QPSK EVM Measurement Description

QPSK EVM Measurement Description

Last updated: January 5, 2010

How is a QPSK EVM Measurement Made?

The QPSK EVM measurement is to determine the error between the transmitted signal of a UE and the desired ideal signal. The measurement is very similar to the Waveform Quality measurement. The difference is that the expected input signal is a QPSK modulated signal, which is similar to the WCDMA uplink signal with only one code channel. The data carried by the QPSK symbols sequence can be any pattern.

This measurement is designed for the UE to calibrate its IQ modulator without a WCDMA format signal to meet the waveform quality requirements as defined in 3GPP TS 34.121.

Please note that the measurement results will only be valid if a pure QPSK modulated input signal is applied.

QPSK EVM Measurement Parameters

QPSK EVM Measurement Results

QPSK EVM Input Signal Requirements

QPSK EVM Measurement Calibration

This measurement should be calibrated using the Calibrate Measurements function ( CALibration:MEASurements? ) when the temperature has changed by ± 10° C or more since the last calibration. If this situation exists, the integrity indicator value becomes 19 and a message is displayed indicating "Uncalibrated Due to Temperature".

Related Topics