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Multiple Interferering links generation

You have 3 options to generate multiple interferers in SEAMCAT.

Option 1: Generation of multiple interferers which may have different technical characteristics from each other

This option allows SEAMCAT to generates multiple interferers which may have the same or different technical characteristics from each other. You can either add () or duplicate ()

Generation of multiple interferers which may have different technical characteristics from each other.

The feature “to position with” allows the deployment of a second type of interferer (for instance interfering link 1) for which the transmitters will be located at the same location as the transmitters of another type of interferers (i.e. interfering link 2 or interfering link 3). This feature is of interest since it allows deploying these two interferers at the same location (i.e. with the same coordinates) and these two transmitters could be transmitting at the same time while having different transmitter characteristics (e.g. emission mask, antenna radiation pattern…) or with a relative X, Y position set by DeltaX and DeltaY.

If for one interfering link (e.g. interfering link 1) the number of active transmitter is one, then for any extra interfering links, only one Tx is simulated. When the “to position with” feature is selected, any values are grey shaded and only one transmitter is simulated.

Option 2: Generation of multiple interferers with the same characteristics and using a specific deployment modes

Within one interfering link, you can define a number of active interfering transmitters when the mode "None" or "Uniform density" is selected. These active transmitters have the same technical characteristics (i.e. duplicate) and they are deployed according to the mode selected. The iRSS result is stored as one vector (of size number of snapshots) where for each snapshot the iRSS value is the sum of the X active transmitters.

The number of active transmitters is directly used to compute the simulation radius.

Generation of multiple interferers with the same characteristics and using a specific deployment mode.

This option corresponds to duplicate n times a specific interfering links on a circle or on a hexagonal grid as illustrated below in (a) and (b) respectively. It is available by clicking on (). These interferers have the same characteristics as the reference interfering link. It has the purpose of automatically generating a regular pattern of interfering links.
(a) Circular and (b) hexagonal layout

Auto-generation of multiple interfering links

The multiple generate feature graphical interface consists of 3 parts:

  • Selection of the reference interferer
  • Relative position of this reference interferer to the victim link
  • Layout preview of the new interferers

(a) Selection of the reference interferer

You can choose an interfering link that will be used to clone the new interferers.

Selection of the reference interferers

In the Generate Multiple Interfering Link dialog box, when selecting ok, 6 new interferers will now be present in the workspace, centered to the selected interferer (i.e. interfering link 1).

Generated new interferes, centered on interfering link 1

You can adjust the position of the interferers with respect to either the VLT (Victim link transmitter) or the VLR (Victim link receiver). When the generate multiple feature is run the relative positioning of interfering link mode (i.e. in the victim receiver to interfering transmitter path tab) is by default overwritten. In this case the center of the interferers is set to (1,1) to VLT.

Relative position of the interferer to the VLR or VLT

(c) Layout preview of the new interferers

As a results the preview will display the following illustration

Layout preview of the relative position of the interferer to the VLR or VLT

In the appearing dialog window, you may select:

  • between circular or hexagonal layout (1),
  • the number of tiers of generated multiple cells (2),
  • total number of links in the first tier (3),
  • the intersite distance parameter (4)
  • the displacement angle (5) (θ )
  • the angle offset (6).

(d) Example

The below figure shows an example of scenario that may be used for estimating intra‐service interference to a victim base station of cellular system from mobile transmitters operating in the next tier of co‐channel cells of the same system. The displacement angle is calculated automatically by the dialogue window by evenly spacing the specified number of cells around the 360 deg arc, but you may amend this angle. e.g. in order to achieve placement of multiple cells in a sector of less than 360 deg. The parameter angle offset may be used to specify the offset of an azimuth towards the first interfering cell with regard to the x‐axis, as seen from the centre cell. During the multiple link generation, the intersite distance parameter (0.433 km in the example), in combination with the specified initial offset angle, will overwrite the original coordinates (Delta X/Delta Y) in the Vr‐It path tab setting of the Interfering links.

Example where 1 tier is used to position 4 interferers in a square shape (i.e. corners of a building) with the Vr positioned outside the square