Broadband Signal Transmission Research Articles

Ensuring standardized parameters for the transmission of digital signals by twisted pairs at the technological stage of manufacturing cables for industrial operating technologies

Introduction. In production control and control systems, buildings use many simple devices - sensors to detect light, heat, movement, smoke, humidity and pressure, mechanisms for activation and control of switches, closing devices, alarm, etc. - «operating technologies» (OT). Different communication protocols and field tire technologies, such as Modbus for conditioning systems, Bacnet for access control and Lonworks for lighting, have been traditionally used and used for their connection. Network fragmentation leads to the need to use gateways to transform protocols when creating a single automation system, which complicates the implementation of complex control systems for any object. At the same time, information networks are unified, but the Ethernet protocol used in them for operating technologies for various reasons (technological, cost) has not been widespread. Due to its high bandwidth compared to existing field tire networks, industrial Ethernet is significantly capable of increasing flexibility in the implementation of additional functions in OT. Modern industrial Ethernet networks are based on non - shielded and shielded twisted pair category 5E cables. The presence of additional metal screens in the structure of twisted pair causes the increase in electrical resistance of conductors due to the effect of closeness, the electrical capacity, and the ratio of attenuation in the range of transmission of broadband signals. Purpose. Substantiation of the range of settings of technological equipment to ensure standardized values of the extinction coefficient and immunity based on the analysis of the results of measurements in a wide frequency range of electrical parameters of shielded and unshielded cables for industrial operating technologies. Methodology. Experimental studies have been performed for statistically averaged electrical parameters of the transmission of pairs for 10 and 85 samples of 305 meters long and shielded cables of category 5e, respectively. It is determined that in the frequency range from 1 to 10 MHz, unshielded cables have less values of the attenuation coefficient. In the range of more than 30 MHz, the shielded cables have smaller values of the attenuation due to the influence of the alumopolymer tape screen. It is established that the coefficient of paired correlation between asymmetries of resistance and capacity of twisted pairs is 0,9735 - for unshielded and 0,9257 - for shielded cables. The impact has been proven to a greater extent asymmetry of resistance the pairs on the increasing noise immunity of cables. The influence noise interference on the deviation of the diameter and electrical capacity of the isolated conductor from the nominal values in the stochastic technological process is analyzed. The strategy of technological process settings to ensure the attenuation and the noise immunity in the high -frequency range is substantiated. Practical value. Multiplicative interference, caused by random changes in the stochastic technological process, can lead to a deviation of diameter 2 times from the nominal value at level of probability at 50 %. The equipment settings of the technological equipment must guarantee the coefficient of variation capacity of the insulated conductor at 0.3 % for high level of noise immunity.

Detection range of airborne objects by broadband active-passive radar systems

In the interests of searching and observing aerial objects with low levels of background contrast of secondary electromagnetic radiation and signals of on-board radio-electronic means, it is required to use active-passive radar systems with identification of the belonging of unmasking signs identified by heterogeneous information sensors to one object. When constructing procedures for joint processing of information signals, the issues of determining the range of active and passive search (observation) channels become important when implementing measures to reduce the reflective properties and structural and energy secrecy of the operation of electronic equipment of aircraft. To establish the boundaries of the area controlled by the active-passive radar system, it is necessary to use energy equations for transmitting and receiving broadband signals with a priori indefinite arrival time in a radio channel with scattering and a direct radio channel. The equations are found by integrating spectral equations for inharmonic wave processes propagating in free space in the band of cyclic operating frequencies when approximating the partial directional coefficients of antennas and partial effective scattering areas of objects by power functions of cyclic frequencies. The goal of the article is identification of patterns of influence of object reflective properties and characteristics of airborne radio sources on the range of active-passive radar systems. Using energy equations of transmission-reception of non-harmonic wave processes in a radio channel with scattering and direct radio channel, analytical expressions for determining probabilistic characteristics of signal detection with a priori indefinite arrival time, the possibilities of detecting air objects by broadband active-passive radar systems have been investigated. Ratios of ranges of detection of objects have been found based on the results of receiving and processing of information signals of radar stations and intrinsic radiation of airborne radio-electronic equipment. The revealed regularities of the influence of the object reflective properties and the characteristics of airborne radio sources on the range of radar stations and passive radar complexes allow us to make a rational choice of parameters of active-passive radar system designs in order to achieve the required indicators of the effectiveness of air space control. The energy equations of transmission and reception of broadband signals in radio channels form the basis for the development of proposals to ensure the covert use of aircraft.

Ultrahigh Electromagnetic Wave Transmitting Polyphenylene Sulfide Microcellular Foams Based on Molecular Structure Design for 5G Communication

In the scenario of fifth-generation communication, especially millimeter wave (mmW) transmission, microelectronic material is required to have better signal stability, that is, a lower dielectric constant (Dk) and dielectric loss (Df). This work takes full advantage of the low dielectric molecular structure characteristics in polyphenylene sulfide (PPS) and the nonresidual low dielectric characteristics of supercritical CO2 (scCO2) foaming to enhance the low dielectric performance. The distinct structure of a highly stable thioether bond and highly reactive hydrogen in the benzene ring in the PPS macromolecule enables the oxo-bridging between PPS molecular chains and hence increases PPS melt strength. By further adjusting the regularity in PPS molecular chains to broaden the melting range of PPS crystals, the PPS microcellular foam of large expansion ratio (16.5-fold) with uniform cells is obtained. It has an ultralow Dk of 1.14 and Df of 0.0005 at 3 GHz. In the Ka band of 26–40 GHz, the broadband signal transmission has nearly no loss (∼99%). Furthermore, it has a low density (<0.08 g/cm3), is hydrophobic (contact angle of 123.4°), and reaches V-0 level flame retardancy. This ultrahigh mmW transmission material with excellent comprehensive performance provides an alternative for solving the problems of mmW propagation in the existing dielectric materials.

Photonic Phase-Stabled Transmission of Broadband Signals Based on Passive Compensation

A photonic phase-stabled transmission of broadband signal based on passive frequency mixing compensation is proposed. The mechanism of jitter compensation of aimed broadband signal transmission relies on an adaptive cancellation by mixing two signals under approximately the same external time jittering. A theoretical model is built and the frequency dependent jitter suppression is analyzed and verified. Compared with previous methods, the proposed photonic phase-stabled transmission of broadband signal can withstand faster jittering frequency up to 1 kHz. The experimental results show that the proposed method can significantly reduce the phase drift of the broadband signal of 400 MHz bandwidth. The measured overlapping Allan deviation at the center frequency of 7.2 GHz shows a stability of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3.53\times 10 ^{-14}$ </tex-math></inline-formula> at 100 s average time.

Сравнение качества оптимальной фильтрации наклона дисперсионной характеристики фильтром Стратоновича и сигма-точечным фильтром Калмана

The article deals with the reception and transmission of broadband signals through the ionospheric channel. An increase in the width of the spectrum of transmitted signals leads to a significant effect of the frequency dispersion of the Earth's ionosphere on the quality of information reception. Estimation of dispersion distortions of broadband signals and compensation of their influence in the article is carried out by methods of optimal filtering. Two algorithms for nonlinear optimal filtering of the slope of the dispersion characteristic of the ionospheric channel are compared: using the Stratonovich filter and using the sigma-point Kalman filter. The article presents general analytical expressions for calculating the estimate of the slope of the dispersion characteristic for both algorithms: Stratonovich filtering and filtering using the unscented Kalman filter. In addition, the results of simulation modeling are presented, the purpose of which was to compare the two above-mentioned filtering algorithms within the framework of the task. Three cases of the dependence of the slope of the DC on time are studied: a Markov damped process, a constant process, and a process with random increments for phase-shift keyed signals with different spectral widths under the assumption of large signal-to-noise ratios. It is shown that for signals with a spectral width from 500 kHz to 1 MHz, the unscented Kalman filter adjusts on average 2 times faster, however, the standard deviation of the estimate of the slope of the dispersion characteristic from the true value is up to 1.5 times larger compared to the Stratonovich filter. The duration of the filter adjustment decreases with a decrease in the width of the signal spectrum from 1 MHz to 250 kHz. In the 250 kHz band, both considered filters have approximately the same tuning speed and filtering quality.

A Novel FDTD Approach Considering Frequency Dispersion of FR-4 Substrates for Signal Transmission Analyses at GHz Band

High-speed digital signaling can cause various signal integrity and electromagnetic interference problems. Signal attenuation and distortion can be observed in the gigahertz band owing to the frequency dispersion of substrates. In this article, we propose a frequency-dependent finite-difference time-domain (FDTD) approach for the numerical analyses of flame-retardant type-4 (FR-4) substrates. The proposed FDTD approach provides accurate broadband solutions because it can take into account the frequency dispersion of the substrate. First, the broadband complex permittivity of FR-4 substrates was measured using a balanced-type circular disk resonator and fitted into a Djordjevic model for the FR-4 substrates. Second, we adapted the fast inverse Laplace transform and Prony methods to find the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">z</i> -domain expressions and incorporate them into the FDTD formulation.The validity of the proposed approach was demonstrated by comparing the numerical and experimental results of the differential insertion loss and phase constant of differential microstrip lines. Both results were in good agreement, indicating the validity and usefulness of the proposed approach for simulations of broadband signal transmission in FR-4 substrates.

Broadband Fixed-Beam Leaky-Wave Antenna With Consistent and High Gain Based on Ridge Gap Waveguide

In most communication scenarios, antennas are often required to achieve broadband and directional radiation, and beam squint with frequency is unfavorable for broadband signal transmission. The traditional leaky-wave antennas (LWAs) have beam squint with frequency. In this letter, an LWA with fixed beam direction in a broadband is designed with consistent gain over the band. A ridge gap waveguide (RGW) is adopted to construct a nondispersive structure, and one lateral side is connected to a parallel plate filled with dielectric slab. Thus, leakage radiation is produced at the interface between the RGW and the parallel plate, generating a beam with fixed direction and high gain. The novelty is that in theory the fixed beam can be realized in infinite band owing to the nondispersive waveguide. Finally, a broad band of up to 58% (from 22 to 40 GHz) is achieved due to the limitations of the stopband structure and feeding port. The measured beam is fixed at 41° over the whole band, with a slight beam deviation of 2.6°. The realized gain is consistent over the band with a peak gain of 19.3 dBi. The designing method provides a simple and efficient way to realize the broadband fixed-beam LWAs.

Optical Fiber Communication System and Nonlinear Effects: A Brief Insight

In the modern scenario, optical fiber communication technology has rapidly progressed with continuous exploration of emerging technologies to support more amount of bandwidth, higher data rate and improved security along with reduction in losses and electromagnetic immunity. Optical fiber communication system has remarkably low loss and is reliably capable of meeting the demand of massively increased information traffic employing a minimum number of repeaters in its performance link. In this paper, we discuss broadly optical fiber technology theory, types, working principle with its various merits and demerits in the application scenario. Single-mode graded index fiber has been analyzed in comparison to multi-mode fibers and it has emerged as the most efficient means of broad band signal transmission offering many distinct advantages. The possible consequences of both linear and nonlinear effects of the optical fiber and other limiting factors that influence the performance of propagation characteristics have been discussed which are reasonably relevant to the emerging areas of optical engineering ,photonics and related fiber optic devices.

An Accurately Steerable, Compact Phased Array System for Narrowbeam Ultrasound Transmission

For over more than a decade, ultrasound phased arrays have been playing a leading role in domains such as noninvasive diagnostic examination, nondestructive testing and sonar, and will continue to be indispensable in a wide range of new applications. Unlike the aforementioned traditional scanning systems, many new applications require a transmit-only configuration and work in the low ultrasound frequency range, consequently posing new challenges in low-cost phased array design. However, two sought-after features are still missing in current low-cost ultrasound phased array systems, namely broadband transmission and wide angular beam steering. In this work, a low-cost ultrasound phased array system is presented that enables the transmission of both narrowband and broadband signals. Accurate beam steering is achieved through the concept of Direct Digital Synthesis (DDS). The design features small, wide bandwidth MEMS transducers enabling grating lobe free beam patterns at high frequency and a broad angular beam steering range. The presented prototype supports 64 speaker elements and allows very fine amplitude and phase control over each transducer stage with respectively 10-bit and 12-bit resolution. The beam steering performance is validated for a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${1}\times {10}$ </tex-math></inline-formula> calibrated uniform linear array design. In these measurements, an accuracy in the order of just a few degrees was observed, even at a steering angle of 70° off-axis.

Sparse processing with range migration compensation capability for a frequency agile orthogonal frequency division multiplexing waveform

Digital-to-analogue and analogue-to-digital in a digital array radar limits the transmission and reception of instantaneous broadband signals (IBSs), which makes it a technical bottleneck for digital array radar to obtain an instantaneous broadband high-resolution range profile (HRRP). A frequency-agile orthogonal frequency division multiplexing (OFDM) waveform with a high repetition frequency pulse train is proposed, which uses multiple narrowband OFDM to realise large bandwidth so that the digital array radar can easily realise the broadband working mode. This frequency hopping signal makes the digital array radar have the characteristics of broadband HRRP formation and low interception simultaneously. To solve the problem of range migration caused by high-speed moving targets, a two-stage sparse processing algorithm with range migration compensation capability (FS-RMCSP) in slow time and fast time domains is proposed. By constructing a sparse processing dictionary matrix with range compensation operator according to the phase offset of the moving target echo, the proposed algorithm can complete the compensation of target range migration with high resolution, accurately recover the range-Doppler parameters of target, and realise the coherent accumulation of target echo. The simulation results show that this waveform can obtain the range-Doppler high-resolution characteristics equivalent to the IBS in the radar tracking working mode. Compared with the conventional sparse signal processing algorithm, the FS-RMCSP algorithm significantly improves the performance of target reconstruction in the scene of high-speed moving targets.

DIGITAL ANTENNA ARRAYS SIMULATION

The article describes a simulation model of a digital antenna array, which can be used in broadband signal transmission systems under the influence of broadband interference. The initial information signal has a speed of 19200 bit / s for the I and Q stream. It is proved that the signal level after applying the diagramming of a digital antenna array is four times higher than the signal level without its use, which confirms the advantage of digital radio systems.

Additively Manufactured Dielectric Waveguides for Advanced Concepts for Millimeter-Wave Interconnects

Technology mega trends, such as autonomous driving, multiple-input multiple-output (MIMO), or multi-gigabit communication, drastically increase the demand for ultra-broadband millimeter-wave (mmW) transmission line technologies. A broadband and robust signal and data transmission between components and modules at low cost is a mandatory requirement to ensure high-performance functionality of advanced communication and radar systems. Dielectric waveguides (DWGs) are a highly suitable technology to meet these requirements due to their outstanding transmission capabilities for mmW signals coupled with their high flexibility, low weight, and low cost. Additive manufacturing (AM) processes based on dielectric materials open up new perspectives for fully automated wiring of mmW modules and systems, and they enable cost-efficient application-specific solutions. In this article, we propose novel printed DWG designs with optimized transmission performance. Measurement results of different DWG designs demonstrate the excellent functionality of the proposed transmission line and interconnection concepts. These results and the shown resiliency and practicality of the presented approaches illustrate attractive opportunities for new interconnect technologies based on new manufacturing processes.

Radio-Frequency Impairments Compensation in Ultra High-Throughput Satellite Systems

The quest for massive satellite throughput is relentless, motivating the transmission of broadband signals at multiple Giga-Baud rates. Building low-cost, low-complexity user terminals is essential. These competing drivers conspire to cause analog radio-frequency (RF) components to exceed their tolerance limits. Specifically, analog mixers, anti-aliasing filters and amplification in quadrature frequency-conversion architectures create direct-current (DC) offset and in-phase/quadrature (I/Q) imbalance that is strong and frequency-selective. This paper provides two characterization models of analog RF impairments when the frequency offset is present. Novel digital compensation algorithms with immunity to frequency offset are presented, categorized into equalization with image-rejection capability and image cancellation. Adaptive techniques are utilized that operate without a priori knowledge of RF impairments. Two optimization methods are proposed for the multicarrier scenarios that are useful when using known data samples for factory calibration or in decision-directed mode during field re-calibration. Special consideration is given to estimating the frequency offset during initial factory calibration. Extensive computer simulations reveal that the proposed compensators are robust to frequency offset, provide lossless attenuation of imbalance-induced image and remove DC offset, under numerous scenarios. Cases include when the desired carrier is plagued by image interference from more than one source and on-board high-power amplifier is operated near saturation.

Pulse Characteristics of a Direct Antenna Modulation Transmitter

Direct antenna modulation (DAM) methods using time-varying matching networks offer the possibility to reduce the detrimental effects on broadband signal transmission from a narrowband antenna. We propose time- and frequency-domain models for the effects of a DAM scheme for the transmission of ON-OFF-keyed RF signals and test the validity of the proposed models through over-the-air measurements at 27.12 MHz. Random bit sequences are transmitted separately using both a switched-mode DAM transmitter and a conventional transmitter and received in the far field. Comparison of measured data with our frequency-domain models shows that the DAM transmission method partially removes the effects of narrowband filtering due to the transmit antenna. Models and measurements also demonstrate that the removal of this filter improves the signal quality as observed in eye diagrams of the demodulated received signals. Finally, a simple time-domain model of the DAM transmitter is shown to predict the radiated transient signal under varying synchronization conditions.

Experimental Phase Separation Differential Chaos Shift Keying Wireless Communication Based on Matched Filter

New findings have been identified recently for chaos application in communication systems, including the simplest matched filter to maximize the signal-to-noise ratio (SNR) and the ability to resist multi-path propagation. However, chaos has a broad band frequency spectrum, which impedes its application in the conventional wireless communication systems due to the antenna and transducer bandwidth. To deal with such problem, the chaos generated by a second order hybrid system (SOHS) with a fixed basis function is used for Differential Chaos Shift Keying (DCSK) communication. A sinusoidal and its orthogonal signal are used to separate the reference signal and the information bearing signal, which are transmitted in the wireless channel. In such a way, the obstacle to broadband signal transmission in a wireless channel is overcome. A matched filter, using the convolution of the received signal and the time reverse of the basis function, maximizes the SNR at the receiver. Moreover, the proposed SOHS-DCSK provides an additional bitstream due to the chaotic signal generated by the SOHS, being capable to encode information as well. The two information sub-streams can be transmitted simultaneously in the proposed method, which possesses different bit transmission rates and reliability. In this way, the High Priority (HP) information bits are transmitted at a low transmission rate, while the Low Priority (LP) information bits are transmitted at a higher transmission rate. Hence, the proposed SOHS-DCSK method not only provides a higher data transmission rate as compared to the conventional DCSK but also makes the transmitted signal to be compatible with the conventional transducer and antenna. Due to the matched filter used, the proposed method achieves a lower bit error rate of the HP information as compared to the other existing enhanced DCSK variants for both additive white Gaussian noise channel and wireless communication channel. The numerical simulations and experiments based on the wireless open-access research platform show the validity and superiority of the proposed method.

Adaptive bandwidth mechanism using dual rate OLT for energy efficient WDM–TDM passive optical network

This paper reviews various energy efficient approaches in existence and proposes a Hybrid WDM–TDM PON architecture that allows the adaptive bandwidth allocation mechanism to reduce central office power consumption with acceptable performance. Our proposed architecture allows sending two signals, one broadband and other narrowband to each optical networking unit so an appropriate signal can be utilized according to the traffic demand. In case of very low traffic, only narrowband signal is used and a significant amount of energy consumption and OPEX is reduced. By using $$2\times \hbox {N}$$ power splitter and interleaver, proposed architecture provides broadcasting at both broadband and narrowband signal depending on the required link rate. This further reduces energy consumption and OPEX by avoiding the transmission of same signal from multiple sources. Offered data rates to the optical distribution networks (ODNs) may also be varied by doubling the wavelength spacing of remote node AWG so that two contiguous wavelengths can be transmitted at each port or ODN. This provides the geographical dynamic bandwidth allocation. Proposed architecture also support simultaneous transmission of both broadband and narrowband signals to the ODN to provide bandwidth scalability and network extensibility for supporting future access network in terms of new users and data rates. As two signals are reaching to any ODN, resiliency against OLT TRx and line card failure is also achieved. The performance of the proposed design is verified by simulation results in terms of bit error rate and receiver sensitivity to demonstrate its feasibility for the next-generation optical access network.

Recursive least square–based fast sparse multipath channel estimation

SummaryIn the next‐generation wireless communication systems, the broadband signal transmission over wireless channel often incurs the frequency‐selective channel fading behavior and also results in the channel sparse structure, which is supported only by few large coefficients. For the stable wireless propagation to be ensured, linear adaptive channel estimation algorithms, eg, recursive least square and least mean square, have been developed. However, these traditional algorithms are unable to exploit the channel sparsity. Actually, channel estimation performance can be further improved by taking advantage of the sparsity. In this paper, 2 recursive least square–based fast adaptive sparse channel estimation algorithm is proposed by introducing sparse constraints, L1‐norm and L0‐norm, respectively. To improve the flexibility of the proposed algorithms, this paper introduces a regularization parameter selection method to adaptively exploit the channel sparsity. Finally, Monte Carlo–based computer simulations are conducted to validate the effectiveness of the proposed algorithms.

MIP-Mitigated Sparse Channel Estimation Using Orthogonal Matching Pursuit Algorithm

Wireless communication requires accurate Channel State Information (CSI) for coherent detection. Due to the broadband signal transmission, dominant channel taps are often separated in large delay spread and thus are exhibited highly sparse distribution. Sparse Multi-Path Channel (SMPC) estimation using Orthogonal Matching Pursuit (OMP) algorithm has took advantage of simplification and fast implementation. However, its estimation performance suffers from large Mutual Incoherent Property (MIP) interference in dominant channel taps identification using Random Training Matrix (RTM), especially in the case of SMPC with a large delay spread or utilizing short training sequence. In this study, we propose a MIP mitigation method to improve sparse channel estimation performance. To improve the estimation performance, we utilize a designed Sensing Training Matrix (STM) to replace with RTM. Numerical experiments illustrate that the improved estimation method outperforms the conventional sparse channel methods which neglected the MIP interference in RTM.

Towards Modal Integration of Overhead and Underground Low-Voltage and Medium-Voltage Power Line Communication Channels in the Smart Grid Landscape: Model Expansion, Broadband Signal Transmission Characteristics, and Statistical Performance Metrics (Invited Paper)

The established statistical analysis, already used to treat overhead transmission power grid networks, is now implemented to examine the factors influencing modal transmission characteristics and modal statistical performance metrics of overhead and underground low-voltage/broadband over power lines (LV/BPL) and medium-voltage/broadband over power lines (MV/BPL) channels associated with power distribution in smart grid (SG) networks. The novelty of this paper is threefold. First, a refined multidimensional chain scattering matrix (TM2) method suitable for overhead and underground LV/BPL and MV/BPL modal channels is evaluated against other relative theoretical and experimental proven models. Second, applying TM2 method, the end-to-end modal channel attenuation of various LV/BPL and MV/BPL multiconductor transmission line (MTL) configurations is determined. The LV/BPL and MV/BPL transmission channels are investigated with regard to their spectral behavior and their end-to-end modal channel attenuation. It is found that the above features depend drastically on the frequency, the type of power grid, the mode considered, the MTL configuration, the physical properties of the cables used, the end-to-end distance, and the number, the electrical length, and the terminations of the branches encountered along the end-to-end BPL signal propagation. Third, the statistical properties of various overhead and underground LV/BPL and MV/BPL modal channels are investigated revealing the correlation between end-to-end modal channel attenuation and modal root-mean-square delay spread (RMS-DS). Already verified in the case of overhead high-voltage (HV) BPL systems, this fundamental property of several wireline systems is also modally validated against relevant sets of field measurements, numerical results, and recently proposed statistical channel models for various overhead and underground LV/BPL and MV/BPL channels. Based on this common inherent attribute of either transmission or distribution BPL networks, new unified regression trend line is proposed giving a further boost towards BPL system intraoperability. A consequence of this paper is that it aids in gaining a better understanding of the range and coverage that BPL solutions can achieve; a preliminary step toward the system symbiosis between BPL systems and other broadband technologies in an SG environment.

Broadband Transmission and Statistical Performance Properties of Overhead High-Voltage Transmission Networks

This paper considers broadband signal transmission and statistical performance properties of high-voltage/broadband over power lines (HV/BPL) channels associated with overhead power transmission. The overhead HV/BPL transmission channel is investigated with regard to its spectral behavior, its end-to-end signal attenuation, and its statistical performance metrics. It is found that the above features depend critically on the frequency, the overhead HV power grid type (150 kV, 275 kV, or 400 kV and single- or double-circuit), the coupling scheme applied, the physical properties of the cables used, the MTL configuration, and the type of branches existing along the end-to-end BPL signal propagation. The contribution of this paper is threefold. First, the significant broadband transmission potential of overhead HV lines is revealed. The results demonstrate that, regardless of overhead HV power grid type, the overhead HV grid is a potentially excellent communications medium, offering low-loss characteristics, flat-fading features, and low multipath dispersion over a 25 km repeater span well beyond 100 MHz. Second, regarding the statistical properties of various overhead HV/BPL transmission channels, two fundamental correlations of several wireline systems, for example, coaxial cables and xDSL, are also validated in the case of overhead HV/BPL transmission channels, namely, (i) end-to-end channel attenuation in relation with root-mean-square delay spread (RMS-DS) and (ii) coherence bandwidth (CB) in relation with RMS-DS. Third, fitting the numerical results and other field trial measurements, two regression distributions suitable for each fundamental correlation are proposed.