How to measure EVM?

1. What is an EVM test?
2. How do you calculate EVM error vector magnitude?
3. What is EVM in RF testing?
4. What is the EVM of the modulated signal?

What is an EVM test?

Error Vector Magnitude (EVM), the transmitter modulation accuracy test, is calculated by comparing the actual measured signal with an ideal reference signal to determine the error vector.

How do you calculate EVM error vector magnitude?

In general, EVM is calculated by finding the ideal constellation location for each received symbol, as shown in Figure 1b. The root means square (rms) of all error vector magnitudes between the received symbol locations and their closest ideal constellation locations constitute the EVM value of the device.

What is EVM in RF testing?

EVM (Error Vector Magnitude) is the key metric used to evaluate RF transmitter performance, because it provides a consistent “yardstick” to characterize the transmitter regardless of the receiver implementation and it encapsulates a wide range of possible impairments on the transmitter chain into a single measurement.

What is the EVM of the modulated signal?

Error vector magnitude (EVM) is a common figure of merit for assessing the quality of digitally modulated telecommunication signals. EVM expresses the difference between the expected complex voltage value of a demodulated symbol and the value of the actual received symbol.