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I am trying to understand the concept of EVM and how it is measured at different points in transceiver. I have a basic understanding that the error difference is calculated between two vectors (i.e. ideal and measured symbols on IQ plot) and RMS EVM is computed.

I believe this happens at receiver end after a radio receives signals , goes through RF Front end , converts to baseband and then CFO & SFO estimation/compensation. Once the symbols are mapped onto the constellation , we measure the EVM . Is my understanding correct ?

In my case , I am generating 11b waveform and it goes through the power amplifier model . Want to see houw much the EVM is before and after it goes through Tx hardware impairment module . All I have is time domain IQ samples . TO measure EVM in this case , Do I need to again convert the iq Samples to the respective symbols and then measure EVM ? Can anyone please throw some light on this and suggest any docs which I should go through ?

Jani

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    $\begingroup$ This is answered here I believe, please take a look to see if it applies: dsp.stackexchange.com/questions/67183/… $\endgroup$
    – Dan Boschen
    Commented Jul 27, 2020 at 19:05
  • $\begingroup$ Also you can derive it from a correlation coefficient-- here is the EVM to SNR relationship keysight.com/main/…. and here is the SNR to correlation coefficient relationship: dsp.stackexchange.com/questions/30847/noise-detection $\endgroup$
    – Dan Boschen
    Commented Jul 27, 2020 at 19:08
  • $\begingroup$ (But to do any of that you have to demodulate, so yes to your last question) $\endgroup$
    – Dan Boschen
    Commented Jul 27, 2020 at 19:08
  • $\begingroup$ Thanks Dan.. Going through KS link and SE posts now $\endgroup$
    – Jani
    Commented Jul 27, 2020 at 19:09

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