  Orthogonal time frequency space (OTFS) modulation is a recently proposed
multi-carrier transmission scheme, which innovatively multiplexes the
information symbols in the delay-Doppler (DD) domain instead of the
conventional time-frequency (TF) domain. The DD domain symbol multiplexing
gives rise to a direct interaction between the DD domain information symbols
and DD domain channel responses, which are usually quasi-static, compact,
separable, and potentially sparse. Therefore, OTFS modulation enjoys appealing
advantages over the conventional orthogonal frequency-division multiplexing
(OFDM) modulation for wireless communications. In this thesis, we investigate
the related subjects of OTFS modulation for wireless communications,
specifically focusing on its signal detection, performance analysis, and
applications. These important aspects are discussed based on the review of the
state-of-the-art and a detailed derivation of OTFS modulation from the discrete
Zak transform (DZT). Finally, a summary of future research directions on OTFS
modulation are also provided.
