Performance Analysis of Industrial Cooperative Communication System in Generalized Fading Environment

This paper considers the performance analysis of M-ary phase shift keying industrial cooperative relaying system in Nakagami-m multipath fading channel with Gamma shadowing, which is known as the Generalized-K composite fading channel. Since the paper deals with the industrial environment, the communication channel is also affected by the additive Middleton\u27s Class-A impulsive noise. The bit error rate is used as a performance measure and the closed-form average bit error rate expression was derived. The influence of different fading and noise parameters on the system performance is investigated. The obtained results may be used for the improvement of the present and future industrial wireless communication systems

Performance evaluation of multi-hop relaying over non-gaussian PLC channels

Relaying over power line communication (PLC) channels can considerably enhance the performance and reliability of PLC systems. This paper is dedicated to study and analyze the energy efficiency of multi-hop cooperative relaying PLC systems. Incremental decode-and-forward (IDF) relying is exploited to reduce the transmit power consumption. The PLC channel is assumed to experience log-normal fading with impulsive noise. The performances of single-hop and conventional DF relaying systems are also analyzed in terms of outage probability and energy efficiency for which analytical expressions are derived. Results show that using more relays can improve the outage probability performance; however, this is achieved at the expense of increased power consumption due to the increased static power of the relays, especially when the total source-to-destination distance is relatively small. Results also demonstrate that the IDF PLC system has better energy efficiency performance compared to the other schemes

Cooperative Relaying In Power Line Environment: A Survey and Tutorial

Exchange of information is essential in any society and the demand for faster, cheaper, and secure communications is increasing every day. With other hi-tech initiatives like IPv6 and Internet-of-Things (IOT) already in the horizon, demand for broadband is set to escalate beyond its current level. Inherently laden in the challenges posed by this technology are fresh opportunities in terms of penetration of data services into rural communities and development of innovative strategies for more efficient use of the grid. Though still in its developmental phase/stage, Power Line Communication (PLC) has grown beyond theoretical fantasy to become a reality. The proofs are the readily available PLC systems that can be purchased off the shelfto achieve in-house networking and the much talked about, smart metering technology; generally regarded as the “new bride” in utilities industry. One of the biggest gains of PLC is its use of existing electrical cables, thereby eliminating cost of installation and maintenance of data cables. However, given that the power infrastructure was traditionally built to deliver electricity, data signals do suffer various forms of distortions and impairments as they transit it. This paper presents a tutorial on the deployed wireless system technique which is to be adapted to PLC scenario for the purpose of managing the available source energy for achieving reliable communication system. One of these techniques is the cooperative diversity. Its application and deployment in power line environment is explored. The improvement achieved through cooperative diversity in some PLC systems were presented along with the associated limitations. Finally, future areas of research which will further improve the reliability of PLC systems and reduce its power consumption during transmission is shown

On Performance Characterization of Cascaded Multiwire-PLC/MIMO-RF Communication System

The flexibility of radio frequency (RF) systems and the omnipresence of power cables potentially make the cascaded power line communication (PLC)/RF system an efficient and cost-effective solution in terms of wide coverage and high-speed transmission. This letter proposes an opportunistic decode-and-forward (DF)-based multi-wire/RF relaying system to exploit the advantages of both techniques. The outage probability, bit error rate, and system channel capacity are correspondingly chosen to analyze the properties of the proposed system, which are derived in closed-form expressions and validated via Monte-Carlo simulations. One can observe that our proposed system outperforms the wireless-only system in terms of coverage and data rate, especially when there exists a non-line-of-sight (NLoS) connection between the transmitter and receiver pair.Comment: 5 pages, 4 figure

Robust wireless sensor network for smart grid communication : modeling and performance evaluation

Our planet is gradually heading towards an energy famine due to growing population and industrialization. Hence, increasing electricity consumption and prices, diminishing fossil fuels and lack significantly in environment-friendliness due to their emission of greenhouse gasses, and inefficient usage of existing energy supplies have caused serious network congestion problems in many countries in recent years. In addition to this overstressed situation, nowadays, the electric power system is facing many challenges, such as high maintenance cost, aging equipment, lack of effective fault diagnostics, power supply reliability, etc., which further increase the possibility of system breakdown. Furthermore, the adaptation of the new renewable energy sources with the existing power plants to provide an alternative way for electricity production transformed it in a very large and complex scale, which increases new issues. To address these challenges, a new concept of next generation electric power system, called the "smart grid", has emerged in which Information and Communication Technologies (ICTs) are playing the key role. For a reliable smart grid, monitoring and control of power system parameters in the transmission and distribution segments are crucial. This necessitates the deployment of a robust communication network within the power grid. Traditionally, power grid communications are realized through wired communications, including power line communication (PLC). However, the cost of its installation might be expensive especially for remote control and monitoring applications. More recently, plenty of research interests have been drawn to the wireless communications for smart grid applications. In this regard, the most promising methods of smart grid monitoring explored in the literature is based on wireless sensor network (WSN). Indeed, the collaborative nature of WSN brings significant advantages over the traditional wireless networks, including low-cost, wider coverage, self-organization, and rapid deployment. Unfortunately, harsh and hostile electric power system environments pose great challenges in the reliability of sensor node communications because of strong RF interference and noise called impulsive noise. On account of the fundamental of WSN-based smart grid communications and the possible impacts of impulsive noise on the reliability of sensor node communications, this dissertation is supposed to further fill the lacking of the existing research outcomes. To be specific, the contributions of this dissertation can be summarized as three fold: (i) investigation and performance analysis of impulsive noise mitigation techniques for point-to-point single-carrier communication systems impaired by bursty impulsive noise; (ii) design and performance analysis of collaborative WSN for smart grid communication by considering the RF noise model in the designing process, a particular intension is given to how the time-correlation among the noise samples can be taken into account; (iii) optimal minimum mean square error (MMSE)estimation of physical phenomenon like temperature, current, voltage, etc., typically modeled by a Gaussian source in the presence of impulsive noise. In the first part, we compare and analyze the widely used non-linear methods such as clipping, blanking, and combined clipping-blanking to mitigate the noxious effects of bursty impulsive noise for point-to-point communication systems with low-density parity-check (LDPC) coded single-carrier transmission. While, the performance of these mitigation techniques are widely investigated for multi-carrier communication systems using orthogonal frequency division multiplexing (OFDM) transmission under the effect of memoryless impulsive noise, we note that OFDM is outperformed by its single-carrier counterpart when the impulses are very strong and/or they occur frequently, which likely exists in contemporary communication systems including smart grid communications. Likewise, the assumption of memoryless noise model is not valid for many communication scenarios. Moreover, we propose log-likelihood ratio (LLR)-based impulsive noise mitigation for the considered scenario. We show that the memory property of the noise can be exploited in the LLR calculation through maximum a posteriori (MAP) detection. In this context, provided simulation results highlight the superiority of the LLR-based mitigation scheme over the simple clipping/blanking schemes. The second contribution can be divided into two aspects: (i) we consider the performance analysis of a single-relay decode-and-forward (DF) cooperative relaying scheme over channels impaired by bursty impulsive noise. For this channel, the bit error rate (BER) performances of direct transmission and a DF relaying scheme using M-PSK modulation in the presence of Rayleigh fading with a MAP receiver are derived; (ii) as a continuation of single-relay collaborative WSN scheme, we propose a novel relay selection protocol for a multi-relay DF collaborative WSN taking into account the bursty impulsive noise. The proposed protocol chooses the N’th best relay considering both the channel gains and the states of the impulsive noise of the source-relay and relay-destination links. To analyze the performance of the proposed protocol, we first derive closed-form expressions for the probability density function (PDF) of the received SNR. Then, these PDFs are used to derive closed-form expressions for the BER and the outage probability. Finally, we also derive the asymptotic BER and outage expressions to quantify the diversity benefits. From the obtained results, it is seen that the proposed receivers based on the MAP detection criterion is the most suitable one for bursty impulsive noise environments as it has been designed according to the statistical behavior of the noise. Different from the aforementioned contributions, talked about the reliable detection of finite alphabets in the presence of bursty impulsive noise, in the thrid part, we investigate the optimal MMSE estimation for a scalar Gaussian source impaired by impulsive noise. In Chapter 5, the MMSE optimal Bayesian estimation for a scalar Gaussian source, in the presence of bursty impulsive noise is considered. On the other hand, in Chapter 6, we investigate the distributed estimation of a scalar Gaussian source in WSNs in the presence of Middleton class-A noise. From the obtained results we conclude that the proposed optimal MMSE estimator outperforms the linear MMSE estimator developed for Gaussian channel

For More Energy Efficient Dual-hop DF Relaying Power Line Communication Systems

Energy efficiency in multi-hop cooperative power line communication (PLC) systems has recently received considerable attention in the literature. In order to make such systems more energy-efficient, this paper proposes a relaying technique equipped with energy-harvesting capabilities. More specifically, we consider a dual-hop decode-and-forward (DF) broadband PLC relaying system in which the relay exploits the high noise inherent in PLC channels to further enhance energy efficiency; this system will be referred to as DF with energy-harvesting (DF-EH). This study deploys, particularly, the time-switching relaying protocol for energy-harvesting. An accurate analytical expression for the energy efficiency and a closed-form expression for the average outage probability of the proposed system are derived and then verified with Monte Carlo simulations. For the sake of comparison and to highlight the achievable gains, we also analyze the energy efficiency performances and the average outage probabilities of the conventional DF relaying system, i.e. without energy-harvesting, as well as that of the direct-link approach. Furthermore, various frequency selection and power allocation strategies, namely, optimal frequency selection, random frequency selection and equal power allocation, exploiting the multiple power cables, are studied. Then, the impact of several system parameters such as the energy-harvesting time factor, various idle power consumption profiles, relay location, power allocation as well as different noise scenarios are examined. The results reveal that the proposed DF-EH system is able to provide energy efficiency improvements of more than 30% compared to the conventional DF relaying scheme. It is also shown that the proposed system with optimal frequency selection performs better at low SNR whereas at high SNR the equal power allocation based system will have the best performance

A Comparison between Orthogonal and Non-Orthogonal Multiple Access in Cooperative Relaying Power Line Communication Systems

Most, if not all, existing studies on power line communication (PLC) systems as well as industrial PLC standards are based on orthogonal multiple access schemes such as orthogonal frequency-division multiplexing and code-division multiple access. In this paper, we propose non-orthogonal multiple access (NOMA) for decode-and-forward cooperative relaying PLC systems to achieve higher throughput and improve user fairness. To quantitatively characterize the proposed system performance, we also study conventional cooperative relaying (CCR) PLC systems. We evaluate the performance of the two systems in terms of the average capacity. In this respect, accurate analytical expressions for the average capacity are derived and validated with Monte Carlo simulations. The impact of several system parameters such as the branching, impulsive noise probability, cable lengths, the power allocation coefficients and input signal-to-noise ratio are investigated. The results reveal that the performance of the proposed NOMA-PLC scheme is superior compared to that of the CCR-PLC system. It is also shown that NOMA-PLC can be more effective in reducing electromagnetic compatibility associated with PLC and that increasing the network branches can considerably degrade performance. Moreover, optimizing the power allocation coefficients is found to be of utmost importance to maximize the performance of the proposed system

Physical layer security solutions against passive and colluding eavesdroppers in large wireless networks and impulsive noise environments

Wireless networks have experienced rapid evolutions toward sustainability, scalability and interoperability. The digital economy is driven by future networked societies to a more holistic community of intelligent infrastructures and connected services for a more sustainable and smarter society. Furthermore, an enormous amount of sensitive and confidential information, e.g., medical records, electronic media, financial data, and customer files, is transmitted via wireless channels. The implementation of higher layer key distribution and management was challenged by the emergence of these new advanced systems. In order to resist various malicious abuses and security attacks, physical layer security (PLS) has become an appealing alternative. The basic concept behind PLS is to exploit the characteristics of wireless channels for the confidentiality. Its target is to blind the eavesdroppers such that they cannot extract any confidential information from the received signals. This thesis presents solutions and analyses to improve the PLS in wireless networks. In the second chapter, we investigate the secrecy capacity performance of an amplify-andforward (AF) dual-hop network for both distributed beamforming (DBF) and opportunistic relaying (OR) techniques. We derive the capacity scaling for two large sets; trustworthy relays and untrustworthy aggressive relays cooperating together with a wire-tapper aiming to intercept the message. We show that the capacity scaling in the DBF is lower bounded by a value which depends on the ratio between the number of the trustworthy and the untrustworthy aggressive relays, whereas the capacity scaling of OR is upper bounded by a value depending on the number of relays as well as the signal to noise ratio (SNR). In the third chapter, we propose a new location-based multicasting technique, for dual phase AF large networks, aiming to improve the security in the presence of non-colluding passive eavesdroppers. We analytically demonstrate that the proposed technique increases the security by decreasing the probability of re-choosing a sector that has eavesdroppers, for each transmission time. Moreover, we also show that the secrecy capacity scaling of our technique is the same as for broadcasting. Hereafter, the lower and upper bounds of the secrecy outage probability are calculated, and it is shown that the security performance is remarkably enhanced, compared to the conventional multicasting technique. In the fourth chapter, we propose a new cooperative protocol, for dual phase amplify-andforward large wireless sensor networks, aiming to improve the transmission security while taking into account the limited capabilities of the sensor nodes. In such a network, a portion of the K relays can be potential passive eavesdroppers. To reduce the impact of these untrustworthy relays on the network security, we propose a new transmission protocol, where the source agrees to share with the destination a given channel state information (CSI) of source-trusted relay-destination link to encode the message. Then, the source will use this CSI again to map the right message to a certain sector while transmitting fake messages to the other sectors. Adopting such a security protocol is promising because of the availability of a high number of cheap electronic sensors with limited computational capabilities. For the proposed scheme, we derived the secrecy outage probability (SOP) and demonstrated that the probability of receiving the right encoded information by an untrustworthy relay is inversely proportional to the number of sectors. We also show that the aggressive behavior of cooperating untrusted relays is not effective compared to the case where each untrusted relay is trying to intercept the transmitted message individually. Fifth and last, we investigate the physical layer security performance over Rayleigh fading channels in the presence of impulsive noise, as encountered, for instance, in smart grid environments. For this scheme, secrecy performance metrics were considered with and without destination assisted jamming at the eavesdropper’s side. From the obtained results, it is verified that the SOP, without destination assisted jamming, is flooring at high signal-to-noise-ratio values and that it can be significantly improved with the use of jamming