A Novel Block-Wise Index Modulation Scheme for High-Mobility OTFS Communications

TL;DR

This paper introduces a new block-wise index modulation scheme for OTFS in high-mobility wireless communications, enhancing performance and robustness with a low-complexity detection algorithm.

Contribution

The paper proposes Doppler-IM with OTFS (DoIM-OTFS), a novel block-wise index modulation scheme, along with a customized message passing algorithm for efficient implementation.

Findings

DoIM-OTFS outperforms traditional OTFS without IM.

The CMP algorithm achieves robust performance with imperfect CSI.

Simulation results validate the effectiveness of the proposed scheme.

Abstract

As a promising technique for high-mobility wireless communications, orthogonal time frequency space (OTFS) has been proved to enjoy excellent advantages with respect to traditional orthogonal frequency division multiplexing (OFDM). However, a challenging problem is to design efficient systems to further improve the performance. In this paper, we propose a novel block-wise index modulation (IM) scheme for OTFS systems, named Doppler-IM with OTFS (DoIM-OTFS), where a block of Doppler resource bins are activated simultaneously. For practical implementation, we develop a low complexity customized message passing (CMP) algorithm for our proposed DoIM-OTFS scheme. Simulation results demonstrate our proposed DoIM-OTFS system outperforms traditional OTFS system without IM. The proposed CMP algorithm can achieve desired performance and robustness to the imperfect channel state information (CSI).