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Program
ISPLC 2015 will have a welcome reception on Sunday, March 29th, from 6:00pm to 9:00pm on the second floor of the Edgar A. Smith Building in the Blanton Art Museum Complex on the campus of The University of Texas at Austin. The street address is 200 E. MLK Blvd., Austin, TX 78701. Drinks and appetizers (fruit plate, vegetarian egg rolls, roasted tomatoes, pesto salmon and beef canapes) will be served.
48 technical papers have been scheduled for presentation, of which 15 are invited papers. Excluding the invited papers, the acceptance rate is 62% (33/53).
The technical program will be Monday, March 30th, 8:30am to 5:00pm, and Tuesday, March 31st, 8:30am to 5:00pm. There will be no sessions on Wednesday, April 1st. All paper presentations will be in 20-minute lecture format. The projection system displays in a 16x10 format by default, but also supports a 16x9 format. Please leave three minutes of the 20 minutes for questions and answers.
Parking is available two blocks East of the Edgar A. Smith conference along E. Martin Luther King Jr. Blvd. in the Brazos Street Parking Garage. On Monday and Tuesday, the parking cost is $4/day. To get the reduced price of $4, please bring your parking stub for validation to the Blanton Art Museum, which is open Mondays through Fridays from 9am to 5pm.
Boxed lunches will be provided at the conference venue on Monday and Tuesday. We have tried to meet a wide variety of dietary restrictions.
The IEEE Communications Society Technical Committee on Powerline Communications will meet on Monday, March 30th, from 6:00pm to 9:00pm at the Clay Pit Contemporary Indian Cuisine at 1601 Guadalupe St., Austin, TX, which is about 700m south of the conference venue.
The conference banquet will be Abel's on the Lake on Tuesday, March 31st, from 6:00pm to 10:00pm. Abel's on the Lake is about 5 km from the conference venue. Transportation will be provided via two large shuttle buses.
Technical papers are listed after the following tentative technical program schedule and the link for each paper leads to a PDF version of the full paper on the EDAS Web site (login required):
Monday, March 30
09:00 - 09:20
Welcome
09:20 - 10:00
K1: Keynote Talk on "MIMO et al. in Power Line Communications"
10:20 - 12:00
M1: Noise & Interference Mitigation
- 10:20 Blind Adaptive Analog Nonlinear Filters for Noise Mitigation in Powerline Communication Systems, Invited Paper.
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It has been shown that the performance of power line communication (PLC) systems can be severely limited by non-Gaussian and, in particular, impulsive interference from a variety of sources. The non-Gaussian nature of this interference provides an opportunity for its effective mitigation by nonlinear filtering. In this paper, we introduce blind adaptive analog nonlinear filters, referred to as Adaptive Nonlinear Differential Limiters (ANDLs), that are characterized by several methodological distinctions from the existing digital solutions. When ANDLs are incorporated into a communications receiver, these methodological differences can translate into significant practical advantages, improving the receiver performance in the presence of non-Gaussian interference. A Nonlinear Differential Limiter (NDL) is obtained from a linear analog filter by introducing an appropriately chosen feedback-based nonlinearity into the response of the filter, and the degree of nonlinearity is controlled by a single parameter. ANDLs are similarly controlled by a single parameter, and are suitable for improving quality of non-stationary signals under time-varying noise conditions. ANDLs are designed to be fully compatible with existing linear devices and systems (i.e., ANDLs' behavior is linear in the absence of impulsive interference), and to be used as an enhancement, or as a simple low-cost alternative, to the state-of- art interference mitigation methods. We provide an introduction to the NDLs and illustrate their potential use for noise mitigation in PLC systems.
- 10:40 Maximum Likelihood Decoding of QPSK Signal in Power Line Communications Over Nakagami-m Additive Noise. Invited Paper.
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Power line communications is the use of power lines for the dual purpose of power transmission and data transmission. It is an emerging field of communication for the home area network of smart grid. Power line noise, namely background noise and impulsive noise, significantly affects the performance of power line communication systems. In this paper, we derive the condition for optimum detection of quadrature phase shift keying signals over Nakagami-m distributed additive background noise in power line communication system. The probability density function and the cumulative distribution function of the decision variables for the real part and imaginary part of the background noise are derived. We use the copula approach to model the dependence among the decision variables. The analytical average symbol error rate and average bit error rate of the PLC system is numerically computed. Simulations suggest that the proposed receiver performs significantly better than the existing suboptimal receiver.
- 11:00 Constant Envelope OFDM Transmission Over Impulsive Noise Power-Line Communication Channels. Received Best Student Paper Award.
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Signal blanking is a simple and efficient method to reduce the effect of impulsive noise over power-line channels. The efficiency of this method, however, is found to be not only impacted by the threshold selection but also by the average peak-to-average ratio (PAPR) value of the orthogonal frequency division multiplexing (OFDM) signals. As such, the blanking capability can be further enhanced by reducing the PAPR value. With this in mind, in this paper we evaluate the performance of constant envelope OFDM (CE-OFDM) which has inherently the lowest achievable PAPR of 0 dB; therefore, the proposed system is expected to provide the lower bound performance of the blanking-based method. In order to characterize system performance, we consider the probability of blanking error and signal-to-noise ratio (SNR) at the output of the blanking device. The results reveal that the proposed system can achieve significant improvements over the conventional OFDM blanking-based scheme in terms of minimized probability of blanking error. It will also be shown that output SNR gains of up to 6 dB can be attained over the conventional OFDM blanking-based systems.
- 11:20 A Method for Narrowband Interference Mitigation in OFDM by Minimizing Spectral Leakage
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Current generation narrowband power-line communication systems are OFDM based. They are especially susceptible to narrowband interference (NBI) which is generated by switching power supplies and legacy communication systems. In this paper we propose a novel method for mitigating the effect of narrowband interference. The method exploits a well-known characteristic of NBI spectral leakage in that it is frequency dependent. The method involves intentionally introducing inter-carrier interference at the receiver in a controlled manner in order to mitigate the NBI effect. A simple NBI frequency estimator is also proposed. The combined receiver solution is shown to be within 0.5 dB of the AWGN performance bound for the current G3-FCC standard in the presence of a single NBI.
- 11:40 Performance of Polar Codes with Successive Cancellation Decoding Over PLC Channels
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Polar codes are the first proven capacity achieving codes for a wide array of channels with low complexity. It is considered a next generation candidate for error-correcting codes (ECC) with turbo codes and low-density parity check(LDPC) codes. The aim of this paper was to analyze the bit error rate (BER) performance of polar codes with successive cancellation (SC) decoding over power line communication (PLC) channels. At first, the performance of the polar codes in additive white Gaussian noise (AWGN) and impulsive noise channels will be shown. In addition, a signal level limiter is used to mitigate the degradation of the performance over the impulse noise channels. Thereafter, the performance over real PLC channels is investigated. Simulation results show that polar codes are applicable to PLC channels with lower complexity than a turbo code or a LDPC code
M2: Device Modelling & Measurements
- 10:20 Measurements on Rogowski Coils as Coupling Elements for Power Line Communication in Traction Lithium-Ion Batteries. Invited Paper.
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We propose Rogowski coils as coupling elements for Power Line Communication (PLC) in lithium-ion batteries for electric and hybrid vehicles. Current battery management systems use standard CAN busses for the communication between battery control unit (BCU) and battery modules, which comprises lithium-ion cells. In contrast, in next-generation batteries the BCU should communicate with each lithium-ion cells in a battery pack to make them safer and increase their performance. However, this can lead to data rates up to 2 MBit/s, which cannot be handled by a standard CAN bus. Furthermore, connecting battery modules by CAN bus wires increase costs and bulk. We are investigating new data bus concepts in order to make lithium-ion batteries safer, with less costs, and less bulk. The Power Line Communication is one way to reach this goal. Using a battery pack as a power-line network, however, requires a different coupler system than in mains electricity. This is because of high direct currents up to 1000 A, which could lead to saturation an iron-cored coupler easily. Rogwoski coils are air-cored coils with no saturation effects, no matter how high the current is. In this paper, we show some experimental measurements, such as measurements of the impedance and the transfer function of Rogowski coils. The results show that Rogowski coils are a viable approach as coupler for PLC in lithium-ion battery packs.
- 10:40 A Preliminary Investigation of the UHF Properties of LV Cable for WiFi Over Power Line Communications. Invited Paper.
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In pursuit of a wireless (contactless) power line communications (W-PLC) system for low voltage (LV) power distribution networks, a commonly utilized bundled low voltage electrical cable called Cabtyre, was energized with a range of frequencies up to 3 GHz. The intention was to characterize the cable from a radio frequency radiation perspective for the utilization of standard low voltage distribution cables as antennas in ultra high frequency (UHF) PLC systems. The range of test frequencies extends 550 MHz beyond the present IEEE 802.11g protocol which has a centre frequency of 2.45 GHz and a 80 MHz total bandwidth. The applied tests therefore allow adequately for the maximum bandwidth required with 40 MHz modulation on either side of the 2.45 GHz centre frequency, [1].
- 11:00 Measurement of Powerlines and Devices Using an Inductive Shunt On-Line Impedance Analyzer
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This paper describes an Inductive Shunt PLC coupler, for coupling wideband PLC signals onto power lines with high efficiency and low distortion and shows how this can be used for measuring PLC frequency impedances of power lines, distribution transformers, motors or any other appliance. The paper presents some impedance measurements of power lines, appliances and distribution transformers.
- 11:20 Is Resistive Coupling Feasible for the Reception of Power-Line Communications Data?
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Historically, two classes of coupling circuits have been used for power-line communications (PLC), being capacitive couplers and inductive couplers. In this paper, resistive coupling as a radical and novel approach is investigated specifically for the reception of PLC data. The main goal of this new approach, is to eliminate costs associated with traditional capacitive and inductive couplers, seeing that resistors are the cheapest electronic components available. Only two resistors are required to implement a voltage-divider setup which reduces the harmful ac power waveform to a safe level, after which (cheaper) low-spec components can be used to filter and process the scaled-down, sampled waveform. Simulation results as well as off-line and live experimental results are shown to confirm that the superimposed PLC signal can be extracted successfully with resistive PLC coupling.
- 11:40 Software for Control and Calibration of an Inductive Shunt On-line Impedance Analyzer
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On-line impedance analysis provides useful data to detect the state of health and characteristics of electrical networks in power systems. This paper discusses software for the control, signal processing and calibration of the Inductive Shunt On-Line Impedance Analyzer. The paper shows that the resulting combination of hardware and software results in accurate measurements of impedances over a wide frequency and impedance value range. Some on-line and off-line impedance measurements are presented.
13:00 - 14:40
M3: MIMO PLC
- 13:00 Broadband MIMO Powerline Channel Emulator Verification and Testing Results. Invited Paper.
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We have designed an FPGA based multiple-input multiple-output (MIMO) power line communications (PLC) Channel Emulator in our research lab over the last years. This paper will demonstrate verification and testing results achieved with the emulator. It also presents comparisons between PLC modem performance results at typical channels within the field and their corresponding emulated performances. Furthermore, some steps that were required to optimize the emulation results will be exposed in this paper. Finally, its shown that significant testing of broadband powerline modems is a quite feasible concern.
- 13:20 Proposed Frame and Preamble Structure for MIMO Narrowband Power Line Communications
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Narrowband power line communications (NB-PLC) operating in the 3-500 kHz frequency band is proposed as a solution to support the emerging Smart Grid applications that aim to optimize the efficiency and reliability of the power grids. PLC is attractive for Smart Grid communications as it can be deployed over the existing power grids without any additional infrastructure. However, PLC suffers from impulsive noise and frequency-selective channels which degrade the system's reliability and data rate. Multi-Input Multi-Output (MIMO) PLC is a promising technology to increase the data rate and provide robustness against the PLC interference. In this paper, we consider the design of a MIMO frame and preamble structure that can be efficiently used to perform initial receiver synchronization while ensuring backward compatibility with current NB-PLC standards.
- 13:40 Interference Alignment for MIMO Power Line Communications
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Interference alignment (IA) is a multiplexing gain optimal linear precoding strategy that has been extensively studied in the context of multi-input multi-output (MIMO) wireless interference networks. In this paper, we study the applicability of IA for MIMO power line communication (PLC) in interference scenarios. In particular, we consider different MIMO PLC networks to study the feasibility of IA as well as evaluate the performance in terms of sum-rate for these setups. To this end, we exploit minimum interference leakage (Min-IL) and maximum signal to interference plus noise ratio (Max-SINR) algorithms that were earlier proposed for IA in the context of MIMO wireless interference networks. Our results show that IA can be equally applicable to the MIMO PLC in interference scenarios as well as the sum-rate of the PLC networks can be significantly improved through the exploitation of Max-SINR algorithm. It is found that at high signal to noise ratio (SNR) the performance gain in terms of sum-rate with IA over orthogonal transmission techniques is around 30% for a 3-user 2 × 2 MIMO PLC network.
- 14:00 Multi-User MIMO Broadcasting/Multicasting for Medium-Voltage Narrowband-PLC Networks
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A multiple-input multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM) system is proposed for narrowband power-line communication (NB-PLC) applications in multi-user medium-voltage (MV) broadcast/multicast networks. A 2-input / 3-output spatial channel model response is simulated for a 3-phase MV broadcast network over the 3 − 500 kHz frequency band. We optimize the precoder design according to the signal-to-leakage-plus-noise ratio criterion and show how the design is different from the wireless scenario. The achievable MIMO-OFDM data rates are evaluated for a group-based multicasting scenario under two different grouping criteria. First, we consider a distance-based criterion where the users within the same geographical area receive a common message. Second, we consider a quality-of-service based criterion where the premium users have a lower bit error rate than the standard users. We demonstrate a significant sum-rate gain for the multicast networks over the broadcast networks for a wide range of noise levels.
- 14:20 Design Tradeoffs in Joint Powerline and Wireless Transmission for Smart Grid Communications
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Providing reliable smart grid communication from customers to the local utility is subject to significant challenges from noise, interference, frequency selectivity, and path loss. In this paper, we consider joint smart grid communication transmission over a powerline channel in the 3-500 kHz band and a wireless channel in the 902-928 MHz unlicensed band. Both channels are interference-limited. The interference has been previously modelled as cyclostationary in the time-frequency domain for power line channels and Gaussian mixture for 900 MHz wireless channels. Previous approaches to joint power line and wireless transmission have explored channel modeling, estimation and noise mitigation to improve smart grid communication performance. This paper reviews previous approaches to (a) modeling, (b) channel estimation and (c) noise mitigation in smart grid powerline (3 - 500 kHz) and wireless (901 - 928 MHz) channels. Then, based on these approaches, the paper analyzes design tradeoffs of communication performance vs. implementation complexity for joint transmission.
M4: Network Performance & Simulators
- 13:00 Routing Overhead Optimization in Smart Grid Networks. Invited Paper.
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This paper presents a routing overhead optimization algorithm called Staggered Link Quality algorithm to reduce routing overhead in large scale smart grid networks that use reactive routing protocols. A reduction in routing overhead will result in higher channel utilization and improved throughput. The proposed algorithm is evaluated over both power line and wireless network through experimental and simulation results. It is shown that the proposed algorithm not only reduces routing overhead but also reduces route discovery time and establishes near optimal paths. Reduction in routing overhead of up to 85% is observed under certain network conditions.
- 13:20 An Experimentally Validated PRIME Subnetwork Simulation Model for Utility Applications. Invited Paper.
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This paper presents a PRIME subnetwork simulation model based on OMNeT++ that reproduces the behaviour of real networks. The developed simulation model uses the most common logical topology of a selected real network provided by a previous monitoring process. Thanks to the developed simulation model, different algorithms and utility applications can be tested in the simulation environment without having to perform lengthy field tests. The model has been validated with the firmware upgrade application comparing the total time involved in such operation both in the simulation and in the real environment. Results show that, according to the two-sample t-test, the mean time to perform the firmware upgrade of the network nodes is equal in both environments.
- 13:40 Performance Evaluation of AMR Simultaneous Polling Strategy in a PRIME PLC Network
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PLC is gaining prominence as a solution for Smart Grid developments. However, several aspects still require further research and analysis. Among the different solutions, PRIME (PoweRline Intelligent Metering Evolution) standard is one of the most popular and extended implementations. This paper analyses the performance impact caused by the polling strategy utilized in an auto meter reading (AMR) process for a PRIME PLC network. In particular, the number of connections that the master node is able to manage simultaneously is studied. The time required to read all the meters in the network is utilized as performance metric. In order to replicate the performance of a PRIME's network, a co-simulation framework that combines Matlab and OMNeT++ has been used. This architecture allows to take into account both physical phenomena and control and application message management. Simulated topologies represent a general European low-voltage network. Results highlight the importance of selecting an adequate number of simultaneous connections in order to optimize the use of the channel.
- 14:00 Impact of the Weak Link Count Mechanism on G3-PLC LOADng Routing Protocol
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G3-PLC has been defined for Smart Grid. The electrical grid is considered as a dynamic network because its performance are time-dependant. It is the reason why G3-PLC standard choose adapted technologies to perform communication is such harsh conditions. One of them concerns the packets routing. Data transmission needs to be performed hop-by-hop by using nodes as relays. LOADng routing protocol, initially developed for Wireless Sensor Networks, was chosen but some mechanisms were added to increase its performance on PLC networks. These mechanisms are described in this paper and the weak link count mechanism is specifically studied. This mechanism privileges the best quality routes in place of the shortest routes in the network. The performance of the routing is then analysed by implementing the LOADng protocol on the network simulator Contiki/Cooja. In particular, we evaluate the impact of the frame error rate, the weak link rate and the average number of neighbours on the weak link count mechanism. Thanks to simulations, we determine in which cases this added mechanism improves the performance of G3-PLC LOADng.
- 14:20 Modeling Approach of Broadband In-home PLC in Network Simulator 3
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A modeling of communication networks is often done in hierarchical way. So, in PLC there are multiple models of channel, physical, datalink and other layers, which are realized separately in multiple programming environments. Nevertheless it is often advantages to make a cross-layer optimization of communication protocols. For this purpose multiple separate models have to be unified in one simulation environment. This paper describes a modeling approach of PLC channel, topology generator, physical and datalink layer in ns-3 together. With such approach the authors show that Linear-periodic time-variant (LPTV) property of the PLC channel is useful to be considered for design of MAC scheduler. The developed simulator is setup for in-home PLC environment. It means that noise, impedance models and topology generator are described as stochastic models, which base on statistical measurement results in this environment.
14:40 - 15:00
Coffee Break
15:00 - 16:40
P: Panel Discussion
Tuesday, March 31
08:30 - 09:00
Registration
09:00 - 09:20
Announcements
09:20 - 10:00
K2: Keynote Talk on "Enabling the Internet of Things (IoT) platform for the Utility"
10:20 - 12:00
T1: Signal Processing for PLC Transceivers
- 10:20 Topology Reconstruction for Power Line Network Based on Bayesian Compressed Sensing. Invited Paper.
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Power line communication (PLC) is playing more and more important role in the smart grid (SG). In this paper, in addition to conveying information, sensing topology of the network based on PLC is proposed to expand the area of PLC application, which is further improve the smart property of the grid. By assuming each endpoint of the grid equipped with PLC device, we model the grid as an edge-node network of tree structure. Then, considering the parametric sparsity of the PLC channel, we propose a method to estimate the distances between nodes using Bayesian compressed sensing (CS). Finally, we exploit the proposed dynamic reconstruction algorithm to reacquire the topology of the whole network. Numerical simulation results demonstrate that the proposed Bayesian CS scheme can achieve the distances between nodes accurately especially in high AWGN level with fewer number of pilots, while the dynamic reconstruction algorithm is more effective than the traditional method with low complexity.
- 10:40 Wake-Up Transceiver Protocol for Power Line Communications
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Matthias Kuba (Fraunhofer Institute for Integrated Circuits IIS, Germany)
This paper presents a wake-up transceiver system based on narrowband power line communications (NB-PLC). An energy-pattern based sequence detection algorithm is proposed for the recognition of a wake-up sequence by the receiver. The method is characterized by low computational complexity and does not require channel parameter estimation and adaption. Furthermore, a blind packet repetition technique is introduced that accomplishes periodic impulsive noise avoidance. A realistic and straightforward narrowband power line channel model is presented and the proposed wake-up protocol is verified against it in terms of Monte-Carlo simulations. It is demonstrated, that the method leads to significant improvements compared to state of the art low-complexity PLC systems in typical NB-PLC channels.
- 11:00 A Novel Weight Reset Strategy for the LMS Algorithm Subject to Abrupt Channel Variations
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We discuss a novel strategy to reset the weight vector of the Least Mean Square (LMS) adaptive algorithm when abrupt channel variations occur. Such variations may be caused by line impedance sudden changes, typically due to switching events, and may significantly impact the performance of the LMS algorithms used for adaptive echo cancellation and equalization. Specifically, they may trigger a convergence transient period, whose duration depends on the distance between the current weight vector and the final one. In previous work, a weight reset strategy based on sign inversion was demonstrated in the context of echo cancellation for a power line modem. In this paper, we extend this work by investigating weight reset strategies based on a group of reinitialization vectors, some of which will be likely close to the final LMS optimal weights. The results show that it may indeed be possible to promptly detect abrupt channel variations and properly reset the LMS weights in order to shorten the induced transient period.
- 11:20 A Bit Loading Technique with Reduced Complexity for Periodically Time Varying PLC Channel
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This work focuses on a novel bit loading technique that is capable of reducing the computational complexity associated with the resource allocation approach applied to power line communication system based on orthogonal frequency division multiplexing scheme when the channel is periodically time varying. Basically, the proposed technique exploits the existing correlation among successive microslots within one cycle and/or among cycles of the mains signal to trade computational complexity with data-rate. Numerical results, which are based on measured data, reveal that considerable computational complexity reduction with a low probability of high data-rate loss ratio can be attained and because of that the proposed technique can be an useful to reduce the hardware resource utilization in power line communication transceiver based on orthogonal frequency division multiplexing scheme.
- 11:40 Optimal Power Allocation for Non-Regenerative Multicarrier Relay-Assisted PLC Systems with QoS Constraints
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In this paper we present an iterative algorithm to jointly optimize the source and relay power allocations for a general relay transmission system, i.e. the broadcast-and-multiaccess multicarrier relay system, where the source transmits in two time-slots. Under (but not limited to) the indoor power line communication environment, we examine the issue of minimization of the total network transmission power subjecting to QoS constraints expressed as the capacity lower-bound of the data-link from the source to the destination nodes. In addition to demonstrate the fast convergence of the proposed algorithm, the simulation results also show that with respect to the two-hop relay system and the broadcast-and-forward relay system, the proposed general relay system can satisfy the same QoS requirement while consume less total transmission power.
T2: Channel, Noise and Interference Characterization (I)
- 10:20 Statistical Modeling of PLC-to-DSL Interference. Invited Paper. Received Best Paper Award.
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This contribution presents a new statistical model of PLC-to-DSL interference. The frequency-dependent couplings between power line cables and twisted-pair were estimated from measurements on a large number of residential inside wires. A parametric statistical model based on a mixture of two truncated Gaussian distributions is here set forth. The proposed statistical model allows the statistical evaluation of the impact of PLC interference on various DSL technologies. To the best of the Authors' knowledge, this is the first statistical model for PLC-to-DSL interference to be proposed.
- 10:40 On Modeling of Sporadic Impulsive Noise Rate Within In-Home Power Line Networks
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The paper proposes a methodology to model the impulse rate of sporadic impulsive noise, namely the impulsive noise that is generated by the transients during the switching on/off of electrical appliances. In particular, it is proposed to exploit the publicly available datasets of power consumption measurements campaigns to derive the instants when a switching on/off event occurs. The statistics of the impulse rate is derived considering the data gathered during a six-month measurement in one of the houses of the GREEND dataset. Furthermore, to define the set of appliances that generate sporadic impulsive noise within the considered house, a noise measurement campaign and the corresponding analysis is carried out.
- 11:00 The Impact of PLC-to-DSL Interference on VDSL2, Vectored VDSL2, and G.fast. Invited Paper.
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This contribution presents an analysis of the impact of PLC-to-DSL interference on three wideband DSL technologies: VDSL2, Vectored VDSL2, and G.fast. The impact was assessed via computer simulation, but measured loop responses and measured FEXT were also used together with a large set of PLC interference measurements collected from a large number of residential inside wires. The impact of PLC-to-DSL interference on the achievable data rate is assessed at various loop lengths. We have found that the impact of PLC interference on DSL is small on short loops but it grows quickly as loop length increases. We have also confirmed that the use of vectoring greatly increases the sensitivity to PLC interference as vectoring removes the time-invariant ``blanket'' of crosstalk and leaves DSL exposed to PLC interference as well as to other alien noise.
- 11:20 Channel Characterization for Underwater Broadband PLC Sensor Networks
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For the tasks of navigation and obstacle detection, underwater and surface vehicles mostly rely on sonar, which uses a number of spatially distributed acoustic sensors. In this paper we explore the characteristics of linear bus structures, which is the natural choice for such an underwater sensor network, combining both power and data transmission capabilities, using only two wires. The measurement and modelling results of cables and a bus structure under changing pressure conditions are introduced. These results are essential for the development of a new broadband power line communication (PLC) system.
- 11:40 The Influence of High Pressure Sodium Lamps on the Power Line Communications Channel
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The high pressure sodium lamp is a high energy outdoor light source that belongs to the high intensity discharge lamp family. It comes in different shapes and requires a ballast to start it. The high pressure sodium lamp is a source of interference to the power line communications channel as it injects noise when connected to the 220V mains. This paper investigates the influence of the high pressure sodium lamp on the narrowband and broadband power line communications channel. It is shown that the frequency band: 3kHz – 150kHz is not highly infected whereas in the band: 150kHz – 30MHz, PLC signals compete with Electromagnetic Compatibility (EMC) levels.
13:00 - 14:40
T3: Channel, Noise and Interference Characterization (II)
- 13:00 On PLC Channel Emulation Via Transmission Line Theory. Invited Paper.
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The emulation of power line communication (PLC) channels is an important tool for the analysis and development of PLC systems. Especially for the study of PLC networks, the so-called bottom-up channel emulation using transmission-line theory (TLT) is the proper method. The underlying assumption of this approach is that the power line propagation characteristics are known. That is, the per-unit length (PUL) parameters of the power lines need to be computed. However, especially for multi-conductor lines this can be theoretically and computationally challenging. In this paper, we present a compact overview of the computation of PUL parameters. We briefly discuss the assumptions associated with different solution methods and develop a numerical solver applicable to general multi-conductor transmission lines. Considering a sample set of different cable types, we demonstrate the effects of simplifying assumptions on the accuracy of computed PUL parameters and channel frequency responses.
- 13:20 Statistical Modeling of the Average Channel Gain and Delay Spread in In-Home PLC Channels
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This work describes a complete statistical modeling of the average channel gain in dB (ACG) and the root mean squared delay spread (RMS-DS) for power line communication (PLC) systems. The PLC channel features are estimated from 148,037 channel frequency responses measured in 7 typical different places in an urban area in Brazil. Two frequency bands are considered: from 1.7 up to 30 MHz and from 1.7 up to 100 MHz. The resulting datasets for ACG and RMS-DS were fitted to well known continuous distributions, including symmetric (Logistic and Normal) and asymmetric (Exponential, Gamma, Inverse Gaussian, Loglogistic, Lognormal, Nakagami, Rayleigh, Rician, Skew-normal, t-Student and Weibull) cases. The best distribution fitted to the considered dataset is indicated by the log-likelihood value and three distinct information criteria. The achieved results revealed that the ACG is better modeled by the Skew-normal and the Nakagami distributions for the frequency bands from 1.7 up to 30 MHz and 100 MHz, respectively, whereas the RMS-DS is little bit better modeled by the Gamma distribution, then by the Lognormal distribution, in both frequency bands considered.
- 13:40 The Effects of Periodic Impulsive Noise on OFDM
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The effect of periodic impulsive (short duration) noise on OFDM is investigated. We present results on the nature of periodic impulsive noise, showing that the PDF of periodic impulsive noise is not exactly Gaussian. We also present results showing that periodic impulsive noise can be more devastating to OFDM compared to random impulsive noise. This is because periodic impulsive noise energy is not spread by the FFT on the receiver side of the OFDM, instead it appears periodic in the frequency domain. Results showing the effect of nulling to mitigate periodic impulsive noise are presented. We suggest a simple short block code (as opposed to long block codes) that can effectively combat the effects of periodic impulsive noise.
- 14:00 Electromagnetic Compatibility in Europe for OFDM Based PLC Access Data Transmission in the Frequency Range 150 kHz to 500 kHz
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Electromagnetic Compatibility (EMC) is a key consideration for the development and operation of Power Line Communication (PLC) systems. Applicable EMC requirements and related standards may change depending on the considered regulatory regions (typically Japan, the United States and Europe have different regulations). This white paper focuses on EMC aspects to be considered for PLC roll-outs in the European market in the frequency range 3 kHz to 500 kHz.
- 14:20 A Semi-Hidden Markov Modeling of a Low Complexity FSK-OOK In-House PLC and VLC Integration
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The integration of power line communication (PLC) and visible light communication (VLC) is increasingly receiving a lot of research interest with the advent of (IEEE 1901, ITUT G.9960/61) and IEEE 802.15.7 standards for PLC and VLC respectively. In particular, there is an underlying gain that could be achieved by leveraging the existing ubiquitous power line network infrastructure to render connectivity, while we also exploit the illumination system of power-saving Light Emitting Diodes (LEDs) for wireless data communication. The ubiquitous nature of these two systems makes us belief that VLC can offer a good complementary wireless data transmission technology to the existing In-House PLC in a similar manner broad-band Ethernet connections enjoys the support of Wi-Fi. This paper thus reports an implementation of a low complexity FSK-OOK In-House PLC and VLC Integration, as well as it's Second-Order Semi-Markov Model. The resulting statistical models facilitates the design and evaluation of forward error correcting codes to mitigate burst error occurrences, as well as optimizing the performance of the overall system
T4: Emerging Systems & Solutions
- 13:00 HomePlug Green PHY for the LVDC PLC Concept: Applicability Study
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It has been shown that high-frequency (HF) band power line communication (PLC), that is, the HomePlug 1.0 specification, is feasible for a low-voltage direct current (LVDC) smart grid (SG) system, where power electronics and low-voltage DC are applied to the electricity distribution. In this paper, the applicability of the latest HomePlug specification, Green PHY (GP), is studied within the LVDC PLC concept. Channel characteristics between 2–30 MHz in the HomePlug GP frequency band and noise in the channel from the terminals of the PLC couplers are measured. Furthermore, data transmission tests with HomePlug GP compliant modems are carried out in the LVDC laboratory setup and on the LVDC research site.
- 13:20 6LoPLC for Smart Grid Applications
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The success of next generation power grid will be determined by depth of monitoring, intelligence and control achieved through information and communication technology (ICT). Power Line Communication (PLC) is generally considered a natural communication channel owing to its low cost, availability and scalability. A major requirement for any in-grid communication devices is low power consumption. The devices must also run on communication protocols with built-in reliability and resilience against natural and man-made disruptions. Due to their low cost and relevance, inclusion of low-power devices in smart grid agenda has gained traction and is already a fait accompli. This paper proposed a Low Power Internet Protocol version 6 for PLC (6LoPLC) to increase reliability and maximize network availability with acceptable latency in Advanced Metering Infrastructure (AMI). A model was developed using NS-3 to measure and analyze the performance of low-power Narrow Band PLC (NBPLC) in AMI services. Simulation results are quite promising as they indicated viability of 6LoPLC in smart grid.
- 13:40 Power Line Communication Technology in Industrial Networks
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The PLC (Power Line Communication) technology could be an additional alternative on the market for data transmission in industrial applications, like industrial networks used to collect sensor readings and controlling machines and actuators at field level. Before that, it is necessary to evaluate the industrial networks needs (e.g. data rate, range, security issues, response time and so on) and obstacles for PLC signal (e.g. noise and attenuation provoked by industrial devices) for comparing with the PLC technologies available. This paper presents a study about the industrial needs concerning data transmission, the sources of interference/attenuation for PLC signal in industry and the best PLC technology available for these applications. In the last part, are presented the results of real communication tests with G3-PLC (the chosen standard) MODEMs working in a physically simulated industrial environment. Different bands and subcarrier modulations were tested in order to determine the one with best performance in industrial environment.
- 14:00 High-Voltage Power Line Communication System for Hybrid Vehicle
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Recently, hybrid vehicles (HVs) and electric vehicles (EVs) have become widespread. These vehicles incorporate a large number of electronic devices. In HVs and EVs, a high-voltage (200 V) battery is employed. In the current HVs, the battery supplies power to the Power Control Unit (PCU) for driving a motor, generator and air conditioner compressor. It is expected that such kinds of power electronic devices will increase in number in the future. We previously proposed a power line communication (PLC) that uses a high-voltage power line. In this paper, we present the development of a high-voltage PLC system that can simultaneously control multiple power electronic devices in real time and demonstrate the system operation. First, in a system simulating the structure of a commercially available HV, the results of transmission characteristics and electromagnetic noise characteristics that are superimposed on the high-voltage power line are shown. From these results, the optimum carrier frequency as a PLC is revealed. Then the bit error rate (BER) performance under the above noise environment is clarified by computer simulations. In consideration of the above, specifications of a PLC system of the HV are developed. Finally, we construct a prototype of the high-voltage PLC system and demonstrate that the system can simultaneously control the rotational speed of two motors.
- 14:20 A Novel Power Line Communication System for Outdoor Electric Power Grids
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This paper outlines a novel power line communication (PLC) system that was specified, designed, and prototyped to addresses the features of low-voltage and outdoor Brazilian electric power grids when the frequency band between 1.7 and 50 MHz, which complies with the Brazilian regulation for broadband PLC, is considered for data communication. The proposed PLC system is constituted by a PLC base station and several PLC modems. Also, it makes use of the clustered orthogonal frequency division multiplexing scheme to divide the total frequency bandwidth into several narrowband subchannels. As a result, the maximum throughput achieved by a PLC modem is a fraction of the maximum throughput that a PLC base station can offer and, as a consequence, the computational complexity as well as hardware resource utilization associated with PLC modem is considerably reduced in relation to the PLC base station. Performance analyzes show that data-rate as high as 24 Mbps can be attained in each subchannels at the application level and it can be useful technology for smart grid communication and digital inclusion.
15:00 - 16:20
T5: Transmission and Detection Techniques
- 15:00 Detection of Wireless Signals in Broadband Cognitive PLC Using the Modified 2-D LAD ACC Algorithm. Invited Paper.
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There is a need to fulfill the growing capacity requirements of power line communication (PLC). One way to achieve higher data rates in PLC networks is to operate at higher frequencies and increase the used bandwidth. In the future, the increased PLC frequency range can overlap with several wireless communications systems resulting in interference for these transmissions and vice versa. Commonly used static notching results in inefficient spectrum utilization as in a given place and at a given time only a part of the frequency range may be occupied by other wireless systems. Some wireless signals like FM-signals are very closely spaced. In practice it is impossible to utilize these narrowband unoccupied frequency bands. In this case we can cluster closely spaced signals. Guard bands around detected wireless signals must also be taken into account before defining usable frequency bands for PLC. In this paper, we use the 2-D LAD ACC algorithm to detect and cluster interfering signals. We also further develop the algorithm so that after clustering guard bands are added and reclustering, if necessary, is executed. The performance of this modified 2-D LAD ACC algorithm is analyzed using calculations and spectrum analyzer measurement results obtained from in-office PLC network in the frequency range 80-200 MHz. The results verify that the proposed method performs well by detecting and clustering continuous and non-continuous wireless signals and providing means for clever spectrum utilization in PLC-network.
- 15:20 The Influence of Transmission Power and Frequency Bandwidth on In-home Cooperative Power Line Communication. Invited Paper.
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This paper proposes to analyze the influence of transmission power and frequency bandwidth on in-home cooperative power line communication (PLC) based on channel estimates provided by a measurement campaign. We investigate in-home PLC channels based on cooperation from a single relay whose relay node is located in the middle between source and destination nodes by considering closed-form expressions of the theoretical channel capacity. The analysis is carried out over the amplify-and-forward (AF) and decode-and-forward (DF) protocols, together with the equal gain combination (EGC), selecting combination (SC) and maximal ratio combination (MRC) techniques. Numerical results show that an increase in frequency bandwidth and/or a decrease in transmission power introduce notable channel capacity gains compared to direct link.
- 15:40 Guard Interval Adaptation for In-home Power Line Communication. Invited Paper.
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Nhan Vo (Telecom Bretagne, France); Karine Amis (Institut TELECOM ; TELECOM Bretagne & Université européenne de Bretagne, France); Thierry Chonavel (Institut Télécom; Télécom Bretagne & Université Européenne de Bretagne, France); Pierre Siohan (Orange Labs, France)
This paper aims to analyze the choice of the guard interval (GI) length in PLC systems to optimize the achievable throughput under power and symbol error-rate (SER) constraints. In general, the GI length is chosen so that there is no interference, i.e. the GI length is greater than or equal to the channel impulse response length. However, many previous works have shown that in PLC systems, this GI choice is inefficient in terms of achievable throughput. Indeed, shorter GI evidently results in inter-symbol interference (ISI) and inter-carrier interference (ICI), but the gain offered by shortened GI may exceed the loss caused by interference. In this paper, we propose a simple solution for the GI length adaptation in PLC systems to optimize the achievable throughput.
- 16:00 A New Digital Front End Structure for Cognitive PLC Systems. Invited Paper.
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Hongjian Gao (China Electric Power Research Institute, P.R. China); Gerd Bumiller (Hochschule Ruhr West & University of Applied Sciences, Germany); Weilin Liu (State Grid Corporation of China, P.R. China); Jianqi Li (China Electric Power Research Institute, P.R. China)
Power line channel is hostile for communication. One concept we proposed for reliable communication in power line is to adjust the working band according to different channel conditions. In this paper, a new digital front end (DFE) structure, which combines equivalent complex baseband (ECB) structure and Nyquist windowing at both transmitter and receiver, is proposed to support this concept. By configuring parameters of ECB, it supports flexibly band selection. Besides, out-of-band interference is able to be attenuated to a large extent due to the cascaded low-pass filters in the ECB at receiver. Therefore, it is possible to apply much more simplified analogue front end. The Nyquist windowing at receiver makes side-lobe of narrowband disturbance fall down quickly and concentrates its energy on fewer subcarriers, which benefits the narrowband interference detection. Finally, system performance with the new DFE structure in the presence of in-band and out-of-band disturbance is simulated and compared with classic DFE and equivalent complex baseband (ECB)-based DFE.
T6: PLC System Performance
- 15:00 Powerline-Channel Adopted Layer-Design and Link-Layer for Reliable Data Transmission
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Gerd Bumiller (Hochschule Ruhr West & University of Applied Sciences, Germany)
Narrow Band PLC uses often MAC-protocol stacks designed for wireless systems like IEEE 802.15.4 (used by Prime, PLC-G3 and IEEE 1901.2). Due to the different behavior of the power line channel mainly OFDM based PHY-Layers, significant modulations and decoding times are used. The resulting computation delay is equivalent to 3-5 OFDM symbol times, which has an equivalent effect on the system as a propagation delay. The short ACKs for confirmation are full packages with several OFDM-symbols. The impulsive noise on the channel requires certain packet duration to reach sufficient reliability. Therefore a stop and wait protocol with immediate acknowledgement of each packet cannot reach an efficient channel usage. Additionally it is necessary for reliable PLC systems to accept links with PER (packet error rates) of 20% and more. The theoretical maximum throughput of a channel with PER of 20 % is still 80%. Very often narrowband PLC standardized protocols fail under this condition. This paper presents an adopted Layer-Design to combine all data flows to a node in a single stream and organize a reliable data transmission even for channel with PER of 90% and more. A pipeline structure allows an efficient medium usage and realizes a selective repeat approach. The confirmation is transferred piggy back in packages in opposite direction. Even for the retransmission of a packet the transmission mode and the route can be changed. This approach allows fast reactions on changed network situations without interruption of any link, which is an important requirement to fulfill reliability and real-time requirements for grid control.
- 15:20 Performance of Gabidulin Codes for Narrow-band PLC Smart Grid Networks
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This paper studies the Power Line Communications (PLC) and tackles the problem of criss-cross noise. In the literature, it is proposed to use Reed-Solomon code concatenated with convolutional code associated with an interleaver. For instance in the context of smart grid, some standards like G3 and IEEE 1901.2 use this scheme. However, the narrowband interference and impulsive noise, which are typical in the PLC, make these schemes inefficient. In this paper we propose to replace the Reed- Solomon code by a kind of rank metric code (Gabidulin code) that can correct a whole line or row of a code word, which is arranged in a matrix. Using OFDM modulation, the columns of code matrix contain the OFDM symbols. We show by simulation that the proposed system outperforms the traditional scheme where the PLC channel is subjected to both impulsive noise and narrowband interference.
- 15:40 Analysis Tool for Temporal Evolution of Frame Error Rate Performance in Narrowband PLC
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G3-PLC is a transmission system using the power line channel. This technology and others using the power lines as the communication medium are very interesting for power utilities as operators can use their own infrastructure for communication purposes. Nevertheless, as power lines were not designed to carry data, the performance of a communication may vary depending on many parameters (load, meteorological conditions, season, etc.). To be able to use the power line medium, tools allowing a power utility to determine the performance of a communication using a specific link must be developed. In this paper, an analysis tool capable of monitoring the performance indicators of a G3-PLC transmission throughout the communication will be presented. The tool was used in a field test in Mons, Belgium, to obtain real-cases results. The analysis method applied to the results is presented in this paper.
- 16:00 Feasibility Study of Ubiquitous Sensor Networks by Inductively Coupled PLC Over PV Power Systems
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Simple and low-cost PLC will be required to play a role in the Internet-of-Things (IoT) market such as ubiquitous wireless sensor networks. From the viewpoints of temporal connectivity and obtaining high SNR and stable channels, inductive coupling techniques for the kHz band PLC have been proposed in this paper. The results of three feasibility studies using a photovoltaic power system installed in our laboratory have been described. First, an inductive coupler is applied to the DC power-line channel, because it forms a low impedance loop circuit. It was proved that the DC power-line provided a high SNR channel, so that the simple modulation technique was enough to realize the ubiquitous PLC networks. The second topic is the contactless power supply using the same ferrite core as the PLC coupler. It has been shown that the proposed circuit could supply power of 35mW at the maximum to a wireless sensor node. The third topic is an application of the 1-wire PLC system to aerial cables. A suitable coupling method has been proposed to provide a low signal attenuation channel. The noise characteristic peculiar to PV power-line is also pointed out, that is the amount of noise on a sunny day with cloud occasionally exceeded that on a cloudless sunny day.
- 16:20 High Bitrate Downhole Telemetry System
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The oil and gas industry is the driving force behind pushing embedded communication technologies beyond their originally intended purpose. A downhole power line communication design based on multicarrier modulation methods is commonly implemented in ADSL systems. The system is designed to transmit and receive high-bitrate data on a multiconductor power transmission cable, which is highly contaminated with broadband electrical noise generated by downhole equipment and requires innovative crosstalk cancellation techniques in both the analog and digital domain to achieve better than a 10-6 bit error rate (BER) performance at operating temperatures of 200°C.
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