Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.701093
Title: Power line communication systems
Author: Rabie, Khaled Maaiuf
ISNI:       0000 0004 5990 0812
Awarding Body: University of Manchester
Current Institution: University of Manchester
Date of Award: 2015
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Abstract:
The remarkably increasing demand for communication systems has recently forced the research community to consider power line (PL) networks for data transmission, which is commonly referred to as power line communications(PLC). In particular, this technology becomes more attractive in harsh wireless environments where radio spectrum is scarce or/and propagation loss is high such as in underground structures and buildings with metal walls. PLC can support many applications such as home-networking, internet and smart grid. More specifically, PLC is considered the backbone of smart grids, not only because no extra wiring installation is required, but also because PLC is a through-grid technology which could reduce the reliance of the utility companies on third party connectivity and, consequently, overcome many security and privacy issues. On the other hand, since PLs were not designed for data transmission, communication signals over such channels can degrade tremendously. Contrary to many other communication channels, noise over PLs cannot be described as additive white Gaussian noise. It is rather categorized broadly into impulsive noise and background noise with the former being the most crucial element influencing PLC systems. With this in mind, this thesis will primarily focus on studying and developing advanced techniques and algorithms to reduce the severity of impulsive noise over PL channels. The contributions of this thesis are described as follows. Initially, a thorough review is provided to introduce and compare the challenges facing PLC, PL channel and noise modelling schemes, as well as some noise mitigation techniques. Next, novel approaches are proposed, with different degrees of effectiveness and complexity, to reduce the effect of impulsive noise in orthogonal frequency-division multiplexing (OFDM)-based PLC systems. Firstly, an adaptive hybrid preprocessing system is introduced to improve the performance of the conventional hybrid approach. In this respect, closed-form expressions for the output signal-to-noise ratio (SNR), probability of missed detection and probability of successful detection are derived. Secondly, and unlike existing works which are entirely based on countering impulsive noise at the receiver side, we show that if the OFDM signal is preprocessed at the transmitter side in such a way to minimize the signal peaks, the noise cancellation process can be made more efficient at the receiver. This is accomplished by applying a peak-to-average power ratio reduction scheme such as selective mapping. A closed-form expression for the probability of blanking error of this system is derived. Thirdly, to eliminate the estimation requirement problem of the short-term noise statistics associated with the aforementioned approaches, we propose the dynamic peak-based threshold estimation (DPTE) method. This method relies on utilizing the OFDM signal peak estimates with which optimal blanking is achieved irrespective of the noise parameters. In addition, to realize DPTE, a look-up table algorithm with uniform quantization is exploited and investigated in various system configurations. Furthermore, this thesis explores the performance of multi-carrier code division multiple access (MC-CDMA) systems over the multipath PL channel contaminated with Middleton class-A noise for various spreading codes, namely, Pseudonoise, Walsh-Hadamard and orthogonal poly-phase sequences. Different nonlinear preprocessors are implemented and the corresponding performance is evaluated in terms of the output SNR and symbol error rate.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.701093  DOI: Not available
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