LAUSR

Orthogonal time-frequency space (OTFS) modulation is supposed to outperform the classical orthogonal frequency division multiplexing (OFDM) in the high-mobility communication scenarios. Channel estimation is an important issue for OTFS, and Cramer-Rao low bound (CRLB) provides a benchmark for different channel estimation algorithms. In this paper, we give an exact and detailed formulation of the discrete-time system model for non-ideal pulse-shaping OTFS in both single cyclic prefix (SCP) and multiple cyclic prefix (MCP) cases, and derive the CRLB of channel estimation for SCP-OTFS, MCP-OTFS, and multiple cyclic prefix approximation (MCPA) OTFS cases.