Anritsu 3GPP, Руководство по измерениям

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TD-LTE Signal Analyzer 6-4 TD-LTE Modulation Measurements
3GPP MG PN: 10580-00234 Rev. Y 6-9
6-4 TD-LTE Modulation Measurements
The following parameters are measured in the Modulation Measurement mode.
Power vs Resource Block (RB)
This measurement displays the Power vs RB grid, an RB Color Map, the measurements table,
and measurement progress bar. See
Figure 6-7 on page 6-12 .
Two Dimensional Power vs RB Grid
This view shows the PDSCH power of each RB using color. The y-axis is frequency
(sub-carriers) and the x-axis is time (sub-frames). The number of subcarriers varies
depending on the bandwidth chosen and hence the number of RBs on the y-axis. Each cell
bin the grid corresponds to a particular RB in a particular sub-frame. For TD-LTE, the
number of Active Resource Blocks and Utilization is only displayed for sub-frame 0.
Resource Block Color Map
The color mapping of the RB power level is determined by the
RB Color Map Max Value
and
RB Color Map Range
submenus. Setting these values can be done by entering them manually
or by pressing
Autoscale Color Map
.
Measurements Table
Active RBs
The number of active Resource Blocks in sub-frame 0. An RB is determined to be active
if the measured PDSCH power is above a certain threshold that indicates that the RB
is being used for carrying data.
Utilization
The percentage of Resource Blocks that carry data. It is the number of Active Resource
Blocks in sub-frame 0 divided by the total number of Resource Blocks in sub-frame 0,
expressed as a %.
Channel Power
Channel power is the average total power within the bandwidth and is expressed in
dBm.
OSTP
OSTP is the measurement of the OFDM symbol transmit power.
EVM
The RMS (%) of all of the error vectors between the reconstructed ideal signals and the
received signals, divided by the RMS value of the ideal signals. Individual frame
EVM(RMS) is displayed for the modulation types QPSK, 16-QAM, and 64-QAM. If the
LTE carrier uses 256-QAM modulation scheme, the corresponding EVM measurement
result is displayed, provided Option 886 is installed and activated on your instrument
(see
Figure 6-7 on page 6-12 ).
Cell ID
Cell identifying information sent by the transmitter in the sync signal.
Note The Power Offset is applied to the measured value before matching to a color map.