A Novel Method for Measuring the Characteristics of the Powerline Channel for High Speed Communications

I For the design of existing low rate powerline communication systems it was sufficient to model the channel with parameters such as attenuation, impedance and noise. For high speed power line communication, however, it is important not to model the attenuation only but the complete linear channel distortion. In this paper we present a novel method of measuring the impulse response of the powerline channel. From the impulse response, the complex transfer function can be computed using the Fourier transform. The absolute value of this transfer function shows the attenuation as a function of frequency. The phase information can be used to compute the group delay distortion. This distortion, similar to the impulse response, indicates the maximum symbol length that can be used without equalisation. In addition, this paper shows an elegant way of extracting features from the measured powerline noise. Here, the idea is to sample the channel noise for some time and then to use a joint time-frequency analysis.