It is more favourable to make future broadband waveforms, not as a set of parallel narrowband waveforms, but as a set of parallel mediumband waveforms. Using IFFT and FFT blocks at the transmitter and receiver respectively, traditionally broadband waveforms are designed as a set of parallel narrowband waveforms. But narrowband waveforms have many drawbacks. Because, their signalling rate is low and are exposed to excessive deep fading.
We are looking at future broadband waveforms, not as a set of parallel narrowband waveforms, but as a set of “parallel mediumband waveforms”. Why do these mediumband waveforms matter? It is because, they do signalling at a faster rate, can avoid deep fading and also can afford more interference.
Fig. 2: A depiction of a typical TX-RX pair in the envisioned physical layer architecture for 6G and beyond wireless communication networks [1].
Fig. 2 Depicts a typical TX-RX pair in the envisioned physical layer architecture for 6G and beyond wireless communication networks, where real-time sensing, ray-tracing, reflecting surfaces (RSs) and AI collaborate smoothly to bias a wireless communication link to operate in the mediumband, and to operate optimally. In the depiction, two reflecting surfaces assist the communication actively to create a mediumband channel, whereas many such RSs scattered in the environment do not engage with the given communication, but may be engaging with other communications.
REFERENCES
D. A. Basnayaka and A. Firag, "Integrating mediumband with emerging technologies: Unified vision for 6G and beyond physical layer," a preprint is available in ArXiV.