Waveform, numerology, and frame structure

In this section, we will analyze NR waveform, numerology, and frame structure. We will first talk about scalable numerology, slot duration, and how they help to multiplex different numerologies. Then, we will talk about different NR scheduling schemes and related use cases.

Waveform

NR employs OFDM for downlink and uplink transmissions. These are the very same waveforms that were used in LTE.

Figure 4.12 – A visualization of an OFDM waveform

In the preceding figure, the visualization of an OFDM waveform is presented. It has a symmetric design, and the same waveform is used in downlink and uplink transmissions. Besides supporting MIMO in downlink and uplink transmissions, it also supports flexible numerology.

Within a given numerology, all other subcarriers are zero at sampling points. OFDM is a proven technology, and it has several benefits:

• Frequency diversity
• It’s robust against...