Reliability Of Power Line Communication Research Articles

Noise mitigation method for power line communication based on cross-correlation analysis

Abstract Noise has a significant impact on the transmission rate and reliability of power line communication(PLC), which has become a crucial factor affecting PLC. In order to enhance the noise resistance of PLC, this paper proposes a noise mitigation method for PLC based on cross-correlation analysis. Firstly, the characteristics of OFDM signals based on PSK modulation are analyzed. Subsequently, reference signals are created for the purpose of cross-correlation with the PLC signal. Then, the phase of each subcarrier can be obtained. The PLC signal is reconstructed by utilizing the obtained phase, thereby achieving noise mitigation. Finally, the algorithmic program has been written for the simulation of the method in MATLAB. The simulation results show that the noise mitigation method can successfully remove the noise from PLC signals with signal-to-noise ratios within -20dB.

Optimal Fractional Pilot Duration for a Correlated Receive Diversity Reliable PLC System With Imperfect CSI in Nakagami-m Noise Environment

The paper presents a single-input-multiple-output-based power line communication (PLC) system employing <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${M}$ </tex-math></inline-formula> -ary phase-shift keying signaling for data transmission, with the channels subjected to correlated Rayleigh multipath channels and corrupted by Nakagami- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${m}$ </tex-math></inline-formula> noise environment. The channel state information for the PLC system is obtained prior to data transmission using the minimum mean square error estimation technique, utilizing which a maximum likelihood-based sub-optimal receiver is proposed. The closed-form expression for the symbol error probability (SEP) is derived, for the cases of the channels following exponential and uniform correlations, using a characteristic function approach. Furthermore, the optimal pilot symbol duration is obtained to maximize the normalized error-free data rate of the system, which simultaneously saves on the energy of the pilot symbols and reduces the SEP of the data symbols. The numerical results demonstrate the effect of variation of different system parameters such as signal-to-noise ratio, channel diversity, pilot symbol quality, correlation factor, and the noise shape parameter <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${m}$ </tex-math></inline-formula> of the background noise on the maximum normalized error-free data rate and thereby providing various insights into the system design for a reliable and energy-efficient PLC system with imperfect knowledge of the channels at the receiver.

Optimal Multi-Level Amplitude-Shift Keying Modulation for a Reliable Channel Magnitude Detection-Based Receive Diversity Powerline Communication System

The implementation of a coherent powerline communication (PLC) receiver increases its hardware complexity and energy consumption, which can be tackled by a non-coherent receiver. However, this reduces the reliability of the PLC systems. To meet this trade-off, a novel energy-efficient receiver structure is proposed in this study that exploits the knowledge of the channel magnitude of a receive diversity PLC system. The transmitter employs multi-level amplitude-shift keying (ASK) modulation for data transmission via the PLC channels subjected to Rayleigh multipath phenomenon and corrupted by additive Nakagami-m background noise, which would lead to a superior performance as compared to other modulation schemes owing to the channel magnitude-based proposed receiver. Utilizing the receiver structure, closed-form expression for symbol error probability (SEP) and its asymptotic expression at a high average signal-to-noise ratio (SNR) are derived using a characteristic function approach. Furthermore, to achieve the simultaneous design of an energy-efficient modulation scheme and a reliable PLC system, optimal ASK signaling levels are obtained with a constraint on the total available energy at the transmitter end. The analytical relation of the derived optimal multi-level ASK constellation with the traditional ASK constellation is obtained at high SNR values. The proposed channel magnitude-based receiver is found to achieve full diversity order and numerical results presented provide various insights towards the design of the energy-efficient PLC system.

Zero-Additional-Hardware Power Line Communication for DC–DC Converters

A power line communication (PLC) solution to provide a data link between two or more dc–dc power converters is proposed. The approach does not require additional analog circuitry or high-sample-rate analog-to-digital converters to be added on top of the original system. A modulation and signal injection method for the transmitter, and a sampling and demodulation strategy for the receiver are developed. The PLC frequency band is placed between the control loop cutoff frequency and the power electronics circuit cutoff frequency, in a region that we identify as the “intermediate frequency band”. The transmitter modulates the converter voltage or current output by injecting perturbations into the control loop at the input to the PWM unit. To tolerate unsynchronized transmitter and receiver clocks, a virtual zero-crossing location algorithm is combined with long/short pulse identification to achieve demodulation at the receiver. The solution is verified experimentally and achieves reliable bidirectional PLC communication at 2 kb/s with an 8 kHz receiver sampling frequency.

Optimal Rotated QPSK Constellation for a Reliable SOMA Powerline Communication System in Nakagami-m Noise Environment

An <inline-formula> <tex-math notation="LaTeX">${N}$ </tex-math></inline-formula>-branch receive diversity powerline communication (PLC) system with two users and the transmitter employing a power-domain non-orthogonal multiple access (PD-NOMA) along with a rotated quadrature phase-shift keying (QPSK) modulation scheme, generally known as semi-orthogonal multiple access (SOMA) for data transmission is considered in this paper. The rotation of the data constellation and a proposed pre-processing at the receiver end for each user eliminate the usage of the additional successive-interference cancellation (SIC) hardware generally used in PD-NOMA PLC systems. Furthermore, optimal receiver structures are proposed using which closed-form expressions of the symbol error probability (SEP) are derived for the users using a characteristic function (c.f.) approach. The optimal rotation of the QPSK constellation minimizing the obtained SEP of the system is also derived. The diversity order of the system and the optimal angle of rotation at high average signal-to-noise ratio (SNR) values are found to be dependent only on the number of diversity branches. Moreover, the general dependence of the optimal rotation angle on various system parameters is corroborated by numerical results which provide various insights into the design of a reliable and energy-efficient PD-SOMA PLC system without the use of SIC hardware. The optimal rotation angle of the QPSK constellation also leads to novel optimal constellations for the users which are different than the conventional constellation utilized for data transmission in digital communication systems.

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.

Channel characterization of low voltage electric power distribution networks for PLC applications based on measurement campaign

This paper focuses on the findings outputted by a comprehensive measurement campaign carried out for characterizing and modeling Brazilian outdoor and low-voltage electric power grids for data communication purposes. In this regard, the statistics of average channel attenuation, root-mean-square delay spread, coherence time, coherence bandwidth and achievable data-rate are analyzed by considering the frequency band from 1.7 MHz up to 100 MHz, and thereof statistical models for some channel features are recommended. The periodic variation of these outdoor and low-voltage electric power grids is quantified and presented as a temporal function of the average channel attenuation. Also, mathematical models based on only two parameters representing the power spectral density of both background and impulsive noises are proposed. The results obtained from numerical analyses offer important information about Brazilian outdoor and low-voltage electric power grids for data communication purposes. Also, they constitute an opportunity for increasing the knowledge about this kind of data communication media and for assisting the design of new generations of effective and reliable power line communication systems.

Statistical Characterization of Indian Residential Networks for Powerline Communication

Despite different powerline channel modeling techniques, developed so far, there are still specific dynamic, varying parameters (viz. the random load variation and inconsistent electrical wiring) to be studied for a valid and reliable power line communication (PLC) model. Statistical characterization of PLC channel may provide the required background for refinement of these existent models. In this paper, the Indian residential networks are statistically analyzed in the frequency range of 1-100 MHz. This also includes the comprehensive analysis of line impedance, stationary noise, channel capacity and average channel gain. From the measurements, the noise spectrum density is found to be less than -90 dBm at a frequency less than 1 MHz and is almost constant after 70 MHz. The minimum and maximum channel capacity of the network is 71.5 Mbps and 97.7 Mbps respectively. The Average channel gain is estimated at -30 dB. The paper also reviews the channel transfer function developed by top-down and bottom-top approaches. Finally, some additional factors influencing the PLC channel are also discussed.

An efficient network coding scheme for reliable multicast power line communications

Nowadays, Power Line Communication (PLC) technology is receiving a renewed attention for a wide class of innovative applications and services, mainly thanks to the advantage of using the existing electrical infrastructures, thus reducing the deployment costs. However, such electrical infrastructures have been originally conceived for power distribution and not for data. Hence, signal propagation is affected by more severe impairments than traditional media, such as impulsive noise and frequency selectivity. Furthermore, new emerging PLC applications need more efficient information delivery schemes that encompass both unicast and multicast mode. Towards this end, this paper deals with an efficient Network Coding (NC) based multicast reliable PLC scheme that makes use of (i) a decision direct impulsive noise mitigation approach and of (ii) a scheme based on multiple transmissions of a same symbols in the frequency domain. A suitable optimization procedure is also proposed here with the aim of improving the performance of the proposed scheme, under the constraint of a specified maximum data flow delivery failure probability. Finally, comparisons with alternative solutions are provided in order to highlight the significant advantages of the proposed scheme in terms of data flow delivery delay and overall transmission energy cost, under specific service constraints.