Interpolation of Reflected and Diffracted Rays for Accelerated Ray Tracing Simulation

The problem of efficiently computing an image-based ray-trace for a receiver moving along a linear trajectory in an urban area is considered. The requirement to sample channel information at the Nyquist rate or higher imposes a considerable computational burden. The proposed algorithm instead makes use of the fact that such receivers will move in and out of well-defined finite illumination regions within which reflected and diffracted rays can potentially propagate. Rather than computing an independent ray trace for each receiver location within such regions a simple model for the associated ray is created. This model is based on field information computed at a finite set of locations within the region which is then interpolated to efficiently give amplitude and phase data along the trajectory. The paper demonstrates the effectiveness of this operation within a simulated street canyon environment.