MIMO Info Summary Table
The summary table contains reference values (from Antenna 1) and deviation values (for Antenna 2). The MIMO Multiple Input, Multiple Output: A physical layer (PHY) configuration in which both transmitter and receiver use multiple antennas. Info trace is only available for Downlink MIMO measurements with 2 (or more) Tx Antennas selected and configured for 2 Input Channels.
Metrics are provided for all four paths (Tx0/Rx0;Tx0/Rx1;Tx1/Rx1;Tx1/Rx0). Note, the Antenna 1 path is used as a reference, and therefore has zero values. Using Antenna 1 as a reference is the main difference between the "MIMO Info" summary table and the "Ant 2 Comp Error Summary" table.
"NumTx" (hidden value accessible from .NET API 1) Access Preamble Indicator, or 2) Application Programming Interface) indicates the number of transmit antennas processed for the measurement. This will match the user parameter "Number of Tx Antennas". If this value is "1", then the remainder of the trace will have "N/A" in place of values, and a "NO DATA" trace indicator, because MIMO analysis is not performed.
"NumRx" (hidden value accessible from .NET API) indicates the number of receiver antennas (number of input channels used by the VSA for the measurement).
"Condition Number" indicates the condition number of the MIMO channel matrix. This is a single value indicating the correlation of the MIMO channel, assuming static fading.
(CPICH Common Pilot Channel) Timing Offset is the detected timing offset of the CPICH channel for each path. The Timing Offset is computed assuming the transmitter is time synchronized between antennas. Therefore both Tx0/Rx0 and Tx1/Rx0 are a reference value, and the value for Tx0/Rx1 and Tx1/Rx1 will be identical.
(CPICH) Freq Offset is the detected frequency offset of the CPICH channel for each path. The Freq Offset is computed differently depending on the MimoFreqOffsetModel property. If "Rx" model is selected, the measurement assumes just the transmitter is frequency locked between antennas. Therefore both Tx0/Rx0 and Tx1/Rx0 are a reference value, and the value for Tx0/Rx1 and Tx1/Rx1 will be identical. Otherwise if "Tx" model is selected, the measurement assumes just the receiver is frequency locked between antennas. Therefore both Tx0/Rx0 and Tx0/Rx1 are a reference value, and the value for Tx1/Rx0 and Tx1/Rx1 will be identical
H is the estimated MIMO channel matrix.
(CPICH) Phase Offset and (CPICH) Mag Offset are computed based on the H result described above. The Tx0/Rx0 path is assumed to be the reference with 0deg Phase Offset and 0dB Mag Offset.
How to Make a HSPA+MIMO Despread (x) Trace Data measurement
To learn how to use the Despread Traces parameter to make a Despread (x) Channel Trace Data measurement, see HSPA+ MIMO Overview - Despread (x) Trace Data.
See Also
