MIMO Propagation Modeling

Geometry

Import the required city geometry into AEDT. Choose base station and user device locations. Select the antenna type from the parametric antenna dictionary or design your own antennas/arrays in HFSS. In this example workflow, we import a part of downtown Los Angeles from open street maps. For both MIMO arrays we use connected slot arrays.

Set-up

Configure one terminal as a transmitter and one as a receiver. Create a single frequency set-up with a specified center frequency. For this example, the simulation frequency is 5 [GHz].

Post-Processing

Obtain the channel matrix and calculate its singular values. Apply a 2D Discrete Fourier Transform (DFT) to obtain the angular domain channel.

Multistream Tests

Singular-values of a MIMO channel matrix show distinct non-interfering parallel channels that are capable of carrying separate data streams. With only a single large singular value, as we have in this example, multiplexing multiple data streams is impractical as the environment does not have sufficient scattering.

Angular Domain Channel

Plotting the channel matrix in the angular domain, we observe that most of the signal power at the receiver comes from one angle bin which confirms the fact that the environment has limited scattering at the receiver and thus cannot support many non-interfering data streams. On the contrary, we observe that we have rich-scattering at the transmitter which enables diversity. This comes from distinct angles at the transmitter that fade independently reducing the overall outage probability.