al blind decoding operation described earlier is applied per component carrier. While the total number of channel esti- mates and blind decoding attempts increases compared to the single carrier case, there is no direct proportionality between the number of aggregated carriers and blind decoding attempts [14]. The procedure for PDCCH search space configuration and example search spaces are shown in Fig. 4.22. As we stated earlier, a set of PDCCH candidates are defined for each UE to monitor, which are referred to as PDCCH search spaces. A search space can be categorized as common or UE-specific. In other words, a search space is defined by the PDCCH candidates that need to be monitored. These candidates are determined by a hashing function that operates within New Radio Access Physical Layer Aspects (Part 2) 469 a set of CCEs in a particular CORESET and the monitoring periodicity and offsets that determine when the search space should be monitored (see Fig. 4.22). The UE is required to monitor PDCCH candidates in one or more of the following search spaces [8]: Type0-PDCCH common search space set configured by pdcch-ConfigSIBI in MasterInformationBlock or by searchSpaceSIBI in PDCCH-ConfigCommon or by searchSpaceZero in PDCCH-ConfigCommon for a DCI format, the CRC of which is scrambled with SI-RNTI in the primary cell. Type0A-PDCCH common search space configured searchSpaceOtherSystemInformation in PDCCH-ConfigCommon for a DCI format, the CRC of which is scrambled with SI-RNTI in the primary cell. Type1-PDCCH common search space set configured by ra-SearchSpace in PDCCH- ConfigCommon for a DCI format, the CRC of which is scrambled with RA-RNTI, TC-RNTI, or C-RNTI in the primary cell. Type2-PDCCH common search space set configured by pagingSearchSpace in PDCCH-ConfigCommon for a DCI format, the CRC of which is scrambled with P- RNTI in the primary cell. Type3-PDCCH common search space set configured by SearchSpace in PDCCH-Config with searchSpaceType = common for a DCI format, the CRC of which is scrambled with INT