Dynamic Power Analysis Troubleshooting
Last updated: January 16, 2009
Possible Setup Issues
-
The product of
Steps
and
Step Length
must not exceed 58.260 ms (a total of 58.26 ms of power sequence can be analyzed at a time).
-
Measurement Interval
must be less than or equal to
Step Length
.
-
During remote operation of the dynamic power analysis measurement, it is recommended that you configure the
Trigger Arm
to
Single
.
-
During front panel operation of this measurement, if
Trigger Arm
is set to
Single
(see
Trigger Arm (Single or Continuous) Description
), you must press the
START SINGLE
key to initiate the measurement.
UE Power Calibration:
-
To ensure that the measurement executes as quickly as possible, the UE should transmit its power sequence
continuously
until the measurement completes. This ensures that as soon as the measurement is done auto-ranging, another power sequence is immediately available for measurement. See
Auto-ranging in the Dynamic Power Analysis Measurement for UE Power Calibration
.
-
The measurement is most accurate over a 25 dB range. If the UE's power sequence spans more than 25 dB, the test set will measure and report the power of the entire sequence, but accuracy is degraded for steps that are more than 25 dB below the highest power in the sequence. To measure a power range greater than 25 dB, you must break the power range up into individual power sequences that do not exceed 25 dB.
-
To ensure proper autoranging, you must specify the number of steps in your sequence and their duration using the
Steps
and
Step Length
settings. It is important that you set
Steps
equal or greater than the number of steps in your UE's power sequence so that the entire power sequence is evaluated during the autoranging.
-
To ensure proper triggering when
Trigger Source
is set to
RF Rise
, it is highly recommended that you use trigger qualification for robust triggering (see
Trigger Qualification State
).
-
Each step in the power sequence must be identical in length.
-
RF Rise Trigger Threshold
must be set to within 0 dB to -25 dB of the
Expected Power
.
-
To use the measurement, you must first set
Measurement Frequency
to the expected UE transmitter frequency and set
Manual Power
to the maximum expected power for the sequence. You can perform the dynamic power analysis measurement in
Active Cell Operating Mode
or
FDD Test Operating Mode
. However, since this measurement does not utilize any overhead signalling to control the UE's power or frequency, you must manually set the test set's
Expected Power
and
Measurement Frequency
in either operating mode.
-
The UE's signal may or may not be modulated with an uplink DPCH signal. If the signal is not modulated with an uplink DPCH signal and is offset in frequency from the expected measurement frequency, you may need to use the
Frequency Offset
setting to ensure the most accurate power measurements possible.
-
The test set assumes a crest factor of 3.1 dB for the signal (as is typical for an uplink DPCH signal relative to a CW signal) and thus actually triggers when the input signal reaches the
RF Rise Trigger Threshold
level plus 3.1 dB. If the UE's signal has a crest factor other than 3.1 dB, you must set the
RF Rise Trigger Threshold
level accordingly.
HSDPA or HSPA Power versus Time (
lab application or feature-licensed test application only
)
-
To perform HSDPA or HSPA power versus time measurements, you must be on a
Radio Bearer Test Mode
connection with a
Channel Type
of
12.2k RMC + HSDPA
or 12.2k RMC + HSPA. Note: in
FDD Test
operating mode the test set does not provide radio bearer setup control of the UE. You must configure the UE to synchronize to the test set, demodulate the downlink HS-SCCH and HS-PDSCH channels and generate the appropriate uplink HS-DPCCH (see
Synchronizing the UE to the Test Set's Downlink to Make Measurements
).
-
For HSDPA or HSPA power versus time, it is recommended that you use a
Trigger Source
of
HS-DPCCH
or
External
.