Low Complexity LMMSE Receiver for OTFS

TL;DR

This paper proposes a low complexity LMMSE receiver for OTFS modulation that leverages matrix sparsity and structure to achieve efficient demodulation without sacrificing BER performance.

Contribution

It introduces a novel low complexity linear MMSE receiver for OTFS that exploits matrix sparsity and structure, reducing computational complexity significantly.

Findings

Achieves log-linear complexity in demodulation process

Maintains BER performance comparable to traditional methods

Exploits sparsity and quasi-banded matrix structure

Abstract

Orthogonal time frequency space modulation is a two dimensional (2D) delay-Doppler domain waveform. It uses inverse symplectic Fourier transform (ISFFT) to spread the signal in time-frequency domain. To extract diversity gain from 2D spreaded signal, advanced receivers are required. In this work, we investigate a low complexity linear minimum mean square error receiver which exploits sparsity and quasi-banded structure of matrices involved in the demodulation process which results in a log-linear order of complexity without any performance degradation of BER.