Received Signal Strength Estimation in Indoor Environment Using High Frequency Rytov Approximation

We present a new and improved formulation of Rytov approximation (RA) using the theory of ray tracing in low loss media for solving the direct scattering problem. The resultant model provides an accurate prediction of wave scattering in the presence of electrically large scatterers with high permittivity and small loss tangent. The high validity range and the straightforward linear formulation of the proposed model make it suitable for accurately predicting the received signal strength (RSS) in indoor environments. We provide experimental results from a real indoor environment to show that the proposed method closely matches the experimental RSS values and achieves up to ten times higher validity range than any other existing linear approximate models. Also, since the proposed method provides an accurate solution to the direct scattering problem, it can be an ideal candidate for inverse scattering applications.