 the same precoding vector. To facilitate the use of efficient channel estimation techniques, 5G NR also supports common precoding for all contiguous REGs of the CORESET. To enable coherent processing of the received PDCCH, each REG bundle is transmitted with DM-RS enabling UE-specific beamforming of the control channel. PDCCH supports single-port DM-RS with its resource elements uniformly distributed in the frequency domain with a density of 3 RES per REG. To better control the trade-off between channel estimation performance and frequency diversity, the size of a REG bundle in NR can also be configured by the higher layer and can take the values of two, three, or six REGs. Similar to LTE, PDCCH in NR can be transmitted by using 1, 2, 4, 8, or 16 CCEs depending on the aggregation level. A different number of CCEs is required to adapt the coding rate to the desired coverage of PDCCH and to support different payload sizes of the downlink and uplink control information (DCI/UCI). In NR, a UE can be configured to blindly monitor a number of PDCCH candidates of different DCI formats and different aggregation levels. Depending on the higher layer configuration, CCE-to-REG mapping for a CORESET can be interleaved to provide frequency diversity and interference averaging, or non-interleaved to support localized PDCCH transmission with a UE-specific precoding. There are two types of CORESETs supported by NR: Common CORESET and UE-Specific CORESET (3GPP TS 38.213). The configuration of the common CORESET (denoted as CORESET 0) is indicated by the MIB and is used to transmit control information before RRC connection establishment. In the connected mode, a UE can be configured with one or multiple additional UE-specific CORESETs for further optimized control channel transmission. 3.5 NR Physical Layer Table 3.5.4 DCI formats supported in NR (Release-15). Format Type Direction Description Uplink Grant for PUSCH Uplink Grant for PUSCH Downlink Scheduling of PDSCH Downlink Scheduling of PDSCH Slot format indicator No transmiss