Attenuated-RMMP: A Compressed Sensing Estimation over OTFS Modulation for High Doppler Shift Communications

This paper introduces a novel compressed sensing channel estimation method, termed Attenuated-RMMP, tailored for non-orthogonal waveforms-based orthogonal time frequency space (OTFS) systems in high fractional Doppler shift communications. Leveraging a reduced cyclic prefix OTFS (RCP-OTFS) framework with rectangular pulse shaping, the proposed approach constructs a sensing matrix and applies regularized multipath matching pursuit (RMMP) for channel estimation. To address computational complexity, an attenuated regularization step is introduced in the RMMP process, reducing runtime while maintaining BER performance. Additionally, a Doppler pre-compensation mechanism is proposed to handle high Doppler shifts effectively. Numerical simulations validate the effectiveness of the proposed scheme in terms of bit error rate (BER) and computational complexity.