The multiple-input multiple-output orthogonal time frequency space (MIMO-OTFS) has emerged as a promising scheme for high-mobility wireless communications. The unitary approximate message passing (UAMP) detection has demonstrated outstanding performance in the single-input single-output (SISO)-OTFS system. However, We found that directly employing the UAMP detection for the MIMO-OTFS system results in performance degradation and the emergence of an error floor. Therefore, we propose a minimum mean square error (MMSE)-aided UAMP scheme, incorporating MMSE to assist UAMP by providing the prior information. Notably, we reduce the complexity by setting a signal-to-noise ratio (SNR) threshold, only when SNR exceeds the threshold shall we start the MMSE-aided mechanism. Simultaneously, we analyze the impact of fractional delay and consider it into system model, aiming to optimize the practicality of the system. Simulation results under fast-fading Rayleigh channels demonstrate that the proposed MMSE-aided UAMP significantly outperforms the original UAMP in the medium to high SNR range.
MMSE-Aided Unitary Approximate Message Passing Detection for MIMO-OTFS System
2024-06-24
353964 byte
Conference paper
Electronic Resource
English