h BWChannel-CA Lowest carrier bandwidth Highest carrier bandwidth configuration (RB) configuration (RB) Lower Upper foffset-low foffset-high Spectrum edge-low C-high edge-high Sub-block gap Sub-block Sub-block RF bandwidth Operating band Figure 5.3 Illustration of aggregated BS channel bandwidth for intraband carrier aggregation [5]. New Radio Access RF and Transceiver Design Considerations 663 fedge-high = fc-high +foffset-high. The lower and upper frequency offsets depend on the trans- mission bandwidth configurations of the lowest and highest assigned edge component carrier and are defined as foffset-low = (12NRB-low + 1)SCSlow/2 + WGB (MHz) and foffset-high = (12NRB-high - 1)SCShigh/2 + WGB(MHz), where WGB denotes the lower or upper minimum guard band defined for the lowest and highest assigned component car- rier. In the latter equations, the parameters NRB-low and NRB-high are the transmission bandwidth configurations for the lowest and highest assigned component carrier, SCSlow and SCShigh denote the subcarrier spacing for the lowest and highest assigned component carrier, respectively [5]. It can be shown that the minimum guard band can be defined as WGB=BWchannel/2-SCS(12NRB = + 1)/2, where NRB is the maximum number of resource blocks that can fit into the BS channel bandwidth and SCS denotes the subcarrier spac- ing. Note that an extra SCS/2 guard band is inserted on each side of the carrier due to the relation to the RF channel raster, which has a subcarrier-level granularity and is defined independent of the actual spectrum blocks. Therefore, it may not be possible to place an RF carrier exactly in the center of a spectrum block and an extra guard band would be required to ensure that the RF requirements can be met [10]. Some spectrum allocations may consist of fragmented blocks of spectrum. In the intra-band non-contiguous case, the BS transmits and receives over an RF bandwidth that is split in two (or more) separate subblocks with a subblock gap in between (see Fig. 5.3). A subblock is defined as o