Channel Power Measurement Description; How Is A Channel Power Measurement Made; Input Signal Requirements; Trigger Source - Agilent Technologies 8960 Series Reference Manual

Channel Power Measurement Description

How is a Channel Power Measurement Made?

The channel power measurement is made on the RF input signal after frequency downconversion and an
analog to digital conversion (see
by the test set's digital signal processor (DSP). The signal can be filtered in the DSP with a root-raised cosine
(RRC) filter with a rolloff of 0.22 and a bandwidth equal to the chip rate (3.84 MHz) to comply with 3GPP
34.121 conformance specifications that require RRC filtered power. The filter can also be turned off for
conformance specifications requiring a mean power measurement. When the RRC filter is Off, the bandwidth
of the Channel Power measurement is greater than (1+alpha) times the chiprate, where alpha=0.22.
Differences between the Channel Power and Thermal Power Measurements
When the RRC filter for the channel power measurement is turned on, the results are typically about 0.25 dB
lower than the thermal power measurement results.
Thermal power performance is only specified for signals down to -10 dBm, while the channel power
measurement is able to accurately measure signals down to -61 dBm.

Input Signal Requirements

• This measurement does not autorange, therefore the expected power level from the mobile station (UE) is
set using the current MS Target Power setting, or by using manual receiver power control and specifying
the expected power level. See
• The frequency of the signal being measured must be in the range of 800 MHz to 1000 MHz, or from
1700 MHz to 1990 MHz.
• The level into the test set's RF IN/OUT connector must be in the range of -61 dBm to +28 dBm, measured in
a 3.84 MHz bandwidth.

Trigger Source

The trigger source defaults to Auto for the channel power measurement, and tries to use protocol triggering if
the mobile station (UE) is synchronized to the test set. Immediate triggering is used if the mobile station is not
synchronized.
RF Rise triggering is provided to measure power during PRACH bursts. The burst's on state level must be
>-40 dBm, and the off state level must be <-60 dBm, for this trigger to work correctly.
This measurement can be made over a period of .1 ms to 10 ms (the default is 1 timeslot or 666.7 µs) by
altering the Measurement Interval. The measurement can be made during a specific timeslot by changing the
Trigger Delay.
"Block Diagram" on page
"Receiver Control" .
S:\Hp8960\E1963A WCDMA\4.0 release\Reference Guide\Chapters\wcdma_meas_chanpow_desc.fm
Channel Power Measurement Description
621). The actual power measurement is performed
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