This paper presents an analysis of the noise in multi-conductor power grid networks. This is relevant in multiple-input multiple-output (MIMO) power line communications. In particular, we consider in-building networks and the narrow band spectrum 3-500 kHz. The noise is acquired between the Live and Protective-Earth and between the Neutral and Protective-Earth conductor pairs in a number of outlets. The results show a prominent impulsive time variant behavior. More interestingly, the noise signals in the two conductor pairs are not only correlated, but statistically dependent and in many cases identical. This suggests a form of determinism of the noise signals that can be exploited by spatial noise canceling techniques, one of which is presented in this paper.
