Inclusion of the Receiver Antenna Pattern

The inclusion of the receiver antenna pattern is a post-processing step.

When no receiver antenna pattern is specified, the received-power plots in the areas of interest are based on a hypothetical isotropic (omni-directional) receiver antenna, and only the transmitter antenna is specified. This is sufficient for some mobile-communication scenarios in which the base stations have directional antennas while the hand-held mobile stations have very broad antenna patterns and may be held in any orientation.

To include a directional receiver antenna pattern and obtain the actual received power, click Project > Edit Project Parameter > Propagation tab. Under Consideration of Antenna Properties at Mobile Station, select the Consider Antenna of MS check box. Here, MS stands for mobile station, but it can be any receiving antenna.

Note that the Propagation Paths check box is also selected to save the propagation paths during the regular propagation part of the simulation. This is automatic when you select the Consider Antenna of MS check box because the algorithm has to know, at every potential receiver location (at every pixel in the result plot), from which directions the signals are arriving. Only then can the receiver antenna pattern be included properly.

Click Edit Parameters to specify the receiving antenna pattern and other mobile station settings.

Figure 1. The Edit Project Parameters dialog where you can request the consideration of the receiving antenna.

The orientation of the receiving antenna depends on whether the simulations are performed for an area (area mode) or along a trajectory (trajectory mode).

In area mode, the phi (azimuth) = 0° direction of the antenna pattern points in the X direction (east) of the model, and the phi (azimuth) = 90° direction points in the Y direction (north) of the model.

In trajectory mode, the receiving antenna is thought to be moved along a trajectory, for example, on a vehicle, and will make turns.

Figure 2. The Prediction Trajectories button is used to define a trajectory or you can use the menu: Project > Prediction Area > Prediction Trajectories:: Draw.

As mentioned, in area mode, phi = 0° points in the X direction (to the right). In trajectory mode, phi = 0° also points to the east, but now to the right of the direction of movement. Phi = 90° points forward in the direction of movement.

Whether in area mode or in trajectory mode, the post-processing step of including the receiver antenna pattern is launched through the menu Computation > Propagation incl. Mobile Station, or click the  button, after the regular propagation simulation was completed.

The result is, among other quantities, the actual received power for the receiving antenna. In trajectory mode, the result might look like Figure 3.

Figure 3. Example result of a virtual drive test.

This type of simulation is called a virtual drive test, since it is as if the receiving antenna were being driven along the trajectory. It is not a time-variant simulation, however, since no geometrical objects in the model move with time.