igned. For this purpose, multiple PRBs of the same bandwidth form a PRB grid, as illustrated in Fig. 3.47. A PRB grid formed by subcarriers spaced apart by 392 Chapter 3 PRB N3 PRB N3 BWP(2) NCRB =N 3 +N start BWP (0) PRB 1 PRB 1 PRB 0 PRB 0 PRB N2 PRB N2 BWP(1) PRB 1 Carrier PRB 1 Carrier bandwidth PRB 0 NCRB = 1+N start BWP bandwidth PRB 0 BWP(2) start PRB N1 PRB N1 BWP(0) BWP (1) PRB 1 start PRB 1 PRB 0 PRB 0 in a BWP PRB 0 PRB 0 in a BWP NCRB = 0+N start BWP(0) N BWP(0) start CRB 0 CRB 0 Point A: PRB 0 in reference resource block Point A: PRB 0 in reference resource block Figure 3.48 Mapping between nCRB and NPRB [12,39]. where 1, 4 is a non-negative integer, is a superset of PRB grids with subcarrier spacing 15 kHz. For each numerology and carrier frequency, a resource grid of Ngrid(H)NR. subcarriers and Nsymbol(H) OFDM symbols is defined, starting at a CRB Nstart(H), whose value is signaled via RRC signaling. There is one set of resource grids per link direction (uplink or downlink). There is a single resource grid for a given antenna port p, numerology parameter u and link direction [12,28]. An antenna port is a logical entity which is distinct from a physical antenna. Each antenna port is associated with a specific set of reference signals such that the channel over which a symbol is transmitted on that antenna port can be distinguished from the channel over which another symbol is conveyed on the same antenna port. Two antenna ports are said to be quasi-co-located, if the large-scale properties of the channel over which a symbol is conveyed on one antenna port can be inferred from the channel over which a symbol is conveyed on another antenna port. The large- scale properties include delay spread, Doppler spread, Doppler shift, average gain, average delay, and other spatial parameters [12]. In other words, a UE receiver can assume that the radio chan- nels corresponding to two different antenna ports have the same large-scale properties (e.g., aver- age delay spread, Doppler spread/shift, average delay, 