Specifies the measurement length for the SlotPower measurement. This value is expressed in slots. The SlotPower measurement assumes that there is only one active traffic time slot per subframe, and that the position of this active time slot is the same in each subframe. Additionally, it assumes that there are no pilots present in the received signal.

NI recommends you set a measurement length as a multiple of the number of slots per subframe, that is a multiple of 7. For example, when you set this property to 28 slots, the SlotPower measurement would report results for the 4 active time slots within the specified measurement length. In this example, 28 slots = 4 subframes.

The start of the measurement is determined by the Trigger Type property. Although all the values of the Trigger Type property are supported for this measurement, it is recommended to set the Trigger Type property to Digital Edge with the following options:

  • Digital trigger at the start of active slot, with the Trigger Delay property set to 0 seconds
  • Digital trigger at the start of the subframe, with the Trigger Delay property configured to a value which is equal to the time offset of the active time slot from the start of the subframe

The table shows the values of the Trigger Delay property, when you specify the following active slots values:

Active Slot Trigger Delay (microseconds)
TS0 0
TS1 950
TS2 1625
TS3 2300
TS4 2975
TS5 3650
TS6 4325

If you cannot provide a digital trigger, you can set Trigger Type property to IQ Power Edge to ensure that the measurement starts at the start of an active time slot. To ensure this trigger works properly, NI recommends you complete the following steps:

  • Set the IQ Power Edge Level property to allow triggering for any of the power levels in the active slots
  • Run the RFmx measurement just before generating your signal

If you set the Trigger type property to None, the measurement will automatically detect the start of the first burst and measure the traffic slot in that position in every subframe.

You do not need to use a selector string to configure or read this property for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals.

The default value is 28. The minimum value is 1.

Remarks

The following table lists the characteristics of this property.

Short Name SlotPower Meas Length (slots)
Data type ci32.png
Permissions Read/Write
High-level VIs RFmxTDSCDMA SlotPower Configure Measurement Length
Resettable Yes