About MIMO Info Table (LTE)

MIMO Info Table shows information about the C-RS Cell-specific RS antenna port transmissions detected by the demodulator.

The first column contains the name of the data result, and the other columns display the value of the data result for each C-RS antenna port signal received on a VSA measurement channel (Rx0 = Measurement Channel 1). When there are multiple measurement channels, a horizontal section is added to the table for each additional measurement channel.

The C-RS results in this summary table are calculated regardless of successful demodulation, which means user mappings do not need to be defined for these data results to be calculated. However, the LTE Long Term Evolution signal does need to be demodulated for the IQ impairment results to be calculated, since the IQ data results are calculated from the PDSCH Physical Downlink Shared Channel subcarriers.

RSEVM and RSCTE are calculated with a Symbol Timing Adjust setting of EVM Window Center. When Symbol Timing Adjust is set to a value other than EVM Window Center, these data results may not match the corresponding reference signal EVM Error vector magnitude (EVM): A quality metric in digital communication systems. See the EVM metric in the Error Summary Table topic in each demodulator for more information on how EVM is calculated for that modulation format. and Common Tracking Error data results in the Error Summary and Frame Summary tables.

Below is a table of data results provided and their descriptions. Click on the name of a data result for more information.

MIMO Multiple Input, Multiple Output: A physical layer (PHY) configuration in which both transmitter and receiver use multiple antennas. Info Table data results
Data result	Description
IQGainImb (dB)	IQ gain imbalance
IQQuadErr (deg)	IQ quadrature error
IQTimSkew (nsec)	IQ timing skew
RSCTE (%rms)	Average (RMS) C-RS Common Tracking Error
RSEVM (%rms or dB)	Average (RMS) C-RS EVM Units are determined by the Report EVM in dB parameter.
RSFreq (Hz)	C-RS frequency shift error
RSPhase (degrees)	Average (RMS) C-RS phase error
RSPwr (dB)	Average (RMS) C-RS signal power
RSSymClk (ppm)	Average C-RS symbol clock error
RSTiming (seconds)	C-RS timing error

RSPwr, RSTiming, RSPhase, RSSymClk and RSFreq are set to zero for the reference C-RS/Rx path determined by the Ref Meas Channel and Ref C-RS Port parameters. The values of these data results for other C-RS/Rx paths are reported relative to the reference path.

Averaging

This trace supports averaging over multiple measurements. When Averaging is enabled, value "mm" in the "RMS: mm" or "Peak: mm" annotation at the top of the trace displays how many measurement sweeps have been included in the current average.

Querying summary table data results programmatically

To programmatically query the Trace Summary Table data results using the Summary() and SummaryUnit() methods in the MeasurementData object.

See the How To Query Summary Table Data Results topic for more information.

Syntax: app.Display.Traces.SelectedItem.DataName = "MIMO Info Table1"

The indexes of the MIMO Info Table data values change depending on the number of transmit and receive antenna ports. Instead of using hardcoded indexes to retrieve the data values, you can use a data result name to query the data value.

The data result names for the RS data results in this summary table are formed by concatenating a measurement name with a transmit-receive path. To create the name of a data result for a specific transmit-receive path, append the transmit antenna port and the receive channel to the name of the data result. "Txn" indicates C-RS antenna port n, and "Rxm" indicates VSA measurement channel m.

IQGainImb, IQQuadErr, and IQTimeSkew are calculated for each antenna port instead of each C-RS/Rx path. To create the name of an IQ data result, append only the antenna port to the IQ data result's name.

Each IQ data result is repeated in the list of data results returned by MeasurementData.SummaryNames for each C-RS antenna port. To get the value of an IQ data result for a particular C-RS antenna port, construct the appropriate data name and search for the first data result that matches the data name and does not have "---" as the value. Repeated IQ data results that have a value other than "---" will contain identical numerical values which means that finding the first one is sufficient.

Example

To get the value of IQGainImb for C-RS antenna port 1, search for the first data result matching "IQGainImb" + "Tx1" = "IQGainImbTx1" that does not have a corresponding value of "---".

To get the value of RSPwr for the C-RS1/Rx0 receive path listed on the MIMO Info Table, you would query the data result named "RSPwr" + "Tx1" + "Rx0" = "RSPwrTx1Rx0"

Data Result Name	MIMO Info Table Results
IQGainImb	IQ gain imbalance
IQQuadErr	IQ quadrature error
IQTimingSkew	IQ timing skew
RSCTE	Average (RMS) C-RS Common Tracking Error
RSEVM	Average (RMS) C-RS EVM Units are determined by the Report EVM in dB parameter.
RSFreq	C-RS frequency shift error
RSPhase	Average (RMS) C-RS phase error
RSPwr	Average (RMS) C-RS signal power
RSSymClk	Average C-RS symbol clock error
RSTiming	C-RS timing error