Indoor LTE with MIMO Distributed

Model Type

The model consists of an office building where wireless connectivity using MIMO technology is investigated.

Sites and Antennas

Two omnidirectional antennas are placed at two different sites, Site 0 and Site 1. These antennas are placed at a height of 3.5 m from the ground with significant distance between them. Both antennas have an omnidirectional radiation pattern and use the same carrier frequency of 2120 MHz. In this model, the antennas were configured to use MIMO technology. MIMO streams 1 and 2 were assigned to antennas 1 and 2, respectively.

Tip: Click Project > Edit Project Parameter and click the Sites tab to view the MIMO settings.

Air Interface

The air interface is defined by an LTE wireless standard in LTE_Sample_Indoor_MIMO_Distributed.wst. Orthogonal frequency division multiple access (OFDM/SOFDMA) is the multiple access scheme selected for this air interface. Two-streams MIMO technology is used. Overhead and interference associated with having the two MIMO streams on the same carrier frequency are specified here. Frequency division duplex (FDD) separation between uplink and downlink is set to 190 MHz.

Tip: Click Project > Edit Project Parameter and click the Air Interface tab to view the air interface, MIMO settings, carriers, and transmission modes.

A list of different modulation and coding schemes are found on the Air Interface tab, under Transmission Modes (MCS). Overhead and interference associated with having two MIMO streams on the same carrier are specified here.

Computational Method

The computation method for this model is the dominant path model (DPM). This method focuses on the most relevant path, which leads to shorter computation times compared to the standard ray tracing model (SRT). Empirical losses are used for the computation of the signal level along the propagation path. Empirical losses can readily be determined with measurements.

Tip: Click Project > Edit Project Parameter and click the Computation tab to select the method.

Results

Propagation results show at every location the power received from each transmitting antenna. Results are available for a single prediction plane at a height of 1.5 m.

Network-planning results include maximum data rate, maximum throughput, and number of MIMO streams for both the uplink and downlink. These results can be viewed by selecting Results: Network in the result tree. It is not advantageous to have two MIMO antennas separated by a large distance while operating on the same carrier and transmitting individual streams. In the area between the antennas, the SNIR is often low (their interference is high) and communication may not be possible.