A Time Domain-Based Channel Estimator and Data Detector for OTFS Systems

Orthogonal time frequency space (OTFS) modulation has attracted significant attention recently due to its advantages over orthogonal frequency division multiplexing (OFDM) in high-mobility scenarios. The low-complexity transceiver design is of great significance for OTFS systems. In this paper, we propose time domain-based channel estimation and data detection methods for both single-input-single-output (SISO) and multi-input-multi-output (MIMO) systems. In the proposed method, the data is mapped in the delay-time domain as compared to the delay-Doppler domain in OTFS. By doing this, a few pilots are required to estimate the channel coefficients, and data detection is performed symbol by symbol. Simulation results show the robustness of the proposed method for different Doppler shifts and baseband modulation as compared to a single-tap zero forcing equalizer and message-passing algorithm.