The maximum FFT size in NR is 4096 compared to a maximum FFT size of 2048 in LTE.
Furthermore, NR has a higher spectral utilization than LTE (increased from 90 percent to above 95 percent), and a higher relative subcarrier occupancy for the same FFT size.
For example, in LTE for an FFT size of 2048, the maximum subcarrier occupancy is 1200 (i.e., 58.6 percent).
In NR, for an FFT size of 4096, the maximum number of subcarriers is 3300 (275 RBs x 12 subcarriers per RB) (i.e., 80.6 percent).
As a result, for a subcarrier spacing of 15 KHz, NR supports a larger transmission bandwidth and channel bandwidth.
