Summary
In this chapter, we learned that beam sweeping is required when operating at an mmWave frequency. The use of beam sweeping affects the synchronization signals and PRACH design, since the initial access procedure must account for the directionality of the transmissions.
We have seen how identifying this SS block transmission in each beam with different time indexes and linking the PRACH resources to these indexes helps in this procedure. This directional aspect of the transmission is new to NR.
Finally, we have also gone through some of the considerations about LTE-NR coexistence, especially how the SS block transmissions can utilize 30 kHz subcarrier spacing to avoid interference with the LTE cell-specific reference signals.
In the next chapter, we will detail the remaining downlink and uplink physical channels and signals. We will analyze one of the other different concepts of NR, which is called the PDCCH Control Resource Set (CORESET). We will also see different...