Doppler-Robust Maximum Likelihood Parametric Channel Estimation for Multiuser MIMO-OFDM

TL;DR

This paper introduces a Doppler-robust maximum likelihood parametric channel estimation algorithm for multiuser MIMO-OFDM systems, improving accuracy under severe Doppler shifts without requiring line search, enhancing localization and sensing.

Contribution

It presents a novel multiuser MIMO-OFDM channel estimation method that is robust to Doppler effects and does not depend on line search, advancing the state-of-the-art in high-mobility scenarios.

Findings

Accurately estimates multipath parameters under severe Doppler shifts.

Does not rely on line search, reducing computational complexity.

Enhances localization and sensing in mmWave and subTHz channels.

Abstract

The high directionality and intense Doppler effects of millimeter wave (mmWave) and sub-terahertz (subTHz) channels demand accurate localization of the users and a new paradigm of channel estimation. For orthogonal frequency division multiplexing (OFDM) waveforms, estimating the geometric parameters of the radio channel can make these systems more Doppler-resistant and also enhance sensing and positioning performance. In this paper, we derive a multiuser, multiple-input multiple-output (MIMO), maximum likelihood, parametric channel estimation algorithm for uplink sensing, which is capable of accurately estimating the parameters of each multipath that composes each user's channel under severe Doppler shift conditions. The presented method is one of the only Doppler-robust currently available algorithms that does not rely on line search.