Joint Fading and Shadowing Model for Large Office Indoor WLAN Environments

This paper presents measurements and a propagation model for an indoor wireless LAN (WLAN) scenario that represents an open concept office or laboratory layout with few large obstacles to reflect and refract the transmitted signal. Most mobile WLAN users generally restrict their movements to a small area due to the inability of most WLANs to accommodate hand-offs. As a result, users travel through at most one or two scattering clusters and experience only one or two discrete shadowing values. Hence, this paper will use propagation measurements collected over bandwidths of 10 MHz, to develop a statistical model for shadowing suitable for such an indoor WLAN scenario. Moreover, in indoor environments shadowing varies quickly enough to require some channel estimation algorithms to account for both small scale and large scale statistics. Therefore, this paper will present a distribution that jointly models variations due to both Rician fading and the new shadowing model. An analytical expression for the probability density function (PDF) of the joint distribution will be derived and fit to the experimental propagation data.