Question: In 3GPP-compliant Base Station (BS) conformance testing for TDD, how is the Error Vector Magnitude (EVM) result defined in relation to the measured and reference waveforms?
Option 1: As the absolute difference between the peak power of the measured waveform and the reference waveform.
Option 2: As the ratio of the mean error vector power to the mean reference power, expressed in decibels (dB).
Option 3: As the square root of the ratio of the mean error vector power to the mean reference power, expressed as a percentage (%).
Option 4: As the standard deviation of the phase difference between the measured and reference waveforms over one timeslot.
Explanation: The correct definition of EVM in this context involves comparing the power of the error vector (the difference between the two waveforms after optimization) to the power of the reference waveform. Specifically, it is calculated as the square root of the ratio of the mean error vector power to the mean reference power, and this result is expressed as a percentage. This method provides a clear, quantifiable measure of the discrepancy between the ideal and actual waveforms, which is crucial for assessing base station performance in wireless communication systems like those specified by 3GPP.