Interference Cancellation and Iterative Detection for Orthogonal Time Frequency Space Modulation

TL;DR

This paper introduces a new message passing algorithm for OTFS modulation that effectively cancels interference and detects symbols in delay-Doppler channels, improving performance over traditional methods.

Contribution

It derives the input-output relation for OTFS in delay-Doppler channels and proposes a low-complexity message passing algorithm for joint interference cancellation and detection.

Findings

Effective interference cancellation across various Doppler spreads

Improved error performance over OFDM in Doppler channels

Low-complexity implementation suitable for practical systems

Abstract

The recently proposed orthogonal time frequency space (OTFS) modulation technique was shown to provide significant error performance advantages over orthogonal frequency division multiplexing (OFDM) in Doppler channels. In this paper, we derive the explicit input-output relation describing OTFS modulation and demodulation (mod/demod) for delay-Doppler channels. We analyze the interferences and develop a novel low-complexity yet efficient message passing (MP) algorithm for joint interference cancellation (IC) and symbol detection. The proposed MP algorithm can effectively compensate for a wide range of channel Doppler spreads.