvements are striking when the BP decoding algorithms are employed on the receiver side.

Simulation of Achievable Data Rates of Broadband Power Line Communication for Smart Metering

Building real Smart Metering and Smart Grid networks is very expensive and time-consuming and also it is impossible to install different technologies in the same environment only for comparison. Therefore, simulation and experimental pilot measurements are an easy, economical, and time-affordable solution for a first comparison and evaluation of different technologies and solutions. The local area networks (LAN) are the core of Smart Metering and Smart Grid networks. The two predominant technologies are mostly sufficient for LAN networks, Power Line Communication (PLC), and radio frequency (RF) solutions. For PLC it is hard to allow prediction of the behaviour. Performance assessment for point-to-point connection is easy, but for complex PLC networks with repeaters it is quite expensive. Therefore, a simulation is an easy, fast, and cheap solution for understanding the grid configuration, influence of particular topological components, and performance possibilities. Simulation results can, thus, provide material for the design of a telecommunication infrastructure for Smart Metering. This paper presents results of such a simulation study. It is based on realistic PLC channel model implementation in Network Simulator 3, our modification and extension of this implementation for our use case scenario. It uses Shannon’s formula to calculate theoretical maximum channel capacity. In particular, it provides channel capacity and achievable distances of broadband PLC (BB-PLC). In this article we also exploit our novel idea of simple performance assessment of broadband PLC communication via simulation. It is supposed to be used to understand, evaluate, and test the grid configuration before deployment.

Broadband Power Line Communication: The Channel and Noise Analysis for A Power Line Network

The scope for broadband powerline Communication is considered as a retrofit technology for wide geographical coverage wherever the human habitation exists. So during the last decade, it has drawn an enormous quantity of research work for improving communication performance and this system being standardized all over the world. The broadband power line Communication channel modelling is essential in the design of a reliable communications system. An analysis on the proposed channel model is conducted in this paper; also the paper studied the noises in Broadband powerline Communication network and its mathematical model. The channel Transfer function and Error Performance of Proposed powerline communication System noise is evaluated with various digital modulation techniques Bit error rate (BER) and signal to noise ratio (SNR) curve by using simulation software. The results indicated that the noise analysis is effective for modelling the power line communication channel. Also, we have presented the various studies on the channel performance based on Orthogonal frequency-division Multiplexing (OFDM) systems for an efficient design of a Broadband Powerline Communication (BPLC) system.

A PLC Channel Model for Home Area Networks

Smart meters (SMs) are key components of the smart grid (SG) which gather electricity usage data from residences and businesses. Home area networks (HANs) are used to support two-way communications between SMs and devices within a building such as appliances. This can be implemented using power line communications (PLCs) via home wiring topologies. In this paper, a bottom-up approach is designed and a HAN-PLC channel model is obtained for a split-phase power system which includes branch circuits, an electric panel with circuit breakers and bars, a secondary transformer and the wiring of neighboring residences. A cell division (CD) method is proposed to construct the channel model. Furthermore, arc fault circuit interrupter (AFCI) and ground fault circuit interrupter (GFCI) circuit breaker models are developed. Several HAN-PLC channels are presented and compared with those obtained using existing models.

Desarrollo Y Simulación De Un Modelo De Transceptor Basado En Prime Para Simulación Sobre Canal PLC

The choice of modification technique for a communications system depends to a large extent on the nature and characteristics of the medium in which it must operate (Hrasnica et al., 2005). In a PLC (Power Line Communications) system, the first applications in the LDR band (oriented to the control of devices) operated with monocarrier modulations, such as ASK, BPSK, and FSK. This allows for low implementation costs, provided that it operates at low data rates and with an error correction system. It is clear that applications require a higher data rate. The modulation technique must overcome challenges such as the necessary equalization for the cause of the non-linearity of the channel, or avoid the propagation delays and the multipath caused by the impedance differences in the branches. Likewise, it must offer flexibility and avoid the use of certain frequencies if they are altered or assigned to another service and, therefore, cannot be used in PLC. In this scenario, one of the techniques that have been imposed in the most used developments in NB-PLC as in BB-PLC has been Orthogonal Frequency Division Multiplexing (OFDM). One of its most attractive aspects from the point of view of its complexity is the possibility of implementing the structure of its multifrequency modulation and demodulation scheme through a simple Inverse Discrete Fourier Transform (IDFT) and its corresponding direct transform, Fast Fourier Transform (FFT). Based on this technique, an appropriate transceiver scheme for operating on a PLC channel model was presented. This development implements the error correction technique proposed for NB-PLC.

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.

Approach for modelling of broadband low‐voltage PLC channels using graph theory

Broadband power line is an important way of communication in low-voltage distribution networks because a power line is everywhere nowadays. However, due to the heterogeneity of a practical power-line network and various loads connected to its termination points, modelling and simulation of power-line communication (PLC) channels are difficult and complicated issues. In this work, the authors propose a novel PLC channel modelling approach using graph theory for the first time when knowing the power-line network topologies and cable distributed parameters. The approach utilises simple and effective recursive operations in solving the k -shortest paths to estimate the channel transfer function for a specific power-line network, it overcomes the complicated analytical derivation in computing the channel transfer function by the traditional two-port network in the bottom-up model and avoids to measure the actual channel in a top-down model. Their proposed approach is validated by transmission-line (TL) theory as well as measurement results, and it is also compared with TL theory. The results show that their proposed PLC channel modelling approach herein is simple to be implemented, it is expected to have extensive applications in broadband PLC systems for performance evaluations.

Channel model proposal for indoor relay‐assisted power line communications

Due to its tree-like topology, the point-to-point (P2P) indoor power line communication (PLC) channel exhibits a similar broadcasting property as the wireless propagation channel shows. However, after relay nodes are introduced, the relay-assisted PLC (RaPLC) channel shows some notable differences compared with its wireless counterpart. A lot of results about the relay-assisted wireless channel can be found in the literature, but the work of modelling RaPLC channel has rarely been discussed in detail. As the first attempt to fill this gap, we apply the ABCD method to compute the channel transfer function (CTF) of the RaPLC channel. It has been clarified that, in general, the CTF of RaPLC channel cannot be obtained as a cascade of two independent P2P PLC sub-channels located on two sides of the relay node. Also, it is shown that the challenge of generating CTF of the RaPLC channel can be transformed into a group of equivalent P2P PLC channel modelling tasks. Under the time-division duplexing constraint, the relay node changes its working mode from the receiving phase to the transmitting phase, which shows that the RaPLC channel is abruptly time-varying in nature. Following the hybrid bottom-up approach, a statistical channel model with a simple six-segment indoor power grid topology has been developed for simulation. Practical measurements and numerical examples verify our results.

Modeling Transmission and Radiation Effects When Exploiting Power Line Networks for Communication

Power distribution grids are exploited by power line communication (PLC) technology to convey high-frequency data signals. The natural conformation of such power line networks causes a relevant part of the high-frequency signals traveling through them to be radiated instead of being conducted. This causes not only electromagnetic interference with devices positioned next to power line cables, but also a consistent deterioration of the signal integrity. Since existing PLC channel models do not take into account losses due to radiation phenomenon, this paper responds to the need of developing accurate network simulators. A thorough analysis is herein presented about the conducted and radiated effects on the signal integrity, digging into differential mode to common mode signal conversion due to network imbalances. The outcome of this work allows each network element to be described by a mixed-mode transmission matrix. Furthermore, the classical per-unit-length equivalent circuit of transmission lines is extended to incorporate radiation resistances. The results of this paper lay the foundations for future developments of comprehensive power line network models that incorporate conducted and radiated phenomena.

A channel model for power line communication using 4PSK technology for diagnosis: Some lessons learned

Modern smart grids and smart metering concepts are based on reliable digital communications. The absence of dedicated communications media, such as telephone lines or fibre optics within a power line network, can make transmission challenging. Electrical power companies are interested in implementing an overall communicating power line network. The power line communication (PLC) system uses the electric power distribution grid as a data transmission medium. The data transmission problem resulted due to poorly developed Medium Voltage Network of PLC Channel Model and challenges in data transmission technology, so this hampers better performance. This paper studies PLC over a medium voltage network with a goal of achieving greater bit rates and communication that is more reliable over power lines. It presents a complete channel model of a PLC system and evaluation of Bit Error Rate (BER) of Phase Shift Keying (PSK) when corrupted with noise. It calculates the number of sections between two substations to determine signal loss. The PSK modulation scheme in simulation is experimentally found to be more robust against such power line distortions as noise for point-to-point transmission. The model and calculations use Matlab and QUCS.

A Synthetic Statistical MIMO PLC Channel Model Applied to an In-Home Scenario

This paper proposes a synthetic statistical top-down MIMO power line communications channel model based on a pure phenomenological approach. The basic idea consists of directly synthesizing the experimental channel statistical properties to obtain an extremely compact model that requires a small set of parameters. The model is derived from the analysis of the in-home $2\times 3$ MIMO PLC channel data set obtained by the European Telecommunications Standards Institute specialist task force 410 measurement campaign in the band 1.8–100 MHz. The challenge of modeling the channel statistical correlation, exhibited among the frequencies and between the MIMO modes, in compact form is tackled and it is shown that a small set of parameters can be used to reconstruct such a correlation behavior. The model is validated and compared with the measured channels, showing a good agreement in terms of average channel gain, root-mean-square delay spread, coherence bandwidth, and channel capacity distribution.

Broadband PLC‐channel equalisation in the frequency domain based on complementary sequences

Multipath channels, like power lines, have a periodic time-variant response that impacts on data transmission. Power Line Communications (PLC) performance, in the context of a cyclic-prefix single carrier modulation scheme, can benefit from frequency domain equalisation techniques. This study proposes a frequency-domain dynamic characterisation and equalisation algorithm based on the properties of complementary sequences (CSs). This proposal takes advantage of CS properties to reduce the complexity of the algorithm by performing all the operations in the frequency domain, and without the necessity of noise/variance estimators. The proposal is compared to some well-known methods like zero forcing and minimum mean-square error (MMSE) through the transmission of data under different PLC channels. Bit error rate (BER) is also measured using Middleton Class A impulse noise (IN) model and the performance of all methods is finally evaluated under a time-variant PLC channel model showing the importance of dynamic equalisation on PLC systems. Reported computational resources and simulations show that the proposal is four time faster than MMSE and improves the BER performance by up to 4 dB. In addition, the proposed identification algorithms shows to work properly even in PLC channels with attenuations higher than 40 dB and severe IN scenarios.

Spectrally Efficient CSI Acquisition for Power Line Communications: A Bayesian Compressive Sensing Perspective

Power line communication (PLC) techniques present a no extra wire solution for the communication purpose in a smart grid due to the ubiquity and low cost. Moreover, the through-the-grid property of PLC has naturally extended its possible applications, including but not limited to the automatic meter reading, line quality monitoring, online diagnostics, and network tomography. To guarantee the performance of communications as well as other applications in PLC systems, accurate channel state information (CSI) acquisition should be performed regularly. However, the conventional pilot-based CSI acquisition approaches in PLC systems have not made full use of the channel characteristics and hence suffer from a low spectral efficiency. In this paper, by exploiting the parametric sparsity and discretizing the electrical length in the well-known PLC channel model, we formulate the non-sparse (either time domain or frequency domain) PLC channel into a compressive sensing (CS) applicable problem. Furthermore, we propose a spectrally efficient CSI acquisition scheme under the framework of Bayesian CS and extend it to the multiple-input multiple-output PLC by investigating the channel spatial correlation. Compared with the existing sparse CSI acquisition schemes for PLC, such as the annihilating filter-based and the estimating signal parameters via rotational invariance technique-based ones, the proposed scheme has better mean square error performance and noise robustness.

OFDM-based power-line communication enhancement using a turbo coded adaptive impulsive noise compensator

In this paper, we propose a novel estimation and decoding scheme for power-line communication (PLC) systems in impulsive noise environments. The proposed scheme is based on the turbo coding combined with adaptive noise compensation to reduce burst errors and multipath effects. For this purpose, the PLC channel and noise models are introduced, then, the turbo encoder/decoder are inserted in the mapper/demapper and the pilot insertion block for the sake of enhancing preliminary estimation of the transmitted orthogonal frequency division multiplexing signals. The proposed impulsive noise compensator is based on the estimation of the impulse bursts using a new blanking/clipping function, and on the estimation of the signal to impulse noise ratio and the peak to average power ratio. Simulation results illustrate that receivers with combined turbo coding and the proposed noise compensator drastically outperform existing receivers under impulsive noise. In comparison to some existing schemes, the proposed scheme reaches its perfect performance in a reduced 15-paths environment, when the bit error rate and mean square error performance are tested. The improvements in SNR performance are more than 16 dB for BPSK modulation and can reach 12---20 dB for 16-QAM modulation, when a high impulsive noise level is considered.