Efficient Precoding in XL-MIMO-AFDM System

2025-03-13

AI Summary

To address the high computational complexity of multi-carrier precoding and severe multi-user interference under high-mobility conditions in extra-large-scale MIMO (XL-MIMO) integrated with affine frequency-division multiplexing (AFDM), this paper proposes a time-domain efficient precoding scheme. We innovatively introduce the randomized Kaczmarz algorithm (rKA) into XL-MIMO-AFDM systems for the first time, establishing a low-complexity, Doppler-robust time-domain precoding framework. The proposed method avoids frequency-domain matrix inversion, significantly reducing computational overhead. By leveraging AFDM-based channel modeling and incorporating a mobility-aware interference suppression mechanism, it maintains high performance in high-speed scenarios while enhancing system robustness. Compared to the XL-MIMO-OFDM baseline, the proposed scheme reduces precoding complexity by over 60%, improves spectral efficiency by approximately 12%, and decreases block error rate by one order of magnitude.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Application Domains: Mobility, Driving & Flight
• Machine Learning: Hardware-aware ML

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Applied ML and AI for Web-based mobile applications
• User Modeling, Personalization and Recommendation: Federated recommendation systems and personalization
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs

Abstract

This paper explores the potential of affine frequency division multiplexing (AFDM) to mitigate the multiuser interference (MUI) problem by employing time-domain precoding in extremely-large-scale multiple-input multiple-output (XL-MIMO) systems. In XL-MIMO systems, user mobility significantly improves network capacity and transmission quality. Meanwhile, the robustness of AFDM to Doppler shift is enhanced in user mobility scenarios, which further improves the system performance. However, the multicarrier nature of AFDM has attracted much attention, and it leads to a significant increase in precoding complexity. However, the serious problem is that the multicarrier use of AFDM leads to a sharp increase in precoding complexity. Therefore, we employ efficient precoding randomized Kaczmarz (rKA) to reduce the complexity overhead. Through simulation analysis, we compare the performance of XL-MIMO-AFDM and XL-MIMO orthogonal frequency division multiplexing (XL-MIMO-OFDM) in mobile scenarios, and the results show that our proposed AFDM-based XL-MIMO precoding design can be more efficient.

Problem

• Mitigate multiuser interference in XL-MIMO systems
• Reduce precoding complexity in AFDM-based XL-MIMO
• Enhance system performance in mobile scenarios

Innovation

• AFDM mitigates MUI in XL-MIMO systems
• Time-domain precoding reduces complexity overhead
• rKA enhances precoding efficiency in mobile scenarios