3D Indoor Intelligent Ray Tracing

A fast and accurate 3D ray optical prediction model

Introduction

The mobile radio channel in indoor scenarios is characterized by multi-path propagation. Dominant propagation phenomena inside buildings are
  • the shadowing of walls
  • wave guiding effects in corridors due to multiple reflections
  • diffractions around vertical wedges.
The deterministic ray optical models of WinProp consider all these effects which leads to highly accurate prediction results.

In order to accelerate the time-consuming path determination the Intelligent Ray Tracing (IRT) is based on a preprocessing of the building data, thus combining high accuracy with short computation time.

Propagation paths in an indoor scenario.

Propagation Paths

Each penetration of a wall, each reflection at the surface of a wall and each diffraction at a wedge is a interaction. The Intelligent Ray Tracing considers all propagation paths which fulfill the following criterions:
  • up to 6 reflections (at surfaces of walls/objects)
  • up to 6 penetrations (of walls/objects)
  • up to 2 diffractions (at wedges)
  • up to a total number of 6 interactions (all combinations of reflections, penetrations, and diffractions)

Predicted Results

The 3D INtelligent Ray Tracing (IRT) Propagation Model predicts many results beyond signal level:
  • delay spread
  • power delay profile (channel impulse response)
  • angular spread (at Tx and Rx location)
  • angular profile (at Tx and Rx location)
All these results can be written into ASCII files for further processing with other software tools.

Short computation time due to preprocessing


The IRT is based on the following assumptions:

  • Only a few rays deliver the main part of energy

  • The visibility relation between walls and edges are independent of the position of the transmitter antenna (base station)

  • Often adjacent receiver pixels are reached by similar rays

Based on these considerations, a (pre-)processing of the building database is made once. In this preprocessing the obstacles in the building database are subdivided into small tiles. The visibility relations between these tiles are determined and stored. During the prediction this data can be read and has not to be determined again. This accelerates the computation time significantly.
Division of a wall during the preprocessing.

Sample Predictions

Here some sample predictions with the Intelligent Ray Tracing are presented.

 

Prediction of an old office building in Vienna (Austria).
Prediction of a modern building from Virginia State University.
Directional Channel Impulse Response.
Part of a prediciton with several propagation paths to one pixel.

 

Download a document with a comparison of IRT predictions to measurements.

Download a brochure with all indoor prediction models.

See a comparison between different indoor prediction models.

See the overview over all Ray Tracing models.

See the overview over all indoor prediction models.

Read more about  ray-optical predictions in the 400 MHz range

 

 

 

 

 

 

 

Prediction with Ray Tracing inside a vehicle. Read here more about this topic.

 

 

 

 

 

 

 

 

Example prediction
 in an indoor scenario.