Development of a Statistical Model for Power Line Communications Channels

The powerline can be used for creating an in-house network or for bridging the last mile between the transformer station and the access point of the end-user. The advantage of this transmission medium is the existing, very extensive infrastructure. Each wall outlet can be used as an access point to this netwo1;k. As the powerline has been designed for distribution of energy and not for transmission of data, there are unfavourable channel characteristics with considerable noise and high attenuation. In addition, there are regulatory restrictions by the CENELEC norm EN 50065 ([CEN]) concerning the useable frequency range and the maximtun transmission voltage. These limitations lead to low data rates of up to a few kbitls. In future the regulatory restrictions may change and higher frequencies may be allowed to be used. In order to transmit higher data rates an extended frequency range has to be used. A measurement campaign has been carried out which covered a few hundred powerline channels in the frequency range up to 30 MHz. The campaign comprised the measurement of impedance, transfer function and noise. A statistical analysis of the measurements has been carried out pointing out a lot of characteristic findings. In chapter 2 the measured channel characteristics are described in detail. For understanding the complex characteristics of powerline channels and for developing suited and optimised transmission systems channel models are required. Based on the analysis of the channel characteristics statistical models have been developed which describe transfer characteristics (chapter 3) and noise characteristics (chapter 4) of typical in-house powerline channels. These channel models describe powerline channels by a limited set of parameters in a statistical manner. The models can be used for software and hardware simulations of different transmission techniques. The work has been carried out at the Institute for Communications Technology at the Braunschweig Technical University in co-operation with Siemens AG, Information and Communication Products (ICP), Bocholt.