Electromagnetic compatibility of power line communication systems

The power system has been used for communication purposes for many decades, although it was mainly the power utility companies that used low bit rates for control and monitoring purposes. In the last ten years, however, the deregulation of the power and telecommunication markets has spurred the idea of using and commercializing the power networks for a range of new communication applications and services. The idea has been developed and implemented into both, narrowband and broadband systems, which are defined in terms of the operation frequency band. Depending on the frequency band, the systems over powerlines can be: Narrow-band. They use frequencies ranging from 3-148.5 kHz in Europe, with the upper frequency extending up to 500 kHz in the United States and Japan. In Europe, this frequency range is standardized by CENELEC Standard EN 50065. Broadband. The used frequency range is 1-30MHz; 1-15MHz for outdoor systems and 15-30MHz for indoor systems. In this frequency range, the standardization situation is still unclear and there exist no regulations. The developed applications and systems use different parts of the power network: medium voltage (MV) and low voltage (LV) cabling for outdoor applications and building cabling for indoor applications. These cables are designed and optimized for power transmission at frequencies of 50/60Hz and represent a hostile medium for transmissions at higher frequencies. This thesis concentrates on electromagnetic compatibility (EMC) aspects and some optimization issues of the broadband systems, currently known as Powerline Communications (PLC) or Broadband Power Line (BPL). The work presented here was preformed in the framework of the European project OPERA (http://www.ist-opera.org/). A short description of the project is given in Chapter 1. The second chapter presents the basis, introduction, description and state of the art of the topics of interest for this thesis. That chapter is divided into three parts. Each of these parts starts with a short introduction to the topic to be addressed. The introductions are intended for those not familiar with the topic at hand and they can be skipped by those already knowledgeable of it. The first part of Chapter 2 gives an overview and introduction to telecommunication issues relevant to the thesis, as well as the general technical specifications of the OPERA system. The second part deals with the transmission medium which, for the case of PLC, is the power system. The fundamentals and the different components of the PLC system are given there and the state of the art regarding the transmission channel is presented. The third part deals with the EMC and standardization issues related to the technology. The main contributions of the thesis are presented in chapters 3 to 7. The PLC technology distinguishes itself from other technologies in that it uses already existing, ubiquitous wiring, so that no new infrastructure is needed. On the other hand, using a channel designed originally for other purposes means that it is not optimized for the frequencies and applications of interest for broadband transmission. If PLC is to compete with other technologies, these problems have to be well understood and solved, so that the system can be optimized by taking into account the parameters and constrains of the already existing medium. Although the PLC system is being improved continuously, there are still concerns about emissions, immunity and standardization. These issues are important since PLC operates in an environment already populated by other services at the same frequencies, so that fair co-existence is needed. Moreover, the PLC modem has a combined mains and telecom port and, as a consequence, the standards for conducted emissions from those two types of ports are not directly applicable. In addition, the symmetry of the cables used is low and, therefore, emissions are higher than, for example, emissions from twisted pair cables used in xDSL. A good understanding of emissions and immunity in PLC systems is therefore of great importance for the optimization of the system and for EMC standardization to be based on objective technical criteria. Even if the basic phenomena are essentially the same as for any other wire transmission system, the complexity and variability of the topologies of existing structures is so large that simple, straightforward solutions are often not applicable. Emissions from the cabling are primarily due to the common mode signals. Part of the energy in this mode is injected by the imperfectly balanced output stages of the PLC modems themselves. In addition, the common mode appears at punctual imbalanced discontinuities and distributed asymmetry along the PLC signal path in the power cables. Chapter 3 presents the work performed to improve our understanding of the sources of the common-mode current and the parameters that influence its behavior, including related measurements and simulations. For the purpose of this study, a model house was built at the EPFL's test site. Different cablings were used to study the influence of different parameters on the behavior of the common-mode current since it is the main source for both types of emissions, conducted and radiated ones. The influence of different parameters such as the cable terminations, the symmetry of the termination, the height of the conductors above the ground, the presence of power outlets, switches, empty and occupied sockets and the topology, are analyzed. The data are also used to test two methods used to simulate the differential-to-common-mode conversion and the conducted emissions, namely the transmission line model and the full wave approach provided by the Method of Moments through the Numerical Electromagnetic Code (NEC). In Chapter 4, problems related to PLC immunity testing are treated. We show that the conversion of the differential mode to the common mode is coupled with the reverse conversion by reciprocity. Due to the low symmetry of PLC cabling, part of the injected common mode test signal is converted into a differential mode signal that interferes with the wanted signal at the input of the modem being tested. Depending on the actual symmetry of the Coupling-Decoupling Network (CDN), not specified in the standards, the immunity test may yield erroneous results due to the effect of this differential mode component. Working under the assumption that the CDN is built to exhibit a symmetry similar to that of PLC networks as inferred from its longitudinal conversion loss, we estimate the differential mode disturbance level that the modems should withstand from a narrowband interferer. The bit error rate induced by the presence of the disturbing differential mode current from the CDN is also estimated, for a total physical channel transmission rate of 200 Mbps, to be of the order of 1×10-5 to 5×10-5. Since these rates can be handled by error correcting coding and MAC ARQ procedures, it is concluded that the modems are not likely to suffer any severe performance degradation due to immunity testing if the CDN exhibits a symmetry similar to that of PLC networks. Simulating the complete PLC network or any significant part of it using numerical techniques such as the method of moments proves to be of limited practical use due to the fact that PLC networks extend over many wavelengths. The transmission line approximation, on the other hand, although more efficient and sufficiently accurate for differential mode calculations, is not directly applicable to simulate the EMC behavior since it neglects the antenna-mode currents that are significant contributors to the radiated emissions. Chapter 5 presents a novel approach to evaluate the antenna-mode currents using a modified transmission line theory, thus making this numerically efficient technique applicable to the estimation of emissions in PLC. An integral equation describing the antenna-mode currents along a two-wire transmission line is derived. It is further shown that, when the line cross-sectional dimensions are electrically small, the integral equation reduces to a pair of transmission line-like equations with equivalent line parameters (per-unit-length inductance and capacitance). The derived equations make it possible to compute the antenna mode currents using a traditional transmission line code with appropriate parameters. The derived equations are tested versus numerical results obtained using NEC and reasonably good agreement is found. Another important EMC issue related to PLC is the mitigation of emissions. Chapter 6 describes a technique that has been proposed to achieve a reduction of emissions associated with indoor PLC networks through the introduction of a 180° out-of-phase replica of the PLC signal into the unused neutral-ground circuit. A modification to this technique is proposed based on the selection of the appropriate amplitude and phase of the auxiliary signal, allowing a higher degree of field attenuation. A way of implementing this technique is proposed and studied, namely the integration of a required antenna into the PLC modems themselves. The measured fields very close to the modem allow the determination of the magnitude and phase of the compensation voltage. The proposed implementation should be used only to handle customer complaints, when emissions should be lowered at locations where PLC signals might cause unwanted interference or when additional capacity is required and it can be obtained through the gained signal to noise margin. Although, in principle, due to nonalignment of the wanted and the compensation field directions, minimizing one component of the field may result in an increase of the other components, we show that the application of the technique results in an overall average reduction of 10-20 dB of all the field components in the region of interest. In the same Chapter 6, we address the more general issue of the application of mitigation techniques' gained emissions margin to increase the overall throughput of PLC systems. We show that an increase in the signal power (made possible by the inclusion of mitigation techniques) leads to a considerable increase in the PLC channel capacity. Using a number of simplifications, we show that the capacity of the channel can indeed be increased by up to 66 Mbps for mitigation efficiencies of only 10 dB. We also present the results of laboratory measurements aimed at studying, under controlled conditions, different characteristics of notching in OPERA PLC modems, such as total and effective notch width, notch depth, maximum notch depth, etc. These measurements show that it is possible to obtain attenuations of up to about 45 dB for notches in all frequency bands, 10MHz, 20MHz and 30MHz. What differs for these three bands is the minimum number of carriers that need to be notched to obtain that maximum attenuation. This is an important point, since, to implement notches that have the required depth and width, one must know how many subcarriers to suppress and how deep these need to be reduced. High density PLC deployment requires the increase of overall system data rate. To achieve the higher data rates, frequency reuse in these systems is needed. In Chapter 7, we present the idea for using so-called blocking filters as a possible solution for a frequency reuse. Experimental data obtained on a real distribution network show that the use of blocking filters can, in certain cases, ensure high enough RF separation of the LV feeders belonging to the same substation. In some cases, even with the possibility to design and integrate effective blocking filters, the system needs to provide additional synchronization mechanisms for frequency reuse

Upgrading the Power Grid Functionalities with Broadband Power Line Communications: Basis, Applications, Current Trends and Challenges

This article reviews the basis and the main aspects of the recent evolution of Broadband Power Line Communications (BB-PLC or, more commonly, BPL) technologies. The article starts describing the organizations and alliances involved in the development and evolution of BPL systems, as well as the standardization institutions working on PLC technologies. Then, a short description of the technical foundation of the recent proposed technologies and a comparison of the main specifications are presented; the regulatory activities related to the limits of emissions and immunity are also addressed. Finally, some representative applications of BPL and some selected use cases enabled by these technologies are summarized, together with the main challenges to be faced.This work was financially supported in part by the Basque Government under the grants IT1426-22, PRE_2021_1_0006, and PRE_2021_1_0051, and by the Spanish Government under the grants PID2021-124706OB-I00 and RTI2018-099162-B-I00 (MCIU/AEI/FEDER, UE, funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”)

An experimental investigation into the electromagnetic compatibility aspects of high frequency power line communications

Power line communications technology, long established for low data rate applications, is now charting new territory with respect to data rates and provided services. This can only be achieved by increasing PLC operating frequencies from the low frequency band (below 148.5 kHz) to the high frequency band (1 MHz and upwards). There is now only one technical barrier to widespread deployment - Electromagnetic Compatibility. Existing low voltage power networks are optimised for the safe supply of electrical energy. Low voltage cables are often pseudo co-axial in their cross section, but when high frequency signals are coupled onto the network, part of the signal will be radiated. There is therefore a potential for interference to be caused to legitimate users of the radio spectrum. This thesis, and the experimental program underlying it, seeks to quantify potential problems and to propose mechanisms by which they could be mitigated to the extent that wide scale deployment of PLC networks becomes possible. The first part of the thesis offers a detailed introduction to the topics of electricity supply networks, power line communications, modulation techniques and electromagnetic compatibility. Existing EMC standards are examined and although some do not directly cover power line communications networks, key principals are drawn for later use in standards development. The thesis then seeks to examine the mechanisms by which high frequency interference might be caused. Radio propagation modes are discussed and a clear technical distinction is drawn between localised interference from a single PLC network to an individual radio user, and cumulative interference from wide spread deployment of PLC systems. Both such scenarios are examined in detail. The experimental program IS described quantifying radiated signal strength regression from a number of power networks and at a number of operating frequencies within the high frequency band. In this context, signal strength regression is the rate at which electrical field strength reduces with increasing measurement distance. The experimental setup uses a conventional signal generator to supply single test frequencies of known power spectral density, which are coupled onto a power network. The subsequent radiated signal is received via a conventional antenna and radio receiver at a number of locations surrounding the power network at known distances, and signal regression is derived. The experiment was repeated for a number of different frequencies and at representative urban, suburban and rural locations. Indeed, the experimental technique was evolved over a number of months to allow increased portability of the signal receiving equipment, and hence the number of measurements that could be taken. From the experimental results, presented both In tabular and graphical format, a number of conclusions can be drawn. Firstly, based on these results, antenna factors in the order of 85 dB/m can be expected of power line communication networks. It can be concluded that the field strength regression to be anticipated from PLC networks is likely to be significantly below the -20 dB per decade 'free space' regression figure that has often been used in interference models. In fact a regression figure of -35 dB/decade IS more representative of ground wave propagated interference from PLC networks. It is also possible to conclude that the adoption of orthogonal frequency division multiplexing as a multi-carrier spectral technique offers specific advantages in EMC terms. Due to its nature, it is possible to apply a frequency 'mask' to an OFDM based PLC system. Such a mask might be static, applied on a national or regional basis in order to guarantee non-interference with specific frequencies, for example those used for emergency radio channels. It would also be possible to add a dynamic frequency mask, controllable on each PLC system, to mitigate interference with radio services operating within the PLC operating band

Performance Evaluation of Powerline Technology on Low Voltage Distribution Networks

Powerline technology (PLT) employs the electrical distribution network to transmit data in addition to supplying power. PLT is currently employed to provide data networking in many domestic environments, and is expected to play a major part in the development of the forthcoming Smart Grid. Given that the electrical distribution network was not designed with data transmission in mind, electromagnetic radiation from the network can give rise to interference. Regulators and researchers have considered the impact of such widespread radiation, and investigations of the various aspects of powerline have been conducted over the last decade. Despite this prolonged period, however, there remains a lack of agreement on the typical performance of such networks or the implications for regulation policy. An accurate model of the radio frequency (RF) properties of the typical electrical distribution network would be extremely valuable in developing standards and informing policy. The aim of this thesis is to provide a cohesive approach to determining the RF characteristics of a typical domestic property and applying such parameters to model the performance of PLT. The thesis reviews the recent development of broadband PLT, the progress made by the more prominent regulators, and the trials undertaken to define the key parameters affecting propagation. A detailed experimental programme carried out both in the laboratory and at typical sites is described. An empirical model of the RF performance of a UK domestic low voltage distribution network (LVDN) is developed from analysis of the experimental results. It is shown via this analysis that discrete measurements of the conducted and radiated parameters can be related and that the RF performance of the LVDN can be described by Conversion and Radiated Loss. The radiated field is shown to comprise the combined common mode current to the LVDN and common bonding network (CBN). The thesis concludes with consideration of the future development of powerline technology, particularly in support of the Smart Grid development

Ultra wideband gigabit powerline communication

PhDPowerline Communication (PLC) has long been established for low data rate applications by the electric supply companies. Since 1991, the European CENELEC standard EN 50065 has ruled the use of 3 - 148.5KHz frequency range for narrow band PLC applications. Sim- ilar standard has been established by the IEEE in the US, where a frequency range of 50 - 450KHz is available. The fast growth of Internet since the 1990s accelerated the demands for digital communication services. Furthermore, with the develop- ment of in-home networking, there is a need to establish high speed data links between multiple household devices. This makes PLC sys- tems march rapidly into the high frequency range above 1MHz. Exist- ing broadband PLC system in the 1.6 - 30MHz frequency range only provides data rates smaller than 200Mbps. With the growing demand of multimedia services such as High De nition (HD) video streaming, much faster transmission speed up to Gigabits per second is required and this can be achieved by increasing the operating frequencies. Ultra Wideband (UWB) transmission in free space provides extremely broad bandwidth for short-range, high data rate applications. If UWB signals could be transmitted over the powerline channels in the high frequency range above 30MHz, data rates up to gigabits per second could be achieved. In this thesis, the possibility of implementing ultra wideband trans- mission over the low voltage indoor powerline is investigated. The starting point is to understand the signal propagation characteristics over powerline cables, in the UWB frequency range. Experimental re- sults indicate that the signal degrades at an acceptable rate over the mains cable in a scaled down UWB frequency band (50MHz - 1GHz), which provides a potential operation band for UWB over PLC ap- plications. Key component for the PLC system, a broadband Radio Frequency (RF) coupler is designed and developed, to introduce UWB signals to the transmission channel. With the channel properties and coupling unit, extensive experimental investigations are carried out to analyse the powerline network environment, including channel loss, noise and radiated emission. Furthermore, theoretical channel capac- ity and link budget are derived from measured parameters. It is shown that the indoor powerline is a suitable media for data transmission in the high frequency range from 50 to 550MHz in the home environment. Finally, system level performance is analysed by modelling the Phys- ical Layer (PHY) data transmission. The Multiband-OFDM UWB proposal for IEEE 802.15.3a standard is used to predict the transmis- sion performance under di erent propagation paths and data rates. The research work conducted in this project has proven that UWB over PLC is highly feasible for future in-home applications. With the global promotion of smart grid applications, UWB over PLC will play an important role in providing high speed data transmission over the power networks

Power line communication (PLC) channel measurements and characterization.

M. Sc. Eng. University of KwaZulu-Natal, Durban 2014.The potential of the power line to transport both power and communication signals simultaneously has been realized and practiced for over a century, dating back to the 1900’s. Since the key aspect of power line communications being its expansivity, its implementations were largely as a retrofit technology. This motivation of power line communication is typical for low-, medium-, and high voltage distribution networks. Beyond the “last mile” part, there’s an uprising appeal for intra-building networks currently targeted for home automation (smart homes/buildings) and in-building networking. The optimum use of the existing power line channels has been a focus area for researchers and designers, with the inherent channel hostility proving a serious drawback for high speed data communications. The low-voltage electrical network has unpredictable noise sources, moreover it has two other main disadvantages as a communication channel. The first short coming has to do with the unknown characteristics of the power cable and topology of the network, the second arises from the time-dependent fluctuation of the impedance level of the power line as the loads are switched into and out of the power line network in an unpredictable manner. These factors determine the behaviour of the power line channel when a high frequency signal is impressed on it. This study has shown that the behaviour of indoor power line channels can be captured using a multipath based model even with limited qualitative and/or quantitative knowledge of the network topology. This model is suitable for typical indoor power line channels where knowledge of the topology is near impossible. Some of the feed parameters are obtained through measurements. With sufficient adjustment of control parameters, this model was successfully validated using sample measured channels from the numerous measurements. Through noise measurements, this study has established that impulsive noise is the rifest in the frequency band of interest. The impulsive energy rises well above background noise, which translates to possible data “black outs”. The statistics of the components of this noise are presented. A model of sufficient simplicity is used to facilitate the qualitative description of the background noise through its power spectral density. Two descriptions are provided in terms of the worst and best case scenarios of the background noise occurrences. The model has a good macroscopic capture of the noise power spectral density, with narrow-band interference visible for the worst case noise. Due to the multipath nature of the power line channel, this study also presents the dispersive characteristics of the power line as a communication channel. The power delay profile is used to determine parameters such as first arrival delay, mean excess delay, root mean square delay spread and maximum delay spread. The statistics of these parameters are presented. Also, the coherence bandwidth of power line channels is studied and its relationship with the rms delay spread is developed. It is in view of this work that further research in power line communication and related topics shall be inspired

AI/ML assisted Li-Fi communication systems for the future 6G communication systems

Η πανταχού παρούσα εξάπλωση της ασύρματης σύνδεσης κατά την τελευταία δεκαετία είχε ως αποτέλεσμα μια τεράστια αύξηση του όγκου της κίνησης και μια τεράστια ζήτηση, η οποία δημιούργησε μια αξιοσημείωτη πίεση στους πόρους του δικτύου που δεν μπορούν να διαχειριστούν εξαρχής λόγω της σπανιότητας του εύρους ζώνης. Επομένως; Η Optical Wireless Communication θεωρείται ως η αναδυόμενη λύση για τα τρέχοντα δίκτυα ραδιοφώνου, όπου λειτουργεί στην εκμετάλλευση του φωτός ως ασύρματος φορέας και έχει ταξινομηθεί ως φιλική προς το περιβάλλον τεχνολογία λόγω της βιωσιμότητας και του επιπέδου ασφάλειας. Το Light-Fidelity (LiFi) είναι το πιο πρόσφατο παράδειγμα της οπτικής ασύρματης επικοινωνίας όπου υπάρχουν νέα χαρακτηριστικά όπως π. Στο σύστημα έχουν εισαχθεί τεχνικές διαμόρφωσης πολλαπλών φορέων και τεχνολογίες πολλαπλής πρόσβασης. Αυτή η αναφορά παρουσιάζει τη διαδικασία σχεδιασμού ενός πομποδέκτη LiFi που χρησιμοποιεί το MATLAB. όπου όλα τα μέρη του συστήματος προσομοιώθηκαν για να μιμηθούν ένα σύστημα LiFi σε ένα εσωτερικό περιβάλλον που είναι ένα δωμάτιο με διαστάσεις 5 x 5 x 3 m. Ο πομποδέκτης έχει χαρακτηριστεί με χρήση οπτοηλεκτρονικών συσκευών περοβσκίτη λόγω της πολλά υποσχόμενης απόδοσής του όσον αφορά την εκπομπή φωτός και την ανίχνευση. Ωστόσο, έχει προκύψει σημαντικός όγκος θορύβου λόγω της φωτοανίχνευσης που έχει μετριαστεί με την εισαγωγή ενός ενισχυτή transimpedance μετά τον φωτοανιχνευτή και την εφαρμογή ενός μηχανισμού εκτίμησης καναλιών στην πλευρά του δέκτη. Τα ληφθέντα αποτελέσματα έδειξαν ότι το σχεδιασμένο σύστημα μπορεί να επιτύχει περίπου 3,5 Mbps με 25dB SNR και λιγότερο από 4x10^(-6) BER χρησιμοποιώντας 5 πομπούς με 1000 LED σε κάθε πομπό, χωρίς να λαμβάνεται υπόψη καμία εξωτερική πηγή θορύβου όπως ο θόρυβος περιβάλλοντος. Οι πιθανοί περιορισμοί για ένα τέτοιο σύστημα είναι οι προδιαγραφές των οπτοηλεκτρονικών συσκευών που περιλαμβάνουν, την επιφάνεια της συσκευής, το οπτικό πεδίο του φωτοανιχνευτή και τη γωνία μισής ισχύος του LED. Ωστόσο, τα συστήματα οπτικών ασύρματων επικοινωνιών είναι πιο ευέλικτα για βελτιστοποίηση και τα σχέδια μπορούν να τυποποιηθούν σύμφωνα με την ζητούμενη υπηρεσία και τη φύση του περιβάλλοντος λόγω της ποικιλίας των διαθέσιμων συσκευών με χαμηλό κόστος.The ubiquitous spread of the wireless connection during the last decade has resulted in a tremendous growth in the traffic volume and a huge demand, which created a remarkable pressure on the network’s resources that can’t be managed due to bandwidth scarcity in the first place. Therefore; Optical Wireless Communication is considered as the emerging solution for the current radio networks, where it works on exploiting light as a wireless carrier and it has been classified as eco-friendly technology due to its sustainability and safety level. Light-Fidelity (LiFi) is the most recent paradigm of the optical wireless communication where new features such as; multicarrier modulation techniques and multiple access technologies have been introduced to the system. This report presents the design process of a LiFi transceiver using MATLAB; where all system parts were simulated to imitate a LiFi system in an indoor environment which is a room with dimensions of 5 x 5 x 3m. The transceiver has been characterised using perovskite optoelectronic devices due to its promising performance in terms of light emission and detection. However, a considerable amount of noise has been resulted due to the photodetection that has been mitigated using inserting a transimpedance amplifier after the photodetector and implement a channel estimation mechanism at the receiver side. The obtained results have demonstrated that the designed system can achieve around 3.5Mbps with 25dB SNR and less then 4x10^(-6) BER using 5 transmitters with 1000 LED at each transmitter, without considering any external source of noise such as the ambient noise. The prospective limitations for such a system are the optoelectronic devices specs which include, the device’s surface area, the photodetector’s field of view, and the half power angle of the LED. However, the optical wireless communication systems are more flexible to be optimized and the designs can be standardized according to the requested service and the environment nature due to the variety of the available devices with low cost

Experiments with Radiated Interference from In-Home Power Line Communication Networks

Abstract-Power line communication (PLC) technology is at a tipping point and may become ubiquitous as a home networking technology. However, there are concerns regarding RF interference between PLC networks and other radio operators. It is imperative that the interference dynamics of PLC systems be fully understood in advance of any large-scale roll-out. In this work, we experiment with two interference scenarios: notch-infilling due to non-linear mixing and mitigation of radiated emissions using RF chokes. In our controlled test bed environment, we measure RF emissions from the power line devices in the 1 MHz to 30 MHz range. Through the results and simulation, we demonstrate that the effect of non-linear devices may be less of a concern than initially thought, and that simple methods can be employed to control local RF interference

TV White Space and Broadband Power Line Communications for Indoor High Speed Networks

Current indoor networks have growing data rate demands to satisfy high speed applications. Broadband power line communications (BPLC) and TV white space (TVWS) communications are considered as effective solutions for indoor networks. However, they encounter several challenges concerning coexistence with wireless services. In this thesis, cooperative BPLC and TVWS is investigated in the very high frequency (VHF) band, for the aim of complementing each other to deliver enhanced performance. The main contributions of the thesis are multi-folds. In the first contribution, a general statistical based path loss mapping (GSBPL) approach is proposed for modelling the path loss of indoor low voltage (i.e. 220 v) BPLC. Also, a simplification method is proposed for computing the channel transfer function, which is proved to be more general and computationally more efficient than the previous method in literature. The feasibility of the cooperation between BPLC and wireless communications is thus concluded, through comparing their corresponding path losses. In the second contribution, a general model is proposed to map the TVWS interference with the BPLC in the VHF band, through exciting antenna mode currents along low voltage BPLC cables. A new model is presented for current conversion from antenna to differential mode, which includes a general formula for the antenna mode characteristic impedance and two solutions to the formulated problem: a) a numerical solution referred to as the antenna theory numerical (ATN) approach; b) an analytical solution referred to as the enhanced TL approximation (ETLA) approach. This is the first reported work to obtain the antenna mode characteristic impedance by the antenna theory. The ETLA approach outperforms the previous frequency-independent solution and requires a reduced complexity over the ATN approach. In the third contribution, new hybrid systems utilising BPLC and TVWS are proposed in the VHF band referred to as white BPLC (WBPLC). Two cases are considered in the proposed system: a) point-to-point WBPLC multiple-input multiple-output (MIMO) system, where a power allocation algorithm and an iterative precoding technique are proposed to maximise the ergodic capacity, subject to the constraints of total power and interference limit at the TV primary user (PU) receiver (Rx); b) point-to-multipoint WBPLC MIMO system. The overall network downlink capacity maximisation problem is investigated, using an efficient algorithm for power and subcarrier allocation among different users