Dominant Path Prediction Model

A fast and highly accurate Prediction Model for all Scenarios

Motivation

Ray-optical propagation models are still very time-consuming – even with accelerations like preprocessing. And what is even more important, they rely on a very accurate vector database. Small errors in the database influence the quality of the prediction. On the other hand, empirical models are – for example- based on dedicated propagation effects like the over-rooftop propagation (COST 231) or on other pre-defined scenarios. As a consequence of these restrictions, a new Propagation Model has been developed, the Dominant Path Prediction Model. Some characteristics of this model:

  • The dependeny of the accuracy of the vector database is reduced
  • Only the most important propagation path is considered, because this path delivers the main part of the energy
  • No time-consuming preprocessing is required (in contrast to IRT)
  • Short computation times
  • Accuracy reaches oder exceeds the accuracy of ray-optical models (see comparison documents for IDP and UDP)

The Dominant Paths


Analyzing typical propagation scenarios shows that in most cases one propagation path contributes more than 90% of the total energy (see figure of typical channel impulse response below). The DPM (Dominant Path Model) determines exactly this dominant path between the  transmitter and each receiver pixel. So the computation time compared to ray tracing is reduced significantly and the accuracy is nearly identical to ray tracing (as path loss values are determined in logarithmic scale).



Comparison of different prediction models


Empirical models (like COST 231 models) consider only thae direct path between a transmitter and a receiver pixel (figure on the left). Ray Tracing models (like IRT) determine numerous paths (figure in the middle). As shown in the figure on the right, DPM determines only the most relevant path.



 
Read more about the Rural Dominant Path Model.
Read more about the Urban Dominant Path Model.
Read more about the Indoor Dominant Path Model.

 

 

 

Settings for the Dominant Path Model (click here to enlarge).

Rural Dominant Path Model

 

This is a sub-model for rural scenarios. In addition to the topographical database, clutter- and morpho databases can also be taken into account for the computation.

Urban Dominant Path Model

 

For urban scenarios, this sub-model is used. Not only urban building-databases are considered, but the topographical is also consulted for computation. For the prediction two path-searching algorithms exist: 2D and 3D. Waveguiding effects of street canyons help to achieve most accurate results.

 Indoor Dominant Path Model

 

Using indoor scenarios, this sub-model is considered. Two prediction-modes are available, 2D and a full 3D mode. Transmissions through walls are also taken into account, as well as special waveguiding effects which lead to very accurate results.