Analysis of coloured noise in received signal strength using the Allan Variance

The received signal strength (RSS) of wireless signals has been widely used in communications, localization and tracking. Theoretical modelling and practical applications often make a white noise assumption when dealing with RSS measurements. However, as we will show in this paper, the noise present in RSS measurements has time-dependency properties. In order to study these properties and provide noise characterisation, we propose to use the Allan Variance (AVAR) and show its better performance in comparison with direct analysis in the frequency domain using a periodogram. We further study the contribution of each component by testing real RSS data. Our results confirm that the noise associated with RSS signals is actually coloured and demonstrate the appropriateness of AVAR for the identification and characterisation of these components.