Efficient Precoding in XL-MIMO-AFDM System

This paper explores the potential of affine frequency division multiplexing (AFDM) to mitigate the multiuser interference (MUI) problem by employing frequency-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, AFDM has better robustness to Doppler shift than orthogonal frequency division multiplexing (OFDM) in user mobility scenarios, which further improves the system performance. However, the multicarrier nature of AFDM has attracted much attention and 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-OFDM in mobile scenarios, and the results show that our proposed AFDM-based XL-MIMO precoding design can be more efficient in complexity and performance.