Bayesian-based Symbol Detector for Orthogonal Time Frequency Space Modulation Systems

TL;DR

This paper introduces a Bayesian-based detector for OTFS systems that significantly improves bit-error-rate performance in high Doppler and interference conditions, outperforming existing detectors.

Contribution

A novel Bayesian-based OTFS detector employing PIC and DSC schemes for iterative interference cancellation, enhancing performance in high ICI environments.

Findings

Achieves BER < 10^{-5} at SNR > 14 dB in high ICI conditions

Outperforms state-of-the-art OTFS detectors in simulation

Effective in high Doppler spread scenarios

Abstract

Recently, the orthogonal time frequency space (OTFS) modulation is proposed for 6G wireless system to deal with high Doppler spread. The high Doppler spread happens when the transmitted signal is reflected towards the receiver by fast moving objects (e.g. high speed cars), which causes inter-carrier interference (ICI). Recent state-of-the-art OTFS detectors fail to achieve an acceptable bit-error-rate (BER) performance as the number of mobile reflectors increases which in turn, results in high inter-carrier-interference (ICI). In this paper, we propose a novel detector for OTFS systems, referred to as the Bayesian based parallel interference and decision statistics combining (B-PIC-DSC) OTFS detector that can achieve a high BER performance, under high ICI environments. The B-PIC-DSC OTFS detector employs the PIC and DSC schemes to iteratively cancel the interference, and the Bayesian concept to take the probability measure into the consideration when refining the transmitted symbols. Our simulation results show that in contrast to the state-of-the-art OTFS detectors, the proposed detector is able to achieve a BER of less than $10^{-5}$, when SNR is over $14$ dB, under high ICI environments.