A Deterministic Satellite-to-Indoor Entry Loss Model

Advances in satellite and receiver technology make former denied areas like indoors accessible for satellite based radio services. As a consequence, suitable penetration loss models are of significant importance for service availability planning. Standard penetration loss models ignore the building layout in relation to the transmitter-receiver geometry. Within this paper, we introduce the term entry loss as a measure for the additional loss of a wideband impulse received at the geometrical line-of-sight path delay caused by the building materials. Knowing the received power caused by indoor multipath propagation, the penetration loss and the entry loss are deterministically related. As a contribution, we propose an entry loss model which is able to include the geometrical relation of walls, receiver and transmitter positions. Within the model, we treat walls, windows and doors as apertures and, therefore, as sources for signal penetration and diffraction. A verification of the model using wideband channel sounder measurement data is performed. By simulations, we show the comparability between existing models and the proposed one. Moreover, a short description on the usage of the proposed entry loss model for wideband channel simulations is provided.

I. Introduction

Providing satellite services for ground based receivers is an important field for many industrial companies. Using satellites, a global coverage for both communications and navigation applications can be achieved without the need of a local infrastructure. One example is the Global Positioning System (GPS) which is working worldwide. The main problem of satellite compared to ground based radio systems is that satellites' signals are received with a considerably lower power compared to signals from ground based transmitters. Particularly for indoor located terminals, the received satellite signal strength is in general extremely low which often makes the service unavailable. Due to improvements in satellite and receiver technologies, the possibility of receiving satellite signals indoors increases. Therefore, applications with an indoor located satellite terminal are becoming more and more interesting. A major key factor, especially for service availability planning, is to assess the additional received power loss for the indoor placed receiver compared to pure free space propagation.