Abstract
Terahertz (THz)-band communications are a key enabler for
future-generation wireless communication systems that promise to
integrate a wide range of data-demanding applications. Recent
advancements in photonic, electronic, and plasmonic technologies are
closing the gap in THz transceiver design. Consequently, prospect THz
signal generation, modulation, and radiation methods are converging, and
the corresponding channel model, noise, and hardware-impairment notions
are emerging. Such progress paves the way for well-grounded research
into THz-specific signal processing techniques for wireless
communications. This tutorial overviews these techniques with an
emphasis on ultra-massive multiple-input multiple-output (UM-MIMO)
systems and reconfigurable intelligent surfaces, which are vital to
overcoming the distance problem at very high frequencies. We focus on
the classical problems of waveform design and modulation, beamforming
and precoding, index modulation, channel estimation, channel coding, and
data detection. We also motivate signal processing techniques for THz
sensing and localization.