Digital communications over power lines is an old idea that dates back to the early 1920s, when the first patents were filed in this area. Since then, power utility companies have used power line communications (PLCs) for a couple of decades for narrowband applications such as metering and control. In the past decade, however, there has been a renewed interest in the possibility of exploiting power line cables as a broadband communications medium. Moreover, as opposed to the past where the focus was on low rate utility applications and broadband Internet access, today’s interests spans several important applications: indoor wired local area network (LAN) for residential and business premises, in-vehicle data communications, smart grid applications (advanced metering and control, peak shaving, mains monitoring, distribution automation), and other municipal applications, such as traffic lights and lighting control, security, etc. For some of these applications, products are already available on the market, allowing bit rates in the order of several hundreds of megabits per second (Mb/s). Such products are specified by IEEE and ITU-T standards, of by Industry Alliances.
The topic of PLCs is difficult as it lies at the intersection of several fields: circuit analysis, transmission line theory, electromagnetic theory, signal processing, and communications and information theory. It is certainly true that these considerations also apply to other (and more conventional) communications channels such as the wireless or the telephone channel, however, today, communications engineers have the availability of abstracted and simplified models for the wireless and telephone channels because the initial efforts devoted to the modeling of these classical channels date back many decades. Therefore, a shift from the electromagnetic and circuit analysis to the communication domain has naturally occurred with time. This is not yet true for the power line channel, whose modeling is still tied to approaches and tools of other-than-communications disciplines, so that adequate channel models have not yet been standardized, and there is no widely accepted channel model similar to those derived for mobile radio or telephone channels. The consequence of this is that a solid communications and information theoretic approach to PLCs is still lacking, and general results on the ultimate performance achievable over the power line channel are scarce.
Most of the published papers on PLC have appeared in the IEEE Transactions on Consumer Electronics, the IEEE Transactions on Power Delivery, the IEEE Transactions on Industry Applications, and the IEEE Transactions on Industrial Electronics, whereas very few papers on PLCs have appeared in publications traditionally dealing with communications problems. This complicates bibliographic research so we believe that this Best Readings on PLC can become a valuable bibliographical resource to those starting to work on PLCs and who find themselves with the objective difficulty of dealing with a bibliography composed of many technical papers scattered across a very large number of diverse journals and conferences.
Issued January 2015
- List of IEEE ComSoc Journals/Periodicals/Conferences
Magazines and Journals
IEEE ComSoc owned and co-sponsored Magazines and Journals that accept papers on PLC are:
- IEEE Communications Magazine
- IEEE Network
- IEEE Communications Letters
- IEEE Communications Surveys & Tutorials
- IEEE Journal on Selected Areas in Communications
- IEEE Transactions on Communications
- IEEE/ACM Transactions on Networking
- IEEE/KICS Journal of Communications and Networks
- IEEE Transactions on Smart Grid
Additional IEEE Journals that accept papers on PLC are:
- Proceedings of the IEEE
- IEEE Transactions on Power Delivery
- IEEE Transactions on Power Apparatus and Systems
- IEEE Transactions on Consumer Electronics
Other non-IEEE journals that accept papers on PLC are:
- Journal of Electrical and Computer Engineering (Hindawi)
- European Transactions on Telecommunications (EIT)
- International Journal of Electronics and Communications (AEÜ)
- Journal of Communications (Academy Publisher)
- Telecommunication Systems (Springer)
- Journal on Advances in Signal Processing (EURASIP)
The premiere IEEE conference dedicated to all aspects of PLCs is the IEEE International Symposium on Power Line Communications and Its Applications (ISPLC). This conference was started in 1997 by communications researchers in Europe and Asia and became an IEEE ComSoc portfolio conference in 2006. ISPLC proceedings are available on Xplore starting from year 2005, and the proceedings for the years 1997-2004 have been made available online by the IEEE ComSoc Technical Committee on Power Line Communications (TC-PLC).
Main IEEE ComSoc portfolio conferences that accept papers on PLCs are listed below:
Additional IEEE conferences that accept papers on PLCs:
- IEEE Transmission and Distribution Conference and Exposition
- IEEE-Workshop on Power Line Communications
- IEEE Consumer Communications and Networking Conference (CCNC)
- IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)
- Highlight of 2014 Updates
This 2014 update is based on a redesigned template, the list of best readings has been updated and revised when necessary, and best readings on new PLC topics were also added, e.g. EMC (with both radio and wires), MIMO, Smart Grid, and PLC for vehicles.
List of 2014 Contributors
Prof. A.J. Han Vinck (Chair) – University of Duisburg-Essen, Essen, Germany.
Francisco J.Cañete Corripio
Hendrik C. Ferreira
Haniph A. Latchman
- Overview Books
H. Ferreira, H. Grove, O. Hooijen, and A.J.H. Vinck, Power line communication, Wiley Encyclopedia of Electrical and Electronics Engineering (ed. J. Webster), Wiley 1999.
A very informative overview of historical developments, challenges, and opportunities using power line communications.
Powerline Communications, K. Dostert, Prentice-Hall, 2001.
Already a classic, this book reviews technical challenges and provides design guidelines for the use of power lines for telecommunications.
Power Line Communications - Theory and Applications for Narrowband and Broadband Communications over Power Lines, Editors: H.C. Ferreira, L. Lampe, J. Newbury, and T.G. Swart, Wiley and Sons, Ltd., June 2010.
This is the most comprehensive text on power line communications available today and thus a good starting point for anybody entering the field, as well as researchers and practitioners already familiar with power line communications. It covers a broad range of topics (including channel modeling, standards, coding and modulation, coupling) pertinent to the design, implementation, and application of power line communications systems, with contributions by over 30 experts in the field.
- Overview Papers
Overview Papers are listed in the various sections dedicated to specific topics.
- Special Issues
H.A. Latchman, L.W. Yonge, “Power line local area networking,” IEEE Communications Magazine, vol. 41, no. 4, April 2003.
There are five articles. An overview on the history of PLC as well as a description of ongoing research, applications, regulatory activities, market perspectives, and commercial applications of PLC. Theoretical and Field Performance Comparison between 802.11 Wireless and Power Line Home- Plug 1.0 indoor Protocols. Performance of indoor communication channels that use discrete multitone modulation.Techniques for extending in-home power line LANs to the neighborhood transformer using OFDM.
S. Galli, A. Scaglione, K. Dostert,“Broadband is power: internet access through the power line network,” IEEE Communications Magazine, vol. 41, no. 5, May 2003.
This issue contains an overview of the topology of the mains network, including both the medium and low voltage parts, and a discussion about the many regulatory issues involved in power line communications. The advantages and disadvantages of many modulation and coding schemes are put face to face with the unique challenges of the power line channel, pointing out new research directions and solutions for the indoor and outdoor environments. It also contains advanced signal processing techniques based on multicarrier code-division multiple access and turbo multiuser detection to enable high-speed data communications over the low-voltage power distribution network. Two short articles summarize the results of two ongoing field trials of power line communications in the USA and Europe.
F.N. Pavlidou, H.A. Latchman, A.J. Han Vinck, R.E. Newman, "Powerline communications and applications,” International Journal of Communication Systems, vol. 16, issue 5, June 2003.
The purpose of this Special Issue is to collect representative research in the general area of low-voltage and medium-voltage PLCs (PLC channel characterization, measurements and theoretical analysis, economic and regulatory impacts, PLC in-building networking, Internet access and applications beyond the Internet) in order to underscore the global progress and to motivate further work in this area. Seven papers were selected. Included are papers on EMC and mitigation in indoor environment, measurements, MAC and PHY protocols, modelling and simulation results, multicarrier transmission on indoor power lines and the low voltage grid.
E. Biglieri, S. Galli, Y.-W. Lee, H.V. Poor, H. Vinck, "Special issue on power line communications," IEEE Journal on Selected Areas in Communications, vol. 24, no. 7, July 2006.
For this issue, 13 papers were selected. The papers can be divided into two main categories: Channel Modeling, and Communications and Signal Processing. In the section Channel Modeling there are six papers on the modeling of the outdoor and in- door power line channels, plus a paper that deals with a unique environment: communications over mass transit power traction networks. The section on Communications and Signal Processing deal with the optimization of the physical-layer of PLC systems, and the analysis of the media access control scheme of HomePlug 1.0, an industry specification on which many commercially available PLC modems are based.
M.V. Ribeiro, L. Lampe, K. Dostert, H. Hrasnica, "Special issue on advanced signal processing and computational intelligence techniques for power line communications," EURASIP Journal on Advances in Signal Processing, vol 2007.
This special issue contains seven papers, which are dedicated to advanced signal processing techniques for communications. Topics include several modulation and detections techniques, synchronization and error control coding.
M.V. Ribeiro, J. Szczupack, M.R. Iravani, “Special Issue on Emerging Signal Processing Techniques for Power Quality Applications,” EURASIP Journal on Applied Signal Processing, Volume 2007.
The purpose of this special issue is to bring together works done by researchers with different background in signal processing, power systems, and power quality with the common goal of developing a better understanding about the applicability of signal processing in the power quality field and of drawing the attention of the signal processing and power system communities to this challenging field. The 11 papers are divided into four categories: challenges and trends, classification, detection, and diagnosis, transient modeling and analysis, spectral analysis. Most of these papers contain results validated by measurements.
L. Lampe, A.M. Tonello, D. Shaver, “Power line communications for automation networks and Smart Grid," IEEECommunications Magazine, vol.49, no.12, Dec. 2011.
The four articles in this feature topic issue cover a broad range of aspects of PLC for automation networks and smart grid. The selection of articles contains valuable new and overview information for professionals working in the PLC area, and also provides an interesting read for the generally knowledgeable engineer and manager who wants to learn about the possibilities, challenges, and solutions for PLC.
J. Anatory, M.V. Ribeiro, A.M. Tonello, A. Zeddam, “Power-Line Communications: Smart Grid, Transmission, and Propagation,” Journal of Electrical and Computer Engineering, vol. 2013.
The papers make an ensemble with a topic spectrum ranging from improved maximum likelihood detection of spread frequency shift keying (S-FSK) in PLC automatic meter reading (AMR), radiation mitigation for PLC, optimal receiver impedance design for SNR maximization in broadband PLC, PLC for Smart Grid applications, improvements of G3-PLC technology for Smart-Home/Building applications, and finally an overview of the HomePlug AV2 technology.
JSAC Series on Smart Grid Communications in the IEEE Journal on Selected Areas in Communications, vol. 30, no. 6, July 2012. Series Editorial Board: N. Golmie, L. Lampe, A. Scaglione, and E. dmund Yeh
The articles in this issue can be grouped into 4 main sub-topic areas, namely, scheduling and load balancing, energy pricing, routing, and security. A broad range of topics are covered, from load scheduling to electrical vehicles in the smart grid.
- Articles of Historical Nature
J.T. Tengdin, “Distribution line carrier communications - an historical perspective,” IEEE Transactions on Power Delivery, vol. 2, no. 2, April 1987.
This paper presents some history but important, also the results from experimental trials. State of the art is 1987. It is written from the perspective of systems that General Electric and Rockwell International implemented. It considers noise, signal propagation, filtering at the input of the receiver and coupling mode. Many useful graphs with numerical parameters investigating frequency dependency are presented. The performance of the Golay error correcting code in case studies is presented.
H.C. Ferreira and O. Hooijen, “Power line communications: an overview,” Transactions of the South African Institute of Electrical Engineers, vol. 86, no. 3, Sept. 1995.
Wide coverage of topics. State of the art in 1995. Extensive bibliography of references pre-1995. Includes a systems level and historical overview. Topics include the channel with emphasis on noise and disturbances, impedance, coupling and channel modeling. Communications systems and solutions are discussed, as well as electromagnetic compatibility and interference. Some typical numerical parameters and graphs are presented.
N. Pavlidou, A.J. Han Vinck, J. Yazdani, and B. Honary, “Power line communications: state of the art and future trends,” IEEE Communications Magazine, vol. 41, no. 4, April 2003.
This paper presents a short but valuable overview of some fundamental physical considerations, and also the state of the art around 2003. It covers the channel, noise, modulation techniques, coding, medium access, standards and market. Some useful numerical parameters and graphs are presented for the channel and noise.
A. Majumder and J. Caffery Jr., “Power line communications: an overview,” IEEE Potentials Magazine, vol. 23, no. 4, Oct. - Nov. 2004.
A good short tutorial introduction. State of the art in 2004. Wide coverage but not in analytical depth. Recommended as a first read with sufficient comprehensive coverage.
M.S. Yousuf and M. El-Shafei, “Power line communications: an overview - Part I,” International Conference on Innovations in Information Technologies, Dubai, 18-20 Nov. 2007.
M.S. Yousuf, S.Z. Rizvi, and M. El-Shafei, “Power line communications: an overview - Part II,” Information and Communication Technologies: From Theory to Applications, Damascus, 7-11 April 2008.
This is a two part paper. It covers a short overview and historical introduction, without great analytical depth. The emphasis is on introducing standards. It briefly discusses some fledgling standards around 2008. The paper has most value in introducing the Homeplug standards.
M. Schwartz, "Carrier-wave telephony over power lines - early history," IEEE Communications Magazine, vol. 47, no. 1, Jan. 2009.
Excellent account of the use of power line communications for voice communications in the early 1900s.
- Articles on Standards
S. Mak and D. Reed, "TWACS, a new viable two-way automatic communication system for distribution networks. part I: outbound communication," IEEE Transactions on Power Apparatus and Systems, vol. 101, no. 8, Aug. 1982.
S. Mak and T. Moore, "TWACS, a new viable two-way automatic communication system for distribution networks. part II: inbound communication," IEEE Transactions on Power Apparatus and Systems , vol. 103, no. 8, Aug. 1984.
Two-Way Automatic Communications System (TWACS) is an UNB-PLC technology that has found substantial deployment in the USA, especially in rural areas. TWACS uses disturbances of the voltage waveform for outbound (substation to meter) communication and of the current waveform for inbound (meter to substation) communication. TWACS is used for both AMR and distribution automation and, despite its very low data rate (~100 bps), it is today used in the largest AMI and Direct Load Control Demand Response systems in the world (Florida, USA).
I. Berganza, A. Sendin, A. Arzuaga, M. Sharma, and B. Varadarajan, "PRIME interoperability tests and results from field," IEEE International Conference on Smart Grid Communications (SmartGridComm), Gaithersburg, MD, Oct. 4-6, 2010.
The PRIME (PoweRline Intelligent Metering Evolution) specification was developed by PRIME Alliance to provide an OFDM based narrowband PLC standard over the CENELEC-A band. The first paper gives a nice overview of the PRIME standard, with a focus on the certification and interoperability tests defined by the PRIME Alliance, to ensure openness and future-proof technical performance with multi-vendor solutions. PRIME is now an NB-PLC technology approved in the ITU-T as Recommendation G.9904.
K. Razazian, K., M. Umari, A. Kamalizad, V. Loginov, and M. Navid, "G3-PLC specification for powerline communication: overview, system simulation and field trial results," IEEE International Symposium on Power Line Communications and Its Applications (ISPLC), Rio de Janeiro, Brazil, 28-31 March 2010.
This paper contains an overview of the multi-carrier based industry specification named G3-PLC, which is a NB-PLC technology now approved in the ITU-T as Recommendation G.9903. In particular, the physical layer is addressed, which operates in the low-frequency band, from 35.9 kHz to 90.6 kHz. The block-diagram of the G3-PLC system and the transmission frame format are explained. Simulations are discussed showing the expected performance of G3-PLC modems over simple channels with low-pass filters and AWGN. Afterwards, some field trial results on actual medium-voltage and low-voltage power line channels are presented. In particular, results are presented for the first time showing performance of modems residing on opposite sides of a 20 kV - 220 V transformer that interfaces an MV power line to an LV power line.
Hoch, M., "Comparison of PLC G3 and PRIME," IEEE International Symposium on Power Line Communications and Its Applications (ISPLC’11), Udine, Italy, April 3-6, 2011.
G3-PLC and PRIME are two NB-PLC techncology that have been first developed in industry alliances and then standardized in 2012 the ITU-T as International standards – Recommendations G.9903 and G.9904, respectively. In this paper, the Physical Layers described in these two technologies are presented and compared from a theoretical perspective and also by contrasting simulation results. The frequency range is from 35 to 91kHz and OFDM (Orthogonal Frequency Division Multiplexing) is employed in both cases. In the simulations, the Katayama model is used to generate colored and cyclostationary noise together with AWGN and a collection of frequency selective channels. The transmission system performances is analyze for several modulations allowed in both technologies. NB-PLC transceivers compliant to G.9903 (G3-PLC) and G.9904 (PRIME) are the only multicarrier-based NB-PLC technologies actually deployed in the field.
Oksman, V.; Jin Zhang, "G.HNEM: the new ITU-T standard on narrowband PLC technology," IEEE Communications Magazine, vol.49, no.12, Dec. 2011.
This paper provides a technical overview of the ITU-T G.hnem standard (Recommendation G.9902), which defines a NB-PLC OFDM-based technology. The G.hnem network architecture is briefly described, including the domain structure and protocol reference models. Also, the physical layer details are addressed: channel coding, modulation parameters, frequency band plans, and carriers distribution. The transmission frame format, with the preamble and symbols for channel estimation and physical layer header, is explained. Finally, an overview of the data link layer is given.
M.K. Lee, R.E. Newman, H.A. Latchman, S. Katar, and L. Yonge, "HomePlug 1.0 powerline communication LANs - protocol description and performance results," International Journal of Communication Systems, Special Issue: Powerline Communications and Applications, vol. 16, no. 5, pp. 447-473, June 2003.
This paper was the first publication describing the details of the FFT-OFDM based PHY and the CSMA/CA MAC for HomePlug 1.0 specification, as well as the cross layer design and adaptations for the challenging broadband PLC channel (2-28 MHz), along with prioritized channel access. The paper presents theoretical and simulation performance results for the HomePlug 1.0 protocol complemented by ideal laboratory measurements with actual HomePlug 1.0 devices and field tests in a residential building. Theoretical PHY throughput was shown to be 14 Mbps and sustained measured MAC throughput up to 7 Mbps. The HomePlug 1.0 CSMA/CA protocol is also used in all later HomePlug-based Broadband PLC standards such as HomePlug AV and IEEE 1901.
M.Y. Chung, M.-H. Jung, T.-J. Lee, and Y. Lee, "Performance analysis of HomePlug 1.0 MAC with CSMA/CA," IEEE Journal on Selected Areas in Communications, vol.24, no.7, pp. 1411-1420, July 2006.
The world's first BB-PLC ANSI standard to be approved was the TIA-1113. The standard is largely based on the HomePlug 1.0 specifications and defines a 14 Mbps PHY based on OFDM. The first paper gives a comprehensive description of the MAC and PHY specification of the protocol and the second paper gives a good description of the CSMA/CA-based MAC and also analyzes in depth its performance.
K.H. Afkhamie, S. Katar, L. Yonge, and R. Newman, "An overview of the upcoming HomePlug AV standard," International Symposium on Power Line Communications and Its Applications (ISPLC), Vancouver, BC, Canada, pp. 400-404, 6-8 April 2005.
This paper gives an overview of the HomePlug AV specification in terms of augmentations of the HomePlug 1.0 MAC and PHY in order to achieve an order of magnitude improvement in throughput, while preserving backward coexistence and interoperability with HomePlug 1.0 devices. The paper describes how some of the system level choices were influenced by either the characteristics of the power line channel, the regulatory environment, application requirements, or by implementation constraints. In particular the paper shows how the use of an adaptive modulation scheme, using up to 10 bits per carrier as well as more efficient turbo coding, results in effective MAC throughputs of approximately 70 Mbps. The paper also describes a novel TDMA/CSMA MAC optimized for realtime multimedia applications. The HomePlug AV is one of the major contributing specifications included in the IEEE 1901 Standard.
S. Galli, H. Koga, and N. Kodama, "Advanced signal processing for PLCs: Wavelet-OFDM," IEEE International Symposium on Power Line Communications and Its Applications (ISPLC), Jeju Island, Korea, April 2-4, 2008.
This paper gives some details on the HD-PLC solution for a BB-PLC transceiver which is based on Wavelet-OFDM. Comparisons with windowed FFT-OFDM are also made. This technology has been included as one of the two PHYs of the ratified IEEE 1901 standard and it is the first standard ever made that includes wavelets in its specifications.
J. Abad, A. Badenes, J. Blasco, J. Carreras, V. Dominguez, C. Gomez, S. Iranzo, J.C. Riveiro, D. Ruiz, L.M. Torres, and J. Comabella, "Extending the power line LAN up to the neighborhood transformer," IEEE Communications Magazine, vol.41, no.4, pp. 64-70, April 2003.
This paper provides a description of the FFT-based 45Mbps and 200 Mbps OFDM PHY and CSMA/CA MAC developed by DS2/UPA. The paper also describes several large scale PLC test results involving thousands of PLC nodes using this technology.
S. Galli and O. Logvinov, "Recent developments in the standardization of power Line communications within the IEEE," IEEE Communications Magazine, vol. 46, no. 7, pp. 64-71, July 2008.
The IEEE 1901 Working Group was established in 2005 with the goal of developing a standard for high-speed (>100 Mbps) communication devices using frequencies below 100 MHz and addressing both HAN and access applications. The standard was recently ratified at the end of 2010. This paper gives an overview of the IEEE 1901 Broadband over Power Lines standard. Although the paper is some years old, the technical proposal has not changed between 2008 and 2010 when the standard was ratified so the information given in the paper is accurate.
S. Goldfisher and S. Tanabe, "IEEE 1901 access system: An overview of its uniqueness and motivation," IEEE Communications Magazine, vol. 48, no. 10, pp. 150-157, Oct. 2010.
This paper addresses the access part of the IEEE 1901 standards, and explains the underlying rationale for the features of the access specifications. Particular emphasis is given to topological aspects of the access cluster.
V. Oksman and S. Galli, "G.hn: the new ITU-T home networking standard," IEEE Communications Magazine, vol. 47, no. 10, Oct. 2009.
The ITU-T started the G.hn project in 2006 with a goal of developing a worldwide recommendation for a unified HAN transceiver capable of operating over all types of in-home wiring: phone lines, power lines, coax and Cat 5 cables. The G.hn PHY and MAC were ratified by the ITU-T as Recommendations G.9960 and G.9961. The paper provides an overview of the G.hn PHY and MAC and shows similarities in the channel characteristics of several wireline channels.
Yu-Ju Lin, H.A. Latchman, R.E. Newman, S. Katar, “A comparative performance study of wireless and power line networks,” IEEE Communications Magazine, vol.41, no.4, pp.54,63, April 2003.
This paper presents a theoretical and field performance comparison of the IEEE 802.11 and the HomePlug 1.0 CSMA protocols, the latter also being used in IEEE 1901, addressing such issues as coverage, channel stability, and reliability as QoS support for multimedia.
S. Galli, A. Kurobe and M. Ohura, "The inter-PHY protocol (IPP): A simple coexistence protocol for shared media," IEEE International Symposium on Power Line Communications and Its Applications (ISPLC), Dresden, Germany, March 29 -April 1, 2009.
The topic of PLC coexistence is receiving growing attention due to the presence of multiple non-interoperable PLC standards, e.g. IEEE 1901 Wavelet-OFDM, IEEE 1901 FFT-OFDM, and G.hn. This paper gives an overview of the coexistence mechanism that has been included as mandatory in the IEEE 1901 standard and has also been ratified by the ITU-T as Recommendation G.9972
- Topic: Channel Modeling
Channel Transfer Function (In Part Also Additive Noise)
H. Philipps, “Performance measurements of power line channels at high frequencies,” International Symposium on Power Line Communications and its Applications, Tokyo, Japan, pp. 229-237, March 24-26, 1998.
This paper is a pioneering work concerned with indoor PLC channels for broadband applications. It presents interesting measurements results about important characteristics of the transmission channel: the input impedance, frequency response, impulse response, and noise power spectral density. These measurements cover the frequency band up to 30 MHz and are registered at different locations: apartments, detached-houses and university buildings. Different sources of noise are also identified, and their influence on the channel behavior is also briefly discussed. Based on the measurement results, a simple model for the channel is suggested: a linear time-invariant filter plus some additive noise components. This work mainly presents a qualitative analysis of indoor PLC channels behavior.
O.G. Hooijen, “A channel model for the residential power circuit used as a digital communications medium,” IEEE Transactions on Electromagnetic Compatibility, vol. 40, no. 4, pp. 331-336, Nov. 1998.
Another pioneering work, which discusses the main features of the power line channel at low frequencies. It focuses on distribution networks in urban, suburban and rural areas. Measurements for noise power spectral density, network impedance and the attenuation and phase shift that signals experience in the band from 9-95kHz are discussed. A first classification of noise components is also presented, with four categories: background noise, single event impulse noise, noise synchronous to the mains frequency and narrow-band noise.
D. Liu, E. Flint, B. Gaucher, and Y. Kwark, “Wideband AC power line characterization,” IEEE Transactions on Consumer Electronics, vol. 45, no. 4, pp. 1087-1097, Nov. 1999.
This paper provides quantitative information about channel parameters useful for PLC system design. It presents a characterization of indoor power line channels by measuring multiple links, selected among the available outlets at four houses. The measurements are for channel transfer functions and noise power spectral density, considering the frequency range up to 60MHz. A statistical analysis of the mean attenuation and the delay spread is given, and the noise power spectral density for some particular appliances and at several outlets are estimated. Furthermore, the evolution of some of these parameters along a day is shown.
F.J. Cañete, L. Diez, J.A. Cortes, J.T. Entrambasaguas, “Broadband modelling of indoor power-line channels,” IEEE Transactions on Consumer Electronics, 48 (1), 175-183, Feb. 2002.
This article discusses, possibly for the first time in PLC, a channel modeling based on a structural approach, which will be later called bottom-up. First, some examples of measurements of in-home channel responses, noise and load properties (impedance and emitted noise) are presented. The proposed approach is to estimate the channel response and noise from the physical characteristics of the power network (cables and topology) and the connected loads. Then, a procedure to calculate the complete channel response, in a deterministic way, is described. This simulator is based on the interconnection of a tree-like set of transmission lines. Besides being one of the first papers dealing with channel time variations, this paper also proposes for the first time “constrained randomization” of network topologies (where the constraining is based on mimicking deployment practices) coupled with transmission line theory. This became a fundamental part of modeling attempts published in the last decade, the ones often put in the category “bottom-up.”
M. Zimmermann and K. Dostert, “A multipath model for the power line channel,” IEEE Transactions on Communications, vol. 50, no. 4, pp. 553-559, April 2002.
This is a seminal work introducing the parametric multipath channel model for broadband PLC applications. The proposed model has received wide acceptance in the research community, evidenced by a considerable citation index. In detail, the paper presents an analytical model of the complex transfer functions of typical PLC networks in the frequency range from 500 kHz to 20 MHz. The main advantage of the model is that it covers fundamental effects with a small set of parameters. The accuracy of the model has been verified in a variety of environments. The sophisticated strategy to estimate the model parameters has proven to be highly effective and easy to use. Due to its overall conciseness and convincing results, the model has been used to define reference channels, e.g. within the European OPERA project, being important for a standardized evaluation of PLC system performance.
T. Esmailian, F.R. Kschischang, and P.G. Gulak, "In-building power lines as high-speed communication channels: channel characterization and a test-channel ensemble," International Journal of Communication Systems, vol. 16, no. 5, pp. 381-400, June 2003.
This paper describes one of the very first attempts to define a PLC statistical channel model. The approach followed in this model is a hybrid approach where deterministic channel models based on transmission-line theory are coupled with Monte Carlo simulations. The proposed modeling requires the generation of random in-home topologies using the US National Electric Code to set constraints on the topologies in terms of number of outlets per branch, wire gauges, inter-outlet spacing, etc. Then, for each generated topology, the transfer function is calculated using classical transmission line theory tools. Although the generalization of this approach requires the knowledge of the electric codes of every country, this paper represents an important step forward in the definition of a statistical PLC channel model.
F. J. Cañete, J. A. Cortés, L. Díez, and J. T. Entrambasaguas, “Analysis of the cyclic short-term variation of indoor power line channels,” IEEE Journal on Selected Areas in Communications, vol. 24, no. 7, pp. 1327-1338, July 2006.
This paper explains and models the periodically time-varying behavior of the channel transfer function in PLC systems due to the mains voltage cycle in AC power networks. Measurements carried out at different locations are discussed and employed to characterize the behavior of some loads, the time-varying channel response, and non-stationary received disturbances. Furthermore, a statistical analysis of parameters related to the time variation is presented. Finally, a channel model is proposed, composed of a linear periodically time-varying (LPTV) filter plus some cyclostationary noise, where the periodicity is synchronized with the mains cycle. This work is useful to evaluate the influence that channel time variation may have on the performance of PLC systems.
S. Galli and T.C. Banwell, “A deterministic frequency-domain model for the indoor power line transfer function,” IEEE Journal on Selected Areas in Communications, vol. 24, no. 7, pp. 1304-1316, July 2006.
This paper contains a wide introduction to channel modeling strategies in PLC, covering both the multi-path models and models based on transmission line theory. The author addresses the issue of grounding and its effect on the communications channel. For the first time, an accurate communication channel model based on multi-conductor transmission line (MTL) theory and modal decomposition is set forth. The proposed modeling approach allows treating both grounded and ungrounded PLC links under the same formalism of cascaded transmission matrices. Together with companion papers published in the IEEE Trans. Power Del. in 2005, the author shows that, if properly modeled, the PLC channel exhibits more determinism than what was commonly believed. The IEEE 1901 Broadband over Power Lines Standard references this work in Annex G.
T. Sartenaer and P. Delogne, "Deterministic modeling of the (shielded) outdoor power line channel based on the multiconductor transmission line equations," IEEE Journal on Selected Areas in Communications, vol. 24, no.7, pp. 1277-1291, July 2006.
This paper applies multiconductor transmission line theory for accurate deterministic modeling of the channel transfer functions for PLC access networks using underground cables. The multidimensional scattering matrix formalism is applied to PLC networks including multiconductor cable segments, derivation points, and termination loads. Examples of outdoor PLC networks with different types of cables are presented and the proposed modeling is tested by analyzing the obtained impulse responses.
M. Tlich, A. Zeddam, F. Moulin, and F. Gauthier, ”Indoor power line communications channel characterization up to 100 MHz - part I: one-parameter deterministic model” and "Part II: time-frequency analysis," IEEE Transactions Power Delivery, vol. 23, no. 3, pp. 1392-1409, July 2008.
These two papers characterize indoor power line channels in the frequency range from 30 kHz to 100 MHz. In Part I measurements of channel transfer functions from different sites are presented. Based on these results, a channel classification according to channel capacity is performed and an approximated deterministic channel model for every class is given. Furthermore a detailed observation of peaks and notches of the transfer function is documented, and a statistical model is devised. Finally a multipath channel generator is proposed, taking the statistical behavior of magnitude and group delay into account. Part II focuses on time-frequency analysis based on the measurement results from Part I. Time delay spread and coherence bandwidth are determined and significant changes of these parameters in dependence of frequency range are discussed. The relation between time delay parameters and the channel classification presented in Part I is outlined as well as the relation between coherence bandwidth and delay spread for the frequency range from 2 MHz to 100 MHz. The importance of these two papers is mainly given by the fact that an extended frequency range of up to 100 MHz is covered. Thus they can be considered as primers to prepare the way for the next generation of high speed PLC systems aiming at data rates up to 1 Gbit/s.
S. Galli, "A simplified model for the indoor power line channel," IEEE International Symposium on Power Line Communications and Its Applications (ISPLC), Dresden, Germany, Mar. 29 – Apr. 1, 2009.
This paper reports for the first time some important properties of the power line channel. First, it presents correct values of the Root-Mean-Square Delay Spread (RMS-DS) of the PLC channel pointing out that what has been usually reported in the PLC literature is duration of the impulse response and not the RMS-DS. Then, the paper confirms that channel gains and RMS-DS of indoor PLC channels of US homes are lognormally distributed. Finally, the paper also reports that channel gains and RMS-DS of indoor PLC channels are negatively correlated, thus suggesting that channels that introduce severe multipath are also characterized by large attenuation. These results are important building blocks for defining statistical channel models and for the correct interpretation of the performances of ISI mitigation techniques.
S. Galli, “A Novel Approach to the Statistical Modeling of Wireline Channels,”IEEE Transactions on Communications, vol. 59, no. 5, May 2011.
This paper extends the results of the ISPLC 2009 conference paper confirming that PLC channel fading and Root-Mean-Square Delay Spread (RMS-DS) are log-normally distributed random variables in US homes, Japanese homes, and US Medium Voltage lines. The paper also confirms that channel power gain and RMS-DS are negatively correlated lognormal random variables in a variety of cases such as PLC residential Low Voltage channels and underground PLC Medium Voltage channels. Further analysis of other wireline channels allows reporting a strong similarity between some properties observed in power line channels and the ones observed in other wireline channels, e.g. coaxial cables and phone lines. For example, it is here reported that channel power gain and logarithm of the RMS-DS in DSL links are linearly correlated random variables. Exploiting these results, a statistical wireline channel model where tap amplitudes and delays are generated in order to reflect these physical properties is proposed. Although wireline channels are considered deterministic as their impulse response can be readily calculated once the link topology is known, a statistical wireline channel model is useful because the variability of link topologies and wiring practices give rise to a stochastic aspect of wireline communications that has not been well characterized in the literature. Finally, it is also pointed out that alternative channel models that normalize impulse responses to a common (often unitary) power gain may be misleading when assessing the performance of equalization schemes since this normalization artificially removes the correlation between channel power gain and RMS-DS and, thus, Inter-Symbol Interference (ISI).
A. M. Tonello and F. Versolatto, “Bottom-up statistical PLC channel modeling - Part I: topology model and efficient transfer function computation,” IEEE Transactions Power Delivery, , vol.26, no.2, pp. 891-898, April 2011.
A. M. Tonello and F. Versolatto, “Bottom-up statistical PLC channel modeling - Part II: inferring the statistics,” IEEE Transactions Power Delivery, vol. 25, no. 4, pp. 2356–2363, Oct. 2010.
A comprehensive analysis of the in-home PLC channel statistics and their dependency from the topological information, as for instance, the layout area, the loads intensity, the wiring structure, is reported in these two papers. The study is carried out with the use of a bottom up channel generator that exploits a structured description of topologies derived from the observation of wiring practices and norms in Europe. The convergence of the results obtained with the channel simulation tool and those from experimental data is also shown.
F.J. Cañete, J.A. Cortés, L. Diez, J.T. Entrambasaguas, “A channel model proposal for indoor power line communications,” IEEE Communications Magazine, 49 (12), 166-174, Dec. 2011.
This paper presents a novel approach to develop a statistical power-line channel generator based on bottom-up modeling. The model consists of quite simple power-network topologies with few transmission lines and loads which exhibit an impedance chosen among a reduced set of available impedances. The statistical parameters are of physical nature: the kind of cable (determining the transmission lines parameters), the cable lengths (randomly chosen), and the connected loads (which may be time-invariant or linearly and periodically time-varying). The behavior of randomly generated channel responses is validated against two hundred actual measurements. It is shown that the mean attenuation, delay spread and coherence bandwidth distributions exhibit a reasonable fit. The random channel generator is offered to the community on the authors’ website.
M. Zimmermann and K. Dostert, “Analysis and modeling of impulsive noise in broadband power line communications,“ IEEE Transactions on Electromagnetic Compatibility, vol. 44, no. 1, Feb. 2002.
This work is an important contribution toward simulation and emulation of PLC noise, helping the PLC system designer to reduce or mitigate the impact of challenging disturbances. The authors elaborate on the fundamental basics toward analysis and modeling of impulsive noise within power line channels in the frequency range from 200 kHz to 20 MHz. Based on measurements at various locations like apartments and transformer substations, both in rural and industrial areas with an overall observation time of nearly 90 hours, five general classes of noise are defined: colored background noise, narrow-band noise, periodic impulsive noise asynchronous to the mains frequency, periodic impulsive noise synchronous to the mains frequency, and asynchronous impulsive noise. Characteristic parameters of impulses, such as impulse rate, disturbance ratio, impulse width and amplitude, 'inter-arrival' time and burst events, are examined and statistically evaluated in the time domain. A detailed analysis enables the concise modeling of realistic noise scenarios. The proposed classification of noise from this paper has been widely accepted in the PLC community, so that it is now a common base for the description of noise in different PLC environments.
V. Degardin, M. Lienard, A. Zeddam, F. Gauthier, and P. Degauquel, “Classification and characterization of impulsive noise on indoor power lines used for data communications,” IEEE Transactions on Consumer Electronics, vol. 48, no. 4, pp. 913-918, Nov. 2002.
This paper investigates the statistics of impulsive noise for broadband indoor PLC. From measurements over two days in a house with a large number of appliances connected to the power lines about 1700 waveforms of impulses were collected. These impulses have been analyzed both in time and frequency domain, and categorized into five classes. Probability distributions for pseudo frequencies, inter-arrival time, pulse duration, and peak value are presented with additional discussions on pulse statistics.
M. Katayama, T. Yamazato, and H. Okada, “A mathematical model of noise in narrowband power line communication systems,” IEEE Journal on Selected Areas in Communications, vol. 24, no. 7, pp. 1267-1276, July 2006.
This paper focuses on the non-stationary features of PLC noise. All results are based on measurements of narrow-band indoor noise. Evaluating these measurements, it is shown that PLC noise can be modeled as a colored Gaussian random process whose variance is a periodic function synchronous to the absolute value of the mains voltage. A simple expression of the instantaneous variance with a small set of parameters is introduced. With the proposed model, PLC noise can be described concisely with a few parameters, so that noise waveforms can easily be generated, enabling benchmarking for design and evaluation of PLC systems.
J. A. Cortés, L. Díez, F. J. Cañete, and J. J Sánchez-Martínez, "Analysis of the indoor broadband power line noise scenario,” IEEE Transactions on Electromagnetic Compatibility, vol. 52, no. 4, pp. 849-858, Nov. 2010.
This paper presents a detailed analysis of indoor broadband power line disturbances, namely background noise, impulsive noise and narrow-band interference. The study is based on the results of a measurement campaign at different locations. The used methodology combines time-domain techniques with signal processing algorithms that capture the cyclostationary nature of most noise terms. Particular attention is devoted to impulsive noise, revealing aspects of its behavior that were not covered in previous works. Illustrative noise waveforms are shown and also statistical parameters are extracted.
- Topic: Coupling
P. A. Janse van Rensburg and H. C. Ferreira, “Coupling circuitry: understanding the functions of different components,” International Symposium on Power Line Communications and Its Applications, Kyoto, Japan, pp. 204-209, 2003.
This is an introductory paper to the concepts of filtering and LV power-line coupling. This paper examines coupling and de-coupling circuit typically used in PLC. It particularly shows dependency of filtering characteristics of filtering capacitors and de-coupling inductors on the load. It also analyses a coupling transformer and concluded that the leakage inductance with series capacitor forms a resonant band-pass filter that can be modelled in terms of simple LRC circuit. From there design equations are derived and verified for transfer function for different values of L, C and R.
P. A. Janse van Rensburg and H. C. Ferreira, “Design of a bidirectional impedance-adapting transformer coupling circuit for low-voltage power-line communications,” IEEE Transactions on Power Delivery, vol. 20, no. 1, Jan. 2005, pp. 64-70.
This paper explains the design of transformer coupling circuits. It specifically details step-by-step design of 1:7 coupling transformer and its amplitude response measurement. To achieve impedance adaptations, relationship between power line impedance values and bandwidth of coupling filters are also discussed. Analysis of the various aspects of the coupling transformer is given. To review its performance, amplitude response of the designed coupler is measured and the circuit shows similar filter characteristic in both transmitting and receiving directions. The influence of unsteady power line impedance and power waveform on the circuit is also examined. The paper concludes that power line impedance and coupling transformer’s turn ratio are key factors to ensure bidirectional symmetry in coupling circuits.
O. Bilal, E. Liu, Y. Gao, T.O. Korhonen, “Design of broadband coupling circuits for power line communication,” International Symposium on Power Line Communications and Its Applications (ISPLC), Saragoza, Spain, April 2004.
This paper begins by explaining the importance of coupling unit in a PLC system. It goes further to discuss various aspects, modes and types of coupling units for broadband communication from practical point of view and examines electronic components required. General guideline for design of each type coupling circuits and its characteristics are also given. Assessments of the coupling circuits in terms of transfer function and PLC channel measurements under typical channel noise and impedance conditions are presented.
Abraham, K. C., and S. Roy, “A novel high-speed PLC communication modem,” IEEE Transactions on Power Delivery, vol. 7, no. 4, April 2004.
The circuit proposed in this paper provides solution to characteristic impedance matching in distribution and low voltage lines. The principle of this design presented here are (i) The coupling capacitor is selected such that it has a large impedance at 50/60 Hz thereby cutting off the mains frequency. (ii) Resonance between coupling capacitor and coupling transformer’s primary winding inductance at carrier frequency. This method is not really new, however, the major drawback of previous approaches was the use of iron core transformer which suffers non-linearity. The major contribution here is the use of coaxial solenoid or air coils of different diameters between primary and secondary air coils is selected to reduce inductive coupling. Analysis of the field trial results showed the new design outperforms the state-of-the –art PLC modem.
- Topic: EM Interference
To the Radio Channel
Amirshahi, P., and M. Kavehrad. "Medium voltage overhead power-line broadband communications; transmission capacity and electromagnetic interference," Int. Conf. on Power Line Communications and Its Applications (ISPLC’05), Vancouver, Canada, April 6-8, 2005.
This paper investigates electromagnetic limitations as part of work undertaken to evaluate multipath channel impulse response and transmission capacity limit in medium voltage distribution network for BPLC. Making reference to National Telecommunication & Information Administration (NTIA) on the potential interference from BPLC, channel capacity values in frequency range 1 – 100MHz was studied and results presented. The authors recorded that in theory, with line symmetry (balanced load), emissions from differential aerial currents cancel each other at far end field but that is not the case with MV power lines as they are typically asymmetric. This asymmetric causes widening of near and far end field patterns. The paper concludes that discontinuity increases EM interference, hence the line and load impedances must be matched to avoid it. Adaptive impedance matching is proposed as a way of avoid discontinuities.
J.M. Silva, B. Whitney. "Evaluation of the potential for power line carrier (PLC) to interfere with use of the nationwide differential GPS network," IEEE Transactions on Power Delivery, vol. 17, no.2, Feb. 2002.
This paper examines the impact interference from PLC transmitter on the new nationwide Differential Global Positioning System (NDGPS); a satellite-based radio-navigation system developed by US Department of Defense to provide worldwide coverage and positioning information. Using HP spectrum analyzer, 0.6 m diameter active loop antenna and a digital GPS, measurements at different locations around transmission lines are presented and analyzed for 120kv/345kv multiple transmission lines. It was concluded that in regions close to power lines, PLC signal was strong enough to affect DGPS receiver performance and proposed frequency separation as a solution.
To the Wired Channel
B. Praho, M. Tlich, F. Moulin, A. Zeddam, and F. Nouvel, “PLC coupling effect on VDSL2,” IEEE International Symposium on Power Line Communications and Its Applications (ISPLC’11), Udine, Italy, Apr. 2011.
This paper describes a laboratory experimental study of VDSL2 and PLC coexistence, which takes into account both radiated and conducted interference. Several tests are performed to assess the impact of PLC interference on VDSL2 performance by looking at customer’s cable category, coexistence length, distance between power and telephone lines, and types of crosstalk scenarios.
J. Maes, M. Timmers, and M. Guenach, “Spectral Compatibility of In-Home and Access Technologies,” IEEE International Symposium on Power Line Communications and Its Applications (ISPLC’11), Udine, Italy, Apr. 2011.
The mutual impact of an in-home network (G.hn PLC) and a Digital Subscriber Line access link (both regular and vectored VDSL2) is evaluated via simulation. Authors propose a basic spectrum balancing solution that mitigates PLC interference by shaping the G.hn transmit power on the frequency bands that overlap with DSL.
- Topic: Modulation & Coding
E. Biglieri, "Coding and Modulation for a Horrible Channel," IEEE Communications Magazine, vol.41, no. 5, pp. 92-98, May 2003.
This tutorial paper is well suited for the reader who wishes to get acquainted with PLC. It provides a brief overview of the technical challenges for PLC at the physical layer. It describes relevant channel models and main impairments for reliable communication, and it reviews modulation techniques at large, including spread spectrum, single carrier and multi-carrier, as well as their adaptive realizations and relevant coding schemes.
T. Schaub, “Spread frequency shift keying,” IEEE Transactions on Communications, vol. 42, no. 2/3/4, pp. 1056-1064, Feb./March/April 1994.
Frequency shift keying (FSK) is an attractive modulation scheme for the narrowband low data-rate PLC applications. However, the transmission at only one frequency per symbol duration is susceptible to strongly colored background noise and narrowband interferences as experienced in PLC. This article presents a spread-FSK (S-FSK) modulation and demodulation technique, which enables reliable communication even in the presence of the narrowband interferences. The two frequencies of the binary S-FSK are chosen relatively far apart such that narrowband interference only destroys one of the two transmission frequencies and demodulation can still take place using the undisturbed channel on an on-off keying (OOK) basis.
A.J. Han Vinck “Coded Modulation for Power Line Communications,” AEÜ Journal, 2000, Jan 2000.
This paper discusses the application of coded modulation to power-line communications. M-ary FSK is combined with diversity and coding to make the transmission robust against permanent frequency disturbances and impulse noise. A particular example of a coding/modulation scheme is presented that is in agreement with the CENELEC norms. The scheme can be considered as a form of coded Frequency Hopping and is thus extendable to any frequency range. This paper also stimulated renewed interest on the topic of permutation code construction, leading to many subsequent papers in the fields of Information Theory and Discrete Mathematics.
L. Lampe and J. B. Huber, “Bandwidth efficient power line communications based on OFDM,” AEÜ International Journal of Electronics and Communications, vol. 54, no. 1, pp. 2–12, 2000.
One of the first papers about coding and modulation with OFDM for PLC. The paper infers the capacity achievable with OFDM using a stochastic representation of the channel transfer function. The combination of a large signal constellation and low rate codes in order to obtain a fixed target rate proves to be advantageous both for coherent and bandwidth efficient non-coherent transmission over power lines.
E. Del Re, R. Fantacci, S. Morosi, “Comparison of CDMA and OFDM techniques for downstream power-line communications on low voltage grid,” IEEE Transactions on Power Delivery, vol.18, no.4, PP1104-1109, Oct 2003.
This paper provides a fair comparison between direct sequence code division multiple access (DS-CDMA) and orthogonal frequency division multiplexing (OFDM) systems for broadband downstream power-line communications (PLCs). The considered schemes seem particularly suitable for high bit rate broadcast flexible communications on low voltage grid in order to guarantee local access. The performance of the considered systems is expressed in terms of bit error rate (BER), derived by simulations under the assumptions of frequency-selective multipath fading channel and additive colored Gaussian noise according to the in-building networks model, under the same overall working conditions of bandwidth occupation, transmitted power, and global data rate.
HC Ferreira, A.J. Vinck, TG Swart, I de Beer, “Permutation trellis codes,” IEEE Transactions on Communications, vol. 53, no. 11, pp 1782-1789, November 2005.
Following Vinck’s paper in 2000 on applying permutation block codes to Power Line Communications, the new concept of permutation trellis codes is now introduced and a generalized construction procedure is presented, applying the technique of distance-preserving mappings. Minimum-distance decoding follows naturally, using the Viterbi algorithm. Furthermore the performance of these codes is investigated when combined with multi-tone frequency-shift keying modulation and non-coherent detection in a diversity scheme, to make transmissions robust against narrowband, broadband, and background noise disturbances, such as those encountered in power-line communications, This paper also stimulated many subsequent papers in the fields of Information Theory and Discrete Mathematics since it presented a solution to the construction of permutation arrays with good Hamming distance properties.
M. Crusiere, J-Y. Baudais, and J.F. Hélard, “Adaptive spread spectrum multicarrier multiple-access over wireline,” IEEE Journal on Selected Areas in Communications, vol. 24, no. 7, pp. 1377-1389, July 2006.
The resource allocation, i.e., bit and power loading, in multicarrier PLC is important to maximize data throughput. In this paper the resource allocation problem is addressed for the multiuser case in a system that combines OFDM with linear precoding. The proposed algorithm realizes user multiplexing together with the dynamic allocation of subcarriers, codes, bits, and power.
L. Lampe, R. Schober, and S. Yiu, “Distributed space–time coding for multihop transmission in power line communication networks,” IEEE Journal on Selected Areas in Communications, vol. 24, no. 7, pp. 1389-1400, July 2006.
Multihop transmission (or the use of repeaters/relays) is attractive for PLC to bridge large distances and/or achieve high data rates. This paper is one of the earliest works considering the use of space-time coding techniques, developed for wireless communications, in the PLC setting. Using statistical indoor channel models for PLC, it is demonstrated that so-called distributed space-time block codes, which enable relaying without centralized resource allocation, lead to improved transmission range/reliability and delay.
A. M. Tonello, “Wide band impulse modulation and receiver algorithms for multiuser power line communications," EURASIP Journal on Advances in Signal Processing - Special Issue on "Advanced signal processing and computational intelligence techniques for power line communications,” vol. 2007, art. id. 96747, 2007.
This is the first paper, among very few, that considers impulsive ultra wide band (UWB) modulation for PLC. A simple modulation scheme that, when combined with code division multiple access and bit-interleaved coding, provides robust performance in the presence of severe channel frequency selectivity and impulsive noise. This is the result of spreading the symbol energy both in frequency (through the wideband pulse) and in time (through the spreading code and the bit-interleaved convolutional code). Several novel frequency domain algorithms are proposed for detection in the presence of impulsive noise and multiple access interference. In addition, a novel statistical broadband PLC channel model is described.
A. M. Tonello and F. Pecile, “Efficient architectures for multiuser FMT systems and application to power line communications," IEEE Transactions on Communications, vol. 57, no. 5, pp. 1275-1279, May 2009.
To provide better spectrum notching capability and robustness to narrow band interference, which allows better coexistence between PLC and radio systems, filter bank modulation schemes can be used. In this paper, ﬁltered multitone modulation (FMT) for broadband multiuser PLC is considered. Compared to conventional OFDM, or pulse shaped OFDM, that privileges the sub-channel time confinement, FMT privileges the sub-channel frequency confinement. An important issue is the implementation complexity of FMT. The paper proposes a novel efficient digital implementation of both the synthesis and the analysis ﬁlter banks, and the performance is evaluated in typical PLC channels.
Coding & Impulse noise analysis/mitigation
S. Miyamoto, M. Katayama, and N. Morinaga, “Performance analysis of QAM systems under class A impulsive noise environment,” IEEE Transactions Electromagnetic Compatibility, vol. 37, no. 2, pp. 260-267, May 1995.
In many communication channels, interference produced by man-made machinery are much more structured (or impulsive) than AWGN. In PLC, the noise includes both background and impulsive components. Effects of background noise on the communication systems are well understood. Designing reliable communication under impulsive noise, however, is still a challenge. This article expands our knowledge by investigating the transmission quality of QAM systems under the influence of class-A impulsive noise. It is first presented that the real and the imaginary parts of the complex impulsive noise samples are dependent. The numerical results show that the receiver performance in an impulsive noise channel is much worse than that achieved in a Gaussian noise channel. The design of a reliable receiver structure is also presented.
J. Haering and A. J. H. Vinck, “OFDM transmission corrupted by impulsive noise," International Symposium on Power Line Communications and Its Applications (ISPLC), Limerick, Ireland, April 2000, pp. 9-14.
OFDM is an attractive modulation scheme for the high data rate PLC applications. However, the reliability of OFDM transmission is strongly influenced by impulse noise, experienced in PLC. This paper studies the influence of the impulse noise on the transmission capacity. By presenting the enormous loss in the achievable rate when using a conventional receiver, the authors stress the importance of designing a receiver matched to impulse noise. This paper is one of the earliest works proposing a simple iterative impulsive noise suppression algorithm, which exploits the noise structure in the time and frequency domain. It is shown that the error rate performance can be significantly improved.
S. V. Zhidkov, “Analysis and comparison of several simple impulsive noise mitigation schemes for OFDM receivers,” IEEE Transactions on Communications, vol. 56, no. 1, pp. 5-9, Jan. 2008.
In PLC, the reliability of transmission is strongly influenced by the impulse noise. Due to its simplicity, clipping or blanking techniques are often used in practical applications. This paper demonstrates how to improve transmission reliability by applying simple impulse noise mitigation techniques at the receiver. One important point is the application of clipping and blanking (nulling) techniques together. The results presented for the communication under impulsive noise show that the joint clipping-blanking technique outperforms pure blanking and clipping techniques.
R. Pighi, M. Franceschini, G. Ferrari, and R. Raheli, “Fundamental performance limits of communications systems impaired by impulse noise,” in IEEE Transactions on Communications, vol. 57, pp. 171-182, Jan. 2009.
It has commonly been assumed that multi-carrier (MC) schemes are more robust to impulse noise, typical of PLC systems, than single-carrier (SC) ones. This paper questions and complements this belief showing that, while it is indeed correct for uncoded modulations, conventional coded MC schemes operating at typical rates may be significantly more sensitive to impulse noise than SC ones. The analysis considers the impact of impulse noise on the performance limits of SC and MC communication and is mainly based on the information rate achievable by standard linear modulations with interleaved coding.
D. Fertonani and G. Colavolpe, “On reliable communications over channels impaired by bursty impulse noise,” IEEE Transaction on Communications, vol. 57, no. 7, pp. 2024-2030, July 2009.
While most impulse noise models used for performance analysis and system design are inherently memoryless, actual PLC channels are characterized by the occurrence of impulse bursts. Based on a simple two-state Markov-chain model, this paper addresses the achievable information rate of systems impacted by bursty impulse noise. It also proposes detection schemes to account for the memory induced by the noise bursts and analyzes their performance for representative systems employing low-density parity-check (LDPC) codes. The analysis shows that non negligible performance improvements are indeed achievable.
- Topic: MAC
H. Hrasnica, A. Haidine, and R. Lehnert, "Broadband Powerline Communications Networks: Network Design," John Wiley & Sons Inc., UK, June 2004.
After the 2001 book from Dostert, this is the first book on PLC that gives insight on performance aspects of resource allocation mechanisms taking the time-variant PLC channel into account. Also multi-hop communications is studied. The book also covers planning algorithms for PLC access networks. Here the limited coverage and therefore the optimal placement of repeaters is discussed. Optimization algorithms are presented.
S. Katar, B. Mashburn, K. Afkhamie, H. Latchman, R. Newman, "Channel adaptation based on cyclo-stationary noise characteristics in PLC systems," IEEE International Symposium on Power Line Communications and Its Applications (ISPLC), Orlando, FL, USA, Oct. 2006.
One peculiar characteristic of the PLC channel is the cyclic variation of the noise power with the phase of the underlying AC line cycle. This is one of the earliest papers that proposes a channel adaptation mechanism exploiting the cyclic variation of the power line noise and that reports the achieved performance enhancements.
G. Bumiller, L. Lampe, and H. Hrasnica, "Power line communication networks for large scale control and automation systems," IEEE Communications Magazine, vol. 48, no. 4, pp. 106-113, April 2010.
This paper provides a very readable account of a number of previous works proposing single-frequency networking for PLC when used for control and automation applications such as envisaged for Smart Grid. The requirements on PLC networks comprising many nodes spread over relatively wide areas supporting mentioned applications are discussed, based on which a hybrid medium access protocol and single-frequency networking repeater concepts are advocated.
H. Hrasnica, A. Haidine, “Modeling MAC Layer for Powerline Communications Networks, " Proc. SPIE 4211, Internet Quality and Performance and Control of Network Systems, Feb. 2001.
In this work, a PLC network and system structure is analyzed in temrs of its disturbance scenario. After that, a logical structure for the powerline MAC layer is defined and a reservation MAC protocol providing collision free data transmission is proposed. The protocol proposal allows both data and voice transmission with a higher priority for the voice connections. The remaining network capacity is used for data transmission which is expected to be internet traffic as a typical service applied to the PLC access networks. A simulation model is developed for the investigation of the PLC MAC layer which includes also modeling of different disturbance scenarios. Two variants of the MAC protocol are considered: an ALOHA protocol, which allows collisions in the signaling channel; a fixed access method, realized by a collision-free polling access schema. The performance of these two protocol variants are compared for a network without disturbance and a network affected by PLC disturbances.
- Topic: Multiple Input Multiple Output PLC (MIMO-PLC)
L. T. Berger, A. Schwager, P. Pagani, D. Schneider, Editors, MIMO Power Line Communications: Narrow and Broadband Standards, EMC, and Advanced Processing, CRC Press, February 2014.
This book sees the contribution of many experts in the field of PLC MIMO. It includes a general description of PLC (including power line channel and noise characteristics and modeling), covers recent standards which incorporate MIMO (e.g., ITU G.hn, IEEE 1901, HomePlug AV2, IEEE 1905.1) and the narrowband OFDM-based latest IEEE and ITU-T standards for Smart Grid, discusses signal processing methods and presents case studies and field trials.
Systems, Models and Performance
L. Stadelmeier, D. Schill, A. Schwager,D. Schneider, J. Speidel, "MIMO for In-home Power Line Communications," Source and Channel Coding (SCC), 2008 7th International ITG Conference on, pp.1,6, 14-16 Jan. 2008.
After introducing the MIMO concept for in-home PLC operating on three-wire lines, including phase, neutral and protective earth conductors, this paper analyzes the theoretical capacity increase on measured channels. Different MIMO schemes are compared regarding their suitability for the PLC channel. Exploiting common mode reception, namely a 2x3 or 2x4 MIMO, average capacity gains above a factor 2 are demonstrated.
D. Schneider, J. Speidel, L. Stadelmeier, D. Schill, "Precoded Spatial Multiplexing MIMO for Inhome Power Line Communications," Global Telecommunications Conference, 2008. IEEE GLOBECOM 2008, pp.1,5, Nov. 30 2008-Dec. 4 2008.
This paper assumes channel state information (CSI) is available at the transmitter via a feedback channel and discusses precoding schemes to achieve spatial multiplexing. Appropriate quantization methods to reduce the amount of feedback data are investigated.
R. Hashmat, P. Pagani, A. Zeddam, T. Chonavel, T., "MIMO communications for in-home PLC networks: Measurements and results up to 100 MHz," Power Line Communications and Its Applications (ISPLC), 2010 IEEE International Symposium on, pp.120,124, Mar. 28-31, 2010.
The measurements and results presented in this paper demonstrate that up to 90% enhancement in in-home three-wire PLC channel capacity is possible using a 2x2 MIMO scheme.
F. Versolatto, A. M. Tonello, "An MTL Theory Approach for the Simulation of MIMO Power-Line Communication Channels," Power Delivery, IEEE Transactions on, vol.26, no.3, pp.1710,1717, July 2011.
This paper derives a theoretical description of a MIMO PLC channel in terms of a matrix transfer function. Analytical computations of the per-unit-length parameters of two typical electric cables are provided. The results are in good agreement with experimental measures.
- Topic: Smart Grid
S. Galli, A. Scaglione, Z. Wang, "For the Grid and Through the Grid: The Role of Power Line Communications in the Smart Grid," Proceedings of the IEEE - Special Issue on Smart Grid, vol. 99, no. 6, June 2011.
This paper is not only an excellent and thorough review of the use of PLC technology in utility applications, but also provides both valuable critical analysis of and deep insight into many general aspects of Smart Grid communications and control issues not necessarily related to PLC. The article has different layers, which is organized an0d presented in a language that appeals to experts with various backgrounds and to both academics and practitioners. It also provides one of the most complete bibliographies on the subject. The paper contains also useful statistical information to model the power distribution grid, which is novel. The paper contains a wealth of historical information on the evolution of PLC since its early days, both in the telemetry world as well as in the commercial world, and sheds light on its various stages of standardization. This information is nowhere else to be found in such comprehensive terms. It explains how this process has affected the current penetration of the technology and it also critically discusses what one should expect in near and medium term, especially in relation to the many deployments of Advanced Metering Infrastructures. The paper is especially useful to get a scientifically accurate account of the promise of PLC for the future of the Smart Grid metering infrastructure. The paper won the 2013 IEEE Donald G. Fink Best Paper Award.
W. Saad, Z. Han, H. V. Poor, T. Başar, “Game Theoretic Methods for the Smart Grid,” IEEE Signal Processing Magazine, vol. 29, no. 5, pp. 86-105, September 2012
Application of game theory in the context of Smart Grid for delivering services via the integration of power, communication and control systems. Emphasis is given to PLC and the use of game theory to increase performance through multihop PLC mechanisms.
"A Standardized and Flexible IPv6 Architecture for Field Area Networks," White Paper, Cisco, Jan. 2014.
This paper provides a synthetic and holistic view of open-standards-based Internet Protocol Version 6 (IPv6) architecture for smart-grid last-mile infrastructures in support of a number of advanced smart-grid applications (meter readout, demand-response, telemetry, and grid monitoring and automation) and its benefit as a true multiservice platform. In this paper, it is shown how the various building blocks of IPv6 networking infrastructure can provide an efficient, flexible, highly secure, and multiservice network based on open standards. This paper does not address transition paths for electric utilities that deal with such issues as legacy devices, network and application integration, and the operation of hybrid network structures during transitional rollouts.
- Topic: PLC for Vehicles
Propagation and Noise Characteristics in Cars
M. Lienard, M.O. Carrion, V. Degardin, P. Degauque, “Modeling and Analysis of In-Vehicle Power Line Communication Channels,” IEEE Transactions on Vehicular Technology, vol.57, no.2, pp.670-679, March 2008.
This paper presents the most comprehensive modeling approach for PLC signal propagation in cars. The authors present a deterministic model is based on multi-conductor transmission line theory applied to a topology typical for a wiring harness of a car. In this context, they coin the terminology of direct and indirect paths, emphasizing on the role of the car battery on PLC signal propagation. The results from a statistical evaluation of the model using different configurations are validated with experimental data. In particular, empirical distributions of several important channel parameters are provided.
V. Degardin, M. Lienard, P. Degauque, E. Simon, and P. Laly, “Impulsive noise characterization of in-vehicle power line,” IEEE Trans. Electromagnetic Compatibility, vol. 50, no. 4, pp. 861--868, 2008.
This paper presents statistical models for impulsive (or burst) noise in cars. The models are based on measurement results in several cars of different brands. The authors distinguish between different states of the car, and they provide empirical distributions and mathematical approximations for a number of burst noise parameters. This paper is likely the most extensive published study on the topic.
M. Mohammadi, L. Lampe, M. Lok, S. Mirabbasi, M. Mirvakili, R. Rosales, and P. Van Veen, “Measurement study and transmission for in-vehicle power line communication,” IEEE International Symposium on Power Line Communications and Its Applications (ISPLC), Dresden, Germany, Mar. 29-Apr. 1, 2009, pp. 73-78.
This paper provides a measurement study for PLC in cars putting, and it demonstrates that frequency diversity techniques are needed for reliable communication. It is significant as it introduces a systematic measurement methodology considering different vehicles states that has frequently been adopted by researchers working in this area.
A. Schiffer, “Statistical channel and noise modeling of vehicular DC-lines for data communication,” IEEE Vehicular Technology Conference (VTC-Spring), Tokyo, Japan, vol.1, pp.158-162, 2000.
This paper is a brief account of fairly extensive measurement studies on PLC propagation and noise characteristics of PLC in cars. It is an important early publication making an attempt to model the PLC channel.
T. Huck, J. Schirmer, T. Hogenmuller, and K. Dostert, “Tutorial about the implementation of a vehicular high speed communication system,” International Symposium on Power Line Communications and Its Applications (ISPLC), Vancouver, Canada, Apr. 6-8, 2005, pp. 162-166.
This paper is a significant contribution as it proposes an automotive wiring harness design that takes its reuse for communications into account. This approach for vehicular PLC is fundamentally different from other (published) studies in this field.
PLC Transmission in Cars
V. Degardin, M. Lienard, P. Degauque, and P. Laly, “Performances of the HomePlug PHY layer in the context of in-vehicle powerline communications,” IEEE International Symposium on Power Line Communications and Its Applications (ISPLC), March 2007, pp. 93-97.
P. Tanguy, F. Nouvel, and P. Mazerio, “Power line communication standards for in-vehicle networks,” International Conference on Intelligent Transport System Telecommunications (ITST), Oct. 20-22, France, 2009.
These two papers are good examples of works that present measured throughput results for actual PLC over power lines in cars. They are interesting in that technology originally developed for in-home PLC was tested in automotive environments. The authors report data rates of up to 10 Mbps for single links. The papers are recommended for reading as follow-up to the above channel modeling works.
PLC for Ships
S. Tsuzuki, M. Yoshida, Y. Yamada, H. Kawasaki, K. Murai, K. Matsuyama, and M. Suzuki, “Characteristics of power-line channels in cargo ships,” IEEE International Symposium on Power Line Communications and Its Applications (ISPLC), March 2007, pp. 324--329.
This paper presents an extensive measurement study for PLC signal and noise characteristics when used in cargo ships. It takes the specifics of wiring practices, in particular the use of armoured cables, in those ships into account. This leads to the interesting observation that common-mode transmission with differential-mode reception might be the preferable signal coupling strategy. This paper is a good starting point for researchers or prospective users of PLC on ships.
M. Antoniali, A. Tonello, M. Lenardon, and A. Qualizza, “Measurements and analysis of PLC channels in a cruise ship,” IEEE International Symposium on Power Line Communications and Its Applications (ISPLC), Udine, Italy, Apr. 2011, pp. 102-107.
This paper is presents extensive measurement results for the propagation characteristics for PLC on a cruise ship. Statistical channel parameters and quantitative results for achievable data rates for broadband PLC are derived. An interesting aspect is the consideration of MIMO transmission sending two independent signals over the ship’s three-wire system. It is shown that this almost doubles the achievable rate. This paper is a good starting point for researchers or prospective users of PLC on ships.
PLC for Aircrafts
C. Jones, “Communications over aircraft power lines,” IEEE International Symposium on Power Line Communications and Its Applications (ISPLC), Orlando, FL, USA, Mar. 2006, pp. 149-154.
The significance of this paper lies in the consideration of PLC as a means of reducing the mass, volume, complexity and assembly costs of the wiring harness in aircrafts. It presents experimental results for PLC in a military aircraft that uses a single-wire power bus structure with the aircraft’s chassis as return path. It is a recommended first read for researchers and practitioners interested in this use of PLC.