If the Handoff Waveform Quality measurement is running at the time the power control transient transmission starts (see
Starting the Reverse CLPC Transient
) the measurement will be closed and its operation aborted. Moreover, the Handoff Waveform Quality measurements will not be able to start (become initiated) while the transient transmission is in progress.
How is a Handoff Waveform Quality measurement made?
Handoff waveform quality measurements test a transmitter's modulation accuracy during transmission of a single code channel, the reverse Pilot Channel. The handoff involves changing the current PN (pseudo-noise) offset to force the mobile station to transmit a preamble on the Pilot Channel only. Reverse link power control is changed to alternating up/down bits and waveform quality is measured. After the measurement, the PN offset is returned to the original setting and the power control is returned to the original setting.
Each handoff waveform quality measurement returns a number of measurements which include rho, the percentage of signal energy that correlates with a perfect IS-2000 signal after time offset and frequency error have been removed.
This measurement is designed to analyze signals that are made up of multiple code channels, as in the case of radio configurations three and above.
Waveform quality measurements are made by sampling the down-converted input signal, then applying DSP (Digital Signal Processing) techniques to determine the original data input to the mobile station transmitter's Walsh spreading function for each channel. The DSP then generates a representation of what the "ideal" signal would be given the coding and data in use at the time of transmission. The ideal waveform is then compared with the waveform being measured to determine the waveform quality.
Handoff Waveform Quality measurement results
lists the Handoff Waveform Quality measurements:
Handoff Waveform Quality measurement results
|
Handoff Waveform Quality |
|
Rho |
|
Frequency Error |
|
Timing Error |
|
Carrier Feedthrough |
|
Phase Error |
|
Magnitude Error |
Measurement Behavior
The handoff waveform quality measurement does not provide the Multi-Measurement Count feature in the setup menu.
Handoff waveform quality measurements are always triggered singly (press the
START SINGLE
key to initiate a measurement from the front panel).
Measurement Requirements
Setup:
The following settings are required for the handoff waveform quality measurement:
-
Operating Mode must be Active Cell
-
System Type must be IS-2000 with Radio Config set to (Fwd3, Rvs3) or (Fwd4, Rvs3)
-
A call must be connected
Input Signal:
The handoff waveform quality measurement meets or exceeds specifications when the following input signal requirements are met:
-
The frequency of the signal being measured must be in the range of 412 MHz to 483 MHz, 800 MHz to 960 MHz, or 1.7 GHz to 2.0 GHz, and within 100 kHz of the expected frequency.
-
The signal level into the test set's RF IN/OUT connector must be in the range of -25 dBm to +37 dBm, and within +/- 9 dB of the expected input power (see
RFANalyzer:AUTO:POWer[:SELected]?
) to meet specifications.
Calibrating the Handoff Waveform Quality Measurement
The handoff waveform quality measurement is automatically calibrated during a channel power calibration. Follow the channel power calibration schedule and the handoff waveform quality measurement will be properly calibrated. Refer to
Calibrating the Test Set
for a description of channel power calibration.
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