IQTimSkew (LTE-Advanced)
shows the amount of IQ time skew, or delay between the I and Q channels, averaged over the PDSCH Physical Downlink Shared Channel subcarriers on a C-RS Cell-specific RS antenna port over all VSA measurement channels (Rx0 = Measurement Channel 1).
is expressed in nanoseconds and is calculated from the data in the Measurement Interval.
is calculated for each C-RS antenna port. When a C-RS/Rx path is present, the MIMO Info Table will show the IQ timing skew for the corresponding C-RS antenna port. C-RS/Rx paths with the same C-RS antenna port but different measurement channels will show the same value.
The will show "---" for IQ data results that cannot be calculated from the demodulated data. Cases where the IQ metrics cannot be calculated are as follows:
- The signal has the Precoding mode set to (Spatial Multiplexing), CDD set to , and the number of layers is less than the number of transmit antennas.
- The signal has only UE-RS UE-specific Reference Signal PDSCH allocations (data results do not include PDSCH transmitted on UE User Equipment (e.g. cell phone)-RS antenna ports).
- The signal in the Measurement Interval does not contain at least one PDSCH subcarrier that has a corresponding PDSCH subcarrier in the frequency-mirrored location on the other side of the DC axis.
- The transmitted data is identical on two or more layers and Codebook Idx is set to zero.
- The number of measurement channels is less than the number of C-RS antenna ports.
See Also
