formation are scaled by a factor BPBCH to adjust the PBCH transmit power and then mapped in sequence starting with dPBCH(0) to resource elements (k,1) provided that they are not used for PBCH DM-RSs (see Fig. 4.12). The sequence of complex-valued symbols rppch(0), rppch(1), ., rPBCH (143) con- taining the DM-RSs for the SS/PBCH block is scaled by a factor of PBCH in order to DM-RS 4 OFDM symbols PBCH DM-RS Figure 4.12 Structure of PBCH in time/frequency domain 30]. New Radio Access Physical Layer Aspects (Part 2) 439 Table 4.3: Resource mapping within an SS/PBCH block for PSS, SSS, PBCH, and DM-RS for PBCH [6]. Physical Channel/Signal OFDM Symbol Number / Subcarrier Number k Relative to the Start of an Relative to the Start of an SS/PBCH Block SS/PBCH Block 56,57,...,182 56,57,..., 182 155,183,184,.. 48,4 1,55,183,184 0,1,...,239 0,1,...,47,192,193,...,239 DM-RS for PBCH 0+v,4+v,8+v,...,236+ 0+v,4+v,8+v,...,44+ 192 + v, 196 + V,..., 236 + V adjust the PBCH DM-RS transmit power. They are then mapped to resource elements (k,l) in increasing order of first k (frequency index) and then l (time index), within one SS/ PBCH block. As shown in Table 4.3, the location of PBCH DM-RS is dependent on param- eter V = Ncell mod 4 and is shifted in frequency with different Ncell ID values (see Fig. 4.13 for an example). 4.1.3.2 Physical Downlink Control Channel The data transmission in NR in downlink/uplink direction is generally controlled via MAC scheduling. Each device monitors a number of PDCCHs, typically once per slot, although it is possible to configure more frequent monitoring to support traffic requiring very low latency. Upon detection of a valid PDCCH, the device follows the scheduling decision and receives (or transmits) one unit of data, known as a transport block. The PDCCHs are trans- mitted in one or more CORESETs each of length one to three OFDM symbol(s). Unlike LTE, where control channels span the entire carrier bandwidth, the bandwidth of a CORESET can be configured. In NR, a flexible slot format can be con