 as well as the reasons that the status-quo OFDM waveform continued to be supported in the new radio. Furthermore, the waveform, numerology, and frame structure should be chosen to enable efficient time/frequency utilization for frequency division duplex (FDD) and time division duplex (TDD) deployments, respectively. Table 3.5 summarizes the design requirements concerning the choice of the waveform, which were used to examine the waveform candidates for the NR. Gabor's theory of communication suggests that ideally a multicarrier system such as OFDM must satisfy the following requirements [45]: The subcarriers are mutually orthogonal in time and frequency to make the receiver as simple as possible and to maintain the inter-carrier interference as low as possible. New Radio Access Physical Layer Aspects (Part 1) 315 Table 3.5: Summary of design targets for the waveform [45,47]. Design Criteria Remarks Higher spectral efficiency and High spectral efficiency for high data rates and efficient use of the scalability available spectrum Ability to efficiently support MIMO and multipath robustness Low latency Lower in-band and out-of- Reduce interference among users within allocated band and reduce band emissions interference among neighbor operators Enables asynchronous multiple Support a higher number of small-cell data burst devices with minimal access scheduling overhead through asynchronous operations and enables lower power operation Lower power consumption Low peak-to-average power ratio allowing efficient power amplifier design Lower implementation Reasonable transmitter and receiver complexity and additional complexity complexity must be justified by significant performance improvements Coexistence with legacy and Simplify LTE coexistence mobility Support Robust against Doppler shift to allow high mobility The transmission waveform is well localized in time and frequency. This provides immunity to ISI from multipath propagation or delay spread and to ICI from Doppler spread. A good time localization is required t