E.2 Basic unit of measurement
36.1043GPPBase Station (BS) radio transmission and receptionEvolved Universal Terrestrial Radio Access (E-UTRA)Release 18TS
For 15 kHz, 7.5 kHz,1.25 kHz, 2.5 kHz subcarrier spacing, the basic unit of EVM measurement is defined over one subframe (1ms) for subframe TTI and over one sTTI when supporting sTTI feature in the time domain and subcarriers (180kHz) in the frequency domain:
For 0.37 kHz subcarrier spacing, the basic unit of EVM measurement is defined over one slot (3ms) in the time domain and subcarriers (180kHz) in the frequency domain:
where
is the set of symbols with the considered modulation scheme being active within the subframe or within the sTTI,
is the set of subcarriers within the subcarriers with the considered modulation scheme being active in symbol t,
is the ideal signal reconstructed by the measurement equipment in accordance with relevant Tx models,
is the modified signal under test defined in E.3.
Note: Although the basic unit of measurement is one subframe or one sTTI, the equalizer is calculated over 10 subframe measurement periods to reduce the impact of noise in the reference symbols. The boundaries of the 10 subframe measurement periods need not be aligned with radio frame boundaries.