Resource grid: RE, RB, BWP

The Two-Dimensional Resource Grid

The NR resource grid maps frequency and time into a two-dimensional structure where the horizontal axis represents OFDM symbols and the vertical axis represents subcarriers. The smallest addressable unit is the Resource Element, which occupies one subcarrier in one OFDM symbol. Twelve consecutive subcarriers form one Resource Block, making each RB span one symbol times twelve subcarriers. Within a single slot of fourteen symbols, one RB contains 168 Resource Elements. The maximum carrier size is 275 RBs, though the actual count depends on channel bandwidth and subcarrier spacing.