Detection of broadcast signals in cognitive radio based PLC using the FCME algorithm

This paper investigates interference detection problem for satellite communication systems. With the help of the sorting procedure of the spectrum amplitude, the traditional forward consecutive mean excision (FCME) algorithm and Double-threshold FCME (DTFCME) algorithm are highly complex, which are hard to apply for satellite loads. To address this issue, we propose an improved FCME algorithm based on differential spectrum envelope (DiffFCME) without performance loss. The algorithm takes advantage of the maximum differential value of the received signal’s spectrum envelope to find the no-interference segments, and then use the no-interference segments to calculate initial threshold, thereby reducing the complexity of the algorithm. The simulation results indicate that the proposed DiffFCME algorithm can present quite good detection probability even when relative bandwidth (RBW) of the interference signal is relatively large.

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.

The hybrid wireless and power line communication (PLC) technology greatly improves the reliability of Power Internet of Things network (IoT) and the access ability of the terminals. However, with the development of Power IoT, the topology structure of the network becomes exceedingly complex, and the difficulty of networking is also gradually increasing. To address this issue, this paper proposes a multi-ant colony (MACS) based QoS networking algorithm for hybrid PLC and wireless communication networks. Considering the network QoS parameters and service demands, the networking algorithm constructs the fitness function to evaluate the quality of communication transmission paths, and the MACS algorithm is employed to establish the optimal relay route to complete networking. Numerical results prove that the MACS algorithm has a superior ability to jump out of local optimum than the traditional improved ant colony system (IACS) algorithm. Moreover, our proposed algorithm can construct the optimal relay route under corresponding constraints and demands according to different types of services.

Power line Communications (PLC) has gained a lot of interest for the last mile or access because the normal electric power line is utilized for transmission also communication signals. Considerable research effort has been extended on investigating the technologies about the physical (PHY) layer and the medium access control (MAC) layer. But the transmissions scheduling is still a key design problem, especially in multi-hop PLC networks. In this paper, a time slot reuse schedule (TSRS) is proposed, to scheduled access in the networks. It utilizes time slots assignment with special reuse for the nodes in the cell, to improve the channel efficiency. TSRS is an appealing concept for PLC networks, since there is always a manager controlling the network, and PLC networks are often master slave structure with tree topologies. For successfully preventing the potential collision between the nodes, the performance of networks is improved significantly, which is also corroborated by the simulation results.

Exponential demand for broadband applications has elicited renewed interest in characterizing noise in power line communication (PLC) networks for optimal error performance analysis. PLC is economical and ubiquitous, however due to multipath phenomena and nonstationary impulsive noise, the PLC channel is very harsh to signal transmission. Recent studies reveal that PLC noise is cyclostationary and modelling its characteristic should exploit the spectral and temporal redundancy. In addition, preliminary research shows that PLC noise exhibits self-similarity and can be predicted by fractal theory. In modelling noise employing fractal theory, the Hausdorff dimension (D) needs to be approximated. D is related to Hurst parameter (H), which is a measure of self-similarity. Hence, it is important to estimate H for accurate noise prediction using fractal theory. H parameter estimators assume stationarity in time series data. Therefore, preprocessing is required for the case of PLC noise before estimating H to make it stationary as periodicity and nonstatioanrity affects the H estimators. In this study, we remove the periodicity hidden in the PLC noise obtained from measurement campaign within several university offices, workshops and laboratories. Then long-range dependence is estimated from this pre-processed noise data by employing three estimation algorithms: R/S (rescaled adjusted range) method, aggregated variance method and absolute values of aggregated series method. Results from the said estimation methods though not the same, show that the Hurst parameters obtained from various noise measurements are greater than 0.5, implying presence of self-similarity with long-term memory. Results from this study will find valuable applications in PLC noise modelling using fractal and chaos theory and in error performance analysis in both narrowband and broadband PLC systems.

Power Line Communications have been the subject of an important research work. At the same time, the growing demand for multimedia communications provides a good prospect for PLC as a promising transmission technique for the “last mile” access network. Orthogonal Frequency Division Multiplexing (OFDM) is a spectrally efficient multicarrier modulation technique for high speed data transmission over multipath fading channels. High Peak-to-Average Power Ratio (PAPR) is a major drawback of OFDM. The high PAR of the OFDM signal has to be considered when setting the range of the digital-to-analog converter (DAC) and dimensioning the line-driver. This paper introduced an improved PAPR reduction scheme using constant envelope modulation. Furthermore, by utilizing continuous phase modulation (CPM) in a CE-OFDM system, the PAPR can be effectively reduced to 0 dB. The paper describes a CE-OFDM based modem for Power Line Communications (PLC) over the low voltage distribution network. Relying on a preliminary characterization of a PLC network, a complete description of the modem is given.

Power line communication (PLC) over low-voltage grid, is an attractive technology for no-new-wiring networks. In such typical application fields as home networks and street lighting management system, PLC network is always vulnerable in robustness and the logical link is liable to be destroyed because of the different user's personalities and the special channel properties. To improve the robustness of PLC network, the reasons that lead to the failure of data link are revealed, and the main achievements of randomized initialization protocols for ad hoc networks are studied. According to the study results, a novel low cost intelligent control method in MAC protocol is proposed to automatically maintain the logical connectivity of the PLC network. The performance of the method is evaluated theoretically and experimentally.

Power line communication (PLC) technology has created a niche use in the Internet of Things (IoT) by offering flexible and reliable connection among power-driven IoT devices/sensors over existing wired networks. In IoT over PLC networks, massive real-time data generated by the ever-growing connected devices will eventually pose an overwhelming burden on the IoT cloud, which in turn severely degrades the network performance. To cope with these issues, edge computing (EC) has emerged as a complement to cloud computing, aiming at offloading a portion of computing in the cloud to the network edges closer to the IoT devices. However, confronting a practical scenario that some electrical devices cannot communicate with wireless and mobile networks directly, existing EC paradigms may not be directly applied to IoT over PLC networks. In this paper, we propose a novel EC-IoT over PLC paradigm to reduce the transmission latency while migrating a portion of computing from the cloud to the edges. First, we develop a distributed EC platform to serve terminal users (TUs) in different IoT systems with various IoT services. Second, we put forth a cache-enabled scheme to store the popular contents from the cloud and edge sensors to reduce redundant data transmissions between TUs and the cloud. Finally, our experimental results demonstrate that the proposed EC-IoT over PLC network can significantly reduce energy consumption and transmission latency.

Although Power Line Communication (PLC) is not a new technology, its use to support data transmission over low voltage (LV) distribution networks is still the focus of ongoing research. This thesis focuses on the channel modelling and performance evaluation of narrowband (NB) PLC system. First, the channel modelling approaches of PLC are studied. Then, the proposed PLC channel modelling method based on the bottom-up approach for LV narrowband PLC in a frequency band between 9 kHz and 490 kHz is presented. This proposed model employs the transmission and scattering matrix methods to calculate the transfer function of a typical LV PLC network which comprises two common cable types (copper cables and aluminium conductor steel reinforced). Unlike the top-down approaches, this model is scalable as the network complexity increases and can better describe the network behaviour as a function of physical parameters.In addition, the noise characteristics and popular noise reduction techniques of PLC are studied. The major impairment to the PLC is the impulsive noise which is mainly generated by the switching transient in the network. Hence, a new technique is proposed to mitigate the impact of impulsive noise on data transmission over power lines. This proposed technique is an optimal Clipping/Blanking nonlinearity technique which is based on the minimum bit error rate (BER) search. Results obtained from the simulation of this technique demonstrate that performance has been enhanced in the NB-PLC system. The performance of the narrowband PLC system is also evaluated in both physical (PHY) and medium access control (MAC) layers. Since Orthogonal Frequency Division Multiplexing (OFDM) is a suitable modulation scheme for hostile environment of the power line, it is used to evaluate the PHY layer performance. As a result of the PHY layer performance analyses, it is found that the BER performance between neighbouring points in the typical LV PLC network is reasonable, but communication beyond one hop have to rely on upper layer protocols. In the MAC layer performance evaluation of the PLC system, the widely known random access MAC protocol that uses the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) will be utilised. The MAC performance evaluation of the PLC system demonstrates a significant packet loss in LV PLC network even with a light traffic condition due to the noisy channel. Furthermore, the goodput declines abruptly once the individual transmission rate is high enough to block the network. In addition, the simulation results show that the channel errors can be reduced by adjusting the MAC parameters to allow the re-transmissions mechanisms to recoup the lost packets.

Power Line Communications (PLC) is regarded as the promising home networking technology for smart grid application since the PLC technology enables data transmission via the existing power line. The cooperation between PLC and Wireless Local Area Network (WLAN) will be an effective hybrid solution for Home Area Networks (HANs). In this paper, we consider that Transmission Control Protocol (TCP) packets are transmitting in heterogenous communications network based on PLC and WLAN. The existing TCP congestion control has low effectiveness due to the error-prone power line channel. Therefore, we propose an adaptive rate control to improve TCP performance in the hybrid PLC/WLAN HANs. We exploit the communications mechanism of WLAN to improve the PLC link utilization. The methodology of Heuristic Dynamic Programming (HDP) is employed to obtain the optimal rate policy. The bottleneck link capacity is estimated by neural network training. The sending rate is adapted according to the long-term quality of service (QoS) of applications. Simulation results illustrate that the proposed rate control effectively filters out the negative impact from the instantaneous impulse noise in PLC channel and outperforms the existing TCP.

The reliability and distance of Power Line Communication (PLC) are the most important factors, which limit the application of PLC in practice seriously. This paper discusses the specialties and the methods of building up the PLC networks, uses an improved Dynamic Ant Colony System algorithm (DACS) in dynamic routing of PLC networks, and the multi-path storage technology is given. The improved DACS enhanced the accuracy and efficiency of dynamic routing in two aspects, that is the best tours and the worst tours. A dynamic penalty on worst tours will open up chances for ants to navigate, limit intentions and provide cautions in an ant's decision to move. And ants can get better search guidance by concentrating only the best tours from all groups. The simulation and experimentation indicate that the improved DACS provides an effective dynamic routing method for the expansion of PLC. It is an effective method of improving the reliability of PLC.

As one of the most promising networking technologies, power-line communication (PLC) networks have been gradually used not only in home networking systems but also in industrial IoT (Internet of things). Current studies of PLC medium access control (MAC) protocol (i.e., IEEE 1901) only focus on the single-hop environment; however, in practical industrial IoT and home access communication systems, PLC networks generally utilize a multi-hop architecture. In addition, due to the difference in the MAC standard between 802 series and 1901, existing analytical models of multi-hop IEEE 802.11 wireless networks are not suitable for multi-hop IEEE 1901 PLC networks. In this paper, we propose a theoretical model for performance analysis of multi-hop IEEE 1901 PLC networks, where the impacts of traffic rate (containing relay traffic), buffer size, deferral counter process of 1901, hidden terminal problem and multi-hop environment are comprehensively considered. The modeling process is divided into two parts. In the local modeling part, we construct a brand-new Markov chain model to investigate the carrier sense multiple access with collision avoidance process of IEEE 1901 protocol under the multi-hop environment. In the coupling queueing modeling part, we employ queueing theory to analyze the packet transmission procedure between successive hops. On the basis, we derive the closed-form expressions of throughput, medium access delay, packet blocking probability, end-to-end successful transmission delay and goodput. Through extensive simulations, we verify that our theoretical model can accurately estimate the MAC performance of IEEE 1901 PLC networks in the multi-hop environment.

Characterized by extensive coverage, easy connection and huge application potential, power line carrier communication has gained increasing attention and become a research hotspot in recent years.This paper started by an introduction of the power line carrier communication technology, and then compared it with other networking methods, finally practical power line networking project was proposed.Based on the advantages of power line communication technology, the hardware system was formatted applying four-tier B/S architecture.The computer distance education system was established using ASP technology in the premise of effective protection of network security.Study shows that the power line communication network is a reliable network education resource, of great significance to promote distance education.

Powerline communication (PLC) provides inexpensive, secure and high speed network connectivity, by leveraging the existing power distribution networks inside the buildings. While PLC technology has the potential to improve connectivity and is considered a key enabler for sensing, control, and automation applications in enterprises, it has been mainly deployed for improving connectivity in homes. Deploying PLCs in enterprises is more challenging since the power distribution network is more complex as compared to homes. Moreover, existing PLC technologies such as HomePlug AV have not been designed for and evaluated in enterprise deployments. To this end, we give guidlines for designing PLC networks for providing ubiquitous connectivity in enterprises, based on measurement study of PLC performance in enterprise settings using commodity HomePlug AV PLC devices. Based on our findings, we propose that careful planning of PLC network topology, routing and spectrum sharing can significantly boost performance of enterprise PLC networks.

A cooperative modulation recognition: New paradigm for power line networks in smart grid