5,452 research outputs found

    Performance analysis of orthogonal frequency division multiplexing systems in dispersive indoor power line channels inflicting asynchronous impulsive noise

    No full text
    Hidden semi-Markov modelling of the asynchronous impulsive noise (IN) encountered in indoor broadband power line communications (PLCs) is investigated by considering the statistical distributions of both the inter-arrival time and the duration of asynchronous IN components. Then, the bit error ratio (BER) of orthogonal frequency division multiplexing systems using Q-ary quadrature amplitude modulation is analysed with the aid of the proposed noise model, when communicating over dispersive indoor power line channels inflicting asynchronous IN in addition to the background noise. The authors’ simulation results confirm the accuracy of the analysis and quantify the impact of various factors on the achievable BER performance. The grave impact of asynchronous IN on indoor broadband PLCs suggests that efficient techniques have to be designed for mitigating its effect

    State-of-the-art in Power Line Communications: from the Applications to the Medium

    Get PDF
    In recent decades, power line communication has attracted considerable attention from the research community and industry, as well as from regulatory and standardization bodies. In this article we provide an overview of both narrowband and broadband systems, covering potential applications, regulatory and standardization efforts and recent research advancements in channel characterization, physical layer performance, medium access and higher layer specifications and evaluations. We also identify areas of current and further study that will enable the continued success of power line communication technology.Comment: 19 pages, 12 figures. Accepted for publication, IEEE Journal on Selected Areas in Communications. Special Issue on Power Line Communications and its Integration with the Networking Ecosystem. 201

    The application of iterative equalisation to high data rate wireless personal area networks

    Get PDF

    Characterisation of Signal Amplitude-Frequency for Indoor Power Line Communication Channel in the 1 — 30 MHz Broadband Frequencies

    Get PDF
    The transmission of data signals over power lines is a very promising technique for delivering indoor broadband communication services. However, since power grids were originally designed for high-voltage low-frequency signal transmission, there is a frequency mismatch between the power grid and high-frequency data signals. This mismatch poses a challenge to deploying power lines as a communication channel. Although, studies and researches conducted in several countries have made transmission of data over power lines possible, the behaviour and properties of the power grid cannot be generalised. Hence, the need for in-depth experiment and measurement on the suitability and capability of the Nigerian power grid for data transmission is crucial for proper characterising and modelling of the power line communication (PLC) channel. In this paper, we present experimental measurements and results of the effects of frequency variations on the attenuation experienced by broadband high-speed data signals transmitted over the Nigerian indoor power line network

    Contributions to channel modelling and performance estimation of HAPS-based communication systems regarding IEEE Std 802.16TM

    Get PDF
    New and future telecommunication networks are and will be broadband type. The existing terrestrial and space radio communication infrastructures might be supplemented by new wireless networks that make and will make use of aeronautics-technology. Our study/contribution is referring to radio communications based on radio stations aboard a stratospheric platform named, by ITU-R, HAPS (High Altitude Platform Station). These new networks have been proposed as an alternative technology within the ITU framework to provide various narrow/broadband communication services. With the possibility of having a payload for Telecommunications in an aircraft or a balloon (HAPS), it can be carried out radio communications to provide backbone connections on ground and to access to broadband points for ground terminals. The latest implies a complex radio network planning. Therefore, the radio coverage analysis at outdoors and indoors becomes an important issue on the design of new radio systems. In this doctoral thesis, the contribution is related to the HAPS application for terrestrial fixed broadband communications. HAPS was hypothesised as a quasi-static platform with height above ground at the so-called stratospheric layer. Latter contribution was fulfilled by approaching via simulations the outdoor-indoor coverage with a simple efficient computational model at downlink mode. This work was assessing the ITU-R recommendations at bands recognised for the HAPS-based networks. It was contemplated the possibility of operating around 2 GHz (1820 MHz, specifically) because this band is recognised as an alternative for HAPS networks that can provide IMT-2000 and IMT-Advanced services. The global broadband radio communication model was composed of three parts: transmitter, channel, and receiver. The transmitter and receiver parts were based on the specifications of the IEEE Std 802.16TM-2009 (with its respective digital transmission techniques for a robust-reliable link), and the channel was subjected to the analysis of radio modelling at the level of HAPS and terrestrial (outdoors plus indoors) parts. For the channel modelling was used the two-state characterisation (physical situations associated with the transmitted/received signals), the state-oriented channel modelling. One of the channel-state contemplated the environmental transmission situation defined by a direct path between transmitter and receiver, and the remaining one regarded the conditions of shadowing. These states were dependent on the elevation angle related to the ray-tracing analysis: within the propagation environment, it was considered that a representative portion of the total energy of the signal was received by a direct or diffracted wave, and the remaining power signal was coming by a specular wave, to last-mentioned waves (rays) were added the scattered and random rays that constituted the diffuse wave. At indoors case, the variations of the transmitted signal were also considering the following matters additionally: the building penetration, construction material, angle of incidence, floor height, position of terminal in the room, and indoor fading; also, these indoors radiocommunications presented different type of paths to reach the receiver: obscured LOS, no LOS (NLOS), and hard NLOS. The evaluation of the feasible performance for the HAPS-to-ground terminal was accomplished by means of thorough simulations. The outcomes of the experiment were presented in terms of BER vs. Eb/N0 plotting, getting significant positive conclusions for these kind of system as access network technology based on HAPS
    • …
    corecore