If the user has selected "MIMO" as the simulation type in the Simulation panel, newFASANT will calculate the parameters that characterize the MIMO system defined in the simulation case, in addition to the coupling values. These MIMO results are detailed in the following sections.
Pressing the menu item "Show Results -> MIMO Channel -> View Channel Transfer Matrix" will show the following panel:
Figure: Channel transfer matrix results
If the simulation has more than one step, the user can select the step they want to show the results for, and the same applies for the different simulation frequencies.
The table shows the elements of the channel transfer matrix of the MIMO system. For each value, the table shows the indices of the active antenna and passive antenna pair, as well as the module and phase of the channel transfer matrix element. By selecting any row in the table, the active antenna and passive antenna will be highlighted in the Geometry view, and a line between the two antennas will be drawn. In the geometry panel, transmit antennas are red-colored while receiving antennas are blue-colored.
In this panel, it is also possible to visualize a plot of a certain element of the channel transfer matrix by step or frequency. Pressing the "Show Chart" button will open the Plot Viewer and visualize the selected chart. Refer to the "GUI User Guide" for more details on the Plot Viewer panel.
It is also possible to view a text file with the values of the channel transfer matrix by pressing the "View Text File" button.
Selecting the option "Show Results -> MIMO Channel -> View Channel Correlation" will show the following panel:
Figure: Correlation Matrix results panel
As with the channel transfer matrix panel, the user can select different steps and frequencies to change the shown results (if there is only one step or one frequency in the simulation, the drop-down list will be grayed out).
The "Channel 1 (Tx, Rx)" and "Channel 2 (Tx, Rx)" drop-down lists allow the user to select the two channels for the visualization of their correlation. Each channel is defined by the index of its transmit (Tx) antenna and the index of its receiving (Rx) antenna. If the user selects two different channels, the geometry panel will highlight their antennas and draw a blue line connecting the antennas of the first channel, and a red line connecting the antennas of the second channel. As in the "Channel Transfer Matrix" panel, transmit antennas are red-colored while receiving antennas are purple-colored.
It is also possible to draw a plot of a specific element of the correlation matrix by step or frequency. To do this, the user needs to select whether they want to draw a plot by step or by frequency, select the two channels and press the "Show Chart" button. Doing this will open the Plot Viewer with the selected plot (refer to the GUI User Guide for more information about Plot Viewer functions).
For each combination of step and frequency, the user can export a text file with the values of the correlation matrix. Pressing the "Export text file" button will show the following window:
Figure: Correlation text file format window
In this window, the user needs to the select the format of the generated text file. There are three different options:
Table format (module and phase): Generates a text file with its contents arranged in a table. Each row of the table contains the Channel 1 and Channel 2, each one defined by its transmit antenna (Tx) index and receiving antenna (Rx) index; and the module and phase of the correlation for those channels.
Matrix format (module only): Generates a text file with only the modules of the correlation values. These values are displayed in a matrix format: C lines, with each line containing C space-separated values (where C is the total number of channels).
Matrix format (phase only): The same as the previous format, but the phases of the correlation values are written (instead of the modules).
After selecting the format, the application will show a window in which the user needs to select a location for the text file on their hard drive. The file will be exported to the selected location.
When a MIMO simulation is executed, only the channel transfer matrix and the correlation matrix are calculated. For the user to be able to see the overall capacity of the MIMO system, they first need to specify some parameters.
When the user selects the option "Capacity Postprocess", the following panel is shown:
Figure: Capacity post-process panel
In this panel, the user can specify multiple sets of the following parameters in the table:
- The transmitted power per antenna defines the power, in dBm, that each active antenna transmits.
- The temperature, in Kelvin, is the temperature in each of the passive (receiving) antennas. This temperature is used when determining the signal-to-noise ratio in the receivers using thermal noise.
- The bandwidth is also used when calculating signal-to-noise ratio at the receiver. It represents the bandwidth over which the thermal noise is calculated.
When the user presses the "Calculate" button, the application will run a post-process to calculate the capacity of the MIMO system for each of the parameter sets configured in the table. The Process Log panel will appear showing the progress of the calculation.
Figure: Capacity post-process log
When the post-process has finished running, the user will be able to visualize the results using the options on the "Show Results -> MIMO Capacity" menu.
The menu "Show Results -> MIMO Capacity" provides several options to visualize the capacity of the MIMO system:
Figure: MIMO Capacity menu
The first option, "View Capacity by Frequency", allows the visualization of the capacity in terms of the frequency at a given step. When this option is selected, the following panel will appear:
Figure: MIMO Capacity by frequency
In this panel, the user can visualize many plots by selecting the step, the parameter set and pressing the "Add Series" button. In addition, it is possible to import existing series from a text file and export a currently shown series to a text file. The user can also change the color of the series and delete them.
Selecting the "View Capacity by Step" menu option will show a similar panel:
Figure: MIMO Capacity by step
In this case, the user can visualize the capacity values in terms of the step for a given frequency value. It is possible to add more plots for different frequency values by selecting the frequency and parameter set and pressing the "Add Series" button. The rest of the functionality is the same as in the "MIMO Capacity by frequency" panel.
If the user selects the "Capacity text files" menu option, a panel will appear (right side of the next figure). This panel will ask the user the step and the parameter set they want to see the results for. When the "OK" button is pressed, the requested text file will be shown.
At the bottom of the "Text File" panel, there is a button labeled as "Save as..." that allows the user to save this text file to a user-given location in their local filesystem.