We have investigated a new modulation scheme called `Orthogonal Time Frequency Space (OTFS) modulation’ suited for communication over high-Doppler channels encountered in high-mobility environments and in mmWave frequencies. OTFS modulation multiplexes information symbols in the delay-Doppler (DD) domain. Also, rapidly time-varying channels when viewed in the DD domain are sparse and slowly varying. We have made early contributions in this emerging topic (see the references below). We have analyzed the diversity order achieved by OTFS and the PAPR characteristics of OTFS, proposed low-complexity schemes for OTFS signal detection and channel estimation, and studied MIMO and multiuser OTFS systems.
Vighnesh S Bhat, G. D. Surabhi, and A. Chockalingam, “Performance Analysis of OTFS Modulation with Receive Antenna Selection,” IEEE Trans. on Vehicular Technology, vol. 70, no. 4, pp. 3382-3395, April 2021.
G. D. Surabhi and A. Chockalingam, “Low-complexity Linear Equalization for OTFS modulation,” IEEE Communications Letters, vol. 24, no. 2, pp. 330-334, February 2020.
G. D. Surabhi, Rose Mary Augustine, and A. Chockalingam, “On the Diversity of Uncoded OTFS Modulation in Doubly-Dispersive Channels,” IEEE Trans. on Wireless Communications, vol. 18, no. 6, pp. 3049-3063, June 2019.