A Gaussian beams summation (GBS) algorithm for tracking source excited wave fields in plane stratified media is presented. In the present application the medium is described by layers with constant gradient of the wave speed, and the GB propagators are calculated recursively in a closed form. The algorithm is calibrated for numerical efficacy and accuracy by defining simple physical criteria for choosing the expansion parameters (the beam collimation and the spectral discretization and truncation) that allow for sparse representation of the source-excited angular spectrum of beams. It is validated for a source-excited example in layered media, where it provides a smooth and physically meaningful solution under multipath and caustic conditions and remains accurate for long propagation ranges where phase error tends to accumulate.

We present a software package INDOOR-GBS (Gaussian Beam Summation) designed to simulate indoor electromagnetic field propagation in the ultra wideband (UWB) regime. The package is based on the GBS method where the field of the transmitting antenna is expanded into a superposition of GBs that emerge from the source in a discrete set of directions. Thereafter the beams are traced in the configuration through multiple reflections and transmissions at the walls/ceilings/floors and the field is calculated by summing the contributions of the beams that pass near the zone of interest. The algorithm consists mainly of two phases: a processing phase where the beams are traced through the medium, and a post-processing phase where the field and the channel parameters are calculated for the given source and receiver antennas. The processing phase utilizes a dyadic electromagnetic formulation so that the antennas' properties are used only in the post-processing phase, thus facilitating efficient post-processing calculations for antenna and channel optimization. The algorithm also employs a particular set of isodiffracting GBs (ID-GB), whose propagation characteristics are frequency independent and lead to efficient UWB calculations.