Interpretation of Measurement Results

This section contains expected result values and possible causes of error if the expected results are not met.

Freq (Frequency)

If you are in the channel mode, verify that the correct channelization and channel number are set.

Freq Error (Frequency Error)

The frequency error of the analyzer should be <1 kHz. If it is not, check to ensure that the test set is performing a correct measurement. You can do this by reviewing the frequency reference settings for the test set (refer to "Selecting a Reference")
Ensure that these settings are correct, and that the test set shows reference lock. Lastly, make sure the test set has been powered on, and has been locked for at least 15 minutes.
 If the error is still occurring after performing the above procedures, you will need to check the Base Station equipment for a source of the error. You can also verify that the base station is malfunctioning by turning off its modulation hardware and performing a frequency measurement on the Base Station carrier signal in the spectrum analyzer mode of the test set (refer to "Performing a Basic Spectrum Analyzer Measurement")
 You can use the Frequency Limits setting to make your analyzer indicate automatically whether or not a signal has exceeded the pre-defined limits you set.

Scramble Code

If the Scrambling Code is not as expected, it could be due to an incorrect Base Station setting or to incorrect positioning of the test set. If the correct Scrambling code cannot be located, check the base station settings.

Noise Floor

An unexpectedly high noise floor could be due to interfering signals.
 If you have not already done so, you can reduce the noise floor by activating the IF Equalizer (See "Setting the IF Equalizer" on page 478.)

Threshold

If the Threshold is not as expected, check the following:
 Check the Threshold settings to make sure they are correct. (See "Setting the Active Channel Threshold Level and Auto Threshold Level" for more information.).

EVM Pilot and EVM Comp (Pilot (CPICH) and Composite Error Vector Magnitude

An unexpectedly high EVM could be due to interfering signals, carrier feedthrough, transmitter I/Q modulator, or signal path problems.
If you have not already done so, you can reduce the noise floor by activating the IF Equalizer (See "Setting the IF Equalizer" on page 478.)

PCDE (Peak Code Domain Error)

An unexpectedly high PCDE could be due to interfering signals, carrier feedthrough, transmitter I/Q modulator, or signal path problems.

Carr Feedthru (Carrier Feedthrough)

A good Carrier Feedthrough level is less than -25 dB. The 3GPP standard does not specify Carrier Feedthrough; however, this measurement provides an additional tool to troubleshoot the base station's transmitter.
In the frequency domain, Carrier Feedthrough can show up as an energy spike that can be seen on the spectrum analyzer by closely spanning into the top of the W-CDMA or W-CDMA (with HSDPA) signal. The effects of Carrier Feedthrough can also show up as higher noise levels on the Code Domain Power screen. Carrier Feedthrough can be caused by the lack of isolation across the mixer and cavity of the transmitter's I/Q modulator.

Chan Pwr (Channel Power)

If the Channel Power level is not as expected, check pilot dominance and the number of Scrambling codes visible. All visible sectors will contribute to channel power. Also, check Amplifier Capacity and Utilization as they could have exceeded the maximum capacity. A high power data call could be indicated by a very wide and tall bar.

CPICH (Common Pilot Channel)

CPICH will vary with distance from the base station and clear line of sight to the antenna. If the CPICH is not as expected, check pilot dominance and base station settings (ratio to other control channels should be good).

Control Channel Delta (D) Powers

The Delta results should match the Base Station settings. If not, ensure the Base Station settings are as expected.