Augustine Ikpehai

Channel characterisation of cooperative relaying power line communication systems

Power line communication (PLC) technology offers a promising platform for numerous communication applications. The power lines however can significantly attenuate communication signals operating in high frequency band. For this reason, multi-hop PLC systems become desirable. In this paper, we investigates the effect of multi-hop relaying on the power line channel transfer function. Measured results are compared with results obtained from sumulations in Matlab. Results show that the presence of relays between a transmitting and a receiving PLC nodes can intensify the attenuation and frequency selectivity. Measurements show that maximum attenuation increases with number of relays.

Location prediction optimisation in WSNs using Kriging interpolation

Many wireless sensor network (WSN) applications rely on precise location or distance information. Despite the potentials of WSNs, efficient location prediction is one of the subsisting challenges. This study presents novel prediction algorithms based on a Kriging interpolation technique. Given that each sensor is aware of its location only, the aims of this work are to accurately predict the temperature at uncovered areas and estimate positions of heat sources. By taking few measurements within the field of interest and by using Kriging interpolation to iteratively enhance predictions of temperature and location of heat sources in uncovered regions, the degree of accuracy is significantly improved. Following a range of independent Monte Carlo runs in different experiments, it is shown through a comparative analysis that the proposed algorithm delivers approximately 98% prediction accuracy.

Vector OFDM Transmission Over Non-Gaussian Power Line Communication Channels

Most of the recent power line communication (PLC) systems and standards, both narrow-band and broadband, are based on orthogonal frequency-division multiplexing (OFDM). This multiplexing scheme, however, suffers from the high peak-to-average power ratio (PAPR), which can considerably impact the energy efficiency, size, and cost of PLC modems as well as cause electromagnetic compatibility (EMC) issues. This paper investigates the performance of vector OFDM (VOFDM), which has inherently better PAPR properties, over non-Gaussian broadband PLC channels equipped with two nonlinear preprocessors at the receiver. In addition, the low PAPR property of the VOFDM system is exploited to further enhance the efficiency of the nonlinear preprocessors. The achievable gains are studied in terms of the complementary cumulative distribution function of the PAPR, probability of noise detection error, and the signal-to-noise ratio at the output of the nonlinear preprocessors. For comparisons sake, the performance of conventional OFDM systems is also presented throughout this paper. Results reveal that the proposed system is able to provide up to 2-dB saving in the transmit power relative to the conventional OFDM under same system conditions, which eventually also translates into a system that is more resilient to EMC limits, reduced cost, and size of PLC modems. It is also shown that the achievable gains become more significant as the vector block size of the VOFDM system is increased.

6LoPLC for smart grid applications

Reliable monitoring, intelligence and control achieved through Information and Communication Technology (ICT) will determine the success of next generation power grid. This paper proposes a Low Power transmission of Internet Protocol version 6 in PLC (6LoPLC) to provide network reliability with acceptable latency in Advanced Metering Infrastructure (AMI). The analysis presented here are preliminary results from an ongoing research that attempts to leverage existing wireless techniques to achieve energy efficiency in PLC. 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 obtained so far are quite promising.

Kriging interpolation based sensor node position management in dynamic environment

The use of Wireless Sensors Network (WSN) is growing not only in popularity, but also in scope and application. Poised to shape the way we monitor the environment, wireless sensors has a lot of potentials waiting to be unlocked. Performance of WSN is largely determined by coverage and positioning of the sensor nodes. However, to be accepted as de-facto solution for monitoring different phenomena in our physical world, it is necessary to develop acceptable standards for its configuration and deployment. Motivated by this requirement, this paper investigates Kriging interpolation algorithm as an efficient location management system. With the aid of Kriging interpolation, it will be demonstrated later in this paper how targets of interest can be classified and monitored in a distributed manner for better accuracy. Effectiveness of this method on a large scale was established by applying it to temperature-based sensor network in a dynamic environment. Kriging interpolation sensor management is expected to improve coverage, reduce power consumption and enhance performance of sensor nodes and by extension the network.

Energy-Efficient Vector OFDM PLC Systems With Dynamic Peak-Based Threshold Estimation

Power line communication (PLC) has made remarkable strides to become a key enabler of smart grid and its applications. Existing PLC systems are based on orthogonal frequency division multiplexing (OFDM), which has a high peak-to-average power ratio (PAPR). This paper presents vector OFDM (VOFDM) with advanced signal processing at the receiver to improve the energy efficiency of the PLC system. Results show that, due to its low PAPR properties, VOFDM is less sensitive to impulsive noise and provides a reduction of 5.8 dB in transmit power requirement relative to conventional OFDM. Furthermore, unlike the existing impulsive noise cancellation methods, the adopted signal processing technique also improves the SNR at the receiver by 2.1 dB, which further reduces the power requirement of the PLC transceiver. Together, these can simplify design, reduce cost, and improve energy efficiency of future PLC transceivers.

Smart street lighting over narrowband PLC in a smart city: The Triangulum case study

As municipalities continue to embrace digital revolution in a bid to become smarter cities, the unique intersection between ICT and development road map is inspiring new innovative applications. While this quest for smart city continues, the transformation of street lighting has become a topical issue. As part of ongoing investigation in Triangulum smart city project, this paper presents some simulation results on the use of narrowband powerline communication (NPLC) for street lights monitoring and control. The results show that, with low power, NPLC can support a 3.5km network of street lights without using a relay. It is also shown that, when the data packet size quadruples, latency degrades by up to 22.63% (242.03ms) in the worst case.

Home energy management system over low-power narrowband PLC

The need for efficient use of energy has inspired intelligent load control strategies in the home area network (HAN) using the power of Information and Communication Technologies (ICT). This paper investigates the use of low-power Narrowband Power Line Communication (NPLC) to support home energy management system (HEMS). Compared with low power wireless systems, it will be shown that using low-power Narrowband PLC (NPLC), packet success rate can be improved by approximately 85.32%, 208% and 85.32% in dense, sparse and large networks respectively. These results imply that low power NPLC is a feasible alternative for HEMS where low power wireless network is limited or inadequate.

Virtual microgrids: a management concept for peer-to-peer energy trading

The proliferation of distributed energy resources (DERs) and smart technologies has enabled the integration of microgrid generation into the energy supply chain. This paper proposes the use of energy trading agents (ETA) in the overlaying communication system in a neighbourhood area network (NAN) in which a number of microgrids (MGs) are grouped together into logical clusters called virtual MGs (VMGs) to minimize operational costs. To decouple the communication network from the grid topology and study the communication performance, each VMG is assigned an ETA such that prosumers in a VMG exchange messages only with the ETA rather than uncontrolled messaging in the network. Although this reduces the amount of network traffic, a key question is on how to determine the optimal location of the ETAs. For VMGs of regular shapes, we formulate this as a simple minimization problem of Euclidean distances of regular shapes. Our results show that by employing ETAs, the model reduces the distance traversed by a prosumer by 40%.