SCN 0-3000 1200 N kHz + 50 M kHz; N = 1:2499, ME{1,3,5} 3N (M - 3)/2 2-7498 3000-24,250 3000 MHz + 1.44 N MHz; N = 0:14,756 7499 + N 7499-22,255 24,250-100,000 24250.08 MHz + 17.28N MHz; N = 0:4383 22,256 + N 22,256-26,639 The synchronization raster signifies the frequency positions of the synchronization block that can be used by a UE for frequency acquisition when the UE has not received an explicit signaling indicating the synchronization block position. A global synchronization raster is defined for all frequencies. The frequency position of the synchronization block is defined by parameter SSREF with a corresponding global synchronization channel number (GSCN). The GSCNs are numbered in increasing frequency order as shown in Table 3.11. The physical resource block number is NPRB = 10 for the synchronization raster mapping to the synchronization block resource elements [9]. 3.6 Frame Structure and Numerology 3GPP NR is designed to operate from 450 MHz to 100 GHz with a wide range of deploy- ment scenarios, while supporting a variety of services. Given OFDMA was chosen as the multiple-access scheme for the downlink and uplink, it is not possible for a single numerol- ogy to satisfy the requirements of various use cases. Therefore, NR defines a family of OFDM numerologies for various frequency bands and deployment scenarios. The advantage of 3GPP NR relative to LTE is that it defines multiple numerologies which can be mixed and used simultaneously. A numerology is defined by a subcarrier spacing and a CP. The requirements for the OFDM subcarrier spacing is determined based on the carrier frequency, phase noise, delay spread, and Doppler spread. The use of smaller subcarrier spacing would result in either large EVM due to phase noise or more stringent requirements on the local oscillator. The small subcarrier spacing further leads to performance degradation in high Doppler scenarios. The required CP overhead and thus anticipated delay spread sets an 384 Chapter 3 Table 3.12: Supported OFDM parameters in NR [12].