Interpolation of reflected and diffracted rays for accelerated ray tracing simulation

Abstract

The efficient computation of an image-based ray trace for a receiver moving along a linear trajectory in an urban area is considered. Sampling channel information at the Nyquist rate or higher imposes a considerable computational burden, and the proposed algorithm instead utilizes the observation that such receivers will enter and exit well-defined lit regions, which define the precise extent within which reflected and diffracted rays can potentially propagate. A simple model for the associated ray is created within each lit region, obviating the need to perform an independent ray trace for each receiver location. The simple model is based on field information computed at

locations within the region. Polynomial and cubic spline interpolation is used to efficiently model amplitude and phase data along the trajectory. The paper validates the approach and demonstrates its effectiveness in the context of a simulated street-canyon environment.