s the average constellation error with respect to the farthest constellation point (i.e., the distance between the reference- signal and measured signal points in I-Q plane). In NR, the EVM measurement is conducted for all bandwidths and each NR carrier over all allocated resource blocks and downlink subframes within 10 ms measurement period. The boundaries of the EVM measurement periods are not necessarily aligned with radio frame boundaries. 3GPP defines the reference points at which the [transmitter] EVM is measured at the receiver based on which the EVM must be measured after the FFT and a zero-forcing equalizer (per subcarrier amplitude/phase correction) in the receiver [9]. The basic unit of EVM measurement is defined over one subframe in the time domain and NRB BW subcarriers (180 kHz) in the frequency domain as follows [9]: where T is the set of symbols with the considered modulation scheme being active within the subframe, F(t) is the set of subcarriers within the NRB BW subcarriers with the considered modulation scheme being active in symbol t, I(t,,f) is the ideal signal reconstructed by the measurement equipment according to the relevant transmitter model, and Z'(t,f) is the mod- ified signal under test defined as follows [9]: where z(v) is the time-domain samples of the signal under test, Ai is the sample timing dif- ference between the FFT processing window relative to the nominal timing of the ideal sig- nal, f is the RF frequency offset, o(f) is the phase response of the transmitter chain, and 326 Chapter 3 a(f) is the amplitude response of the transmitter chain. In the above equations, the basic unit of measurement is one subframe and the equalizer is calculated over 10 subframes to reduce the impact of noise on the reference symbols. The boundaries of the 10 subframes measurement periods are not necessarily aligned with radio frame boundaries. The EVM is averaged over all allocated downlink resource blocks with the considered mod- ulation scheme in the frequency domain, and a minimum of 10 downl