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 ?